Citation
Development of a Self-Propelled Citrus Canopy Shaker for Harvesting Semi-Dwarfed High Density Plantings

Material Information

Title:
Development of a Self-Propelled Citrus Canopy Shaker for Harvesting Semi-Dwarfed High Density Plantings
Creator:
Al-Dosary, Naji Mordi Naji
Publisher:
University of Florida
Publication Date:
Language:
English

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Agricultural and Biological Engineering
Committee Chair:
BURKS,THOMAS FRANCIS
Committee Co-Chair:
PORTER,WENDELL A
Committee Members:
SCHUELLER,JOHN KENNETH
LEARY,JAMES DANIEL
ROKA,FRITZ MICHAEL
Graduation Date:
5/3/2014

Subjects

Subjects / Keywords:
Acceleration ( jstor )
Buckles ( jstor )
Canopy ( jstor )
Citrus trees ( jstor )
Crop harvesting ( jstor )
Fruits ( jstor )
Grapefruits ( jstor )
Mechanical harvesting ( jstor )
Tree felling ( jstor )
Tunnels ( jstor )
acceleration
beaters
branches
canopy
citrus
dislodgement
engines
fruit
harvester
hydraulic
injuries
mechanical
motors
pipe
pvc
self-propelled
sensors
shaft
shakers
shaking
speed
steering
valves
City of Gainesville ( local )

Notes

General Note:
The harvesting field trials pointed out that the harvesting machine's forward speeds had a significant effect on the percentage of grapefruit harvested by canopy shaking. The highest average detachment percentage was 80.03 % at the lowest forward speed of 0.62 mi/hr, while the minimum detaching percentage 72.98 %, was the result of the machine forward speed of 1.42 mi/hr. The initial trials also found that changing the lengths of the turn buckles to adjust the shaking beaters position on the canopy shaker significantly affected the grapefruit detachment percentage at the 10 % level of significance. The third beaters' position (turn buckles length 16 inches) had the highest average of 87.97 %. The beaters shaking speed also significantly affected the grapefruit detachment percentage at the 10 % level of significance. By increasing the beater shaking speed from 56.50 to 73 in/sec, the grapefruit detachment percentage increased up to 79.72 % (the maximum average). Also, by increasing the length of the additional beaters, the maximum grapefruit detachment percentage increased to 93.29 %. On the other hand, the average magnitude of the acceleration (g) among the tree canopy branches increased significantly (average magnitude 8.65 g) when the shaking beater number was increased from 14 beaters to 26 beaters. Looking at the previous findings, this study recommends operating the new prototype citrus harvesting machine either at forward speed 0.62 mi/hr or 1.42 mi/hr, with the turn buckle length at 16 inches, and the beaters' shaking speed at 73 in/sec. These configurations resulted in higher grapefruit detachment percentages, with averages 93.56 % and 93.52 %, respectively. Finally, some minor visible damages, such as splits to some branch crotch angles, have occurred during grapefruit harvesting due to impact of the harvester's beaters with the branches underneath tree canopies. However, when operating at a harvesting width of 69 inches, which was utilized during May 2013 canopy shaker field operations, no damages to the grapefruit tree trunks were observed. The trunks were unaffected by the harvester's shaking beaters unless the harvester's operator could not maintain the main trunk of each tree as the center of the harvesting direction.

Record Information

Source Institution:
UFRGP
Rights Management:
All applicable rights reserved by the source institution and holding location.
Embargo Date:
5/31/2016

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1 DEVELOPMENT OF A SELF PROPELLED CITRUS CANOPY SHAKER FOR HARVESTING SEMI DWARFED HIGH DENSITY PLANTINGS By NAJI MORDI NAJI AL DOSARY A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 201 4

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2 201 4 Naji Mordi Naji A l Dosary

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3 To Almighty Allah for his boundless generosit ies and boundless support in my life and also to my wife and children for their sincere love and patience

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4 ACKNOWLEDGMENTS First and foremost a sincere praise be to the Almighty Allah, who prefers many graces that are countless for his continuous welfare and help so that I could successfully complete my graduate studies and research work I extend my deep sincere thanks and high appreciation to Dr. Tomas Frances Burks, the supervisor president of my PhD. s tudy for his real respect, advice s and guidance through my course of study research procedures and even the writing of this dissertation. I would also like to include my deep appreciation all of my Supervisory Committee Members: Dr. John K. Schueller, Dr. Fritz M. Roka, Dr. James D. Leary, and Dr. Wendell A. Porter for their vigorous discuss ion and eventual acceptance of this dissertation. Also, I extend my sincere thanks and appreciation to Michael J. Zingaro, the ABE engineering technician for his great efforts to build and test the new prototype of the ci trus harvesting machine, which was utilized for this research Moreover my special thanks to Mr. Lee Jones the president of the GeoSpider, Inc. who harness ed the financial potential of the corporation to funding the development team so they could complete the design of the research machine My appreciation also goes to Dr. Dorota Z. Haman, the chair of the Agricultural and Biological Engineering Department Dr. Ray A. Bucklin, the graduate student coordinator, and all the faculty and staff for their sincere respect and support Also, I extend my sincere thanks and appreciation to the staff of the Plant Science Research and Education Center (PSREC) of the University of Florida located in Citra for giving me the opportunity to do my e xperiments and harness the potentials of the PSREC to accomplish my field trials. I also extend my special sincere thanks to the ELI lecturer, Valentina Komaniecka for her respect, care, and help in my study of the E nglish language M y deep thanks go es t o my friends: Ahmed Al Jumaili, Mazin Saber, Nikhil P. Niphadkar, Sundar Subbiah, Kyusuk You,

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5 and Zhijiang Ni for the true respect, help, and valuable advice I received during my Ph.D. studies. Also, I give my sincere thanks and appreciation to my government, the Kingdom of Saudi Arabia, represented by the Ministry of Agriculture for giving me the opportunity since 2007, attend the University of Florida to complete my graduate studies in A gricultural and B iological E ngineering my preferred program In c onclu sion, I extend my deepest thanks and gratitude to my brother Shabeb Abdullah Al Khalaf for his concern and always kee ping in touch with me during my expatri ation. I would also like to give my deep thanks appreciation, and best wishes to all my family members: my mother, father (May Allah forgive him), sisters, brothers, wife, and children for their perspicuous concern, prayers, and patience until I finished my research studies.

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6 TABLE OF CONTENTS page ACKNOWLEDGMENTS ................................ ................................ ................................ ............... 4 LIST OF TABLES ................................ ................................ ................................ ......................... 10 LIST OF FIGURES ................................ ................................ ................................ ....................... 13 LIST OF OBJE CTS ................................ ................................ ................................ ....................... 19 LIST OF SYMBOLS ................................ ................................ ................................ ..................... 20 ABSTRACT ................................ ................................ ................................ ................................ ... 24 CHAPTER 1 INTRODUCTION ................................ ................................ ................................ .................. 26 General Information ................................ ................................ ................................ ................ 26 Research Objectives ................................ ................................ ................................ ................ 28 2 LITERATURE REVIEW ................................ ................................ ................................ ....... 29 Overview ................................ ................................ ................................ ................................ 29 Excitation of Trunks and Individual Limbs of Trees to Extract the Ripe Fruits ............. 30 Shaking the whole Tree Canopies to Extract the Ripe Fruits ................................ .......... 33 Dealing with Citrus Fruit Directly for Choosing and Picking (Selective Harvesting) .... 38 An Overview of the Pragmatic Differences of the Mechanical Harvesting Machines ........... 39 Analysis of the Vibration duri ng the Period of the Mechanical Harvesting ........................... 40 3 MATERIALS AND METHODS ................................ ................................ ........................... 56 Assembly Design Procedures of the Citrus Canopy Shaker (Theoretical) ............................. 56 The Raised Horizontal Beaters Design ................................ ................................ ............ 59 Vertical Beaters Pivot Shaft Design ................................ ................................ ................ 63 Vertical Crank Shaft Design ................................ ................................ ........................... 64 Horizontal Push Rods (Interchanging Turn Buckles) Design ................................ ......... 66 Vertical Connecting Beam (Interchangin g Beam) Design ................................ .............. 68 Realistic Design of the Principal Canopy Shaker Machine ................................ .................... 70 Harvester Modifications for the Final Performance Tests of the Citrus Shaker Harvesting Machine ................................ ................................ ................................ ............ 87 The Intended Field of the Citrus Fruit Trees ................................ ................................ .......... 96 Theoretical An alysis of the Tree Branches Deflection ................................ ......................... 102 Field Measurements Procedure ................................ ................................ ............................. 106 Procedures for Estimating the Values of the Tree Canopy Acceleration Magnitude .... 107 The Essential Field Measurements after the Harvesting Period ................................ .... 112

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7 The Operational Economics of the Mechanical Citrus Harvester ................................ ........ 114 Method of Statistical Analysis of the Experiments Data ................................ ...................... 120 4 RESULTS AND DISCUSSION ................................ ................................ ........................... 124 Effect of the New Canopy Shaking Machine on Citrus Harvesting ................................ ..... 124 Final Results of the Preliminary Harvesting Machine Design ................................ ............. 125 Effect of the Harvesting Machine Forward Speeds on the Field Harvesting ................ 125 Effect of the Harvesting Machine Tunnel Widths on the Field Harvesting .................. 127 Effect of the Shaking Speeds of the Harvester Beaters on the Field Harvesting .......... 129 Effect of the Interaction between the Machine Forward Speeds and its Tunnel Widths on the Field Harvesting ................................ ................................ ................. 132 Tunnel Widths on the Field Harvesting ................................ ................................ ..... 135 Forward Speeds on the Field Harvesting ................................ ................................ ... 140 Tunnel Widths, and the Machine Forward Speeds on the Field Harvesting ............. 145 Distribution of Acceleration Magnitude in the Grapefruit Tree Canopy ............................. 153 Shaking Acceleration Distribution by Diverse Beaters Penetrations into the Harvested Grapefruit Canopies ................................ ................................ .................. 154 .......... 158 ................................ ... 162 Final Results of the Final Citrus Harvesting Machine Design ................................ ............. 167 Effect of the Harvesting Machine Forward Speeds on the Field Harvesting ................ 167 Effect of Beaters Positions of the Harvesting Machine on the Field Harvesting .......... 168 ............. 170 Effect of the Inte raction between the Machine Forward Speeds and its Shakers Positions on the Field Harvesting ................................ ................................ .............. 171 Effect of the Interaction betwee Beaters Positions on the Field Harvesting ................................ ................................ 174 Effect of the Interaction between th Forward Speeds on the Field Harvesting ................................ ................................ ... 177 Effect of the Interaction between the Machin ........ 181 Effect of Length of the New Canopy Shakers on the Citrus Harvesting .............................. 188 Distribution of Acceleration Magnitude in the Grapefruit Tree Canopy ............................. 192 Shaking Acceleration Distribution for the Final Design of the Shaking Beaters on One Grapefruit Canopy ................................ ................................ .............................. 192 Acceleration Distribution by the Final Design of the Shaking Beaters into Three Harvested Grapefruit Canopies ................................ ................................ .................. 196 5 COMPARISON RESULTS DEPENDING ON THE IMPROVEMENT OF THE SHAKING SHAKERS DESIGN ................................ ................................ ......................... 200 Effect of the Harvesting Machine Forward Speed on the Field Harvesting ......................... 200 Effect of the Beaters and Tree Canopy Engagement on the Field Harvesting ..................... 201

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8 Effect o ............................ 202 Effect of the Machine Beaters Number on the Citrus Canopy Shak er Harvesting Machine Efficiency ................................ ................................ ................................ ........... 203 Acceleration Magnitude Distribution on the Grapefruit Tree Canopy by the Two Shaker Designs ................................ ................................ ................................ .............................. 205 6 ECONOMIC ANALYSIS OF THE NEW CANOPY SHAKER MACHINE ..................... 207 The Econ omic Performance ................................ ................................ ................................ 207 Observations of the Grapefruit Orchard Damages ................................ ............................... 211 Grapefruit Orchard Damages by the Preliminary Canopy Shaker Design .................... 211 Grapefruit Orchard Damages by the Final Canopy Shaker Design .............................. 215 The Harvesting Process May Have Been Affected by the Field Conditions ........................ 221 Future Studies of the New Representative Citrus Canopy Shaker Modification ................. 225 7 CONCLUSION ................................ ................................ ................................ ..................... 227 APPENDIX A HYDRAULIC SYSTEMS ................................ ................................ ................................ .... 231 Hydraulic Control Systems of the Innovative Continuous Canopy Shaker harvesting Machine ................................ ................................ ................................ ............................. 231 The Hydraulic Control System of the Beaters Shaking Speed ................................ ...... 231 inary Design) ................................ ................................ ................................ ....................... 232 The Hydraulic Control System for the Harvesting Tunnel Width of the Canopy Shaker and the Steering System (Preli minary Design) ................................ .............. 233 The Modified Hydraulic Control System of the Beaters Shaking Speed with a Shaker Brake System ................................ ................................ ................................ .................... 234 B A PROTOTYPE OF THE SELF PROPELLED CITRUS CANOPY SHAKING MACHINE ................................ ................................ ................................ ............................ 235 The Overall Appearance of the Preliminary Citrus Harvesting Machine Design ................ 235 The Overall Appearance of the Final Citrus Harvesting Machine Design ........................... 236 The New Citrus Harvesting Machine Transportation ................................ ........................... 237 The Machine Orientation Control System ................................ ................................ ............ 238 The Hydraulic Cylinders for the Machine Steering Control System ............................ 238 The Hydraulic Steering Control Valve for the Machine Steering Control System ....... 239 The Improvem ent of the Canopy Shaker Systems ................................ ............................... 240 Basic Components of the Initial and Final Shaker Systems ................................ .......... 240 C THE ACCELERATION MAGNITUDE ................................ ................................ .............. 241 Machine on the Acceleration Magnitude Distribution in the Grapefruit Tree Canopy .... 241

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9 the Acceleration Magnitude Distribution in the Grapefruit Trees Canopies .................... 242 D THE SHAKING BEATERS POSITIONS ................................ ................................ ........... 243 E THE DEVELOPMENT TEAM ................................ ................................ ............................ 245 F PE RFORMANCE OF THE NEW CITRUS CANOPY SHAKER ................................ ...... 247 LIST OF REFERENCES ................................ ................................ ................................ ............. 251 BIOGRAPHICAL SKETCH ................................ ................................ ................................ ....... 256

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10 LIST OF TABLES Table page 3 1 The field measurements of the pulled forces achieved by effect of different manual orange limb deflections. ................................ ................................ ................................ ..... 61 3 2 Most important parts diameters of the representative harvester design (initial design). ... 69 3 3 Variety of the fruit pulling forces which were measured on the intended grapefruits. ... 101 3 4 The results of the impact of the ant icipated economic variables' on harvesting costs. .... 117 3 5 Estimated operating expense of the new self propelled citrus harvester w ith its trucks for the harvest season 2013 14. ................................ ................................ ....................... 119 3 6 Average operating expenses of the grapefruit manual harvesting. ................................ .. 119 3 7 experiments in the summer harvest of 2013. ................................ ................................ ... 122 3 8 Statistical design of the operating variables test that were used for the final citrus ................................ ............... 123 3 9 experiments in the winter of 2014. ................................ ................................ .................. 123 4 1 The average of the detached fruit (fruits/tree). ................................ ................................ 126 4 2 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 1 26 4 3 The average of the fruits deta chment percentage (%). ................................ .................... 126 4 4 The average of the detached fruit (fruits/tree). ................................ ................................ 128 4 5 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 128 4 6 The average of the fruits detachment percentage (%). ................................ .................... 128 4 7 The average of the detache d fruit (fruits/tree). ................................ ................................ 131 4 8 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 131 4 9 The average of the grapefruit detachment percentage (%). ................................ ............. 131 4 10 The average amount of the detached fruit (fruits/tree). ................................ ................... 134 4 11 The average of the adhere d fruit on the trees (fruits/tree). ................................ .............. 134

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11 4 12 The average of the grapefruit detachment percentage (%). ................................ ............. 134 4 13 The average of the detached fruit (fruits/tree). ................................ ................................ 139 4 14 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 139 4 15 The average of the grapefruit detachment percentage (%). ................................ ............. 139 4 16 The average of the detached fruit (fruits/tree). ................................ ................................ 144 4 17 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 144 4 18 The average of the grap efruit detachment percentage (%). ................................ ............. 144 4 19 The average of the detached fruit (fruits/tree). ................................ ................................ 150 4 20 The average of the adhered fruit on the trees (fruits/tree). ................................ .............. 151 4 21 The average of the fruit beads detachment percentage (%). ................................ ............ 152 4 22 The average magnitu depending on operating the two beater units independently at two shaking speeds. ....... 166 4 23 depending on operating the two beater units simultaneously at two shaking speeds. ..... 166 4 24 The average of the detached fruit (fruits/tree). ................................ ................................ 168 4 25 The average of the fruits detachment percentage (%). ................................ .................... 168 4 26 The average of the detached fruit (fruits/tree). ................................ ................................ 169 4 27 The average of the fruits detachment percentage (%). ................................ .................... 169 4 28 The average of the detached fruit (fruits/tree). ................................ ................................ 170 4 29 The average of the grapefruit detachm ent percentage (%). ................................ ............. 171 4 30 The average amount of the detached fruit (fruits/tree). ................................ ................... 173 4 31 The average of the grapefruit detachment percentage (%). ................................ ............. 173 4 32 The average of the detached fruit (fruits/tree). ................................ ................................ 176 4 33 The average of the grapefruit det achment percentage (%). ................................ ............. 176 4 34 The average of the detached fruit (fruits/tree). ................................ ................................ 180 4 35 The average of the grapefruit detachment percentage (%). ................................ ............. 180

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12 4 36 The average of the detached fruit (fruits/tree). ................................ ................................ 186 4 37 The average of the fruit beads de tachment percentage (%). ................................ ............ 187 4 38 The averages of the detached grapefruits (fruits/tree) and the grapefruits detachment percentage (%). ................................ ................................ ................................ ................ 191 4 39 A precise average magnitude of the acceleration (g) among the tree canopy branches, depending on the deli mited accelerometer sensors locations, and the final machine operating variable into one tree canopy. ................................ ................................ .......... 194 4 40 A precise average m agnitude of the acceleration (g) among the tree canopy branches, depending on the delimited accelerometer sensors locations, and the final machine operating variables at three different tree canopies. ................................ ........................ 198 6 1 Estimated costs of the ownership (fixed) and operation (variable). ................................ 209 6 2 Estimated the unit costs ($/box) of the new mechanical harvester. ................................ 210 6 3 Comparison of harvest cost: new mechanical harvester versus manual harvesting. ....... 210 C 1 A precise average magnitude of the acceleration (g) among the tree canopy branches, depending on the delimited accelerometer sensors locations, and the machine operating variables into one tree canopy (the pre test results). ................................ ....... 241 C 2 A precise average magnitude of the acceleration (g) among the tree canopy branches, depending on the delimited accelerometer sensors locations, and the machine operating variables at three different trees canopies (the pre test results). ...................... 242 D 1 The shaking beaters penetrations into the grapefruit canopy depending on the turn buckle length. ................................ ................................ ................................ ................... 243 E 1 Directory of the basic contribution of the citrus harves ter elements design .................... 245 F 1 Amount of the detached grapefruit (fruits/tree). ................................ .............................. 247 F 2 Amount of remaining grapefruit on trees (fruits/tree). ................................ .................... 248 F 3 Grapefruit detachment percentages (%). ................................ ................................ .......... 249 F 4 Averages of the grapefruit detachment percentage (%). ................................ .................. 250

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13 LIST OF FIGURES Figure page 2 1 A pair of OXBO continuous fruit canopy shakers with fruit conveyers. ........................... 43 2 2 A pair of KORVAN c ontinuous fruit canopy shakers with fruit conveyers. ..................... 43 2 3 Self propelled BEI harvesters for blueberries fruit. ................................ ........................... 44 2 4 An adjustable long beam shaker and its fingers mounted on an agricultural tractor. ........ 44 2 5 A pair of apple harvester machines. ................................ ................................ ................... 45 2 6 Sketch of a canopy shaker. ................................ ................................ ................................ 45 2 7 Sketch of a citrus harvester machine with fruit conveyer. ................................ ................. 46 2 8 Schematic of dragged citrus canopy shaker. ................................ ................................ ...... 46 2 9 Self propelled apple harvester with horizontal canopy shakers. ................................ ....... 47 2 10 A cit rus canopy air shaker towed by a tractor. ................................ ................................ ... 47 2 11 Blueberry harvester machine. ................................ ................................ ............................ 48 2 12 Thornless blackberry harvester machine. ................................ ................................ .......... 48 2 13 An apple harvester for small tree canopies with catch frame. ................................ ........... 49 2 14 Sketch of a continuous pair spokes drum s canopy shaker dragged by a tractor. .............. 49 2 15 Sketch of a continuous pair spokes drums canopy shaker with oranges fruit conveyer. ................................ ................................ ................................ ............................ 50 2 16 A citrus fruit canopy shaker. ................................ ................................ .............................. 50 2 17 Fruit harvester machine. ................................ ................................ ................................ ..... 51 2 18 Citrus picking system by using a robotic arm. ................................ ................................ ... 51 2 19 Robotic arm modules with end effectors. ................................ ................................ .......... 52 2 20 A trunk shaker system. ................................ ................................ ................................ ....... 52 2 21 A canopy shaker unit drawn by an agricultural tractor. ................................ ..................... 53 2 22 A pair of citrus canopy shakers and two catch systems. ................................ .................... 53

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14 2 23 Three ways to attach the acceleration units throughout the experiment process. .............. 54 2 24 Diagram of the acceleration sensors and data collection procedure. ................................ 54 2 25 LabVIEW block diagram of the data acquisition. ................................ ............................. 55 2 26 Diagram of the acceleration sensors positions, and procedures of the instrumentation experiments. ................................ ................................ ................................ ....................... 55 3 1 A representative self propelled citrus tree canopy shaker (preliminary design). .............. 56 3 2 Field measurement of the citrus fruit detachment force. ................................ ................... 62 3 3 Basic design of the horizontal beater and its load. ................................ ............................. 62 3 4 Basic design of the vertical beaters pivot shaft and its load. ................................ ............. 64 3 5 Basic design of the vertical crank shaft and its load. ................................ ......................... 66 3 6 Basic design of the horizontal push rod and its loads (reciprocating turn buckle). ........... 67 3 7 Basic design of the vertical connecting beam and its load. ................................ ............... 69 3 8 Major components of the innovative citrus canopy shaking machine (preliminary design). ................................ ................................ ................................ ............................... 72 3 9 Two hand engine throttles (cables) of the preliminary citrus canopy shaker design. ........ 73 3 10 Schematic diagram of the hydraulic cont rol system of the self propelled canopy shaker, two extension systems, and steering system. ................................ ......................... 76 3 11 Hydraulic control system diag ram for the two shaking units of the citrus canopy shaker. ................................ ................................ ................................ ................................ 77 3 12 Some flexible hydraulic hoses were used for the hydraulic control systems of the citrus canopy shaking machine. ................................ ................................ ......................... 77 3 13 The electrical schematic diagram of the Mitsubishi diesel engine ignition system and its implements. ................................ ................................ ................................ ................... 79 3 14 The electrical schematic diagram of the Yanmar diesel engine ignition system and its implements with 12 volt on/off wheels brake solenoid valves. ................................ ......... 80 3 15 .......................... 84 3 16 (shakers brake). ................................ ................................ ................................ .................. 84 3 17 Electrical instrument panels of the citrus canopy shaking machine. ................................ 85

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15 3 18 Movable wheels frames of the citrus canopy shaker with carrier bearing hinge (spindle). ................................ ................................ ................................ ............................ 85 3 19 Some hydraulic system components of the preliminary self propelled canopy shaker ................................ ........................... 86 3 20 Final prototype citrus canopy shaking machine. ................................ ................................ 87 3 21 New extra beaters attached to the original shaking beater s. ................................ .............. 88 3 22 New position of the harvesting machine control systems. ................................ ................. 89 3 23 Eaton hydrostatic pump with a swash plate mechanism for the harvesting machine wheels drive. ................................ ................................ ................................ ...................... 90 3 24 Crank shaft (motor shaft) of the citrus harvesting machine. ................................ ............. 91 3 25 A new vertical motor shaft (crank shaft) with a flywheel supported by pillow block bearing. ................................ ................................ ................................ ............................... 91 3 26 Some components of the hydraulic system of the preliminary design have been reduced in order to provide some power for the final design of the canopy shaker. ......... 93 3 27 Schematic diagram of the hydraulic control system of the two canopy shakers units' extension, and steering system for the final harvester design. ................................ ........... 94 3 28 Schematic diagram of the hydraulic control system of the self propelled canopy shaker transport speed for the final harvester des ign. ................................ ........................ 9 5 3 29 Citrus field (Oranges) in the PSREU at UF, 09/22/2011. ................................ .................. 97 3 30 Citrus field (Grapefruits) in the PSREU at UF, 05/24/2013. ................................ ............. 97 3 31 Longitudinal and lateral extension of the branches of the orange trees. ............................ 98 3 32 Longitudinal and lateral extension of the branches of the grapefruit trees. ....................... 98 3 33 Grapefruit trees in the PSREU field. ................................ ................................ .................. 99 3 34 Grapefruit trees in the PSREU field after pruning process. ................................ ............... 99 3 35 The grapefruit maturity before the harvesting period of the season of 2013 14. ............ 101 3 36 A homogeneous load distribution lying on a clamped free beam. ................................ .. 105 3 37 The preliminary citrus canopy shaking machine through its harvesting performance in the summer harvest of 2013. ................................ ................................ ........................ 106 3 38 An organization chart of the vital acceleration processes for data gathering. ................. 109

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16 3 39 Some of the X16 1C acceleration sensors attached to some citrus tree branches. .......... 109 3 40 The shaking beater mechanism. ................................ ................................ ....................... 111 3 41 Grapefruits on the ground after the harvest operation by the new canopy shaking machine (the preliminary design). ................................ ................................ ................... 113 3 42 Grapefruits on the ground after the harvest operation by the final canopy shaking machine (final test) were calculated manually. ................................ ................................ 113 4 1 Comparison results for the effect of the interaction between the three operating variables on the amount of the detached grapefruit (fruits/tree). ................................ ..... 150 4 2 Comparison results for the effect of the interaction between the three operating variables on the amount of remaining gr apefruit on the trees (fruits/tree). ..................... 151 4 3 Comparison results for the effect of the interaction between the three operating variables on the grapefruit detachment percentage (%). ................................ .................. 152 4 4 Acceleration magnitude distributions into the grapefruit tree canopy by 10 inches of turn buckle length (front view). ................................ ................................ ....................... 157 4 5 Acceleration magnitude distributions into the grapefruit tree cano py by 11 inches of turn buckle length (front view). ................................ ................................ ....................... 157 4 6 Acceleration magnitude distributions into the grapefruit tree canopy b y 12 inches of turn buckle length (front view). ................................ ................................ ....................... 158 4 7 Acceleration magnitude distribution into the grapefruit tree canopy by the first beaters shaking speed (front view). ................................ ................................ ................. 161 4 8 Acceleration magnitude distribution into the grapefruit tree canopy by the sec ond beaters shaking speed (front view). ................................ ................................ ................. 161 4 9 ................. 165 4 10 Comparison results for the effect of the interaction between the three operating variables on the amount of the detached grapefru it (fruits/tree). ................................ ..... 186 4 11 Comparison results for the effect of the interaction between the three operating variables on the grapefruit detachment percentage (%). ................................ .................. 187 4 12 long shaking beaters). ....................... 190 4 13 Acceleration magnitude distributions into one grapefruit tree canopy by the highest beaters shaking speed (front view). ................................ ................................ ................. 195 4 14 Acceleration magnitude distribution into three diverse grapefruit trees canopies by the highest beaters shaking speed (front view). ................................ ............................... 199

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17 5 1 Effect of the changing in the shakers design with the shaking machine speed on the grapefruit detachment percentage. ................................ ................................ ................... 201 5 2 Effect of the changing in the shakers design with the shaking beaters position on the grapefruit detachment percentage. ................................ ................................ ................... 202 5 3 Effect of the changing in the shakers design with the shaking speed on the grapefruit detachment percentage. ................................ ................................ ................................ .... 203 5 4 Final effect of the changing in the shaker design on the grapefruit detachment percentage (the highest and second highest detachment percentage). ............................. 204 5 5 An acceleration magnitude result on the grapefruit tree canopy by operating the two shaker models with a high beater shaking speed. ................................ ............................ 206 6 1 The preliminary citrus harvesting machine during its operation. ................................ .... 212 6 2 and the gray part is a flexible round PVC pipe). ................................ .............................. 212 6 3 ................................ ........ 213 6 4 ........................... 213 6 5 Grapefruit trees after the May 2013 harvesting trials seem to be in good health. ........... 214 6 6 The final citrus harvesting machine during its field operation in the winter of 2014. ..... 217 6 7 the gray part is the flexible UHMW polyethylene white pipe at the de fault position). ... 217 6 8 Broken trees occurred unintentionally due to moving the shaking machine in a nks had beaten by the lowest shaking beater. ........................ 218 6 9 Some injured branches due to treatment of the new shaking beaters. ............................. 218 6 10 Bark damage occurred on some branches due to treatment of the new shaking beaters. ................................ ................................ ................................ ............................. 219 6 11 Tree defoliation due to January 2014 treatments of the improved shaking beaters. ........ 219 6 12 Some grapefruits with their stems due to treatment of the new shaking beaters. ............ 220 6 13 Grapefruit trees irrigation system after the harvesting trials. ................................ .......... 220 6 14 Uniform grapefruit tree canopy involved by the harvesting machine tunnel of the final design. ................................ ................................ ................................ ...................... 222

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18 6 15 Heterogeneous grapefruit tree canopy forced b y the internal tunnel of the final shaking machine design. ................................ ................................ ................................ .. 223 6 16 Some misshapen grapefruit trunks. ................................ ................................ .................. 223 6 17 Grapefruits hanging down close to the ground due to the tree canopies pruning of summer 2013. ................................ ................................ ................................ ................... 224 6 18 Grapefruits hanging down close to the ground due to the tree canopies pruning of winter 2014. ................................ ................................ ................................ ..................... 224 A 1 Major components of the hydraulic system of the two canopy shakers units. ................ 231 A 2 Major components of the hydrostatic drive of the preliminary self propelled shakers machine. ................................ ................................ ................................ ........................... 232 A 3 The hydraulic system components of the harvesting tunnel width extension and the steering drive system of the preliminary shaker machine. ................................ ............... 233 A 4 Previous hydraulic system components of the two canopy shakers units with the eliminated shakers motors brake ports (two on/off solenoid valves). ............................. 234 B 1 The final view of the preliminary design of the continuous citrus canopy shaking machine. ................................ ................................ ................................ ........................... 235 B 2 The final view of the final design of the continuous citrus canopy shaking machine. .... 236 B 3 Easy machine transportation. ................................ ................................ ........................... 237 B 4 Two hydraulic cylinders utilized for the machine orientation system mounted on the front wheels frame of the citrus canopy shaking machine. ................................ .............. 238 B 5 A steering control valve with its steering wheel utilized for the machine orientation system placed on t he front top of the citrus canopy shaking machine. ............................ 239 B 6 Basic components of the preliminary canopy shaker units. ................................ ............. 240 B 7 Basic components of the final canopy shaker units. ................................ ........................ 240 D 1 Dimensions of the new self propelled canopy shaker machine. ................................ ...... 244 E 1 The self propelled canopy shakers machine development team. ................................ ..... 246

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19 LIST OF OBJECTS Object page 6 1 Video of innovative citrus canopy shaker performance (.mp4 file 10.4MB) .................. 216 6 2 ..................... 216

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20 LIST OF SYMBOL S A c The a rea of the cross section of the materials used (in ch 2 ) The a ctual endurance strength (psi) The m aterial factor T ype of stress factor The r eliability factor The size factor The e ndurance strength (psi) The s ection modulus (inch) The d esign factor The t ensile ( ultimate ) strength (psi) The y ield strength (psi) The m ean bending moment ( lb in ) The a lternative bending moment ( lb in ) The s tress concentration factor The d iameter of the materials used (inch) F m The mean force (lb) F a The alternative force (lb) F max The maximum force (lb) F min The minimum force (lb) The y ield strength in shear under actual conditions (psi) The e ndurance strength in shear under actual conditions (psi) Pi, a mathematical constant

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21 M max The maximum bending moment ( lb in ) M min The minimum bending moment ( lb in ) The shaft torque ( lb in ) The shaft bending moment ( lb in ) D f The branch diameter at the point of the force effect (inch) I Moment of inertia ( in ch ) L bf Length of the branch to the point of force effect (inch) F Pull force that affected on tree branch (lb) E Modulus of elasticity (psi) M Bending moment ( lb in) y Beam or branches deflection (in) w Force that affected on the beam (lb) x The beam length from the fixed end (inch) The length of beam, branch, or the turn buckle links (inch) c 1 Constant value of the beam deflection equation c 2 Constant value of the beam deflection equation y The ultimate vertical deflection of the clamped free beam (inch) ymax The maximum deflection (inch) o The original length of the tree limbs before applying the fo rce (inch) The chang e in the length of the tree limbs after applying a pull force (inch) The resultant of the magnitude of the acceleration data (g) The magnitude of the acceleration at x axis (g) The magnitude of the acceleration at y axis (g) The magnitude of the acceleration at z axis (g)

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22 r The radius of the crank (inch) The angular displacement of the crank (radian) The angular displacement of the shaking beater (radian) a The shaking beaters regular amplitude at the jointing point of the shaking beater with the turn buckle (inch) A The amplitude at the shaking beater free end (inch) 1 The length of the shaking beater to the jointing point of the beater with the turn buckle (inch) 2 The length of the shaking beater from the jointing point of the beater with the turn buckle to the beater free end (inch) L The original length of the shaking beaters (inch) The crank shaft angular velocity (rad/sec) S a The typical beater's speed at the jointing point (a) of the beater and the turn buckle link (inch/sec) S A The bold speed of the shaking beater at the beater free end (inch/sec) F d The citrus fruit dislodgement percentages (%) N d The number of the dislodged fruit (count) N r The number of the fruit remaining on the citrus tree (count) Y The expected overall yield production of the citrus field (ton/hectare) w t The absolute total fruit mass of each citrus tree separately (lb ) a b The distance between the citrus trees lines (ft) and the distance between the citrus trees on each row (ft) Hc The overall operations cost of the mechanical harvesting ( $/hr) P M The p rice of the mechanical harvester ($) Y H The p redicted yearly operation hours (hr/year) M L The l ife expectancy of the mechanical harvester (year ) R i The r ate of interest (%/year)

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23 R t The r ate of tax (%/year) R rm The r ate of the mechanical harvester maintenance (%) L f The l ubrications factor P w The harvesting machine p ower (kw) F p The p rice of fuel ($/gal) F cns The c onsumption of fuel (gal/kw.hr) L ms The l abor monthly salary ($) O mo The p redicted average of the operation hours for each month (hr/month) Mfd1 Lowest f orward s peed of the h arvester ( m i/ h r) Mfd2 Highest f orward s peed of the h arvester ( m i/ h r) Tw1 Default width of the internal tunnel of the citrus harvester (in) Tw2 Second width of the internal tunnel of the citrus harvester (in) Bp1 First beaters position by 12 inches of t he turn buckle length (in ) Bp2 Default beaters position by multiple lengths of the turn buckles (in ) Bp3 Third beaters position by 16 inches of the turn buckle length (in ) Shs1 Lowest b eaters s haking s peed (inch/sec) Shs2 Second b eaters s haking s peed (inch/sec) Shs3 Highest b eaters s haking s peed (inch/sec)

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24 Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy DEVELOPMENT OF A SELF PROPELLED CITRUS CANOPY SHAKER FOR HARVESTING SEMI DWARFED HIGH DENSITY PLANTINGS By N aji M ordi N aji A l D osary Ma y 2014 Chair: Thomas Frances Burks Major: Agricultural and Biological Engineering The harvesting field trials pointed out that the harvesting machine forward speeds had a significant effect on the percentage of grapefruit harvested by canopy shaking. The highest average detachment percentage was 80.03 % at the lowest forward speed of 0. 62 mi/hr whi le the minimum detaching percentage 72.98 % was the result of the machine forward speed of 1. 4 2 mi/hr The initial trials also found that changing the lengths of the turn buckles to adjust the shaking beaters position on the canopy shaker significantly af fect ed the grape fruit detachment percentage at the 1 0 % level of significance The turn buckles length 16 inches ) had the highest average of 87.97 %. T he beaters shaking speed also significantly affected the grapefruit detachment percentage at the 1 0 % level of significance By increasing the beater shaking speed from 56.50 to 73 in/sec, the grapefruit detachment percentage increased up to 79.72 % ( the maximum average ) Also, by increasing the length of the additional beaters the maximum grapefruit detachment percentage increased to 93.29 %. On the other hand, the average magnitude of the acceleration (g) among the tree canopy branches increased significantly (average magnitude 8.65 g) when the shaking beater number was increased f rom 14 beaters to 26 beaters

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25 Looking at the previous findings, this study recommends operating the new prototype citrus harvesting machine either at forward speed 0. 62 mi/hr or 1.42 mi/hr with the turn buckle length at 16 inches and the beaters shaking speed at 73 in/sec Th ese configuration s result ed in higher grapefruit detachment percentage s with averages 93.56 % and 93.52 % respectively Finally some minor visible damages such as splits to some branch crotch angles, have occurred during grapefruit harvest ing due to impact s underneath tree canopies. However, when operating at a harvesting width of 69 inches which was utilized during May 2013 canopy shaker field operations, no damages to the grapefruit tree trunks were observed The trunks were unaffected by the shaking beaters unless the maintain the main trunk of each tree as the center of the harvesting direction

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26 CHAPTER 1 INTRODUCTION General Information The United States of America is second in terms of global citrus crop produc tion (13 million tons of citrus crops in the 2007 08 season), only to Brazil (15.912 million tons of orange fruits for the season of 2007 08) In the United States, the State of Florida lead s c itrus production with approximately 9,119,000 tons of fruit (203.8 million 90 lb boxes) during the 2007 08 season which is approximately 70 % of the total United States citrus crop Meanwhile, the second leading producer was California with 3,470,000 tons of fruit production during the same harvest season (the United States Department of Agriculture (USDA) and NASS, 2009). The State of Florida has more than 12 thousand citrus producers who cultivat e 569 thousand acres of citrus farmlands with almost 74 million citrus trees (Florida Department of Citrus, 2008). During the early 1 950 s, Florida was the hub for the citrus industr y leading to a heavy demand for manual citrus harvesting Toward the end of 1960 s and early 1970 s manual citrus harvesting became a less economically viable solution as local labor costs had increased and there was shrinki ng labor force (Whitney, 1995). As a result, expenditu res for manual harvesting increased from $ 0.65 per box in 2000 to $ 0.91 per box in 2010 assuming estimated laborers productivity at eight boxes per hour (Roka, 2010). Thus, due to the increase in t he cost of manual harvesting, interest in mechanization of citrus harvesting increased significantly Mechanical citrus harvesting by shaking either the trunk or canopy, has been the most successful and most common ly used harvesting approach in Florida citrus production Thus, with citrus harvesting mechanism s still under development and increasing cost of labor in citrus harvesting efforts i n mechanical harvesting have been devoted to develop ing a method of mechaniz ing citrus harvesting by new mechan ical approaches

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27 Consequently, when using mechanical harvesting systems, estimates suggest that well over 50 percent of the total cost of citrus harvesting will be conserved (Brown, 2002 and 2005). In the l ate 1950s early 1 980s interest in mechanical har vesting of citrus began to grow due to the increase in the production of citrus and lack of access to citrus hand harvesters But by 1990 in Florida, none of the early developed mechanical harvesting technologies had been implemented, due to the freezes, hurricanes, and spread of some citrus trees diseases during the 1980s, and the fear of the harvesting machines contributi ng to the distribution of these diseases ( Whitney and Harrell, 1989 ). Since 1994, with a renewed confidence in mechanical harvesting, the Florida citrus industry and the FDOC became more interested in develop ing mechanical harvesting especially for processed orange s, since the Florida growers were tending to ward high er density planting of citrus trees (65 to 180 trees per acre) This ef fort was intended to decrease the citrus harvesting cost and increase labor productivity During this period, eight harvesting systems were manufactured depending on the citrus tree canop y arrangement. Some of these 8 harvesting systems achieved 10 % to 75 % savings of harvesting cost s and more than 5 times labor productivity increase s (Brown, 2005). So, the number one priority of the citrus industry w as the In addition, b ecause the Huanglongbing (HLB) bacteria know n as a major citrus greening disease which can cause damage to citrus trees, w as reported in China in 1919, and then in Florida in 2005, the citrus production economy in Florida wa s adversely affected. This disease causes fruit to drop and tree s produce sm all er fruit th us decreasing the tree productivity. There is no technique to eradicate the greening disease but some practices for growers that have emerged to reduce spread of the disease such as management of grove greening ( UF IFAS, 2014)

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28 Recently, the use of small citrus trees with high density is intended to be the standard over Florida citrus farmlands. So subsequently, the further development of citrus harvesting mechanisms promises to be a continuing empower ing agent of economic viabil ity Even though development of mechanized harvesting methods for citrus trees ha s been going on for 30 to 40 years on traditional tree sizes, the primary purpose for this research was to design a reliable self propelled over the top canopy shaker machi ne for harvesting citrus trees grown in h igh density hedgerow s with si z e controlling citrus rootstocks (trees are grown at an average height less than ten feet). Research Objectives The main objective of this research is to design a canopy shaker prototype for the high density semi dwarfed citrus trees These trees are planted in a high hedgerow density. T he specific designated core sub objectives included in this research are listed below : 1. Design and build a prototype of an innovative self p ropelled o ver the top citrus harvesting machine using canopy shakers, which can be utilized to harvest citrus trees with canopy height of 10 feet or less 2. Test that prototype to assess the optimal performance under existing citrus grove conditions The test assessment includes: a) Determine the optimal shaking frequency, and shaking time to obtain best fruit removal. b) Determine the optimal shaker beater configuration and stroke for best fruit removal. c) Monitor the i nfluence of shaker stroke, frequency, a nd beater design on the tree canopy excitation.

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29 CHAPTER 2 LITERATURE REVIEW Overview Since the mid 1950 s th er e has been a growing interest among Florida citrus growers to change the citrus harvesting method by using new innovative mechanical techniques. M echanical harvesting techniques could reduce the manual work force ( harvesting laborers ) which previously has greatly influence d the cost and time required for harvesting Hence, several fruit harvester manufact urers became involved in developing mechanical harvesting technologies These manufacturers include: Korvan Industries Inc., Lynden, WA and OXBO International Corporation, Byron, NY (Peterson, 2003) Littau Harvest er Inc., Blueberry H arvester, Stayton, Oregon, Weygandt Inc., Canby, Oregon, and BEI International, LLC, South Haven, MI (Peterson and Takeda, 2003), Everglades Harvesting & Hauling, Inc., LaBelle, FL, Rectangle Harvesting, LLC, Avon Park, FL, Sam Adams, F elda, FL, T & S Harvesting, Felda, FL, and Mutual Harvesting, Inc., Lakeland, FL (Futch and Roka, 2005) These companies began competing in the development of the fruit harvesting systems as show n in Figures 2 1, 2 2, and 2 3. Moreover, according to previous scientific research, methods for the development of harvesting machines were depend ent on three primary methods for removing ripe fruit s from the citrus trees. These three methods were a) shaking the trunks and individual li mbs of trees to extract the ripe fruit s b) shaking t he whole tree canopies to extract the ripe fruit s and c) manual or robotic picking method (selective harvesting). These three methods are described briefly in the following topics :

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30 Excitation of T run ks and Individual L imbs of T rees to E xtract the Ripe F ruit s A sweet cherries harvester for fresh market us ing a catch frame with inclined conveyer and a single hydraulic arm shaker with a rapid displacement actuator (RDA) method was developed by Peterson and Wolford (2001) Later, a s weet cherries harvester utilizing two long hydraulic arms (joysticks) with the RDA method was designed by Peterson et al. (2003) to impact cherr y tree limb and trunk displacement acceleration. Detachment of the sweet cherries depend ed on cherry tree limbs and trunk oscillations. From a single RDA harvester, the sweet cherries harvested ranged between 85 to 92 % with 2 to 6 % fruit injury. Whereas, 90 % of the cherries fruit were detached, at a harvesting rate between 85 and 1 58 trees per hour for the two identical RDA harvesters mounted on each end of th e cherr y harvester. Bohannon (1969) designed a citrus fruit harvester under U.S. Patent Number 3,485,025 filed on December 9, 1966 for fruit removal by using oscillation of notched rods (three ri gid rods and four dynamic rods), which were mounted on a parallel horizontal platform with oscillations between 1,000 and 5,000 times per minute. These rods were placed on a single boom long arm with fruit conveyer apparatus. P roductivity of between 400 to 500 boxes per day was obtained by this harvester Erdo an et al. (2003) reported an apricot harvester and its performance, which use d a single hydraulic limb shaker in T arm was 3.34 meters i n length and 8.5 cm in diameter. A hydraulic motor included in the design was used to furnish oscillations to the arm for tree limb shaking. The apricot limb oscillation s were between 20 to 60 mm amplitude for 5 second s duration, with frequencies of 10 to 20 Hz. O ptimum apricot detachment without tree limb or bark injury, required 5 second oscillation s at 15 Hz f requency and 40 mm of arm amplitude. In contrast, 400 minute s of labor were required to manually harvest an apricot tree

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31 In Spain, during the harvest of 2003 04 a trunk shaker which was mounted to a tractor (76 k w ) was investigated to detach olives from the olive trees, using an unbroken oscillation (one periodic oscillation) and couple d short periodic oscillation s (two periodic o scillations) U sing that tree trunk shaker with tree acceleration of 210 m/s and oscillation s between 20 to 25 Hz, the two periodic oscillations (10+10 second) detached the olives within 20 second s of continuous shaking. Furthermore, 90 % detachment of th e olive s w as achieved using 13.3 second s of oscillation time. Oscillation time of more than 16 to 18 second s was not effective on olive det achment which show ed that a long period of oscillation was unfavorable. Also, by the end of olive harvesting season, 13.3 seconds of oscillation used at the beginning of harvesting season had diminished to two seconds of the canopy oscillation time (Blanco Rold n et al., 2009). In the 2011 citrus harvesting season, the Oxbo olives harvester (engine 17 3 hp) was adapted to harvest Florida small young orange trees. Overall machine dimension s were 252 inches (length) and 143 inches (width). Also, d imension s of the machine internal tunnel were 54 inches (1.37 m) of the tunnel width and height from 108 to 1 38 inches (2.74 3.50 m) The primary results of the se harvesting trials indicated an appropriate fruit picking rate up to 95 % but the m achine needs to be adapted to harvest citrus tree canop y planted with a high density (Ehsani and Khot, 2012). Loghav i and Mohseni (2006) investigated limb vibrations on lime fruit removal by developing an adjustable long beam shaker (1.2 to 2 meters long) attached to a tractor as shown in Figure 2 4. The clamper that works as fingers (has two fingers) grasp the lime limbs to transfer vibration s to the lime fruit. The design mechanism has been tested using three shaking frequencies (5, 7.5, and 10 Hz) and three shaking extensi on s (40, 80, and 120 mm). The force of

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32 1.93N was used for ripe limes and a 13.6 1 N force for unripe limes. With shaking frequency of 10 Hz and shaking extensi on of 120 mm, all the lime fruit s were removed (100 %). Comparatively, a shaking frequency of 10 Hz w ith 80 mm of beam extensi on resulted in 98.5 % of the lime fruit s being harvested Peterson and Bennedsen (2005) describe d a rapid displacement actuator (RDA) apple harvester that utilized a single and three rapid impulses for apple detachment on the long and short limbs of apple trees ( grown in spring of 1999 ). It was implemented on a Y trellis tree prototype using a hydraulic joystick (a long horizontal reaping arm (78 inches) with 2 inches stroke displacement). The fallen fruit landed on the top of a pa dded conveyer. A total of 53 to 72 % of th ose apples were injur y free quality Both long and short tree limbs of those apple trees showed similar numbers of fruit detachment and fruit quality. Peterson and Wolford (2003) developed an apple harvester that included two identical limb harvester s for small apple trellis es, as represented in Figure 2 5. Each limb harvester utilized a long hydraulic arm (a long joystick) for the apple trunk oscillation s and collecting conveyer. The rapid displacement actuator me thod was used for apple detachment. From the 95 % of total apples detach ed, between 86 and 95 % of the apples were retrieved using that harvesting method Of the eight varieties of apples that were studied, fresh market graded four types of apples between 86 to 90 %. Less than 5 % of the apples were left on the apple tree s and less than 11 % of the apples were lost to the ground. Torregrosa et al. (2006) presented an analysis report for different mechanical harvesting systems used for apricots fruit s in Sp ain thr oughout the 2001, 2002, and 2003 seasons aimed at reduc ing harvesting time and costs. The different harvesting systems were used to snap the fruit by using an apricot trunk shaker with an inverted catching frame ( upside down um brella) for

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33 fruit to fall on. The trunk shaker and catch frame, and a storage container were hung from a tractor (50 kw) on a three point hitch The continuous trunk shaker and catch frame were pulled by the tractor with forward speed s between 0.7 and 2.5 km/h. A 13.7 to 22.5 Hz frequency was required to dislodge the apricots fruit s with acceleration between 51 and 590 m/s. These harvesting systems were compared to a manual tree shak ing method by laborers hands. The apricots fruit s harvested by machine detached in less than 2 .4 seconds which was less than the time required to harvest the fruit by hand l aborers Besides, costs of harvesting was reduced from 0.107 euro/kg for manual harvesting to between 0.006 and 0.039 euro/kg by operat ing those mechanical harvesters Torregr osa et al. (2009) presented the comparison of orange and mandarin harvesting during the harvesting seasons from 2006 to 2009 in Spain, comparing a trunk shaking by an exten da ble long arm with clamper two long arms (2 and 1.8 meters) and a frequency of 18 21 Hz with manual harvesting The frequencies of 9, 15, and 25 Hz were required for the orange trees while the mandarin trees required frequencies of 7.4, 14.6, and 21.6 Hz. The percentages of fruit detachment were higher with the mechanical shaking (73.25 %) than the manual shaking of the tree limbs (55.67 %). Also, the shaking time of 4 and 5 seconds at a frequency of 1 5 Hz were adequate for the optimal percentage of fruit removal (average 65 % of the fruit removal). Shaking the whole T ree C anopies to E xtract the Ripe F ruit s A fruit detachment machine with conveyer apparatus was invented by Visser (2001) and Schloesser (2005) which are shown in Figure 2 6 and Figure 2 7 respectively These harvesters were designed to detach the fruit from the tre e canopy and have it fall onto the conveyer apparatus. Shaker components typically included a rigid single mast (vertical long shaft), rotator cranks, movable arms that extended and retracted in horizontal, and six pairs of free twistable nipper disks. Eac h of the three pairs of nipper disk s engaged each tree at the same time

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34 meanwhile the other three pairs of the nipper disk s retracted to rearward (on the opposite side; close to the vertical mast). Furthermore, each single nipper disk had sixteen sticks (fingers) displaced radial ly at equal angles with linear displacement action provided by cranks. The resulting labor producti vity significantly reduced harvesting time and cost. Likewise, Briesemeister et al. (2006 & 2008) developed a fruit harvester (canopy shakers) with fruit dropping o n the ground (Figure 2 8) and Briesemeister (2002) developed a fruit harvester (canopy shak er) with a retractable conveyer to recover the removed f ruit A prototype self propelled harvester machine with a conveyer belt was developed to harvest six kinds of apples from apple trellis es that had a small horizontal H canopy during the 1987 season in New Zealand as depicted in Figure 2 9. For the canopy shaker of this harvester, six shaking whorls were mounted on an isometric pair of transverse shafts. Each transverse shaft ha d three whorls with identical flexible pinnatisect edges for reducing in jury to the apples The shaking shafts with the flexible whorls were oscillated using a hydraulic motor in order to horizontally excite the apple canopy, with oscillation s between zero to 10 Hz and 26 mm of displacement. The harvesting rate was four trees per hour which w as achieved by 0.3 k m/h of harvester forward speed. O ptimal apple detachment was accomplished at o scillations between 4 to 6 Hz. Furthermore, the apple quality ranged between 42 to 95 % and the apple detachments were measured between 89 an d 97 % with low apples injuries approximated between 3 to 31 % (Lng, 1989). A citrus canopy air shaker is designed to dislodge the citrus fruit as pictured in Figure 2 10. A Propeller fan wa s built with a hydraulic lifting apparatus for the tall tree canopy. With an air velocity of 125 mph 1500 rpm of fan speed, 22.2 N of the fruit dislodgement force and a forward traveling speed of 1mph, the average of fruit dislodgement with an abscission chemical

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35 application was 97 % of fruit removal and a h arvesting speed of 170 trees per hour (Coppock and Donhaiser, 1981). A b lueberry harvester that involved two inclined symmetrical spokes drums has been developed for fresh blueberry market as shown in Figure 2 11. Six spiral catchers are arranged on each mast drum and each spiral catcher was built with 24 uniform 480 mm length sticks The two spokes drums were angled in 45 on the horizontal side an d swung by a harvester gearbox. The sticks length ( 3.80 cm ) penetrated into the blueberry canopy 10 cm. Th e position ing of th e inclined symmetrical spokes drums decreased the fruit losses to 44 % plus the blueberry harveste d was found to be fresh market quality (Peterson et al., 1997). In another evaluation, t he BEI International blueber ries harvester that is shown in Figure 2 3 was utilized to harvest dwarfed citrus trees in the 2011 harvesting season of south Florida. Overall machine dimension s were 252 inches (length), 119 inches (width), and 131 inches (height). Also, d imension s of the machine tunnel were 54 inches of the tunnel width and height from 84 to 9 8 inches The primary harvesting trials resulted in a proper harvesting rate up to 95 % but the m achine need ed to be adapted to harvest citrus tree canop y planted with a high density (Ehsani and Khot, 2 012). In addition, Peterson and Takeda (2003) developed a harvester machine that was designed in 2000 for thornless blackberry (Figure 2 12). The new harvester had two isometric spokes drums shaker s Each drum ha d eight spiral catchers, which were mounted on a 7 inch (18 cm) drum Furthermore, 24 shaking sticks were attached on each spiral catcher. The blackberry harvester also had a conveyer to hold the detached fruit Once the blackberry fruit was detached it was sorted via the laborers hands. S poke pen etration into the blackberry tree s canop ies was from 4 to 6 inches (10 to 15 cm) The trees canop ies were oscillated at frequencies from 5.8 to 7.9 Hz with 105 to 140 N m of applied torque and the harvester forward speed was 0.5 mph

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36 (0.8 km/hr ). However, this eastern thornless blackberry harvest was not successful for blackberry fresh market quality, due to the low percentage of fresh market ra t ing between 36 and 56 %. Crunkelton (1992) invented a fruit harvesting mechanism using lengthwise dislodgement sticks mounted to a vertical mast that was mounted on a tractor publicized in U.S. Patent Number 5,161,358 filed on July 8, 1991. By using retractable and extendable sticks the t ree canopy was engage d by the harvester and the fruit s were removed from the tree branches without injuries (fruits fell to the ground directly) De Mendon a Fava et al. (2005) reported a crop harvester with a piloting system strategy which was described in U.S. Patent Number 6,959,527 B2 filed on February 21, 2003 and deployed in Brazil. The 56 radial shaking spokes were arranged on a vertical rotor drum. When the associated position sensors detect the tree canopy, t wo actuators were used to modify th e vertical rotor drum and pick ing spokes positions This invention determined the harvester position and its trajectory around the tree canopy so that the fruit harvester could to achieve exceptional performance. Peterson et al. (1989) reported the descrip tion of a shaking system for a small continuous fruit harvester used for harvesting blueberry and grape which was described under U.S. Patent Number 4,860,529 filed on August 8, 1988 That harvester utilized a double spokes drum which vibrated the spokes (24 radial sticks set on equal angles for each spokes disc (6 spokes discs)) with varied canopy penetration displacements (0.15, 0.27, and 0.63 inches). In addition, the two spoke drums vibrated in parallel to the spoke drums revolution and the harvester t ravel along trellis rows with three different types of trellis canopy. Contrariwise, Christie and Winquist (1967) had described another berr y harvester utilizing spokes drums that was invented under

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37 U.S. Patent Number 3,325,984 filed on October 28, 1963. T hese spokes drums vibrated perpendicular ly to the spokes drums revolution. Peterson and Miller (1989) indicated an apples harvester that was designed by the Appalachian Fruit Research Station (USDA) as shown in F igure 2 13. That harvester integrated small vertical sticks to dislodge two kinds of apples from the trees by using the canopy pressing method. These apple trees were shaped on trellises that had a T shape. The sticks penetration into the apple tree canopy was 100 mm per second with 345 N of press ing force on each stick. The sticks, with diameters of 13.7 mm and 7.6 mm, were arranged on a rectangle frame of the canopy shaker The detached apples were collected at efficiencies between 88 .8 to 97.5 %. The percentage of injured apples was 1 to 7.4 % b ruised and 7.6 to 21 % cut and punctured Peterson (1998) developed a vertical continuous tree canopy shaker to harvest a tall orange tree canopy. It included two designs The first involved a pair of spokes drum shaker s as presented in Figure 2 14. Each mast drum ha d six horizontal spokes sets arranged on a vertical shaft with 16 radial spokes arranged on each spoke set at equal angles. The spokes were insert ed into the orange tree canopy to a depth of 39 inches, with 10 inches of spoke displacement an d spoke oscillation frequency of 4 to 5 Hz T he continuous pair spokes drum canopy shaker was dragged by a tractor at forward speeds between 1.4 and 3.2 kph with 71 to 91 % of the orange s detach ed to the ground The second harvester was designed to harvest oranges trees more than 13 ft (4 m) in height as displayed in Figure 2 15. The continuous two spokes drums had eight spokes set s (spokes nippers) spaced on each mast drum. Each spoke set had 16 radial sticks arranged at equal angles. 4 6 inches of the sticks were inserted into the orange tree canopy with 10 inches of the horizontal stick displacement and up to 5 Hz sticks oscillation. A conveyer was added to this harvester to catch and transport the detached fruit It was also pulled by a hitch

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38 point on a 90 Hp tractor. T his harvester realized 83 % detachment of the oranges using sticks oscillation of 5 Hz while 80 % of the fruit was removed and colle cted when the sticks oscillated at 4.7 Hz. The canopy shaker described by Hosking (2002) was invented under U.S. Patent Number 2002/0062635 A1 & Number 6,425,233B1 filed on November 29, 2000 (Figure 2 16) Another, described by Daniels (1999) was invented under U.S. Patent Number 5,946,896 filed on January 23, 1998. Th ese canopy shaker s included two fruit detachment sections (four vibration fruit detachment boards) as shown in Figure 2 17. Each board had 18 to 28 vibrating sticks mounted in parallel. The pairs of fruit detachment sections were swung using a hydraulic motor Furthermore, t hese assemblies were mounted onto a single long hydraulic arm. Dealing with Citrus Fruit Directly for Choosing and P icking ( S elective H arvesting) A prototype of a robotic citrus fruit gripper that utilized fruit vision and robotic picking system (robotic arm) depicted in F igure 2 18, was described by Hannan and Burks (20 04). For this design mechanism, the citrus fruit was selected depending on the fruit shape and its color, and the robotic arm pull ed the citrus fruit from its place in the tree canopy H arrell et al. (1989) described a fruit picking system to harvest the fruit from tree s by using a robot The movement of the robot in the process of picking the fruit from the tree was controlled by taking an image of the fruit, localizing position, and t hen using serv o s to move into position to harvest. Lee et al. (2006) developed a citrus harvester to detach the orange stems individually by using an automated and robotic harvester concept. The harvester prototype contained three pneumatic actuators (wit h orange stems cutter) that were mounted onto the movable frame of a forklift machine. With this concept, 84 % of the oranges were collected without significant

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39 injuries. Moreover, Sivaraman (2006) designed and developed a fruit pulling arm robot with an electro hydraulic control system for citrus fruit picking (Figure 2 19). An O verview of the P ragmatic D ifferences of the M echanical H arvesting M achines Recently, in Florida citrus farmlands there are three harvesting systems being used to harvest citrus fruit One of them is a trunk shaker, and the others are citrus canopy shak er s. One with a catch surface use d a pair of self propelled continuous canopy shakers and the other shaker unit was drawn by a tractor. These mechanical harvest ers were designed to reduce the use of hand labor er s and thus the cost of fruit harvesting. The first system operation depends on trunk oscillation by a long clamp arm that send s oscillations to the tru nk for fruit detachment. Meanwhile, both of the canopy shakers have spokes mounted on a nipper disk that penetrate s into the citrus trees canopies to remove the citrus fruit as shown in Figures 2 20, 2 2 1 and 2 2 2 (Hannan and Burks, 2004; Futch and Roka, 2005; and Futch et al., 2005). Citrus harvesting machines were investigated thr oughout the harvesting season of 1996 1997 by Whitney (1999). The citrus harvesting was carried out with a tree canopy shaker mounted to tractor, and a trunk shaking harvester with fruit capture surface, which were used to harvest one side of the tree row 5 5 to 95 % of the oranges were removed from tree canop ies by the canopy shaker (with or without fruit catching frame ) which used force detachment s of 26 to 102 N a nd 4.5 to 5 Hz shaker frequenc ies 84 to 94 % of oranges were detached by using a trunk shaking harvester with catch frame, which used force detachment s between 69 and 115 N 10 Hz trunk shaker frequency and 5 cm of shaker displacement. In Florida, fru it harvesting laborers costs were predicted to be between 1.40 and 1.80 dollars per box. Whereas, fruit harvesting expenses with mechanical harvesting were reduced by more than 50 %. Besides, the advantage of citrus mechanical harvesting was illustrated by contrasting the two widespread harvesting systems that were in use in Florida citrus farmlands

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40 throughout the 1999 00 & 2002 03 seasons A t runk shaking harvester with catch frame, averaged a harvest speed of 185 trees/hr Florida citrus produces also used a continuous canopy shaking harvester, with catch frame, achieving a harvest speed 310 trees/hr Performance results showed 95 % of fruit removal and 91 % of fruit recovery by using the continuous canopy shaking system while fruit removal by the t runk shaking system achieved 94 % with 89 % fruit recovery B oth systems achieved 1 00 boxes per an hour more than the laborers productivities (Roka and Rouse, 2004). By using the continuous canopy harvesting system an d trunk sha ker with catch frame the harvesting labor productivity increased over 5 to 15 times and the citrus harvesting costs w as decreased by 50 to 75 % (Brown, 2002, and 2005). Furthermore, Sanders (2005) showed that the rate of harvesting fruit trees per hectar e using canopy shaking harvester was more than 15 times greater than using manual laborers and more than 2 to 3 times the rate of the trunk shaking harvester. Analysis of the V ibration during the P eriod of the M echanical H arvesting Udumala Savary (2009) and Udumala Savary et al. (2011) conducted a study of the forces of vibration on the citrus tree canopy exposed to the force of the mechanical harvesting (TDCS machine) using an instrument that measures the force required for the citrus fruit s to b e removed. That device was placed on random citrus tree branches (small & large of Hamlin and Valencia trees) and on the citrus fruit s to study the impact of the resistance of citrus fruits to the vibration forces of the mechanical harvester as shown in F igure 2 2 3 The fruit detachment force (FDF) that is required for citrus tree harvesting was measured by using a tiny low g accelerometer (Freescale MMA7260Q) which ha d a sensitivity of up to 6 g with supply voltage in the range of 2.2V and 3.6V, a sin gle pole filter, a with XBee PRO RF module and a small sensor (XBee PRO DigiMesh 2.4 GHz) which was employed as a data

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41 acquisition device between the PC and the accelerometers. These apparatuses were attached together, with a load amplifie r, and coupled to a USB port on a PC. For the FDF application the operating variables examined by this study were : the size of citrus trees (small & large), angles of beaters of the canopy shaker (5, 20, and 35 degrees), and the canopy shaker frequencies (200, 250, and 300 cpm). The accelerometers data (the coordinates of x, y, and z axis) were recorded in t ext file by using the acquiescent LabVIEW VI software as represented in Figure s 2 2 4 and 2 2 5 In addition, the fruit detachment forces FDF (FR) were calculated depending on the accelerometers sense (3 axial acceleration values as recorded in an observable text file) and some standard constants (e. g. accelerometer sensitivity, g value, and the fruit & limbs weight that were selected randomly). In general, this study has proposed that required forces (maximum force), which are applied for the detachment of Hamlin and Valencia fruit during the harve ster operations were 27.20 N and 22.01 N respectively In general, Hamlin fruit required less average force than the Valencia fruit. Additionally, the maximum forces for fruit detachment depending on fruit location were recorded as 24.49 N on the tree s urface and 23.07 N for inside fruit. Depending on the citrus trees sizes, the maximum resultant acceleration values (m/s 2 ) were found to be 136.01 for the large trees with, the beaters angle and frequency of 5 o and 250 cpm and 137.95 for small trees with the beaters angle and frequency of 35 o and 300 cpm. A nother study was carried out by Castro Garca et al. (2008) on the operation of olive harvesting which used a trunk shaker approach. The vibration required for olive tree harvesting was measured using 3 tri axial accelerometers located on various b ranches and one tri axial accelerometer placed on the tree trunk (Figure 2 2 6 ). The tri axial accelerometers used were model PCB 356A02 which ha d sensitivity up to 10 (mV/g), amplitude range 500 g, a

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42 frequ ency range 0.5 to 6000 H z supply current range from 2 to 20 mA and a weight of 10.5 g Also, the specific frequencies applied were in the range of 0 to 256 Hz. The maximum excitation frequency was recorded as 71.5 H z for large trees and 72.4 H z for small trees. In addition, vibrations, which were established by a grape harvester with ground speed of 2.8 km/hr, were estimated for the application of various beating frequencies of 380, 400, 420, 440, and 460 (beats/min) to the vineyard. The plant oscillation was determined by three vibration sensors (tri axial accelerometers) Two accelerometers were posted vertically on some of the grape boughs at different distances (10 and 20 cm from the wire accelerometer on top) while the third accelerometer was placed on top of the trellis wire. The tri axi al accelerometer specifications were a sensitivity of 0.316 (pC/ms 2 ), frequency range 0.1 to 16500 H z and amplitude in range of 50,000 (m/s 2 ) with 2.4 g in weight. Furthermore, the vibration sensors ha d b een attached to an amplifier and dig ital recorder. The vibration measurements were analyzed using LabVIEW 8.0 software. From the results of the operational variables of this experiment, it was found that adequate results were achieved by applying the beati ng frequency 440 (beat/min) (Pezzi and Caprara, 2009).

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43 Figure 2 1. A p air of OXBO c ontinuous f ruit c anopy s haker s with f ruit c onveyer s [Adapted from Futch and Roka, 2005 ] Figure 2 2 A p air of KORVAN c ontinuous f ruit c anopy s haker s with f ruit c onveyer s [Adapted from Futch and Roka, 2005 ]

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44 Figure 2 3 Self p ropelled BEI h arvesters for b lueberries f ruit [Adapted from BEI International, LLC, 2010 ] Figure 2 4. An a djustable l ong b eam s haker and i ts f ingers m ounted o n an agricultural t ractor [Adapted from Loghavi and Mohseni, 2006 ]

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45 Figure 2 5. A p air of a pple h arvester m achine s [Adapted from Peterson and Wolford, 2003 ] Figure 2 6. Sketch of a c anopy s haker [Adapted from Visser, 2001 ]

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46 Figure 2 7. Sketch of a c itrus h arvester m achine with f ruit c onveyer [Adapted from Schloesser, 2005 ] Figure 2 8. Schematic of d ragged c itrus c anopy s haker [Adapted from Briesemeister et al., 2008 ]

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47 Figure 2 9. Self p ropelled a pple h arvester with h orizontal c anopy s hakers [Adapted from Lng, 1989 ] Figure 2 10. A c itrus c anopy a ir s haker t owed b y a t ractor [Adapted from Coppock and Donhaiser, 1981 ]

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48 Figure 2 11. Blueberry h arvester m achine [Adapted from Peterson et al., 1997 ] Figure 2 1 2. Thornless b lackberry h arvester m achine [Adapted from Peterson and Takeda, 2003 ]

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49 Figure 2 13. An a pple harvester for small tree canopies with c atch f rame [Adapted from Peterson and Miller, 1989 ] Figure 2 14. Sketch of a c ontinuous p air s pokes drum s c anopy s haker d ragged b y a t ractor [Adapted from Peterson, 1998 ]

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50 Figure 2 15. Sketch of a c ontinuous p air s pokes d rum s c anopy s haker with o ranges f ruit c onveyer [Adapted from Peterson, 199 8 ] Figure 2 1 6. A c itrus f ruit c anopy s haker [Adapted from Hosking, 2002 ]

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51 Figure 2 1 7. Fruit h arvester m achine [Adapted from Daniels, 1999 ] Figure 2 1 8. Citrus p icking s ystem by u sing a r obotic a rm [Adapted from Hannan and Burks, 2004 ]

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52 Figure 2 1 9. Robotic a rm m odules with e nd e ffectors [Adapted from Sivaraman, 2006 ] Figure 2 20. A t runk s haker s ystem [Adapted from Futch et al., 2005 ]

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53 Figure 2 2 1 A c anopy s haker u nit d rawn b y a n agricultural t ractor [Adapted from Futch et al., 2005 ] Figure 2 2 2 A p air of c itrus c anopy s hakers and two c atch s ystems [Adapted from Futch et al., 2005 ]

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54 Figure 2 2 3 Three w ays to a ttach the a cceleration u nits throughout the e xperiment p rocess [Adapted from Udumala Savary, 2009 ] Figure 2 2 4 Diagram of the a cceleration sensors and d ata c ollection p rocedure [Adapted from Udumala Savary et al., 2011 ]

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55 Figure 2 2 5 LabVIEW b lock d iagram of the d ata a cquisition [Adapted from Udumala Savary, 2009 ] Figure 2 2 6 Diagram of the a cceleration s ensors positions and p rocedures of the instrumentation e xperiment s [Adapted from Castro Garca et al., 2008 ]

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56 CHAPTER 3 MATERIALS AND METHODS Assembly Design Procedures of the Citrus Canopy Shaker ( Theoretical ) The dissertation research concept is to design and develop a novel self propelled over the top canopy shaking machine which is specialized for harvesting of semi dwarf citrus trees where two identical fruit shaker units will surround the canopy of the citrus tree Initially, the shaker machine was modeled using the SolidWorks program to ensure that the machine parts worked together as expected Figure 3 1 shows the SolidWorks model Figure 3 1 A representative self propelled citrus tree canopy shaker (preliminary design)

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57 The essential purpose of th e design process is to analyze how the canopy shakers should be designed so that shakers would deliver suitable fruit removal forces to detach fruit. The fundamental mechanical parts o f the canopy shaker were the chassis frame, shaker modules, hydraulics, wheels and motors, steering system and two engines (18 and 33 Hp) Initially, there were 1 4 shaking beaters with 14 reciprocating ro ds (movable turn buckles that extended horizontally) while in the final design, the number of the shaking beaters increase d to 26 beaters A vertical shaft s upported the beaters (beaters holder shafts), while a rotator crank shaft with a s olid flywheel caused the beaters to oscillate, as depicted in previous figure. D esign analysis will determine the required diameters of the shaking beaters, the two vertical shafts, and the horizontal interchanging rods by first assuming the horizontal load that could be applied at the beaters ends to obtain the suitable limb displacement. The following procedures would be employed to determine the required diameters of the mechanical parts for the new citrus harvester design: 1 Drawing the proper apparatus loads, shears and bending moment diagrams to determine the maximum and minimum bending moment. 2 Identifying the material properties such as; ultimate strength value and yield strength 3 Specifying the factors that will affect the endurance strength. 4 Selecting the stre ss concentration and design factor s In essence, the following equations will be utilized to compute the section modulus S value. Then, using the section modulus, the desired shaft diameters will be determined (Mott, 2004).

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58 (3 1) (3 2) (3 3) (3 4) (3 5) (3 6) Where, is the a ctual endurance strength (psi) is the m aterial factor is the t ype of stress factor is the r eliability factor is the s ize factor is the e ndurance strength (psi) is the s ection modulus (inch) is the d esign factor is the t ensile strength (psi) i s the y ield strength (psi) is the m ean bending moment ( lb in ) is the a lternative bending moment ( lb in ) is the s tress concentration factor is the a rea of the cross section of the materials used (in ch 2 ) is the d iameter of the mate rials used (inch) is the m ean force (lb) is the a lternative force (lb) is the y ield strength in shear under actual conditions (psi) is the e ndurance strength in shear under actual conditions (psi) is a constant number is the yield strength (psi), is the bending moment (lb in), and is the shaft torque (lb in) S ubsequently, the machine design procedures will be handled in the order prescribed.

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59 The Raised Horizontal Beaters Design The shaker s design process w i l l determine the proper diameter of the beaters of the canopy shaker machine under the shaking load. For the beater diameter estimation, field force measurements were taken by of diverse limb deflections as shown in Table 3 1 and Figure 3 2. T he calculation s of table 3 1 values are documented in the equations referenced in 3 2 2 to 3 2 3 later in this chapter The maximum load of 50 l b f (222.41 N) found in Table 3 1 should be enough functional load to deflect the tree branches and their fruits during citrus harvesting to detach the fruit from the tree. Figure 3 3 shows the basic loading design of the horizontal beater (56 inches arc length weighing 20 lb). The beater is shape d like a fue l pump dispenser nozzle The initial design was composed of steel, while the final design had a composite construction with steel components at the crank shaft and PVC pipe at the free end. A s mall metal sleeve ( 0.5 at one end and 0. 2 5 at the other end, and length 4.50 inches) was pushed into the internal holes of the metal pipe and the PVC pipe of the shaking beater (3 inches of the metal sleeve pushed into the PVC pipe and 1.50 inch es pushed into the metal pipe) to join them together Th is innovative new beater design reduce d the gross beater weight from 20 lb to 15 lb with 56 inches arc length and provide s an efficient oscillation for the shakers. Also, this beater design ( composed of rounded metal pipes and PVC pipes) w ould minimize the likelihood of tree canopy damage due to branch and beater collision s The beater load diagram shows the bending moment that occurred at the end of the beaters on the vertical shaft. The maximum bending moment is M max = 1,600 lb in and the minimum bending moment is M min = 800 lb in. Theref ore, for the beater design analysis, the beat er material is specified as AISI 1050 cold drawn steel that has a yield strength of S y = 84 ksi and an ultimate strength of S u = 100 ksi. Those values will be used for all material s of this design.

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60 Then, to complete the beaters design analysis, the equations 3 1, 3 2, and 3 3 will be utilized (Mott, 2004). From the value of bending moment, the maximum bending moment is M max = 1,600 lb in and the minimum bending moment is M min = 800 lb in. Thus, the mean bending momen t is 400 lb in (M m = (M max + M min )/2) and alternating bending moment is 1200 lb in (M a = (M max M min )/2). Because the beaters will be of uniform diameter along the beater length the stress concentration factor is set at K t = 1.0 B ecause this design has a somewhat constant beating rhythm th e design factor for equation 3 2 was selected as N =2.0 The endurance strength of the material under actual working condition s can be determine d by using equation 3 2. The endurance strength is assumed to be S n = 38 ksi for the beaters having S u = 100 ksi. For the wrought steel, the material factor is expected to be C m = 1.0 and the stress type factor of C st = 1.0 for the repeated bending stress. The reliability factor is chosen as C R = 0.81 to achieve a reliability of 0.99. Because the rod diameter was not determined yet, the value of size factor is expected as C s = 0.95 (Mott, 2004). By using these values, equation 3 1 was used to determine the required value of endurance strength = 29,241 psi. Furthermore, equation 3 2 calculated the requir ed section modulus S = 0.09 in ch . By applying the section modulus value to the equation 3 3, the rod diameter came out to be 0.971 inch. T hus the harvester beater diameter was chosen to be 1 inch

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61 Table 3 1. The field measurements of the pulled forces achieved by effect of different manual orange limb deflections Dis. 3.94 (in) Dis. 5.91 (in) Dis.7.87 (in) Dis. 9.84 (in) No Di. f A c I L b f F E F E F E F E in in in in l b f k si l b f k si l b f k si l b f k si 1 0.58 0.26 0.005 33.5 5 2 5 2 8 6 04 10 10 0 7 12 15 10 2 0.61 0.3 0.007 23.5 20 6 2 6 30 14 0 8 42 26 2 8 50 39 1 1 3 0.69 0.38 0.011 32.5 4 1 35 7 3 56 9 6 09 11 9 31 4 0.57 0.25 0.005 43 2 1 35 4 4 0 4 5 6 7 3 6 10 09 5 0.54 0.23 0.004 70 1 1 1 9 2 3 56 3 7 12 4 11 87 6 0.41 0.13 0.001 34 7 7 27 11 17 1 4 14 29 08 16 41 5 5 7 0.54 0.23 0.004 54.5 3 2 81 4 5 6 3 6 11 2 6 8 18 7 7 8 0.78 0.48 0.018 54 2 8 87 3 1 99 5 4 4 4 6 6 65 9 0.85 0.56 0.025 39.5 14 3 87 20 8 29 25 13 8 3 29 20 05 10 0.72 0.41 0.013 41.5 6 2 4 1 9 5 4 2 12 9 6 3 15 15 04 11 0.68 0.37 0.011 48 6 3 08 10 7 71 12 12 3 4 15 19 28 12 0.44 0.15 0.002 34.5 3 2 65 5 6 6 4 7 12 3 9 9 19 91 13 0.67 0.35 0.01 0 43.5 10 4 8 3 15 10 86 20 19 3 1 24 28 96 14 0.84 0.56 0.025 55 18 7 0 1 25 14 59 33 25 6 9 40 38 92 15 0.58 0.26 0.005 31 23 10 73 32 22 .40 41 38 2 6 45 52 49 16 0.58 0.26 0.005 45 3 2 0 3 5 5 07 7 9 4 7 9 15 21 17 0.62 0.31 0.007 60.5 3 2 3 4 5 5 8 4 7 10 9 0 9 17 5 2 18 0.38 0.11 0.001 52.5 2 3 66 3 8 24 5 18 3 1 7 32 05 19 0.77 0.47 0.018 41.5 15 5 21 21 10 9 5 30 20 85 38 33 0 2 20 0.6 0.28 0.006 53 11 8 2 4 15 16 85 20 29 9 6 25 46 8 1 Ave 0.62 0.32 0.009 44.5 8 3 98 1 2 8 95 1 6 16 .1 0 1 9 24 59 S .D. 0.13 0.13 0.007 11. 5 7 2 69 9 5 48 12 9 4 5 14 13 5 2

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62 Figure 3 2 F ield measurement of the citrus fruit detachment force [Photo courtesy of Naji A l Dosary ] Figure 3 3 Basic design of the horizontal beater and its load

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63 Vertical Beaters Pivot Shaft Design The vertical beaters pivot shaft is connected to the end of the shaking beaters to hold them in vertical position and allow them to oscillate to the movement from the movable crank shaft The shaft is mounted to the harvester body by the two flange bearings at the two ends of the beaters shaft B ending moment will occur due to the beater reaction forces. Since the shaft is free to rotate, there will be no torsion loading. The beaters are mounted vertically on each beaters pivot shaft at equal spaces 8 inches apart The Figure 3 4 shows the basic design of the vert ical beaters pivot shaft and its horizontal loads. The maximum bending moment is M max = 5224.84 lb in and the minimum bending moment is M min = 0 lb in. Thus, the mean bending moment is M m = 2612.42 lb.in ((M max + M min )/2) and the alternating bending moment value is M a = 2612.42 lb.in ((M max M min )/2). Therefore, for the beaters pivot shaft design analysis, the shaft material is specified as AISI 1050 cold drawn steel that has a yield strength of S y = 84 ksi and an ultimate strength of S u = 100 ksi. The endura nce strength is assumed to be S n = 38 ksi for the beaters In addition, because the shaft diameter was not determined yet, the value of size factor is selected as C s = 0.85 The design factor for equation 3 2 was selected as N =2.50, since this design has a somewhat uncertain dynamic load from the environment (Mott, 2004). The same techniques and material s that were considered to determine the beater diameter were considered for the beaters pivot shaft diameter calculation Thus, the required value of endurance strength is = 26,163 psi. Furthermore, the require d section modulus value is S = 0.314 in ch . By applying the section modulus value to equation 3 3, the shaft diameter came out to be 1.471 in ch es However, for more operational safety, the sh aft diameter is taken as 1 .50 inches. Depending on the cyclical rotation of the beaters pivot shaft ( 15 degrees) the canopy shakers displacement (beaters penetration), acceleration, and beaters frequency will be determined.

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64 Figure 3 4. Basic design of the vertical beaters pivot shaft and its load Vertical Crank Shaft Design The crank shaft is connected to an aluminum channel by three bearings which in t ur n is connected to the beaters by turn buckles. The crank shaft i s mount ed on the harvester bod y by two flange bearings that are pushed on to the two shaft ends Therefore, the bending moment and torsion will occur on th e crank shaft Figure 3 5 depicts the basic design of the vertical beaters shaft and its horizontal loads. From the value of the ben ding moment, the maximum bending moment is M max = 8729.06 lb in and the minimum bending moment is M min = 0 lb in. Thus, the

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65 mean and alternating bending moment s are equal. Thus, the mean bending moment M m = 4364.53 lb.in is likewise the alternating bending moment M a = 4364.53 lb.in. Therefore, for the beaters shaft design analysis, the shaft material is specified as AISI 1050 cold drawn steel having a yield strength of S y = 84 ksi and an ultimate strength of S u = 100,000 psi. The endurance strength is assumed to be S n = 38,000 psi Also, this shaft is designed with the combination of torsion, shear, and bending moment s So, the calculated maximum torque was = 2,800. 0 lb in and 8729.06 lb in of the moment value will be used to determine the shaft diameter. In addition, because the diameter of the shaft was not determined yet, value of the size factor is selected as C s = 0.85 Also, the value of the stress concentration factor is selected as K t = 1.0 and the design factor for equation 3 6 was selected as N= 2 .0 As a result, the shaft design has a high confidence with a static load (Mott, 2004). Likewise, the same practices and material s that were applied to determine the beaters pivot shaft and its associated beaters diameter would be used for the crank shaft diameter calculation Consequently, the required value of the endurance strength is = 26,163 psi. Furthermore, the require d section modulus value is S = 0. 420 in ch . By applying the shaft torque and moment value s to equation 3 6 the crank shaft diame ter comes out to be 1. 89 6 inch es

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66 Figure 3 5. Basic design of the vertical crank shaft and its load Horizontal Push Rods (Interchanging Turn Buckles) Design In general, for each canopy shaker unit, the beaters pivot shaft and the crank shaft are attached together by seven horizontal rods (turn buckles). Figure 3 6 shows the basic design of the horizontal push turn buckle with its horizontal loads where it is acted upon by two identical forces in opposite di rections ( 116.67 lb compressive load and 116.67 lb pull load). There fore, in the push rod (turn buckle) design analysis, the shaft material is assumed to be as AISI 1020 cold drawn steel that has a yield strength of S y = 51 ksi and an ultimate strength of S u = 61,000 psi. The

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67 endurance strength is assumed to be S n = 23,000 psi for the rod with an ultimate strength S u = 61 ksi. Thus, maximum force (F max ) is 116.67 lb and the minimum force (F min ) will be 116.67 lb. For the specified steel of this push rod, the material factor is expected as C m = 1.0 and the stress type factor is C st = 0.80 for the axial tension. The reliability factor is chosen as C R = 0.81 to achieve a reliability of 0.99. Because the diameter of the reciprocat ing rod was not determined yet, the value of size factor was selected as C s = 0.90 Hence, the design factor was selected as N = 4.0 due to somewhat uncertain dynamic load s for the machine components or environment (Mott, 2004). Thus, the mean force is F m = 0 l b (F m = (F max + F min )/2) and the alternating force is F a = 116.67 lb (F a = (F max F min )/2). By using the values of the estimated forces, the equation 3 1 exercised for required value of endurance strength is = 13,413.6 psi then the endurance strength val ue in shear under actual conditions is = 7,739.65 psi ( = 0.577 ) and S sy = 29,427 psi (S sy = 0.577 S y ). Furthermore, by applying those values in the equations 3 4 and 3 5, the required push rod area will be presented as A c = 0.03 in ch 2 Thus, push rod diameter is 0.1954 inch (1/4 in ch ). Preferably, for more operational safety, the diameter of the reciprocating rod is assumed to be 1/2 inch in circular shape. Figure 3 6. Basic design of the horizontal push rod and its loads (recipr ocating turn buckle)

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68 Vertical Connecting Beam (Interchanging Beam) Design Figure 3 7 shows the basic analysis of the vertical connecting beam design (62 inches in length) and its loads. The vertical connection beam (U shape aluminum channel) is connecte d to seven identical horizontal rods (turn buckles) and the shaker crank shaft by three short aluminum rectangular solid bars (5 4 2 inches) and their connecting radial bearings using two bolts on each side of the short aluminum bar. The maximum bending moment found as M max = 236.6 lb in and the minimum bending moment was M min = 1030.90 lb in. T herefore, for the beam design analysis, the beam material is specified as 6061 T6 aluminum beam in channel shape that ha s a tensile strength of S u = 45 ksi and yield strength of S y = 40 ksi. Those values will be used for all material s of this beam design. Then, for completing the design analysis, equations 3 1 and 3 2 will be utilized (Mott, 2004). So, f rom the values of the be nding moment s the mean bending moment value (M m = (M max + M min )/2) is M m = 397.15 lb in and alternating bending moment value (M a = (M max M min )/2) is M a = 633.75 lb in. The endurance strength is estimated to be S n = 20 ksi for the aluminum beam that ha s an ultimate strength S u = 45,000 psi. Also, the value of the stress concentration factor is selected as K t = 1.0 and because of the static loads, the design factor value selected for equation 3 2 produces is N=3.5. For the aluminum alloy, the material factor is expected as C m = 0.5 and the stress type factor is C st = 1.0 for the repeated bending stress. The reliability factor is chosen as C R = 0.75 to achieve a reliability of 0.999 and the value of size factor is estimated to be C s = 0.90 (Mott, 2004). By using those values, equation 3 1 is exercised for required value of endurance strength = 6,750 psi. Moreover, equation 3 2 presented that the require d section modulus value is S = 0.298 in . Consequently, the specified size for t his beam is expected to be 3 inches (depth) and 1.75 inch es (width) but for more adequate design, aluminum c shape beam with size 5 inches in depth and 2.25 inches in width is chosen (Mott, 2004)

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69 Finally, the design of the new canopy shaker machine consi st s of several main assemblies. The first one is the symmetric rigid exoskeleton, second and third are the two main movable parts, the crank shaft and the beaters pivot shaft. The fourth effective part is the extended rods (seven horizontal interchanging p ush turn buckles on each side ) with an aluminum channel, which are used to deliver the linear speed from the crank shaft to the beaters pivot shaft for each shaker unit So, the selected member diameters for these essential parts are shown in Table 3 2. Figure 3 7. Basic design of the vertical connecting beam and its load Table 3 2. M ost important parts diameters of the representative harvester design ( initial design) Parts Designed D iameter (in) Calculated D iameter (in) Beaters 1 ( H ollow M etal) & 0.5 (PVC P ipe) 0.971 Beaters Pivot S haft 1.50 1.471 Crank S haft 1.50 1. 89 6 Interchanging R od 0.50 0.195 Connecting B eam 5 ( D epth) 2.25 ( W idth) 3 ( D epth) 1.75 ( W idth)

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70 Realistic Design of the Principal Canopy Shaker Machine The self propelled citrus canopy shaker is design ed specifically for harvesting of fruit from semi dwarf citrus trees planted in hedgerow. With this canopy shaking system, some important parameters need to be determined through the course of this study to obtain an excellent harvesting operation. These factors can include: dislodgement forces, forward speed s of the harvester, rotational speed s of the shaki ng beaters, beater stroke length, the numbers of the beaters on the shaking apparatus, and the vibration period Other fac tors of interest which will depend on shaker effectiveness, are the desired harvest efficiency, amount of tree debris and the limb and bark damage The canopy shaker ass embly shown in Figure 3 8, provides the source of tree canopy excitation necessary to detach the fruit. The shaker modules are mounted within a welded framework that forms a tunnel around the tree. The frame is composed of rectangular steel tub ing segments ( size 330.25 inch es 530.25 inch es and 640.25 inch es ) which are mounted on two pairs of front and rear hydraulically powered wheels with Firestone tires ( 2612.00 12 ) T he lateral distance between wheels (side to side) is variable depending on the exten da ble hydraulic cylinders on top of the harvester but should be not less than 69 inches or more than 101 inches in overall width. Both shakers, which transfer the shaking motion i nto the tree canopy to dislodge the citrus fruit, have a semi curved shape (1 inch diameter metal part and 1/2 inch of the PVC part diameter 56 inches in arc length) which reduce s tree injury and increase s the interacting surface with the tree along the length of the shaking beaters. After the first test of the shaking machine, the hollow PVC pipes were replaced by flexible solid 1 inch ( O D) round PVC grey rods 32 inches long. T est ing of the solid PVC rods revealed fatigue can occur when using high shaking frequenc ies Initially, two hydraulic motors (model E aton, C har Lynn W 162 1146 003 type displacement of 195 cc/rev, 10 gpm, and pressure 1800 psi) were used to provide the

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71 continuous spinning motion of the two vertical crank shafts (three crank throws on each shaft). Later, two new hydraulic motors (model Eaton, Char Lynn 2000 series 104 1009 006 type, with displacement of 6.20 cu.in/rev (101.6 cc/rev), 20 gpm, and pressure 3000 psi) were utilized because the previous hydraulic motors had a limited m aximum rotational speed of 2 00 rpm. T wo squads of shaking beaters are extended horizontally on each side of tree, and arranged on two primary beaters pivot shafts The number of the beaters per side depends on the height of the citrus trees and the beaters spacing. The vertical beaters pivot shaft which holds e ach reciprocating beaters squad of seven identical bent beaters derives its motion from the rotational movement of the crank shaft that is vertically coupled to its associated hydraulic motor In order to maintain crank shaft rotational momentum, a solid steel flywheel ( i.e., 1 27 lb weight, diameter of 19.50 inche s, and 1.50 inch in thickness) wa s mounted on the upper end of each crank shaft to ensure that the vertical crank shaft rotates at a constant rotational speed E ach flywheel is coupled to the hydr aulic motor shaft and th e upper end of each crank shaft by using an appropriate mechanical shaft coupling. T he tree canopy will be partially surrounded when the pair of harvester shaking beaters form s and is operated within the adjustable machine tunnel The tunnel dimensions are initially 69 inches with a variable width (69 101 inches) 104 inches in height from the ground 90 inches in depth The dimension of the citrus harvester exoskeleton was determined to be 1 2 1 inches of the minimum span width (12 1 to 15 3 inches) 107.50 inch es in total height from the ground 114 inches in machine total length. In addition, the beater assemblies will be extended into the tree canopies when the canopy shaker is being passed t hrough the citrus groves. The range of beaters penetration within the tree canopies is modulated by modifying the length of the short connecting rods (reciprocating turn buckles),

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72 which have a reciprocating movement horizontally between the crank shaft and the vertical beaters pivot shaft. Displacement of the shakers stroke is modified by adjusting the turn buckle length. Displacement of the shakers stroke is constant with crank diameters of 6 inches. Also, the shaking speeds (synchronized speeds) of the 14 beaters can be changed by regulating the hydraulic motors speed manually via adjust ing the speed of the Mitsubishi engine (maximum engine speed is 3000 rpm) or the two flow control valves which are a part of the John Deere relief valve block To achieve t he full potential engine speed on both engines each engine throttle can be adjusted by unlocking it, and pulling it from its initial hooking position, as shown in Figure 3 9. Figure 3 8 Major components of the innovative citrus canopy shak ing machine ( preliminary design)

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73 Figure 3 9 Two hand engine throttles (cables) of the preliminary citrus canopy shak er design [Photo s courtesy of Naji A l Dosary ] Overall the citrus harvester has three major hydraulic operational systems : hydraulic control system for canopy shaker transport speeds, hydraulic control system of the beaters shaking speeds, and hydraulic control system for the width of the internal tunnel of the canopy shaking machine ( both right and left side horizontal movement). The hydrostatic transmission system of a John Deere 3225B golf lawn mower by Eaton (model 70119 400 type of a single rotator piston pump wi th a swash plate mechanism that can be adjusted manually, 3600 rpm, pressur e 4500 psi, and displacement of 23.6 cc/rev (approximate) ) is utilized to provide forward/reverse and speed control requirements and results in suitable field transport speed s Consequently, an open center hydraulic directional control valve (prince moto r spool valves with a manual control lever joystick handle) set is used to control all the wheel motors (four identical motors made by Ross) Wheel drive is achieved by four independent wheel motor s made by Ross (m odel ME 103108 CCCB type low speed and high torque at 399 rpm, displacement of 169 cc/rev, and pressure is 3000 psi) attached to Two speed controls of the engines

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74 associated wheel hubs and tires. T he rear and front wheels are independent four wheel drive and synchronized to move simultane ously (forward or reverse travel). Furthermore, hoses with proper fittings carry the fluid flow from the hydrostat ic pump to the proper motors to provide the rotary motion of the harvester whee ls. In general, the canopy shaking machine will be continuou sly moving (self propelled) while the machine is active ly harvesting. The propulsion power is provided by a Yanmar diesel engine out of a John Deere 3225B golf lawn mower ( Yanmar 3TNE84 EJF with 24.9 kw (33.4 h p) and revolution speed up to 3000 rpm) and a triple gear pump (Sets by Danfoss part number AMT1951 and model 163C1001 & AD100C) mount ed to an Eaton hydrostatic pump The front pump outlet of the hydraulic triple pump is employed to supply charge flow to the hydrostatic trans mission while th e other two outlets of the triple pump are recirculating the hydraulic fluid to the reservoir. The front pump of the Danfoss triple pump supplies hydraulic fluid flow to the four wheel motors, extension or retraction of the double acting hydraulic cylinder s, and the steering control valve through the outlet ports of the hydrostatic transmission The schematic diagram of the hydraulic control system of the self propelled canopy shaker is shown in Figure 3 10. Moreover, the shaker motor hydraulic circuit is made up of two identical John Deere 3225B lawn mower pressure relief valves, which send the hydraulic fluid to the hydraulic motor on each shaker (each motor is attached at the top of each flywheel on the crank shaft of each shakers unit) The shaker brake solenoid valves ( O n/ O ff) and the flow control valves in the two J.D. relief valve blocks, hydraulic system. A Toro Reelmaster 5300 D golf lawn mower engine (Diesel engine model Mitsubishi type S3L2 002861 152 3N with 18 hp engine power (13.4 kw) and maximum revolution speed of 3000

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75 rpm) mounted with a triple pump ( by John S. Barnes Corp. 93 1376 & 10294) is utilized to provide power to the shaker fluid system. The three outlet ports of the hydraulic triple pump (front, center, and rear pumps) are combined together and then split 50% 50% to drive the right and left shakers motor s The s chematic diagram of the hydraulic control system of the two canopy shaker unit s is demonstrated in Figure 3 11. For the internal tunnel width extension, f our exten da ble hydraulic cylinders were mounted on the top of the right and left canopy shaker structure and were controlled by an open center hydraulic directional control valve (joystick handle) positioned on the right side of the activating the hydraulic fluid via the operation of the front pump of the John Deere 3225B triple pump through the hydrostatic pump port as previously shown in Figure 3 10. For convenience, the two hydraulic control valves are located on the right and left close to the operator's seat at the front top of the canopy shaker structure so the operator can ea sily control and monitor the systems operations. Moreover, the two engines with their attached triple pump, fuel tank (6 gallon capacity), and the hydraulic oil reservoir (15 gallon capacity) were located underneath the top of the canopy shaker structure and behind the operator's seat The flexible hydraulic hoses rated for 3000, 4000, and 4800 psi pressure (quality of two wire braid hose with female swivel fittings) as shown in Figure 3 12 are used for the high pressure lines through the canopy shaker h ydraulic circuit components and low pressure lines that return the fluid to the hydraulic reservoir respectively The entire machine hydraulic system components and the fluid flow direction are shown in Figures A 1, A 2, and A 3.

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76 Figure 3 10. Schematic diagram of the hydraulic control system of the self propelled canopy shaker, two extension systems and steering system.

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77 Figure 3 11. Hydraulic control system diagram for the two shaking units of the citrus canopy shaker Figure 3 12. Some flexible hydraulic hoses were used for the hydraulic control systems of the citrus canopy shaking machine [Photo s courtesy of Naji A l Dosary ]

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78 The electrical schematic diagram of the Mitsubishi and Yanma r diesel engine ignition systems and their implement ation are both shown in Figure 3 13 and Figure 3 14. Besides the fuel shutoff solenoid and glow plugs, two 12 volt batteries have been employed to provide power to the electrical starting system circuit ry and to all other electrical components. In addition, de energizing circuit s for the 12 volt On/ O ff shakers brake solenoids (two solenoid operated directional valves NC & NO) are added to the electrical wiring diagram of the Mitsubishi engine. Practical ly, as shown in Figure A 4, the solenoid valve (S1) is a normally closed valve with a nonactuated position (12 volt DC current Off) T his valve automatically acts likes a check valve W hen the solenoid is energized (12 volt DC current On), effective pressu re (700 psi) is permitted to flow through the hydraulic hoses to the shakers motor brake ports when the solenoid valve (S2) is in a normally open valve position (12 volt DC current Off) to release pressure (release brake) to the hydraulic reservoir W hen t he solenoid is energized (12 volt DC current On), the pressure is not permitted through it to release the shaker s parking brake. However, revisions were made and the hydraulic brake circuit s of the crank shaft motors were eliminated to save more power f or the shakers mechanism E ven though the new hydraulic motors for crank shafts do not have brake port s the two John Deere relief valve blocks which include two solenoid valves ( O n/ O ff), are utilized to curb the rotational speed s of the two crank shafts Otherwise, the speed can be manually controlled by operating the two control valve knobs.

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79 Figure 3 13. The electrical schematic diagram of the Mitsubishi diesel engine ignition system and its implements

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80 Figure 3 14. The electrical s chematic diagram of the Yanmar diesel engine ignition system and its implements with 12 volt o n/off wheels brake solenoid valves.

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81 Each shakers pressure relief valve (John Deere pressure relief valves) shown in Figure 3 15 conta ins a n On/Off solenoid valve (12 volt DC current), flow control valve (shakers speed control), and forward & reverse switch (directional flow control). T o prevent crank shaft motor rotation, the hydraulic fluid will be dumped directly to the hydraulic reservoir (relea se pressure). The flow control valve is used to adjust the crank shaft motor s rotation to the required rpm for citrus canopy vibration. By using the forward and reverse valve switch (i.e., electrical switch on the control panel) the high pressure flow wi ll be directed to run the crank shaft motor s in backward or forward rotation a s necessary The shakers solenoids and forward & reve rse switch es electrical circuit is appended to the electrical wirings diagram of the Mitsubishi engine (Figure 3 16). Moreo ver, for quick and easy access to an appropriate control function, the shaker control and Mitsubishi engine instrument panel is positioned seat. The instrument panel includes an ignition key switch, a bundle of fuses, momentary on/off preheat toggle switch, and a visible indicator LEDs cluster (oil pressure LED, air preheated LED, water temperature LED, and battery discharge LED) as shown in Figure 3 17. Also in order to run the Yanmar engine, the instrument panel led lights are located slightly to the left of the an ignition key switch, fuel shutoff solenoid toggle switch, relief pressure valves engagement switches (four t oggle switches for the two pressure relief valves), two wheel parking brake toggle switches, and an indicator LEDs cluster (engine oil temperature LED, engine water temperature LED, air preheated LED, and battery discharge LED) as shown in Figure 3 17. Th e wheel motion when the canopy shaker is not in use is regulated by energizing the two solenoid operated poppet valves NC (S3 & S4) via the two parking brake switches (the solenoids are independent from one an other) The

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82 two parking brake switches are located on the control box (blue/white box) positioned on the left On de energizing th e se solenoid valves, the hydraulic fluid will be prevented from moving to the four wheel motors an d subsequently dumping pressure back to the hydrostatic pump inlet or into the hydraulic reservoir. Furthermore, two hydraulic steering cylinders (8 inches stroke) are mounted on the pivoting front wheel frames (extended length 23.25 inches, retracted len gth 15.25 inches, and maximum pressure 3000 psi) These steering cylinders enable a smooth angular turn (left or right) by means of the steering control valve that is connected to the steering wheel. The cylinders allow the machine operator to pivot the fr ont wheels almost 45 degree s in either direction for steering as shown in Figure B 4 The wheel support frame is mounted on bearing spindles, which allow the four tires to turn 3 6 0 degree s for special machine tunnel expansion as shown in Figure 3 18. To ensure that both of the front wheels have an efficient synchronized turn without skidding require d that a 50 % :50 % flow divider be installed, which likewise required pressure relief to insure that neither side of the circuit exceeded the system pressure lim it. To accomplish this, two inline relief valves were added to the steering control circuit as shown in Figure 3 19. In the c u rre nt operation, the rear wheels are fixed and the wheel steering eff ort is accomplished by the front wheels. A steering control valve (model Toro Reelmaster 5300 D HGF16011 made by TRW, Ross) with its associated steering wheel is utilized to extend out or retract in the two steering cylinders as shown in Figure B 5 Two hydraulic circuit selector switches have been inserted in to the steering control circuit and the tunnel width hydraulic circuit. Both of the se selector switches are utilized to direct the f low of the hydraulic fluid to either the steering hydraulic circuit or the hydraulic circuit for internal tunnel width (widt h extension or retraction) One of the selector valves (directs high

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83 pressure e (directs a low pressure T) is on the right side. Four separate cylinders (16 inches stroke ), which are connected in series, are controlled by the hydraulic directional cont rol valve (joystick handle) for extension or retraction of the harvesting tunnel width. Because the load of the two engines is concentrated at the rear part of the harvester body, the two large size cylinders (3.25 inches bore size) were located at the rear of the machine structure while the two small size cylinders (3 inches bore size) were located at the front. To operate the hydraulic steering circuit, the knob of the right selector valve is fully pulled up while the knob of the left selector valve is wholly pushed down. Otherwise, for the extension cylinders functions, the knob of the right selector valve is pushed down while the knob of the left selector valve is pulled up thus releas ing the hydraulic fluid pressure while the hydraulic steering circuit is idle Basically, the steering hydraulic circuit should always be synchronized with the hydraulic circuit of the four wheels drive. The weight of the self propelled can opy shaking machine, which requ ires a single operator has a gross weight of approximately 75 00 lb D esign of the prototype continuous citrus canopy shaking machine is shown in Figure B 1 Also, this new design provides for easy transportation as shown in Figure B 3.

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84 Figure 3 15. The John Deere pressure relief valve ( shakers pressure relief valve ). [Photo s courtesy of Naji A l Dosary ] Figure 3 16. Electrical operating circuit of the right and left John Deere pressure relief valves (shakers brake).

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85 Figure 3 17. Electrical instrument panel s of the citrus canopy shak ing machine [Photo s courtesy of Naji A l Dosary ] Figure 3 18. Movable wheels frames of the citrus canopy shaker with carrier bearing hinge (spindle) [Photo s courtesy of Naji A l Dosary ]

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86 Figure 3 19. Some hydraulic system components of the preliminary self propelled canopy shaker [Photo courtesy of Naji A l Dosary ]

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87 Harvester Modifications for the Final Performance Tests of the Citrus Shaker Harvesting Machine The main objective of this dissertation research was to develop an effective mechanical harvester for semi dwarf citrus trees. So, a prototype self propelled citrus canopy shaker machine was designed and tested on grapefruit trees that were harvested in the summer 2013. The harvesting efficiency of the preliminary design did not provide enough information to make a valid decision about the machine performance. The maximum value of the fruit detachment rate was 58.06 %, while the maximum average of the fruit detachment percentage was 41.58 %. So, to design a more effective mechanical citrus harvesting machine, some modification s were made to the pr eliminary harvester design The final prototype citrus harvesting machine is presented in Figure 3 20 Accordingly, the modifications made to the shaker machine are discuss ed in the following section Figure 3 20 Final prototype citrus canopy shaking machine. For the final performance trials of the canopy shaking machine, the hollow gray PVC pipes were replaced by flexible 1 inch OD and 0.50 inch ID UHMW polyethylene white pipe 30

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88 inches in length with 3 inches inserted into a 6 inch steel coupling pipe The other end of the steel coupling pipe was installed o nto 3 inches of the steel beater pipe. This was done to avoid fatigue that may occur when using high shaking speeds Also, to insure that tube is connect ed securely to the steel beater pipe a 2 4 inch long solid steel bar was installed into one end of the flexible pipe and the other end of the steel beater pipe. The total length of th e beater was increased to 58 inches. Also, 12 UHMW hollow rods (length of 30 inches, OD 1 inch, and ID 0.50 inch) were attached to the shaking system by mounting 3 pairs of extra beaters on the main steel pipe of each shaking unit as shown in Figure 3 21 The additional beater is designed to work at an angle with the original beater position and the vertical distance between each beater on each shaking unit is 3.5 0 now had 1 3 beaters, which were arranged vertically and extended horizontally. Figure 3 21 New extra beaters attached to the original shaking beaters. A) Rear view of the machine and B) t he machine front view. [Photos courtesy of Naji A l Dosary ]

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8 9 Also, to more easily adjust each engine speed by its throttle a push pull throttle with associated thread lock and knob was relocated underneath the harvester as shown in Figure 3 22 The Eaton hydrostatic pump, which has a swash plate mechanism, shall be adjusted manually by using a single lever handle. The hand regulator was also relocated underneath of the right side of the harvester operato as shown in Figure 3 23 U sing the swash plate of the hydrostatic transmission, the operator can change the speed range of the machine and this transmission pump also provide s a dynamic brake that can easily stop the harvester movement. In addit ion, c hanging the swash plate direction ( reverse or forward ) will correspondingly change the direction of movement of the shaking machine Figure 3 22 New position of the harvesting machine control systems. [Photo courtesy of Naji A l Dosary ]

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90 Figure 3 23 Eaton hydrostatic pump with a swash plate mechanism for the harvesting machine wheels drive. [Photo courtesy of Naji A l Dosary ] In order to reduce the length of the crank shaft, the three cranks on the original vertical motor shaft (crank shaft) were trimmed and redesigned to have two cranks ( 3 inches throw radius ) which were then mounted on a solid steel shaft of total length 54 inches and 1.5 0 inches in diameter. To insure that the crank shaft wa s strong enoug h, the original central crank was replaced with short er shaft of a total length of 16 inches and diameter of 2.5 0 inches Each vertical motor shaft is supported by a flange bearing at the bottom (2 bolt flange bearing) and a shaft coupling at the top end as well as having the flywheel mounted to the crank shaft by a steel flange. A steel shaft (length of 12 inches and OD 2 inches) with two steel flanges welded on each end wa s used to connect the flywheel to the hydraulic motor of the shakers Meanwhile, t he flywheel was lowered from the hydraulic motor about 14 inches as shown in Figure 3 24 A. Also, to have a smooth er shaft rotation, a split pillow block bearing (2 inches, ID) wa s used to support the crank shaft on the harvester body (Figure 3 25 ).

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91 Figure 3 24 Crank shaft (motor shaft) of the citrus harvesting machine. A) The final crank shaft design and B) preliminary crank shaft design. [Photos courtesy of Naji A l Dosary ] Figure 3 25 A n ew vertical motor shaft (crank shaft) with a flywheel supported by pillow block bearing [Photo courtesy of Naji A l Dosary ]

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92 The final modification of the shaking machine in volved the hydraulic control system of the self propelled 4 wheel drive system. The original pre test design of the har vester (preliminary design) had 2 solenoid operated poppet valves NC for the brake system T hese were removed since wheel motor leakage prevented proper braking (Figure 3 26 ). Also, to gain additional power for the 4 wheel drive the pressure line of the s teering pump and the harvester tunnel extension cylinders w ere plumbed directly to the rear pump of the John Deere triple pump. Now, the rear pump of the Danfoss triple pump supplies the hydraulic fluid flow to the four hydraulic cylinders for extension or retraction of the tunnel width of the harvester and also the steering pump. The low pressure of this circuit will go back directly to the reservoir. The s chematic diagram of the hydraulic control system of the shaker units' extension and steering system is shown in Figure 3 27 On the rig two spools directional control valve (dual lever handles) wa s placed to control the harvester internal tunnel width The extension cylinders on each side will now be handl ed by one lever handle as presented in Figure 3 22 The front pump of the triple pump now supplies the charge flow to the hydrostatic transmission pump for the four wheel drive motors Mean while the low pressure of this circuit will go back to the inlet ports of the hydrostatic transmission pump or to the reservoir. The schematic diagram of the hydraulic control system of the self propelled 4 wheel drive system is shown in Figure 3 28 Finally F igure B 2 shows the final design of the continuous citrus c anopy shaking machine.

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93 Figure 3 26 Some components of the hydraulic system of the preliminary design have been reduced in order to provide some power for the fi nal design of the canopy shaker. [Photo courtesy of Naji A l Dosary ]

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94 Figure 3 27 Schematic diagram of the hydraulic control system of the two canopy shakers units' extension, and steering system for the final harvester design.

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95 Figure 3 28 Schematic diagram of the hydraulic control system of the self propelle d canopy shaker transport speed for the final harvester design

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96 The Intended Field of the Citrus Fruit Trees F ield experiments for the canopy shaking machine performance evaluation were accomplished at a citrus grove at the Plant Science Research and Education Unit of the Universi ty of Florida, 20 miles south of the City of Gainesville at Hawthorn Prairie, Marion County, Florida (+29 24 28.50" N, 82 08' 22.10" W). The grove included the following varieties, Hamlin, Valencia, and Ray Ruby scion s. As desired, the citrus hedges ha d been arranged in spac ing of 10 ft 20 ft for Valencia strain and 12 ft 20 ft apart for the Hamlin strain (Figure 3 2 9 ). However, these were not dwarf trees and thus exceeded machine height capacity. To determine prop er machine operations and improve the harvest efficiency of the shaker machine the first trials (pre test) were performed on the grapefruit trees (Ray Ruby scion) which were dwarfed to less than 10 feet tall as shown in Figure 3 30 In May and June, 20 13 (90 o F approximately ) the late season harvest of the Ray Ruby grapefruit (2012 13) was completed, with the new season fruit start ing to emerg e on the trees The grapefruit hedges ha d been arranged in a space of 8 ft between trees and 20 ft between rows with average productivity of the grapefruit orchard of 55,143 .00 fruit s per hectare (approximately 2 5 ton/ha or 78 fruit s/tree in average yields). Furthermore, the branches of the oranges and grapefruit trees varied significantly as presented in Figures 3 31 and 3 32 Most of the trees ha d low hanging branches reaching to the field soil. Nevertheless, skirting and pruning were done canopies to adjust the canopy height to be about 8 ft and width of nearly 7 ft. The f ield experimen ts of the final prototype harvester design were executed on the same Ray Ruby orchard to determine the harvesting machine performance improvements. The final trials were performed on January 6 201 4 ( 51 o F ), which was the winter season harvest of the Ray Ruby grapefruit (201 3 1 4) with average productivity of the grapefruit orchard of 76,020 .00 fruits per hectare (approximately 3 4 48 ton/ha or 113 grape fruits /tree in average yields). Before

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97 harvesting the branches of the grapefruit tree s were skirted and pruned on November 1 8 th of 2013 to set the canopy height and width to nearly the actual size of the internal dimensions of the harvesting machine (Figure 3 33 ). Furthermore, a small percentage of the grapefruit production was lost as a result of the pruning process as shown in Figure 3 34 Figure 3 2 9 Citrus field (Oranges) in the PSREU at UF 09/22/2011 [Photo courtesy of Naji A l Dosary ] Figure 3 30 Citrus field (Grapefruits) in the PSREU at UF 05/24/2013 [Photo courtesy of Naji A l Dosary ]

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98 Figure 3 31 Longitudinal and later al extension of the branches of the orange trees [Photo courtesy of Naji A l Dosary ] Figure 3 32 Longitudinal and later al extension of the branches of the grapefruit trees [Photo courtesy of Naji A l D osary ]

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99 Figure 3 33 Grapefruit trees in the PSREU field A) Grapefruit trees before pruning and B) the grapefruit trees after the pruning process [Photo s courtesy of Naji A l Dosary ] Figure 3 34 Grapefruit trees in the PSREU field after pruning process. A) Pruning was done u nderneath the grapefruit canop ies and B ) grapefruits were dropped out of the canop ies because of the canop ies pruning [Photo s courtesy of Naji A l Dosary ]

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100 A study was conducted prior to the h arvesting period for the season of 2013 14, where fruit pulling force s were measured to see if they could distinguish the fruits maturity on the tree canopies. Aside from color change, a n indicator of grapefruit ripeness may be the lowest fruit pulling force A lthough unripened grapefruit will continue to ripen after harvesting when the fruit is ripest provides the best time for fruit harvesting and allows the fruits to snap easily from the tree. Figure 3 35 and Table 3 3 shows the variety of the fruit pulling forces which were measured on the grapefruit trees. The maximum pulling force was 30 lb f and the minimum fruit pulling force was 6.75 lb f while the average of the pulling force was 19.15 lb f The final trials of the improved harvester design (fin al test) were performed on January 6 th 2014.

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101 Table 3 3. Variety of the fruit pulling forces which were measured on the intended grapefruit s Treatments Date Temperature Fruit pulling force lb f 2013/2014 F o Min. Max. Ave. 1 11/11 70 11 29 19.80 2 11/18 68 20 28.50 24.10 3 11/20 60 15 25 21.80 4 11/25 62 13 26 18.80 5 11/27 55 11 21 16.30 6 12/01 71 10 22 17.00 7 12/04 83 6.75 15 12.45 8 12/09 86 14 20 16.80 9 12/12 62 14 23 18.40 10 12/15 63 15 30 22.20 11 12/18 51 14 19 16.20 12 12/22 85 20 30 24.20 13 12/25 72 15 23 19.60 14 12/29 68 16 25 20.40 15 1/2 68 12 26 18.20 16 1/5 83 16 26 20.20 Average 19.15 Figure 3 35 T he grapefruit maturity b efore the harvesting period of the season of 2013 14 Days

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102 Theoretical Analysis of the Tree Branches Deflection In general most of the previous scientific research ( i.e., experimental or theoretical research ) done on plant harvesting, w as done to create technique s to direct the appropriate oscillation toward t he target trees. Whichever harvesting approach was used to produce tree oscillations (trunk s or branches shaking machine ) the ones that were able to optimally transfer those o scillations to trunks or branches resulted in the high est percentage of fruit harvested. Late ly, in Florida citrus groves three contemporary harvesting systems (TSC, CCS C, and T CS) have been deployed to remove citrus fruit s from the bulk of citrus trees. Subsequently, distribution of the adequate tree limb loads ( w ) which are d irected by the beaters of the canopy shaker, can be represented as a homogenous load distribution subjected on a clamped free beam as expressed in Figure 3 36 Therefore, by determining the fundamental y at any position of x on the cantilever beam can be calculated as (AWC, 2007): By deeming any x section that posts a distance x from the free end of beam, the solution of the beam deflection is supposed to be: For the clamed free beam, the bending moment equation is defined as: In addition, the bending moment can be identified by: (3 7 ) (3 8 ) (3 9 )

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103 Particularly, the boundary conditions at the beam fixed end ( x = ) and free end ( x = 0) will be considered So, for the beam position at the fixed end ( x = ), the boundary condition where no obvious deflection will be i s: Moreover, from the other side where the free end ( x = 0) of the cantilevered beam, the boundary condition where no b ending moment is: Therefore, by substituting the bending moment in term of x the second differential equation will be: Thus, by integrating the second deferential equation, the first deferential equation will be symbolized as: Besides, by integrating the first deferential equation, the beam deflection equation will be obtained as: From the equations ( 3 1 4 ) and ( 3 1 5 ) with the boundary conditions at the fixed end of the clamped beam, the values of the constants c 1 and c 2 are: (3 10) (3 11) (3 12) (3 13) (3 14) (3 15)

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104 By taking the first derivative of y and equal to zero, will obtain: Moreover, by substituting c 1 into equation (3 1 6 ) and replac ing x = also setting the result equal to zero, will obtain: Subsequently, by substituting the equations of the two constants c 1 and c 2 into equation ( 3 1 5 ), the ultimate vertical deflection of the clamped y ) at any value of x with homogenous load distribution assumed to be: ymax ) at the free end of the clamped free beam where x will be equal to zero ( x = 0 ) is supposed to be: (3 16) (3 17) (3 18) (3 19) (3 20) (3 21) (3 22)

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105 Where, E is the tree limbs modulus of elasticity and is a constant area moment of inertia of the limbs. Thus E modulus of elasticity calculation will be resulted as: Where, F is the force applied to the limb, A is the cross section area, o is the original length of the limb before applying the force, and is the chang e in the length of the limb after applying the force. Therefore, the area moment of inertia calculation assumed to be when the limb takes a circular cross section as: Where, D is the limb diameter. Figure 3 36 A homogeneous load distribution lying on a clamped free beam (3 23) (3 24)

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106 Field Measurements Procedure M e chanical harvesting is employ ed generally to shorten the harvesting time and raise the field crop productivity. Therefore, there are two type s of harvesting systems used in Florida citrus farms depend ing on the shaking approach used (e.g. shake the tree canopy or shake the trunk of tree causing the fruit to fall out from the tree ste ms). For the citrus harvesting, mechanical harvesting utilizes the generat ion of a moderate vibration into the tree canopy. Accordingly, the fundamental component o f the canopy shaker is optimally shakin g the beaters to impart those oscillations efficiently to the citrus tree canopies thus maximizing the harvested fruit yield So measurements were performed during the operation of the shaking machine in the citrus field (Figure 3 37 ) to determine the n ecessary shaking speed for fruit dislodgement when the beaters are vibrating, the acceleration of the tree limbs as a result of the shaking action, the harvesting width for the beaters penetration, and the injuries caused to the tree s branches. The dislo dged fruits, which fell on the field ground, and the citrus fruit s that are remained on the trees were collected manually. Figure 3 37 The preliminary citrus canopy shak ing machine through its harvesting performance in the summer harvest of 2013 [Photo s courtesy of Naji A l Dosary ]

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107 T he essential harvesting measurement procedures that were used throughout t his study will be shown in the following sections. Procedures for Estimating the V alues of the Tree Canopy A cceleration M agnitude An a ccele rometer is often utilized for diverse applications where it is considered for vibration acceleration or shock analysis It is often used with the fast Fourier transform (FFT) algorithm for analyzing the vibration data results (sampled signals) regardless of the variation in the vibration frequency The measurement of acceleration can be applied to different spots i n the tree canop y (branches o r fruits) for measuring acceleration in the fruit, which can be correlated to fruit detachment Trees we re instrumented using Triaxial USB A ccelerometers model X16 1C (GCDC) that have an amplitude range up to 16 g, sample rates up to 200 Hz, and weigh 55 gm with the associated battery. The accelerometer power was supplied by a detachable AA battery (1 5A) or a +5 volt PC power supply. For field acceleration data record ing an easily removable 2 GB card is built in (self memory storage). Fortunately the GCDC X16 1C Triaxial USB Accelerometer does not require an intricate supplement data acquisition device f or transmitting the acceleration data to the portable computer or special software program ( USB terminal interface is included). The raw acceleration data (a mixture of time and voltage data) was obtained as a stream of instant ly recorded numbers, which we re written, viewed, and analyzed through the creati on of a text file and x, y, and z axis figures by either Microsoft Excel or WordPad The test file of the acceleration data which is actually a built in application of the XLR8R is compliant with java programs (Java (TM) Platform Standard Edition 6.0), as revealed in Figure 3 38 Through the XLR8R java application, the acceleration analysis was shown in graphical plots as a function of time (g force vs. time) Later, the fast Fourier transform (FFT) was utilized as necessary to g ather data on the frequency response of the shaking beaters of the

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108 harvester or branches of the grapefruit canopy This data was displayed as a plot of the power spectrum versus frequency response (time signal and frequency spec trum graphs). Before testing began, 15 USB accelerometer sensors model X16 1C were randomly placed on various branches at different locations in the canopy of the fruit tree (Ray Ruby grapefruit) and attached using plastic adhesive tape The 15 USB accel erometer sensors were used to estimate the dynamic acceleration (acceleration magnitude) during the harvesting operations as shown in Figure 3 39 Moreover, a rotational speed instrument (digital tachometer) was utilized to obtain the rotational speeds of the crank shaft (rpm) and the beater rotational speed s (shaking speeds in/sec ) during the various harvest ing operations. For p recise data analysis of the most important measurements, the practical gravitational accelerations ( ) on the citrus tree branches for each axis (i th ) of the three orthogonal axes coordinates (x, y, and z axis) from each X16 1C acceleration sensor were developed using the Java XLR8R program. Subsequently, the resultant of the magnitude of the acceleration da ta ( ) could be calculated by using the following equation of the RSS me thod (Bedford and Fowler, 1995). The acceleration magnitude, (3 2 5 )

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109 Figure 3 38 An o rganizati on chart of the vital acceleration processes for data gathering Figure 3 39 Some of the X16 1C a cceler ation sensors a ttached to some citrus tree branches. [Photo s courtesy of Naji A l Dosary ] The ordinary distance at point (a) and the beater end spot (A) as shown in Figure 3 40 can be determined by using a proper displacement of the slider crank formula (Srivastava et al., 2006). So, the regular amplitude at the jointing point (a) of the shaking beater and reciprocating rod (turn buckle) will be : ( 3 2 6 )

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110 Where: a is the beater displacement at the jointing point of the beater and the coupling (turn buckle) link (inch) r is the radius of the crank (inch) is the length of the reciprocating rod (inch) and is the angular displacement of the crank (radian) Then, from the basic beater length ratio, the amplitude at the beater free end ( A ) would be resulted by : (3 2 7 ) (3 2 8 ) Finally, the typical beater's speed (S a ) at the jointing point (a) of the beater and reciprocating rod (turn buckle) is presented by the subsequent equation (Srivastava et al., 2006 ): (3 2 9 ) Where, is the crank shaft angular velocity (rad/sec)

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111 From the beater length ratio, the high speed of the beater at the beater free end ( S A ) could be considered as re vealed in equation 3 30 below: Also as shown in Figure 3 40 is the angular displacement of the shaking beater (radian) So, depending on the crank throw radius (3 inches) and position of the connection p oint between the shaking beater and turn buckle linkage (i.e., the input speed situation on the shaking beater ) the beater angular displacement for the preliminary harvester design was equal to 15 degree s The linear displacement at the beater free end rang ed between 15 and 20 inches For the final citrus harvester design, the s haking beaters penetrations into the grapefruit canopy depending on the turn buckle length are revealed in Table D 1. Figure 3 40 The shaking beater mechanism. (3 30 )

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112 The E ssential Field M easurements after the H arvesting Period After the end of each harvesting (shaking) operation, the data that was collected include d the required measurements of the number of detached fruits that released from the trees and the number of fruits remaining on the trees which were snatched manually. Meanwhile, the damage to tree branches was visually evaluated The number s of the large citrus fruits, which were detached by the shakers, w ere counted manually as shown in Figure s 3 41 and 3 42. In addition, the number s of the fruits left on the trees (unaffected by the canopy shaker) were enumerated separately. Consequently, the percentag es of the citrus fruit s that are detached by each shaking operation ( F d ) will be calculated mathematically by using the equation in the following format (Erdo an et al., 2003): Fruit detachment percentage, (3 3 1 ) Where: N d is the number of the most detached fruit (count) and N r is the number of the fruit remaining on the citrus tree (count) Thus, by knowing the total production of some citrus trees ( detached and hang ing fruit), the expected overall yield production of the citrus field per hectare ( Y ) can also be calculated by the following formula (Buyanov and Voronyuk, 1985): Overall citrus fruit yield, (3 3 2 ) Where: w t points to the absolute total fruit mass of each citrus tree separately (lb ), a indicates the distance between the citrus trees lines (ft) and b indicate s the distance between the citrus trees on each row (ft) Likewise, if the tree damage has taken plac e during each shaking operation, the visible injuries to the tree s branches or limbs were assessed after each harvest operation

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113 Figure 3 41 G rapefruits on the ground after the harvest operation by the new canopy shaking machine (the preliminary design) [Photo s courtesy of Naji A l Dosary ] Figure 3 42 G rapefruits on the ground after the harvest operation by the final canopy shaking machine (final test) were calculated manually. [Photo courtesy of Naji A l Dosary ]

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114 The Operation al Economics of the Mechanical Citrus Harvest er Indeed the citrus crops are the largest planted crops in the State of Florida. Florida ha d more than 6,000 citrus grower s planting almost 554,400 acres of a ll citrus varieties producing about 129 million 90 lb boxes of fresh orange fruits and 122.6 million 90 lb boxes of processed oranges through 475,900 acres during the 2006 season Approximately 75 % or more of the United States orange crop is pr oduced in the State of Florida Thus, every season, 5,000 workers are hired for orchard care and somewhere between 20 to 25 thousand labor er s for fruit harvesting (Roka et al 2009) Although the need for the number of labor er s in the citrus fields has been red uced by using the mechanical harvesting approaches (e.g., the CCSC requires 6 labor er s while the TSC desires 3), the presence of a sufficient number of employ ees is still necessary during the harvest Also, the fruit quality (fresh market fruit), requires the presence of hands to complete the following field operations: fruit picking, f ruit removal and recovery, roadsiding, and hauling J uice processing requires additional labor for : removing t he plants debris that is transported by the harvest machin e loa d, and the T CS system also requires hands for gleaning the shaken fruit on the ground, late mature fruit detachment, and repair and replacement of field trees (Roka et al 2009). E xpenditures for manual harvestin g have increased from 0.65 dollar s per box (5.15 $/hr) in 2000 to 0.91 dollar s per box (7.25 $/hr) in 2010 with the same labor s productivity, which is estimated at eight boxes per hour Mechanical harvesting offers a potential to substantial reduce harvesting costs. Based on cost and harvesting capacity data from existing citrus mechanical harvesting system, it is projected that if mechanical harvesting was fully adopted by juice orange growers, the cost of fruit harvesting could be lowered to 0. 75 dollars per box (Roka, 2010). Since the early 1 950 s the citrus growers and the harvester manufacturing industries in Florida started to consider new approaches for citrus harvesting, particularly, a substitute for

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115 manual harvesting. In late 1960s to early 1 970s mechanical citrus harvesting became a b urning need as the large r number of citrus acres demand ed a larger labor force that in turn increase d the overall labor cost which became difficult for the citrus growers to afford. Therefore, some citrus growers (e.g., 31,000 acres of orange plantings) shifted from the hand harvesting to the mechanical harvesting system s for the following reasons: the shift in emphasis of the citrus industries, who are dependent on efficient citrus harvesting, and some government sectors toward the development of a new citrus harvesting technology to replace manual harvesting and the increasing demand of the global market especially for orange juice. For Florida citrus growers ( i.e., as represented in Figure 3 by Roka et al 2009), citrus production costs were lower than the costs of Florida harvesting (pick & roadside) between the seasons of 1994 95 and 2007 08 T hese results led some citrus grower s (almost 7 %) to transition to mechanical harvesting In the 2006 2007 growing season, production costs were increased due to the increase in costs of labor involved in harvesting and combating diseases (i.e. citrus greening (HLB) and canker ). M echanical harvesting helped both, by more efficient harvesting, and reducing the need for manual labor er s in harvesting (i.e., reduce laborers practices that will reduce the likelihood of disease spread, which may be manually transferred between citrus trees) Furthermore, pesticid e applications and the replant ing of citrus trees were estimat ed to increase the cost of the orchard care. Moreover, advancing technologies of citrus harvesting provide d a chance for additional urban growth by enhancing the farmland values ( $ 25,000/acre) By using any of the mechanical harvesting system (CCSC, T CS, or TSC) with the abscission agent (CMNP) and the appropriate orchard design, labor productivity increased and thus decreased the costs of citrus harvesting. Also, the mechanical harvesting reduce d the number of the citrus labor er s so the risks associat ed with controlling labor and the cost of management were less. Finally, comparing the

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116 performance of the three mechanical harvesting systems TSC, CCSC, and T CS with the manual harvesting for the Hamlin and Valencia blocks found that the number of tree s that were harvested in an hour by these systems was recorded as 190 229, 361 466, and 184 298 respectively while the labor er s harvest ed 2 to 4 trees per hour. Also, the labor ers productivi ty with the mechanical harvesting systems was assumed to be 76 96, 103 122, and 16 20 (box/hr) respectively in contrast to labor er s productivity without the mechanical harvesting techniques which was estimated at about 8 to 1 2 (box/hr) (Roka et al., 2009). The harvesting costs ($/hr) were assumed to be affected by field operations such as t he type of harvesting machine system (TSC, CCSC, or T CS) t ree design ( e.g., skirting, pruning, and hedging) ( $/acre ), c hemical applications ( i.e. CMNP) ( $/acre ), the amount of f ruit detachment ($/hr), fruit recovery ($/box), fruit picking and hauling ($/box or goat), fruit gleaning ($/box), t ree repair and replacement repair to the irrigation system ($/hr) and t he fixed costs (i.e. d epreciation cost, interest payment, taxes, or insurance cost ) ($/box or year ly yield) Genera lly, the lower harvest cost is an important economic objective for a new mechanical harvest er design ( Roka, 2008 and Roka et al., 2009). Accordingly, the effect of each shift cost of harv esting is presented in Table 3 4 (Roka et al., 2009)

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117 Table 3 4 The results of the impact of the anticipated economic variables' on harvesting costs [Adapted from Roka et al., 2009 ] No. Anticipated economic variables The harvesting cost effect 1 The type of harvesting machine system The mechanical harvesting assumes to save more than 50 % of the harvesting cost where CCSC needs 6 labors and TSC requires 3 labors, while manual harvesting needs 20 25,000 labors and an increase the harvesting speed (1 84 466 tree/hr) 2 Fruit detachment Raising the fruit detachment up to 90 95 % 3 Fruit recovery Raising the fruit recovery up to 87 99 % will reduce the gleaning cost 4 Fruit picking, roadsiding, and hauling Different harvesting machines manufactured according to the situation of the orchard design where one type requires a team of workers to accumulate the fruits on the surface while the other machines allow the citrus fruit to fall on a suitable fruit interception surface for collectin g and transporting to the truck out of the field. So that will affect the harvesting cost. 5 Fruit gleaning Mechanical harvesting cost with gleaning estimate to 1.25 dollar per box while 1 dollar per box without gleaning 6 conveying debris The debris that is included during the fruit loads will incre ase the transportation cost and raises the haul cost 7 Trees design (skirting, pruning, and hedging) Will decrease the tree damages, increase the harvesting machines performance, and will defi ned the proper mechanical harvesting system 8 Damage on the citrus trees, irrigation system, and trees repair and replacement The damage on the citrus trees and irrigation system will not let the citrus grower allow mechanical harvesting since the repair and replacement costs will increase 9 Chemical applications (CMNP) By joining the CMNP application with the mechanical harvesting system the harvesting cost will be reduced, % of the fruit det achment force is re duced. Also, 50 % of the field s yield (fruiting trees) is reduced by neglecting remov al of the late ripe and immature fruits from the trees twigs so the CMNP application will help to remove the late ripe and immature fruits during the harvesting time. 10 The fixed costs Depreciation cost, interest payment, taxes, or insurance cost should be considered throughout the harvesting cost calculation.

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118 Subsequently, the overall operations cost ( Hc $/hr) of the mechanical harvesting of the new citrus fru its harvester and two trucks can be determined by using the calculation of the following equation of cost with the coefficients in Table s 3 5 and 3 6 (El Gindy et al., 2009): Where, Hc is the g ross cost of the mechanical harvesting by the machine ($/hr) P M is the p rice of the mechanical harvester ($) Y H is the p redicted yearly operation hours (hr/year) M L is the l ife expectancy of the mechanical harvester (year) R i is the r ate of intere st (%/year 8 % of the harvester price/year, Hunt, 1977 ) R t is the r ate of tax (%/year) R rm is the r ate of the mechanical harvester maintenance (%) L f is the l ubrications factor ( i.e., that is estimated equal to 0.90) P w is the machine p ower (kw) F p is the p rice of fuel ($/gal) F cns is the c onsumption of fuel (gal/kw.hr) L ms is the l abor monthly salary ($ expected as 10.90 $/hr, USDA, 2011 ) and O mo is the p redicted average of the operation hours for each month ( i.e., it is anticipated equal to 14 5.50 h ou r/month) As a final point by laying the proposed values of the parameters cost as shown in Table s 3 5 and 3 6 below in the former equation of cost 3 3 3 the gross cost of the new prototype harvester operation ($/hour) will be prominently identi fied (Muraro, 201 2 and Hunt, 1977 ) (3 33)

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119 Table 3 5 Estimated o perating expense of the new self propelled citrus harvester with its trucks for the harvest season 2013 14 Coefficients of the Mechanical Harvesting Cost by the New C itrus Harvester Classification Cost Expected purchase price ($) 250,000 1 Life expectancy (years) 10.00 2 Yearly operation hours (hr/year) 873 3 Power Hp (kw) 51.40 (38.3) (for two engines) Maintenance cost ($/hr) 57. 2 7 1 ( 25,000 $/season) R ate of interest (%) 8 .00 4 Insurance rate ($/year) 0.25 % of purchase price 4 Local rate of tax (%) 6.25 Local price of fuel ($/gal) 3.85 Estimated consumption of fuel (gal/kw hr) 0.016 Local price of oil ($/hr) 0.98 (5.99 $/1quart) From prior equation 3 3 3 Gross cost of mechanical harvesting by the new machine Hc ($/hr), 1 52.38 include truck operating cost Table 3 6 Average operating expenses of the grapefruit manual harvesting. Coefficients of t he Manual H arvesting Cost Operation Type Cost ($/box) Grapef ruit picking 0.71 5 Grapef ruit roadsiding 0.95 5 Total c ost of manual harvesting 1. 66 1 estimated cost based on similar machine ; 2 estimated machine life ; 3 estimated yearly hour based on similar machine ; 4 Hunt, 1977; and 5 Muraro, 201 2

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120 Method of Statistical Analysis of the Experiments Data Practically, the field trials for the preliminary canopy shaker design include the following three typical operating variables: 1 Two forward speeds (ground sp eeds) of the canopy shaker 2 Three rotational speeds of the shaking beaters (i.e. three rotational speeds of the motor s that are driving the beaters shaft s via the crank shaft s ) 3 Two different scales of the shaker stroke displacement (i.e. either the harvest er tunnel width or the shaking beaters position) The statistical test design within the citrus field of the PSREC, used completely randomized design method (C.R.D.) The effect of all the variables (i.e. two forward speeds of the shaker machine three rot ational speeds of the shaking beaters (shaking speeds) and three positions of the shakers ) on the amount of the removed fruits and the limbs injuries were analyzed to evaluate the performance of the citrus canopy shaking machine. Thus, there will be 1 2 co efficients (2 3 2 ) in total. The procedure of measurement was replicated three times on three different trees with a constant set of coefficients to achieve precise results. Consequently, to accomplish this statistical design, 36 random citrus trees (o ne tree for each experimental unit) are desired. The distribution method of these coefficients in the citrus field experiments was not discriminated. ANOVA, an analysis of variance u se the General Linear Model (G LM. or GLIMMIX ) through the pack of SAS, the statistical analysis software (SAS Institute Inc., 2012) at 90 % of the level of significance (p=0.10) will be considered. Typically, SAS is applied to make a decision about the contributive parameters that could have a significant effect on the canopy sh aker performance for the citrus fruit detachment and tree injuries. Simultaneously, the less significant difference method (L.S.D.) will be utilized to know the differences between the means of these coefficients and the effect of the interaction between t he operating variables in order to determine the most influential factors on both the performance of the harvesting

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121 machine as well on the other operating variables. Moreover, the interaction between the operating variables can be publicized within the fo llowing distinctive domains: 1 The effect of the forward speed s (ground speeds, mph) of the canopy shaker 2 The effect of rotational speed s of the beaters (shaking speed s inch / sec ) 3 The effect of the shakers displacement s ( harvest er tunnel width inch ) 4 The effect of interaction between the forward sp eeds of the canopy shaker and rotational speeds of the shaking beaters 5 The effect of interaction between the forward speeds of the canopy shaker and the harvest er tunnel width 6 The effect of interaction betwee n the rotational speeds of the shaking beaters and the harvest er tunnel width 7 The effect of the interaction between the forward speeds of the canopy shaker, the rotational speeds of the beaters, and the harvest er tunnel width ( shaking beaters positions ) Therefore, the previous equations 3 2 9 and 3 30 were used to determine the shaking speed s of the harvester beaters (linear speed) at the input point, which is the connecting point between the beater and the turn buckle link, and the output shaking speed at the end point of the beater (maximum shaking speed) depending on the rotational speed of the crank shaft that was measured by using the tachometer Consequently the combination of the citrus field experiments were included the following variables as shown in Table 3 7

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122 Table 3 7 Operating variables that were used for the preliminary citrus experiments in the summer harvest of 2013 Series Crank Shaft S peed (rpm) Input Beaters S peed S a (inch/sec) Output S peed at the Free E nd of the B eater S A (inch/sec) Harvester Forward S peed (mi/hr) Machine I nternal T unnel W idth (inch) 1 124.40 40 91.43 0.90 69 2 176.80 56 128 1.20 7 5 3 229.20 73 166.87 ------Turn B uckle L ength (inch) Acceleration T rials 1 144.10 45.30 103.54 10 2 209.54 65.90 150.63 11 3 --------------------12 For the harvest of winter 2014, the field trials for the harvest efficiency of the final canopy shaker design (final test) include d the following three typical operating variables: 1 Two forward speeds (ground sp eeds) of the canopy shaker. 2 Two rotational spe eds of the shaking beaters (i.e. two rotational speeds of the motor s that are driving the beaters shaft s via the crank shaft s ) 3 Three different scales of the shaker stroke displacement (positions of the shaking beaters i.e., three different turn buckle lengths ) As was previously done for the statistical test design and data analysis within the field experiments of the preliminary harvester design in the late summer harvest of 2013, the same examinations were accomplished by using 1 2 coefficients (2 2 3) in total for the final harvester design performance test in the winter harvest of 2014 as shown in Table 3 8 The performance measurement procedures were replicated five times on five different trees with constant set of the coefficie nts to achieve precise results. Consequently, to accomplish the statistical design of the field experiments of the final citrus harvester design 60 random grapefruit trees (one tree for each experimental unit) were utilized. The combination of the citrus field experimen ts included the following variables as shown in Table 3 9

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123 Table 3 8 S tatistical design of the o perating variables test that were used for the final citrus in the winter of 2014 The Grapefruit Orchard Lines Harvest Direction Operating V ariables Line 1 Line 2 Line 3 Machine Forward S peed s Beaters S haking S peed s (Knob t urn n umber of the f low c ontrol v alve) Beaters P osition s (Turn b uckle l ength, inch) Fast Forward Speed Lowest Shaking Speed 2.5 16 Fast Forward Speed Highest Shaking Speed 3 12 Fast Forward Speed Lowest Shaking Speed 2.5 Default position North South Slow Forward Speed Lowest Shaking Speed 2.5 16 Slow Forward Speed Highest Shaking Speed 3 12 Slow Forward Speed Lowest Shaking Speed 2.5 Default position Fast Forward Speed Highest Shaking Speed 3 16 Fast Forward Speed Lowest Shaking Spee d 2.5 12 Fast Forward Speed Highest Shaking Speed 3 Default position Slow Forward Speed Highest Shaking Speed 3 16 Slow Forward Speed Lowest Shaking Speed 2.5 12 Slow Forward Speed Highest Shaking Speed 3 Default position Each treatment (12 treatments) was replicated five times on five different trees. Table 3 9 Operating variables that were used for the final experiments in the winter of 201 4. Series Crank Shaft Speed (rpm) Input Beaters Speed S a (inch/sec) Output Speed at the Free End of the Beater S A (inch/sec) Harvester Forward Speed (mi/hr) Turn Buckle Length (inch) 1 178.98 56.50 131.02 0.62 12 2 230.00 73.00 167.80 1.42 Default Position 3 ----------------16 Turn Buckle Length (inch) Acceleration Trials 1 2 02 .00 6 3. 74 1 4 7.8 7 12 Beaters default position refers to set ting the first beater on top for each unit with turn buckle length of 15 inches, the second beater on top set with turn buckle length of 14 inches, and the next 5 beaters down set with turn buckle length of 12 inches.

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124 CHAPTER 4 R ESULTS AND DISCUSSION Effect of t he New Canopy Shaking Machine on Citrus Harvesting Practical experiments of the new prototype of the citrus harvester were carried out at the Plant Science Research and Education Center in Citra (PSREC), which is located 20 miles southeast of the city of Gainesville. In this study, the operational effectiveness of the preliminary prototype of the citrus h arvesting machine was done to investigate the effect s of certain operating variables, such as the harvester velocity ( i.e., 0.90 and 1.20 mi/hr), harvesting tunnel width ( i.e., 69 and 75 inches), and the shakers shaking speed ( i.e., 40, 56, and 73 inc h/sec) on the fruit dislodgement rate (harvester efficiency) and the distribution of the acceleration magnitude (g) on the grapefruit tree canopy. Also, the improved effectiveness of the final design modifications were investigate d to determine the effec ts o n velocity (i.e., 0.62 and 1.42 mi/hr were the average low and high forward speed s of the harvester machine rs position (i.e., turn buckles length at default position, 12, and 16 i nches), and the shaking speed (i.e., 56.50, and 73 inch/sec) on the fruit dislodgement rate (harvester efficiency) The distribution of the acceleration magnitude (g) i n the grapefruit tree canopy at a harvester tunnel width of 69 inches was also investiga ted. default position was set as follows; the first beater from top had a turn buckle length of 15 inches, the second beater from top had a turn buckle length of 14 inches, and the next 5 beaters tapered down to a turn buckle length of 12 inches. The obtained harvesting data ha s been analyzed statistically using statistical analysis software (SAS) at 90 % level of significance to distinguish the most important operational variables of the new prototype harvester and to determine whether there is a ny significant interaction among them. The results have been presented below :

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125 Final Results of the Preliminary Harvesting Machine Design Effect of the Harvesting Machine Forward Speeds on the Field Harvesting Table 4 1 shows the effect s of forward speeds of the preliminary harvest er machine on the amount of grapefruits dropped from the tree canopies. In general, machine forward speed affects the time for shaking trees canopies, where increasing the harvester forward speed decreases canop y shaking time, and shaking time increase d with low forward speed s From the field trial s it was found that the shaking time for the highest forward speed ( 1.20 mi/hr) was almost 4.30 sec/tree, while the shaking time for the lowest forward speed ( 0.90 mi/hr) was almost 6.49 sec/tree. It was found that the average amount of detached grapefruit decreased at the highest forward speed ( 1.20 mi/hr). When the forward speed increased, the highest speed gave the lowest average of detached grape fruit ( 1 1 fruit s / tree). T he average amount of grapefruits ranged between 1 1 fruit s / tree for the second forward speed (1.20 mi/hr) and 21 fruit s /tree for the first speed (0.90 mi/hr) so the average amount of detached fruit is decreased by inc reasing the harvester forward speed. Thus, by applying the statistical analysis to the field data it was found that at the 10 % level of significance there is an obvious significant difference between the influence of the low and high speed in this stud y on the amount of detached grapefruit s Also, Table 4 2 shows that there is no significant difference at the 10 % level of significance for the influence of the harvesting machine forward speeds on the amount of attached fruits on the grapefruit trees. As observed, by increasing the forward speed, the average amo unts of the attached grapefruits on the trees were decreased. The amount of attached fruit s ranged from 5 7 fruit s /tree for the speed 0.90 mi/hr to 55 fruit s /tree for the highest speed 1.20 mi/hr. Meanwhile, influence of the harvester forward speeds on the fruit detachment percentage is shown in Table 4 3. The table shows that by increasing the harvester forward speed from 0.90 mi/hr to 1.20 mi/hr, the perce ntage of the detached grapefruits will be decreased from 29.54

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126 % to 18.71 % respectively. From the result ing analysis it was found that statistically there is a clear significant difference at the 10 % level of significance of the harvesting machine forward speeds influence on the grapefruit detachment percentage s which were extracted out of the tree canopies. Table 4 1. The a verage of the detached f ruit ( fruit s / t ree) Forward Speed of the Harvester (mi/hr) Symbol 0.90 Mfd1 1.20 Mfd2 Ave. 21 a 1 1 b S .D. 15.17 8.72 Averages, which have been followed by the same letter in the row do not have a significant difference statistically at a 0.90 confidence level. Table 4 2. The a verage of the a dhered f ruit on the t ree s ( fruit s / t ree) Forward Speed of the Harvester ( m i/ h r) Symbol 0.90 Mfd1 1.20 Mfd2 Ave. 5 7 a 5 5 a S .D. 30.88 44.01 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level. Table 4 3. The a verage of the f ruits detachment p ercentage (%) Forward Speed of the Harvester ( m i/ h r) Symbol 0.90 Mfd1 1.20 Mfd2 Ave. 29.5 4 a 18 7 1 b S .D. 14.94 11.84 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level.

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127 Effect of the Harvesting Machine Tunnel Width s on the Field Harvesting The results of the adjustable machine tunnel width s influence on the amount of the detached fruit are shown in Table 4 4. Numerically, the tunnel width of 69 inch es reveals a high amount of detached grapefruits (18 fruit s /tree), while the large tunnel width (75 in ches ) gives 16 fruit s /tree of detached grape fruit s As ha s been observed, by increa sing the machine tunnel width the amount of detached fruits will be decreased but there were no significant differences at the level of 10 % significance of the effect of the tunnel width at 69 inch es and tunnel width at 75 inch es on the average of the detachment quantity of the grapefruit s The reason for that maybe the machine was working at tunnel width greater tha n the lateral width of the tree canopy in the field or the large tunnel width did not provide enough penetration for the machine beaters which decrease d the amount of detached fruit s Furthermore, Table 4 5 shows the effect of the harvesting tunnel widths on the average amount of g rapefruit s remaining on the tree s The results reveal that by increasing the harvester tunnel width from 69 inch es to 75 inch es the average amount of the fruit remaining on the tree canopies will be increased from 45 fruit s /tree to 67 fruit s /tree respectively. Therefore, there was an increas e in the amount of fruit remaining on the tree canopies by increase of the machine tunnel width S tatistical analysis found there were no significant differences between the effect of the harvester tunnel width at 69 inch es and the extended width at 75 inch es on the average amount of attached grapefruit s on tree canopies at the 10 % level of significance In addition, data in Table 4 6 illustrate s the influence of the harvester tunnel width on the average of the fruits detachment percentage (%). As shown in Table 4 6, the fruit detachment percentage is decreased by increas ing the machine tunnel width from 69 inch es to 75 inch es In other words, increasing the harvester tunnel width from 69 inch es to 75 inch es leads to decrease in the percentage of fruit detachment from 27.31 % to 23.64 %. According to the statistical analy sis, by the 10 % level of significance it was found that there

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128 was no significant difference between the effectiveness of the two harvester tunnel widths on the fruits detachment percentage Table 4 4. The a verage of the detached f ruit ( fruit s / t ree) Tunnel Width of the Harvester ( i n) Symbol 69 Tw1 75 Tw2 Ave. 18 a 16 a S .D. 18.93 6.76 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level. Table 4 5. The a verage of the a dhered f ruit on the t ree s ( fruit s / t ree) Tunnel Width of the Harvester ( i n) Symbol 69 Tw1 75 Tw2 Ave. 4 5 a 67 a S .D. 31.07 37.12 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level. Table 4 6. The a verage of the f ruits detachment p ercentage (%) Tunnel Width of the Harvester ( i n) Symbol 69 Tw1 75 Tw2 Ave. 27 31 a 23.6 4 a S .D. 15.56 14.02 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level.

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129 Effect of the Shaking Speed s of the Harvester Beaters on the Field Harvesting In terms of the machine beater frequency, Table 4 7 shows the influence of diverse levels of the machine beater s speeds (beater s vibrations) on the average amount of the detached grapefruit ( fruit s /tree). When the beaters shaking speed is increased from 40 in/sec to 56 in/sec, the average amount of detached fruit s increased from 10 fruit s /tree to 2 8 fruit s /tree, while the fruit s quantity decreased at the highest beaters speed 73 in/sec to 12 fruit s /tree. U nexpectedly, field observation s indicated that at beaters shaking speed of 73 in/sec, the rotational speed of the left crank shaft was unstable as the beaters engaged with some sturdy tree branches especially one s with significant heavy limb structure an d lots of cramped crotch angles Thus the tree canopy and limb size crotch density and the tree yield s may have led to the difference of the amount of grapefruit detached or left on the tree canopies F rom the statistical analysis at the 10 % level of s ignificance it was found that there is no significant difference between the influence of the beaters speeds 73 in/sec and 40 in/sec on the average amount of the detached fruit, but there is a significant difference between the influence of the second shaking speed 56 in/sec and both the low (40 in/sec), and high (73 in/sec) shaking speed on the amount of detached fruit On the other hand, w h ere the number of detached fruit w as lower the amount of attached fruit left on trees was higher, as shown in T able 4 8. In general, when the beaters shaking speed is increased from 56 in/sec to 73 in/sec, the actual av erage amount of fruits remaining on the tree canopies decreased from 80 fruit s /tree to 2 2 fruit s /tree, while increasing the shaking speed of beaters from 40 in/sec to 56 in/sec led to an increase in the average amount of attached fruits remaining on the grapefruit trees from 56 fruit s /tree to 80 fruit s /tree. According to visible differentiations between the averages of the attached fruits for the shak ing speed 40 in/sec and 73 in/sec, as well as between 40 in/sec and 56 in/sec, and also between the speed 56 in/sec and 73 in/sec, it was found that statistically there is a significant difference between the second beaters

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130 speed 56 in/sec and third shaking speed 73 in/sec O n the contrary there are no significant differences between the first shaking speed 40 in/sec and second speed 56 in/sec, or between the first beaters speed 40 in/sec and the third shaking speed 73 in/sec in terms of the average amount of the attached grapefruit s ( at the 10 % level of significance ) In addition, Table 4 9 shows the effect of diversity in the harvester beaters speed on the proportion of the average detachment of the grapefruit s It is obvious that with increase in the harvester beaters speed from 40 in/sec to 73 in/sec, the grapefruit detachment rate will be increased from 17.90 % to 35.77 %. Ostensibly, there are effective differences between the beaters shaking speeds so according ly, the statistical analysis fou nd there are significant differences between the effects of the machine beaters spe eds on the average of the fruits detachment percentage at the level of significance 10 % In other words, that mean s there are significant differences between the lowest be aters shaking speed 40 in/sec and the highest beaters shaking speed 73 in/sec, as well between first speed 40 in/sec and the second 56 in/sec, and also between the second beaters shaking speed 56 in/sec and the third beaters speed 73 in/sec in terms of the average amount of the grape fruit s detachment percentage ( at the 10 % significance level )

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131 Table 4 7. The a verage of the detached f ruit ( fruit s / t ree) Beaters Shaking Speed (inch/sec) Symbol 40 Shs1 56 Shs2 73 Shs3 Ave. 10 b 2 8 a 12 b S .D. 6.79 17.18 4.89 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level. Table 4 8. The a verage of the a dhered f ruit on the t ree s ( fruit s / t ree) Beaters Shaking Speed (inch/sec) Symbol 40 Shs1 56 Shs2 73 Shs3 Ave. 56 cd 80 ac 2 2 bd S .D. 31.02 33.26 5.01 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level. Table 4 9. The a verage of the grapef ruit detachment p ercentage (%) Beaters Shaking Speed (inch/sec) Symbol 40 Shs1 56 Shs2 73 Shs3 Ave. 17.90 c 26.20 b 35.77 a S .D. 16.59 12.38 8.01 Averages, which have been followed by the same letter in the row, do not have a significant difference statistically at a 0.90 confidence level.

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132 E ffect of the Inter action between the Machine Forward Speed s and its Tunnel Width s on the Field Harvesting Table 4 10 illustrates the effect of inter action between the forward speeds of the harvesting machine with the harvesting tunnel width s on the amount of the detached grapefruit. From this inter action it was found that the highest average amount of detached fruit s was equal to 30 fruit s /tree caused by inter action between the forward speed 0.90 mi/hr and tunnel width 69 in ches while the lowest amount of detac hed fruit s w ere 6 fruit s /tree as a result of the inter action between the forward speed 1.20 mi/hr and harvesting width of 69 in ches Also, by setting up the statistical analysis for this inter action effect, it was found that the inter action of the ground speed 0.90 mi/hr and the harvester tunnel width 69 in ches on one side and the inter action between the ground speed 0.90 mi/hr and tunnel width 75 in ches ; second ground speed 1.20 mi/hr and tunnel width 75 in ches ; and second ground speed 1.20 mi/hr and tunnel width 69 in ches all on the other side is considered as a clear significant influence r on the detached fruit amount at 90 % level of confidence Also, the result s do not show significant difference s on the amount of detached grape fruit under th e influenc e of the other inter actions, also at 90 % level of confidence. The average amount of the attached fruits on the tree canopies due to the inter action of the machine forward speed s and its harvesting tunnel width s are shown in Table 4 11. By this inter action the average remaining fruits on the trees ranged between 34 fruit s /tree, which was gained by inter action of the harvester speed 1.20 mi/hr and 69 in ches internal width, and 97 fruit s /tree which was gained by the inter action of the forward speed 1.20 mi/hr and the tunnel width 75 in ches The highest average amount of the fruit remaining on the grapefruit tree (97 fruit s /tree) occurs due to the inter action between the machine forward speed 1.20 mi/hr an d tunnel width 75 in ches when compared with other inter actions As a result of this inter action the precise statistical analysis found that the effect of the inter action between diverse machine forward

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133 speeds and its tunnel widths on the attached grape fruits amount is generally assumed as a non significant factor and does not have comparison significan ce at the 90 % confidence level. Furthermore, from the relative relationship between the detached fruit amount and the amount of the fruit that remained on grap efruit trees, the fruit detachm ent percentage is shown in Table 4 12. Table 4 12 also shows the actual results of the inter action between the harvester ground speeds and its tunnel widths on the average grapefruit detachment percentage. Also, as can be seen from Table 4 12, the highest average percentage of the fruit detachment was 36.10 % as a result of inter action between the harvester tunnel width 69 in ches and the lowest ground speed 0.90 mi/hr, while the inter action betwe en the internal tunnel width of 69 in ches and the highest ground speed 1.20 mi/hr resulted in the lowest percentage of the fruit detachment, 1 8.53 %. From the data results, by increasing the speed from 0.90 mi/hr to 1.20 mi/hr with the tunnel width 75 in ch es the fruit detachment percentage will be decreased, and likewise the detachment percentage will decreased by increasing the machine forward speed with the width also set at 69 in ches On the other hand, by decreasing the machine internal tunnel width f rom 75 to 69 in ches with a constant ground speed 0.90 mi/hr, the average fruit detachment percentage will be increased to 36.10 % and at the forward speed 1.20 mi/hr, the fruit detachment percentage will increase from 18.53 % to 19.07 % by increasing the harvesting width from 69 to 75 in ches Statistically, it is clear that the inter action influence of the harvester tunnel width 69 in ches and ground speed of the harvester 0.90 mi/hr on one side and the inter actions between the first harvester ground spee d 0.90 mi/hr and its tunnel width 75 in ches ; harvester speed 1.20 mi/hr and harvesting tunnel width 75 in ches ; and the ground speed 1.20 mi/hr and tunnel width 69 in ches all on the other side recorded clearly as having high significant differences on the fruit

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134 detachment percentage The other inter actions were overall recorded as not having significant e ffects on each other on the proportion of the detached fruit at the 10 % level of significance Table 4 10. The a verage amount of the detached f ruit ( fruit s / t ree) Tunnel Width ( i n) Harvester Forward Speed ( m i/ h r) Ave. 0.90 1.20 75 15 b 20 b 16 69 30 a 6 b 18 Ave. 21 1 1 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 11. The a verage of the a dhered f ruit on the t ree s ( fruit s / t ree) Tunnel Width ( i n) Harvester Forward Speed ( m i/ h r) Ave. 0.90 1.20 75 57 a 97 a 67 69 55 a 34 a 45 Ave. 5 7 55 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 12. The a verage of the grapef ruit detachment p ercentage (%) Tunnel Width ( i n ) Harvester Forward Speed ( m i/ h r) Ave. 0.90 1.20 75 25.17 b 19.07 b 23.64 69 36.10 a 18.53 b 27.31 Ave. 29.54 18.71 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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135 Effect of the Inter action s and the Machine Tunnel Wi dth s on the Field Harvesting Influence of the inter action between internal tunnel width s and beaters shaking speed s of the citrus harvester on the amount of the detached grapefruit is shown in Table 4 13. As can be distinguished in Table 4 13 with the specific harvester beaters speed 56 in/sec the amount of detached fruits will be decreased by increasing the harvester tunnel width but the detached grapefruit amount at the highest shaking speed 73 in/sec and the lowest shaking speed 40 in/sec will increase by increasing the internal width of the harvesting tunnel. Moreover, for both tunnel width s 69 in ches and 75 in ches th e amount of the detached fruits increased by increasing the beaters shaking speed from 40 in/sec to 56 in/sec but the amount o f detached fruit decreased at the highest shaking speed of 73 in/sec. The average amount of detached fruit ranged between 8 fruit s /tree as a minimum average due to the inter action of the tunnel width of 69 in ches and beaters shaking speed of 73 in/sec an d 47 fruit s /tree as a maximum average which resulted from the interaction of beaters shaking speed 56 in/sec and harvesting width 69 in ches Statistical analysis found that the effect of the inter action between the harvesting tunnel width 69 in ches and the harvester beaters shaking speed 56 in/sec on one side and the inter actions between the other beaters shaking speeds and harvester internal tunnel widths on the other side, is recorded as having a high statistically significan ce on the amount of det ached grapefruits at 0.10 level of significance. In contrast, the other inter actions between other beaters shaking speeds and the harvesting tunnel widths had no statistically significant effect on the amount of detached grapefruits on each other at a lev el of significance 10 %. For the grape fruits remaining on the tree canopies, the results in Table 4 14 pointed out the impact of the inter action s between the harvester beaters shaking speed s and its internal tunnel width s on the average amount of fruit that remained on the canopies. The highest average

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136 amount of fruit remaining on the tree canopies was 85 fruit s /tree as a result of the inter action between the shaking speed 40 in/sec and tunnel width 75 in ches This recognizable amount of fruit s resulted from the fact that the beaters penetration into the canopies was not sufficient to shake the whole tree canopy synchronously with the lowest shaking speed 40 in/sec. Also, the minimum average amount of the attached fruit was 19 fruit s /tree base d upon the inter action between the tunnel width 69 in ches and the beaters shaking speed 73 in/sec This average amount of fruit is obtained since the beaters penetration into the tree canop ies was reasonable enough to shake it fully with the highest shak ing speed 73 in/sec. Also, it can be observed from Table 4 14 that by increasing the shaking speed from 40 in/sec to 73 in/sec with the highest internal tunnel width 75 in ches the average amount of fruits remaining on the tree canopies is decreased from 85 fruit s /tree to 2 4 fruit s /tree However, at the tunnel width 69 in ches increasing the shaking speed from 40 in/sec to 56 in/sec increased the grapefruits remaining on the canopies, but the highest beaters shaking speed 73 in/s ec resulted in the lowest average amount of grape fruit remaining on tree canopies (19 fruit s /tree). From the statistical analysis results of the obtained data it was found clearly that the inter action effect between the beaters shaking speed 73 in/sec a nd tunnel width 69 in ches on one side and the inter actions between the beaters shaking speed 40 in/sec and tunnel width 75 in ches ; shaking speed 56 in/sec and tunnel width 69 in ches ; and the shaking speed 56 in/sec and tunnel width 75 in ches all on the other side recorded as having a high significant difference on the amount of grape fruit s remaining on the tree canopies at the 10 % level of significance. Also, there were significant differences for the effect of the inter actions between the beaters shaking speed 40 in/sec and the tunnel width 75 in ches on one side and the inter actions between the harvester beaters shaking speed 73 in/sec and tunnel width 75 in ches ; and the beaters shaking speed 40 in/sec and tunnel width 69 in ches

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137 on the other si de on the amount of grape fruit s remaining on the tree canopies at level of significance 10 %. No further significant differences were found between the effect of the other beaters shaking speeds and the harvesting tunnel widths inter actions on each other regarding amount of fruit remaining on the tree canopies at 10 % the level of significance. In addition, Table 4 15 refers to the influence of the inter action between the harvester internal tunnel width s and the beaters shaking speed s on the grape fruit detachment percentage. From the results of the shaking speed and harvesting width inter action the maximum detachment percentage was 41.58 % using the inter action of 75 in ches tunnel width and 73 in/sec of the beaters shaking speed, while the minimu m percentage was 1 2.45 % resulting from the inter action between the shaking speed 40 in/sec and tunnel width 75 in ches Also as observed, the detachment percentage of the grapefruit is increased from 12.45 % to 41.58 % by increasing the shaking speed from 40 in/sec to the highest beaters speed 73 in/sec at the highest tunnel width 75 in ches At the tunnel width 69 in ches the fruit detachment percentage is increased from 20.63 % to 38.05 % by increasing the shaking speed from 40 in/sec to 56 in/sec, while t he fruit percentage decreased to 29.95 % at the shaking speed 73 in/sec This decline at the high shaking speed may have been due to the shaker motor stalling on heavy limb structure. On the other hand, at the shaking speeds 40 in/sec and 56 in/sec, the fr uit detachment percentage increased by decreasing the harvester tunnel width from 75 to 69 in ches but at the beaters shaking speed 73 in/sec, the fruit detachment percentage is increased from 29.95 % to 41.58 % by increasing the tunnel width from the d efault width 69 to 75 in ches Statistically, it is clear that the inter action influence between the harvester tunnel width 75 in ches and the lowest beaters shaking speed 40 in/sec on one side and the harvester tunnel width 75 in ches with the highest beaters shaking speed 73 in/sec; and the default harvester tunnel width 69 in ches with the highest

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138 beaters shaking speed 73 in/sec all on the other side recorded as having significant differences at the level of significance 10 % on the fruit detachment percentage Also, from the statistical analysis it was clear that there are no significant differences due to effect of the inter actions between the other harvester tunnel widths and the beaters shaking speeds on each other at the l evel of confidence 90 % on the p roportion of the detached grapefruits In conclusion, should be noted that for both tunnel widths 75 and 69 inches in increasing the shaker speed from 40 in/sec to 56 in/sec ha s a favorable inter action of grapefruit detach ment percentage, but the maximum grapefruit detachment percentage (41.58 %) had achieved by inter action of tunnel width 75 inches and shaker speed 73 in/sec.

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139 Table 4 13. The a verage of the detached f ruit ( fruits / t ree) Tunnel Width ( i n) Beaters Shaking Speed ( inch/sec ) Ave. 4 0 56 73 75 12 b 18 b 17 b 16 69 9 b 47 a 8 b 18 Ave. 10 2 8 12 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 14. The a verage of the a dhered f ruit on the t ree s ( fruits / t ree) Tunnel Width ( i n) Beaters Shaking Speed ( inch/sec ) Ave. 4 0 56 73 75 85 a 8 1 ac 2 4 bc 67 69 4 1 b c 78 ac 19 b 4 5 Ave. 5 6 80 2 2 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 15. The a verage of the grapef ruit detachment p ercentage (%) Tunnel Width ( i n ) Beaters Shaking Speed ( inch/sec ) Ave. 4 0 56 73 75 12.45 bc 20.27 ac 41.58 a 23.64 69 20.63 ac 38.05 ac 29.95 a 27.31 Ave. 17.90 26.20 35.77 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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140 Effect of the Inter action s and the Machine Forward Speed s on the Field Harvesting The data in Table 4 16 describe influence of the inter action between forward speeds of the harvesting machine with its beaters shaking speeds on the am ount of the detached fruit s. The average amount of the detached fruit ranged between the minimum of 3 fruits /tree, which resulted from the inter action of the highest forward s peed 1.20 mi/hr with the lowest beaters shaking speed 40 in/sec, and the maximum amount of 31 fruits /tree due to the interaction of machine forward speed 0.90 mi/hr and shaking speed 56 in/sec The lowest average amount of the detached fruit 3 fruits /tree occurred at the highest forward speed 1.20 mi/hr which does not furnish enough time to shake the whole tree canopy ( 4.30 sec/tree) when also operat ing at the lowest shaking speed 40 in/sec The highest average amount of detached fruit ( 31 fruits /tree ) was o btained at the lowest forward speed (0.90 mi/hr) which may have furnished enough time (6.49 sec/tree) to shake the whole tree canopy. Also, from the table it can be observed that at harvester beaters shaking speeds of 40 in/sec, 56 in/sec and 73 in/sec, the detached fruit amounts are decreased by increasing the harvester forward speed from 0.90 mi/hr to 1.20 mi/hr. Similarly, at both harvester for ward speeds 0.90 mi/hr and 1.20 mi/hr, increasing the beaters shaking speed from 56 in/sec to 73 in/sec, decreased the detached fruit amounts This may be due to decreased shaker torque at highest motor RPM. It is clear that the maximum average amount of t he detached fruit s occurred at a shak er speed of 56 in/sec for both forward speeds. From the statistical analysis it was found that the inter action e amount of detached fruits does show some significant differences at the level of significance 1 0 %. Clearly, the inter action effect between the beaters shaking speed 40 in/sec and the forward speed of the harvester 1.20 mi/hr from one side and inter actions betwee n the beaters shaking speed 73 in/sec and machine

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141 forward speed 0.90 mi/hr; beaters shaking speed 56 in/sec and machine forward speed 1.20 mi/hr; and the beaters shaking speed 56 in/sec and the forward speed 0.90 mi/hr all on other side recorded as ha ving high significant differences on the average amount of detached grape fruit s Also, there were significant differences for the effect of the inter action between the harvester forward speed 1.20 mi/hr and the beaters shaking speed 73 in/sec on one side and both the inter actions between the harvester beaters shaking speed 56 in/sec and its forward speed 1.20 mi/hr; and the beaters shaking speed 56 in/sec and the forward speed 0.90 mi/hr on the other side on the av erage amount of detached grape fruits at the 10 % level of significance. The inter action between the harvester forward speed 0.90 mi/hr with the beaters shaking speed 40 in/sec and the harvester beaters shaking speed 56 in/sec with its forward speed 0.90 mi/hr has a visible significant eff ect on the average amount of detached grape fruit s Besides that, there were no further significant differences between the effect of the other beaters shaking speeds and the harvester forward speeds inter actions on each other regarding the av erage amount o f detached fruits, at the level of significance 1 0 %. On the other hand, for the remaining fruits on the tree canopies, the partial inter action effect between the harvester forward speed s and beaters shaking speed s on the attached fruits is shown in Table 4 17. The amount of this inter action ranged between a minimum 19 fruits /tree, which resulted from the interaction of the maximum forward speed 1.20 mi/hr and maximum beaters shaking speed 73 in/sec and the maximum of 97 fruits /tree from the inter action between the highest machine forward speed 1.20 mi/hr and shaking speed 56 in/sec. It is clear that the minimal amount of fruit remaining on the tree canopies resulted from the highest shaking speed 73 in/sec at both forward speeds 0.90 and 1.20 mi/hr. Al so, by increasing the harvester forward speed from 0.90 mi/hr to 1.20 mi/hr, the amount of the fruit remaining on the

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142 fruit trees is increased while it is decreased at the shaking speed 73 in/sec from 2 4 fruits /tree to 19 fruits /tree and decreased at the shaking speed 40 in/sec from 5 9 fruit s/tree to 49 fruit s/tree by increasing the harvester forward speed. Meanwhile, at both machine forward speeds, the amount of fruit remaining on trees is increased by increasing the beaters shaking speed from 40 in/sec to 56 in/sec, while it is decreased at the highest shaking speed 73 in/sec. Statistically, at the 10 % level of significance, inter actions between the harvester beaters shaking speeds and its forward speeds did not mak e a significant differences on each other for the amounts of the grape fruit s remaining on the tree canopies. But, there is an obvious significant effect for the inter action between the harvester forward speed 0.90 mi/hr with the highest beaters shakin g speed 73 in/sec and the harvester beaters shaking speed 56 in/sec with its forward speed 1.20 mi/hr on the remaining fruits amount on the tree canopies at a 0.90 confidence level. In addition, from the amounts of detached fruit and the fruit remain ing on the tree canopies, Table 4 18 shows the fundamental aspects of the inter action effect between the beaters shaking speed and the machine forward speed on the grape fruit detachment percentage. The average amount of fruit detachment percentage ranged b etween 7.11 % due to the beaters shaking speed 40 in/sec and forward speed 1.20 mi/hr interaction and 41.58 % from the interaction of forward speed 0.90 mi/hr and shaking speed 73 in/sec As observed from Table 4 18, at both harvester forward speeds, th e fruit detachment percentage increased by increasing the beaters shaking speed from 40 in/sec to 73 in/sec, while the fruit detachment percentage is decreased at each beaters shaking speed by increasing the harvester forward speed from 0.90 mi/hr to 1.20 mi/hr. The highest fruit detachment percentage 41.58 % resulted from the inter action between the specific forward speed 0.90 mi/hr and shaking speed 73 in/sec. This

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143 maximum percentage was obtained by operating the canopy shaker at the highest shaking speed with an enough period of time, which occurs for the lowest forward speed (0.90 mi/hr). The forward speed 0.90 mi/hr gave more time to the machine shakers to shake whole tree canopy. On the other hand, the minimum fruit detachment percentage 7.11 % occurred due to the inter action between the forward speed 1.20 mi/hr and the shaking speed 40 in/sec This percentage was obtained because of the lowest shaking speed operation with the le ast amount of time, which occurred by the highest forward speed (1. 20 mi/hr). The highest forward speed ( 1.20 mi/hr ) may allow less time to shake the whole tree canopy. Statistical analysis showed that the inter action effect of the harvester forward speeds and its beaters shaking speeds on the percentage of detachment fr uit is considered as a high contributor at level of significance 10 %. Briefly, at 10 % level of significance, the inter action influence between the harvester beaters shaking speed 40 in/sec with the harvester forward speed 1.20 mi/hr on one side and all the other inter actions between the harvester forward speeds and beaters shaking speeds on the other side has meaningful influence on the fruit detachment percentage. I n addition, influence of the inter actions between the harvester beaters shaking speed 73 in/sec with the harvester forward speed 0.90 mi/hr on one side and the other inter actions on other side ( machine forward speed 0.90 mi/hr with beaters shaking speed 56 in/sec; machine forward speed 0.90 mi/hr with beaters shaking speed 40 in/sec; ma chine forward speed 1.20 mi/hr with beaters shaking speed 73 in/sec; and machine forward speed 1.20 mi/hr with the beaters shaking speed 40 in/sec ) have meaningful influence on the fruit detachment percentage at the 10 % level of significance The statistical analysis demonstrated a non significant difference between the inter actions of some harvester forward speeds and its beaters shaking speeds on the fruit detachment percentage when the level of significance is 10 %.

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144 Table 4 16. The average of the detached fruit ( fruits /tree) Forward S peed ( m i/ h r) Beaters Shaking Speed ( in/sec ) Ave. 4 0 56 73 0.90 13 bc 31 a 17 acd 21 1.20 3 b 20 ac 8 bd 1 1 Ave. 10 2 8 12 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 17. The a verage of the a dhered f ruit on the t ree s ( fruits / t ree) Forward Spe ed ( mi/hr ) Beaters Shaking Speed ( in/sec ) Ave. 4 0 56 73 0.90 5 9 ac 7 1 ac 2 4 bc 5 7 1.20 49 ac 97 a 19 ac 55 Ave. 55.56 79.67 21.50 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 18. The a verage of the grapef ruit detachment p ercentage (%) Forward Speed ( mi/hr ) Beaters Shaking Speed ( in/sec ) Ave. 4 0 56 73 0.90 23.30 b 29.76 b 41.58 a 29.54 1.20 7.11 c 19.07 ab 29.95 b 18.71 Ave. 17.90 26.20 35.77 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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145 Effect of the Inter action s Harvesting Tu nnel Width s and the Machine Forward Speed s on the Field Harvesting The analysis that c an lead to a satisfying decision about adjusting the harvesting machine operation al variables, which were chosen in this research study (harvester forward speed, beat inter action effect analysis which was done using different operating variables. Table 4 19 shows the inter action effect between the three operating variables on the average amount of the detache d grape fruit s It is observed that the detached fruit amount ranged between the lowest amount 3 fruits /tree that is due to the inter action between the initial beaters shaking speed 40 in/sec, second machine forward speed 1.20 mi/hr, and the machine tunnel width 69 in ches while the highest detached fruit average amount equal to 47 fruits /tree, which is obtained because of the inter action between the initial forward speed 0.90 mi/hr the shaking speed 56 in/sec and internal harvesting width 69 in ches Also, as observed from the field data, the lowest amount is obtained with the highest forward speed (1.20 mi/hr) and the minimum shaking speed (40 in/sec), while the maximum amount of detached grape fruit is obtained by second beaters shaking speed (56 in/ sec) and first forward speed (0.90 mi/hr) which may mean that the shaking time that is obtained from the highest forward speed is less than the shaking time that is available by using the lowest machine forward speed. So, the minimum amount is obtained du e to an inadequate shaking time and shaking speed, while the maximum detached grape fruit amount is obtained from a sufficient shaking time and shaking speed. The statistical analysis revealed that the inter action effect between the beaters shaking speed 56 in/sec, machine forward speed 0.90 mi /hr, and the default tunnel width 69 in ches from one side and all the other harvester operation variables from the other side on the amount of detached fruits shows a significant difference at 10 % of the level of significance Secondly, there is a significant effect as a result of inter action between

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146 the beaters shaking speed 40 in/sec, machine forward speed 1.20 mi /hr, and the default tunnel width 69 in ches from one side and the beaters shaking speed 56 in/sec, machine forward speed 1.20 mi/hr, and the internal harvesting tunnel width 75 in ches from the other side o n the amount of detached fruits at a 0.90 confidence level Thirdly, there is a significant difference between the inter action of the beaters shaking speed 73 in/sec, machine forward speed 1.20 mi/hr, and the default internal tunnel width 69 in ches from one side and the beaters shaking speed 56 in/sec, machine forward speed 0.90 mi/hr, and the internal harvesting tunnel width 75 in ches from the other side on the detached fruits amount at level of significance 10%. In contrast, there were no significant effects found due to inter action between other operati ng variables of the citrus harvester on the amount of detached gra pefruits at the 10 % level of significance as shown in Figure 4 1 Data in Table 4 20 illustrate s influence of the inter action between the machine internal tunnel widths, beaters shaking speeds, and the machine forward speeds on the average amount of the fruit s remaining on the tree canopies. As observed from the obtained data, the lowest amount of remained fruit is 1 9 fruits /tree due to the inter action between the machine forward speed 1.20 mi/hr, the beaters shaking speed 73 in/sec, and the internal t unnel width 69 in ches while the highest amount of remained fruit 97 fruits /tree w as a result of the inter action between the machine forward speed 1.20 mi/hr, beaters shaking speed 56 in/sec, and the internal tunnel width 75 in ches The reason for such huge amount s of fruits remaining on the grapefruit canopies is the second harvesting tunnel width (75 in ches ), which resulted in lesser beaters penetration into the tree canopies than that acquired by the harvesting width 69 in ches Th is constitute d lower penetration than required between the shaking beaters of the harvesting machine and the grapefruit tree canopies.

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147 Furthermore, the statistical analysis proved that there are significant differences from the effect of inter actions bet ween the forward speed 1.20 mi/hr, beaters shaking speed 73 in/sec, and tunnel width 69 in ches from one side and inter actions between the forward speed 0.90 mi/hr, beaters shaking speed 40 in/sec, and tunnel width 75 in ches ; and the forward speed 1.20 m i/hr, beaters shaking speed 56 in/sec, and tunnel width 75 in ches from the other side on the amount of fruit remaining on the tree canopies at the 10 % level of significance. Also, there is a significant difference by the effect of the inter actions between the forward speed 0.90 mi/hr, shaking speed 73 in/sec, and the tunnel width 75 in ches ; and also the forward speed 1.20 mi/hr, beaters shaking speed 56 in/sec, and the harvesting tunnel width 75 in ches on the amount of remaining fruit on the tree c anopies at level of significance 10 % A lso at the same level of significance there is a significant difference from the inter actions between the forward speed 0.90 mi/hr, beaters shaking speed 40 in/sec, and the default harvesting tunnel width 69 in che s on one side and the first forward speed 0.90 mi/hr, beaters shaking speed 40 in/sec, and the tunnel width 75 in ches at other side on the amount of fruit remainin g on the tree canopies There were no significant effects found by the other o perating variable inter actions on the amount of remaining fruit on the tree canopies at the 10 % level of significance as shown in Figure 4 2. Additionally, the critical scientific decision about the appropriateness of the selected operating variables (t harvesting tunnel widths) of the new prototype of the fruit harvesting machine may precisely be taken from the calcul ation results of the percentage of the detached fruit Table 4 21 shows the effect of inter action between the three operating variables (machine forward speed, beaters shaking speed, and the harvester tunnel width) on the average amount of fruit detachment

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148 percentage. The result of that inter action reveals t hat the highest percentage of detached fruit is 41.58 % as a result of inter action between the third beaters shaking speed 73 in/sec, first machine forward speed 0.90 mi/hr, and the harvesting tunnel width 75 in ches This high percentage of detached fruit may have resulted from a combination of the lowest forward speed which provided enough shaking time to shake the whole tree canopy synchronously with an adequate shaking speed 73 in/sec. Furthermore, obtained data shows that the lowest percentage of deta ched grape fruit is 7.11 % as a result of inter action between the first shaking speed 40 in/sec, second machine forward speed 1.20 mi/hr, and the harvesting tunnel width 69 in ches This lowest percentage of detached fruit s resulted from the maximum forward speed which does not provide enough shaking time to shake the whole tree canopy synchronously with the lowest shaking speed (40 in/sec). As observed from the data obtained with the harvesting tunnel width 75 in ches and the forward speed of 0.90 mi/hr, by increasing the beaters shaking speed from 40 in/sec to 73 in/sec, the proportion of detached fruit s is increased from 12.45 % to 41.58 % Also, e ven with the tunnel width of 69 in ches the detachment percentage of the grapefruit is increased from 34.14 % to 38.05 % by increasing the shaking speed from 40 in/sec to 56 in/sec respectively. Also, overall high er percentages of detached fruit s are obtained with the first machine forw ard speed (0.90 mi/hr) compared to the second speed (1.20 mi/hr). Statistica lly, there are significant d ifferences for the inter action effect s between the forward speed 0.90 mi/hr, beaters shaking speed 40 in/sec, and tunnel width 75 in ches from one side and the inter actions between the forward speed 0.90 mi/hr, beaters s haking speed 56 in/sec, and tunnel width 69 in ches ; and also the forward speed 0.90 mi/hr, beaters shaking speed 73 in/sec, and tunnel width 75 in ches from the other side on th e percentage of the detached grape fruit s when the level of significance is 10 %. Als o, there are noticeable differences for

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149 effect of the inter action between the forward speed 1.20 mi/hr, beaters shaking speed 40 in/sec, and tunnel width 69 in ches on one side and the forward speed 0.90 mi/hr, beaters shaking speed 40 in/sec, and tunnel width 69 in ches ; the forward speed 0.90 mi/hr, shaking speed 56 in/sec, and tunnel width 69 in ches ; and also the forward speed 0.90 mi/hr, s haking speed 73 in/sec, and the tunnel width 75 in ches all from the other side on the fruit detachment percentage at the 10 % level of significance A s well as there is a significant difference by effect of the inter action between the forward speed 1.20 mi/hr, beaters shaking speed 56 in/sec, and the tunnel width 75 in ches on one side and the inter action between t he forward speed 1.20 mi/hr, beaters shaking s peed 73 in/sec, and tunnel width 69 in ches on the other side at the 10 % level of significance There were no significant effects found by the other operating variable inter actions on the fruit detachment per centage as shown in Figure 4 3 below In conclusion, it should be noted that for both tunnel widths 75 and 69 inches increasing the shak ing speed from 40 in/sec to 73 in/sec at harvester forward speed 0.90 mi/hr has a favorable inter action on the grapefruit detachment percentage. So, the best decision from the pre test results as shown in Table 4 21, is operat ing the new prototype of a self propelled over the top citrus harvesting machine using canopy shaker at the harvester forward speed 0.90 mi/h r, tunnel width 75 inches, and shaker shaking speed 7 3 in/sec, where the maximum grapefruit detachment percentage 41.58 % was obtained.

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150 Table 4 19. The a verage of the detached f ruit ( fruits / t ree) Tunnel Width ( i n) Harvester Forward Speed ( m i/ h r) 0.90 (Mfd1) 1.20 (Mfd2) Canopy Shakers Speed ( in/sec ) Canopy Shakers Speed ( in/sec ) 40 (Shs1) 56 (Shs2) 73 (Shs3) 40 (Shs1) 56 (Shs2) 73 (Shs3) Ave. 75 (Tw2) 12 bc 16 be 17 bc --20 bd --16 69 (Tw1) 14 bc 47 a --3 ce --8 cd 18 Ave. 13 31 17 3 20 8 Shakers speed 10 2 8 12 Harvester speed 21 11 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Figure 4 1. Comparison results for the effect of the inter action between the three operating variables on the amount of the detached grapefruit ( fruits / t ree)

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151 Table 4 20. The a verage of the a dhered f ruit on the t ree s ( fruits / t ree) Tunnel Width ( i n) Harve ster Forward Speed ( m i/ h r) 0.90 (Mfd1) 1.20 (Mfd2) Canopy Shakers Speed ( in/sec ) Canopy Shakers Speed ( in/sec ) 40 (Shs1) 56 (Shs2) 73 (Shs3) 40 (Shs1) 56 (Shs2) 73 (Shs3) Ave. 75 (Tw2) 85 ad 6 4 ab 2 4 bd --97 ac --67 69 (Tw1) 32 bc 78 ab --49 ab --19 b 45 Ave. 5 9 7 1 2 4 49 97 19 Shakers speed 56 80 2 2 Harvester speed 5 7 55 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Figure 4 2. Comparison results for the effect of the inter action between the three operating variables on the amount of remaining grapefruit on the tree s ( fruits / t ree)

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152 Table 4 21. The a verage of the f ruit beads detachment p ercentage (%) Tunnel Width ( i n) Harvester Forward Speed ( m i/ h r) 0.90 (Mfd1) 1.20 (Mfd2) Canopy Shakers Speed ( in/sec ) Canopy Shakers Speed ( in/sec ) 40 (Shs1) 56 (Shs2) 73 (Shs3) 40 (Shs1) 56 (Shs2) 73 (Shs3) Ave. 75 (Tw2) 12.45 bc 21.47 ab 41.58 ad --19.07 bd --23.64 69 (Tw1) 34.14 acd 38.05 ad --7.11 be --29.95 ace 27.31 Ave. 23.30 29.76 41.58 7.11 19.07 29,95 17.90 26.20 35.77 29.54 18.71 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Figure 4 3. Comparison results for the effect of the inter action between the three operating variables on the grapefruit detachment percentage (%)

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153 Distribution of Acceleration Magnitude i n the Grapefruit Tree Canopy Physically, fruits are harvested when the tensile force between the fruit calyx and the peduncle (stem) exceed the fruits adhesion force, and thus severs the adhesion layer. The adhesion force is variable according to fruit maturity. Several experiments of canop y shaking were done on grap efruit trees to study the branch s dynamic behavior (acceleration upon shaking) during beaters operation with the preliminary prototype citrus harvesting machine (7 beaters per shaking unit) Numerous small acceleration devices (15 USB accelerometer senso rs model X16 1C) were placed on various branches at randomly selected locations in the canopy of a fruit tree (Ray Ruby grapefruit) using plastic adhesive tape as shown in Figure 3 39 The resulting distribution of canopy acceleration s were obtained und er various operating conditions mentioned in this research study (two beaters shaking speeds and three beaters penetrations into the canopy ) where tunnel width w as kept constant at 69 inch es Data configuration is displayed using the Java XLR8R program that is furnished with each X16 1C sensor where the magnitude of the acceleration is calculated and store d inter nally in the X16 1C (i.e., internal calculation) Also, the results of the tree branches oscillation during shaking were re corded with the global clock for a precise time ( m sec) and cluster of three coordinate acceleration s (x, y, and z) S ubsequently the acceleration data were found by using the time domain diagram ( at x axis m sec) o n x, y, and z axes which were initiall y recorded at sample rate of 50 Hz and sample size 30,000 ( counts) versus time domain magnitude of the converted data ( at the y axis gravitational acceleration, g). T hen the resultants of the three coordinate axes are calcul ated and displayed, and figur es generated using the M ATLAB program

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154 Shaking Acceleration Distribution by Diverse Beaters Penetrations into the Harvested Grapefruit Canopies The results of Table C 1, present the time domain magnitudes and averages of th e acceleration that were achieved by operating the harvester beaters at three different tree canopy penetration s (default position 10, 11, and 12 inch es turn buckle length) with a constant beaters shaking speed of 45.30 in/sec and approximately 0.80 mi/hr of the machine forward speed where 15 sensors were deployed i nto one grapefruit tree canopy. The distribution of the acceleration resulting from shaking the tree canopy was uneven with diversity in the magnitudes of acceleration as shown in the following Figures 4 4, 4 5, an d 4 6. The branches behavior changed along the tree canopy cross section (laterally and vertically). The maximum average magnitude wa s equal to 7.804 g, which was achieved by extending the beaters deeper into the tree canopy which was accomplished by increasing the length of the turn buckles between the crank shaft and the beaters to 12 inches The maximum magnitude recorded at the left side of the tree was achieved by setting t he left beaters squad on maximum turn buckle length (12 inch es ), while th e minimum average magnitude of 1.691 g was recorded at the top central band of the tree perimeter using 11 inch es of turn buckle length Furthermore, as a result of moving the beaters out to the canopy perimeter edge by decreasing the length of each turn buckle to 10 inches and running the right beaters squad, the maximum magnitude equal to 6.074 g was recorded at the lower front edge of the tree perimeter. The maximum magnitude gained by increasing the beaters penetration to 11 inch es again using the r ight beaters squad, was 7.255 g also recorded at the lower front edge of the tree perimeter. The maximum magnitude (7.255 g) also resulted at the lower right side of the tree perimeter from operating the right beaters squad while the minimum magnitude value was 1.691 g recorded at the top central edge of the tree perimeter.

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155 At the top of the tree canopy (sensors 2, 8, and 9), the magnitude increased from 2.740 g to 4.319 g by increasing the beaters penetration (increasing the connec ting turn buckle le ngth from 10 to 11 inch es ) but decreased to 1.988 g, which recorded by sensor number 2 under the right beaters influence with the turn buckle length increased to 12 inches. With t he left beaters operation the magnitude increased from 1.910 g to 3.450 g as recorded by sensors 8 and 9, by increasing the harvester penetration (increasing length of the connecting rod from 10 to 12 inch es ). Also, the acceleration magnitude value at the central edge of the tree perimeter and parallel to the forward machine speed track as recorded by sensor number 15 (underneath of the canopy and 20 inches rear of the main trunk) increased from 1.971 g to 2.207 g by increasing both beaters squads (left and right unit) penetration from 10 to 11 inch es, and again, the magni tude decreased by using a turn buckle length of 12 inch es. In the lower part of the tree canopy where sensors 3, 10, 12, and 14 were located on left and right side s of the grapefruit tree, the maximum acceleration magnitude was 6.207 g, using t he 12 inch es turn buckle connection for left the side and 7.255 g using 11 inch es turn buckle connection for the right side Generally, depending on the sensors location the acceleration magnitude imparted by the beaters at all was substantially higher on the lower branches than on the branches on the central top of the tree canopy or the limbs along the central band of the tree canopy (sensor number 15). Also, on the lateral branches above 40 inch es from the ground, the right side of the tree canopy ha d a slightly higher accel eration magnitude (Ave. 3.93 g) than the left side (Ave. 3.52 g) of the tree canopy, while the branches in the cent er of the tree canopy ha d a low er acceleration magnitude average for all beaters penetration s etting s. So, in summary, the tree canopy was receiving different shaking magnitudes from the two beaters squads (left and right harvester units) when the two crank shaft motors operated

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156 In general, the average magnitude of the gravitational acceleration (g) ranged between 3.403 g obtained by operating the two shaking beaters units on 10 inches turn buckle setting and 3.848 g o btained by operating the shaking beaters on 12 inch es turn buckle setting. As observed, by increasing the shaking beaters penetration into the tree canopy, the average magnitude of acceleration (g) on the trees bra n ches increased So, the overall influence of beaters vibration on tree branches was increased with an increase in the shaking beaters penetrat ion displacement. Statistically, Table C 1 shows that there is an observable significant difference at the 10 % level of significance for the influence of the penetration of harvesting machine beaters on the amount of the acceleration magnitude of the tre e branches between the turn buckle length of 10 inch es, and the turn buckle length of 12 inch es Otherwise, there are no significant differences at the 10 % level of significance between the turn buckle length of 10 inch es, and the turn buckle length of 11 inch es, or between the turn buckle length of 11 inch es and the turn buckle length of 12 inch es, on the acceleration magnitude of the grapefruit tree branches. Also there is no further significant difference for the effect of both the tree canopy sides (3.52 g at left and 3.93 g at right) on the acceleration magnitude at the level of significance 10 %.

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157 Figure 4 4. Acceleration magnitude distributions into the grapefruit tree canopy by 10 inches of turn buckle length (front view). [Photo courtesy of Naji A l Dosary ] Figure 4 5. Acceleration magnitude distributions into the grapefruit tree canopy by 11 inch es of turn buckle length (front view). [Photo courtesy of Naji A l Dosary ] Normalized acceleration (g/max.g) Normalized acceleration (g/max.g)

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158 Figure 4 6. Acceleration magnitude distributions into the grapefruit tree canopy by 12 inch es of turn buckle length (front view) [Photo courtesy of Naji A l Dosary ] Shaking Acceleration Distribution Effect by Various Beaters Shaking Speeds For this experiment, 15 USB accelerometer sensors (model X16 1C) were placed on various branches at different locations on three random tree canopies of grapefruit (Ray Ruby grapefruit), with 5 sensors placed into each individual grapefruit tree canopy. The results of the acceleration magnitude distribution on the shaking tree canopies were obtained by using various referenced in Table C 2. The results of Table C 2 show the time domain magnitudes and averages of the acceleration that were achieved by operating the shaking beaters at two different shaking speeds (45.30 and 65.90 in/sec) by setting the knobs of both left and right flow control valves at similar turns (2.50 and 3.0 turns) while keeping the shaking beaters penetration into the grapefruit canopy constant at 1 2 inch es turn buckle length and approximately 0. 80 mi/hr of the machine Normalized acceleration (g/max.g)

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159 forward speed The distribution of the acceleration from the shaking beaters operations on the tree canopy was non uniform with diversity in the magnitudes of the acceleration (g) as represented in Figures 4 7 and 4 8. As previously noted the tree branch behaviors changed along the tree canopy perimeter (latera lly and vertically). The maximum average of the acceleration mag nitude was 8.00 g, obtained at the right side of the tree perimeter (sensor number 14) for of 65.90 in/sec while the minimum average magnitude was 2.286 g res ulting from the 45.30 in/sec beaters speed. The maximum magnitude wa s obtained at the left side of the tree perimeter by running the beaters squad on the second speed (65.90 in/sec) achieving 5.907 g, while the lowest beaters speed (45.30 in/sec) yielde d the minimum magnitude of 2.409 g at sensor number 13. At the top of the tree canopy (more than 52 inch es from the ground), the magnitude increased from 2.286 g to 6.947 g by increasing the harvester beaters speed from 45.30 in/sec to 65.90 in/sec, whic h resulted from the right beaters influence However, the left beaters operation as recorded by sensors 2 and 7, saw an acceleration magnitude increase from 3.01 g to 5.907 g by increasing the harvester beaters speed to 65.90 in/sec. A t the top central edge of the tree perimeter the acceleration magnitude increased from 2.286 g to 3.425 g by increasing both beaters squads speed. The magnitude at the central edge of the tree perimeter and parallel to the machine path, recorded at sensor number 3 (underneath of the tree canopy and 21 inch es behind the main trunk) decreased from 2.088 g to 1.933 g by increasing the beaters speed from 45.30 in/sec to 65.90 in/sec. Measurements were also taken at both left and right sides of the lower canopy perime ter at height s of 45 inch es from the ground and less. The maximum right side acceleration magnitude average was 8.00 g at beaters speed of 65.90 in/sec and 7.387 g at beaters speed of 45.30 in/sec In addition, the maximum left side acceleration magnitude was 4.884 g at a beaters speed of 65.90 in/sec and 3.756 g at a beaters

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160 speed of 45.30 in/sec. Accordingl y, as shown in Figure s 4 7 and 4 8, the comparison of results from different sensors location s showed that the shaking beaters acceleration magnitude at all was substantially higher at lower branches in the tree canopy (45 inches from the ground and less ) than the acceleration magnitude of branches on the top central of the tree canopy and along the central band of the tree canopy (sensor number 3) It appeared that the lateral branches, which are 45 inch es and more from the ground on the left side of the tree canopy received more acceleration magnitude (4.113 g) than the right side (4.109 g) of the tree canopy Finally, th e branches in the central band of the tree canopy have a low acceleration magnitude average at all beaters shaking setting s. In general, the average magnitude of the gravitational acceleration (g) ranged between 3.65 g and 5.055 g, when both shaking beat ers units (right and left) where operated at 45.30 in/sec and 65.90 in/sec respectively. As observed, by increasing the shaking beaters speed from 45.30 in/sec to 65.90 in/sec, the average magnitude of the acceleration (g) on the trees bra n ches will be increased so the influence of the beaters shaking speed on tree branches is to increase acceleration. Statistically, the small letters in Table C 2 shows that there is no significant difference at the level of significance 10 % for the influence of the shaking speed of the machine beaters on the amount of the acceleration magnitude of the tree branches between the lowest shaking speed (45.30 in/sec) and the highest shaking speed (65.90 in/sec). Likewise, there is no further significant difference betwee n the effects of the two different beaters shaking speeds for both tree canopy sides (4.113 g left & 4.109 g right side) on the average amount of the acceleration magnitude at the level of significance 10 %.

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161 Figure 4 7. Acceleration magnitude distribution into the grapefruit tree canopy by the first beaters shaking speed (front view) [Photo courtesy of Naji A l Dosary ] Figure 4 8. Acceleration magnitude distribution into the grapefruit tree canopy by the second beaters shaking speed (front view) [Photo courtesy of Naji A l Dosary ] Normalized acceleration (g/max.g) Normalized acceleration (g/max.g)

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162 Distribution of A cceleration M agnitude on the H Shakers For the acceleration measurement trials beaters wit hout resistance load s from t he grapefruit trees canopies 6 USB accelerometer sensors model X16 1C were and attached using plastic adhesive tape T here were 3 sensors stu ck on 3 different beaters of each shaker unit (3 sensors on right and 3 on left) as shown in Figure 4 9 For these trials, the 1/2" ( O D) hollow PVC pipes were replaced with 32 inches long flexible 1" ( O D) round grey PVC rods The total length of each single b eater is 60 in ches connected to 11.50 inches turn buckle length The first test of these PVC rods revealed that a quick fatigue can occur next to the joining metal sleeve for joining a steel pipe with a PVC rod, when using a high shaking speed of more than 101.50 in/se c So, th e higher shaking speed beyond 101.50 in/sec, was excluded from the testing The result of the acceleration magnitude distribution on the shaking beaters was obtained by operating the beaters at two different shaking speeds (69.32 and 101.50 in/sec) established by setting the two knobs of the flow control valves at 2.0 and 2.5 respectively, as shown in Tables 4 2 2 and 4 2 3 When the individual shakers were operated at speed of 69.32 in/sec, t he a verage magnitude of the acceleration ranged between 5.43 g and 6.65 g, and when operating the individual shakers at shaking speed 101.50 in/sec, the lowest magnitude was 9.18 g and the highest magnitude was 10.39 g. In general, by increasing the shaking be aters speed from 69.32 in/sec to 101.50 in/sec, the average magnitude amounts of the acceleration (g) on the harvester beaters will be increased However, at the first speed 69.32 in/sec, the right shaker unit gives a higher acceleration magnitude than th e left shaker unit. In contrast, at the second speed 101.50 i n/sec, the right shaker unit ga ve an acceleration magnitude less than the left shaker unit as illustrated in Tables 4 2 2 Furthermore, from the s tat istical analysis as shown by small letters at each row in Table 4 2 2 it was found that there is a significant difference between the two shaker

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163 units locations (right or left shakers) on the amount of the acceleration magnitude which was obtained from sensors on the shaking beaters operated at both shaking speeds ( 69.32 and 101.50 in/sec ) at the level of significance 10 % when the two shaker units were operated separately acceleration magnitude ranged betwe en 5.04 g by the right unit and 5.38 g by the left shaker unit at shaking speed 69.32 in/sec, while there was no difference between the right and left shakers magnitude ( 10 g) at the shaking speed 101.50 in/sec. But in general, by increasing the shaking be aters speed from 69.32 in/sec to 101.50 in/sec, the average acceleration magnitude of the two shaker unit s will increase when operating the two shaking beaters units simultaneously as calculated in Tables 4 2 3 Statistically, the small letters in Table 4 2 3 show that there are no significant difference s at the 10 % level of significance for influence of the shakers location (right or left shakers) on the amount of the acceleration magnitude of the shaking beaters when the two shaker units operated simul taneously at different shaking speed s ( 69 .3 2 and 101.50 in/sec). have been caused by the fact that either the two flow control valves of the John Deere relief valves were not adjust ed accurately for both harvester units (two crank shafts) to be precisely the same rotational speed or because of the hydraulic circuit that is connected to the right relief valve is longer than the circuit to t he left relief valve Meanwhile, if the two shak ers motors performance is taken as a comparison of the two shaker motors separately, the two shakers motors (right and left) have no significant differences at the l evel of significant 10 % on the acceleration magnitude where their magnitude s are equal 7.91 g. On the

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164 other hand, when the two shakers motors were operat ed simultaneously, the acceleration magnitude of the right shakers motor is 7.57 g, and the left shakers motor offered more acceleration magnitude equal to 7.69 g but without significant differences at 10 % level of significan ce In general, there is no significant difference between testing the two shakers motors individually or together on the acceleration magnitude results The average magnitude that was recorded by running the two shakers motors independently was 7.91 g and synchronized operation was 7.63 g. Consequently, from the shakers experiment results, there were no considerable differe nces between the obtained acceleration magnitudes that resulted by operating the two shakers units either independently or together which mean s the two shaker units were functioning adequately as required by the canopy shaker field trials

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165 Figure 4 9 [Photo courtesy of Naji A l Dosary ]

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166 Table 4 depending on operating the two beater unit s independently at two shaking speeds. No. of Sensor Beaters Speed at Sensors Spot (in ch /sec) Acceleration Magnitude of t he Left S hakers Unit (g) Acceleration Magnitude of the Right S hakers Unit (g) No. of Sensor Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) 4 69.32 4.92 1.84 6.73 2.24 1 101.5 9.64 4.11 9.1 4.03 5 69.32 5.28 1.84 6.82 2.29 2 101.5 10.65 4.26 9.3 3.99 6 69.32 6.09 2.2 6.39 2.06 3 101.5 10.88 4.2 9.13 3.94 Ave rage of Low Shaking Speed 5.43 b 1.96 6.6 5 a 2. 20 Ave rage of High Shaking Speed 10.39 a 4.19 9.1 8 b 3.9 9 Total Average s 7.91 a 7.91 a Each row averages, which have been followed by different letter, have significant differences among them statistically at a 0.90 confidence level. Table 4 depending on operating the two beater units simultaneously at two shaking speeds. No. of Sensor on Left Beaters Speed at Sensors Spot (in ch/sec ) Acceleration Magnitu de of the Left S hakers Unit (g) Acceleration Magnitude of the Right S hakers Unit (g) No. of Sensor on Right Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) 4 69.32 4.8 1.8 4.86 2.09 1 101.5 9.01 3.96 10 4.2 5 69.32 5.36 1.84 4.94 2.26 2 101.5 10.64 4.19 10.29 3.81 6 69.32 5.98 2.24 5.32 2.18 3 101.5 10.35 4.23 9.99 3.81 Ave rage of Low Shaking Speed 5.38 a 1.96 5.04 a 2.1 8 Ave rage of High Shaking Speed 10 .0 a 4.1 3 10.09 a 3.94 Total Average s 7.69 a 7.57 a Averages, which have been followed by the same letter in each row, do not have significant differences among them statistically at a 0.90 confidence level.

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167 Final Results of the Final Citrus Harvesting Machine Design Effect of the Harvesting Machine Forward Speeds on the Field Harvesting The follow discussion pertains to harvesting results for the final machine modifications and field trials conducted in Jan uary 2014 at the Plant Science Research and Education Center in Citra (PSREC) FL Table 4 24 shows effect s of the forward speeds of the final harvesting machine design on the amount of grapefruits harvested from the tree canopies In general, machine forward speed correlates with the required time for shaking tree canopies, where increasing the harvester forward speed, the resulting total canopies shaking time will be decreased, and shaking time was increas ed with low er forward sp eed s From the field operations it was found that the shaking time resulting from an average forward speed of 1. 4 2 mi/hr was almost 3.88 sec/tree, while the shaking time resulting from the average lowest forward speed of 0. 62 mi/hr was almost 8.75 sec/tree. It was found that the average amount of harvested grapefruit decreased at the higher forward speed 1. 42 mi/hr achieving the lowest average detached fruit of 79 fruits /tree. T he average amount of grapefruits ranged between 79 fruits /tree for the higher forward speed 1. 4 2 mi/hr and 94 fruits /tree for the lowe r forward speed (0. 62 mi/hr) Thus, by applying the statistical analysis to the field data it was found that with 10 % level of significance there is an obvious significa nt difference between the influence of the low and high speed on the amount of detached grapefruit s Meanwhile, the influence of the harvester forward speeds on the fruit dislodgement percentage is shown in Table 4 25 The table shows that by increasing th e harvester forward speed from 0. 62 mi/hr to 1. 42 mi/hr, the average percentage of the detached grapefruits will be decreased from 80.03 % to 72.98 % respectively. From the results analysis it was found that statistically there is a clear significant difference at the 10 %

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168 level of significance of the influence of the harvesting machine forward speeds on the percentage of the detached grapefruit s. Table 4 24 The a verage of the detached f ruit ( fruits / t ree) Forward Speed of the Harvester (mi/hr) Symbol 0. 62 Mfd1 1. 42 Mfd2 Ave. 94 a 79 b S .D. 39.40 31.45 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 25 The a verage of the f ruits detachment p ercentage (%) Forward Speed of the Harvester ( m i/ h r) Symbol 0. 62 Mfd1 1. 42 Mfd2 Ave. 80.03 a 72.98 b S .D. 13.97 16.13 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level. Effect of Beaters Positions of the Harvesting Machine on the Field Harvesting fluence on the amount of the detached fruit are shown in Table 4 26 Numerically, the position of the beaters default setting ( buckles, 12, 14, and 15 inches) reveals a high amount of dislodged fruits (115 fruits /tree), while the short 12 inches turn buckles setting ga ve lower detached numbers of 59 fruits /tree The reason for th e decreased numbers may be that the canopy without pe netrati ng the tree canopy sufficiently to dislodge inner fruit s. Statistically, there were significant differences at the level of 10 % significance of the effect of the beaters positions on the average of the dislodgement quantity of grapefruit s In addit ion, data in Table 4

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169 27 illustrates the influence of the beaters penetrations into the tree canopy on the average of the fruits dislodgement percentage. As shown in Table 4 27 the fruit dislodgement percentage is increased by increasing the beaters penetration into the grapefruit canopy. In other words, increasing the turn buckle length from 12 to 16 inches, leads to increase in the percentage of grapefruit dislodgement from 6 2.32 % to 87.97 %. According to statistical analysis, at the 10 % level of significance, it was found that there were visible significant differences between the effectiveness of the three beaters positions on the fruits dislodgement percentage (%). Tab le 4 26 The a verage of the detached f ruit ( fruits / t ree) Beaters Position (in), ( turn buckle length ) Symbol 12 Bp 1 Default Setting Bp2 16 Bp3 Ave. 59 c 115 a 86 b S .D. 19.89 38.38 22.28 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 27 The a verage of the f ruits detachment p ercentage (%) Beaters Position (in), ( turn b uckle length ) Symbol 12 Bp 1 Default Setting Bp2 16 Bp3 Ave. 62.32 c 79.25 b 87.97 a S .D. 13.91 10.66 8.31 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level.

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170 In terms of the machine beaters frequency, Table 4 28 shows the influence of the machine beater s speeds on the average amount of detached grapefruit ( fruits /tree). When the beaters shaking speed is increased from 56.50 in/sec to 73 in/sec, the average amount of fruit detached increased from 78 fruits /tree to 95 fruits /tree From the statistical analysis at the 10 % level of significance it was found that there is a significant difference between the influences of the beater s speeds 56.50 in/sec and 73 in/sec on the average amount of the detached fruit In addition, Table 4 2 9 shows the effect of diversity in the harvester beater s speed on the proportion of the average dislodgement of the grapefruit s It is obvious that with increase in the harvester beaters speed from 56.50 in/sec to 73 in/sec, the grapefruit dislodgement per centage will be increased from 73.30 % to 79.72 %. Ostensibly, there are effective differences between the beaters shaking speeds so according to the statistical analysis there is significant difference between the effects of the machine beaters speeds on the average of the grape fruit dislodgement percentage at the level of significance 10 %, and there is significant difference between the lowest beater s shaking speed 56.50 in/sec and the highest beater s shaking speed 73 in/sec in terms of the average percentage of grapefruit detached Table 4 28 The a verage of the detached f ruit ( fruits / t ree) Beaters Shaking Speed (inch/sec) Symbol 56.50 Shs1 73 Shs2 Ave. 7 8 b 9 5 a S .D. 21.11 45.32 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level.

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171 Table 4 2 9. The a verage of the grapef ruit detachment p ercentage (%) Beaters Shaking Speed (i nch/sec) Symbol 56.50 Shs1 73 Shs2 Ave. 73.30 b 79.72 a S .D. 11.69 17.97 Averages, which have been followed by the same letter in the row, do not have significant differences among them statistically at a 0.90 confidence level. Effect of the Inter action between the Machine Forward Speeds and its Shakers Positions on the Field Harvesting Table 4 30 illustrates the effect of inter action between the forward speeds of the harvesting machine with the shaking beaters position (beaters displacements ) on the amount of the detached grapefruit s From this inter action it was found that the highest amount of dislodged fruit average 134 fruits /tree resulting from inter action between the forward speed 0. 62 mi/hr and the default position of the shaking beaters while the lowest amount of detached fruits 53 fruits /tree w as a result of the inter action between the second forward speed 1. 4 2 mi/hr and the beater s turn buckle length at 12 in ches Also, by setting up the statistical analysis for this inter act ion effect, it was found that the inter actions of the ground speed 0. 62 mi/hr and the default beaters position from one side and the inter actions between the ground speed 0. 62 mi/hr and beater s turn buckle length at 12 inches ; the ground speed 0. 62 mi/hr and beater s turn buckle length at 16 in ches ; second ground speed 1. 4 2 mi/hr and the default beaters position ; second ground speed 1. 4 2 mi/hr and the beaters turn buckle length at 12 in ches ; and the ground speed 1 42 mi/hr and the beaters turn buckle length at 16 in ches all on the other side are considered as a clear significant influence r on the detached fruit amount at a 90 % level of confidence Also, the result s do not show significant difference s on the amount of detached fruit under the influe nc e of the other inter actions also at 90 % lev el of confidence. Furthermore, from the

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172 relative relationship between the detached fruit amount and the amount of the fruit that remained on grap efruit trees, the fruit detachment percentage is shown in Table 4 31 Table 4 31 shows the actual results of the inter action between the harvester ground speeds and its on the grapefruit detachment percentage. Also, as can be seen from Table 4 31 the highest average percentage of grape fruit detachment was 89.09 % as a result of inter action between the beaters t urn buckle length at 16 in ches, and the lowest ground speed 0. 62 mi/hr, whi le the inter action between the beaters at turn buckle length of 12 in ches and the highe r ground speed 1. 4 2 mi /hr resulted in the lowest percentage of fruit detachment 57.75 % From the data results, it can be shown that, increasing the harvester forward speed from 0. 62 mi/hr to 1. 4 2 mi/hr at all the different positions resulted in a decreased percentage of fruit detachment On the other hand, by decreasing beaters position which means decreasing the turn buckle length from 16 in ches to 12 in ches at all harvester ground speed s the average fruit detached percentage will be decreased from 89.09 % at forward speed of 0. 62 mi/hr and turn buckle length 16 in ches, to 57.75 % as a result of the inter action of the forward speed 1. 4 2 mi/hr and 12 in ches turn buckle length. Statistically, it is clear that the inter action influence of the beaters at turn buckle length 16 in ches and the ground speed 0. 62 mi/hr from one side and the inter actions between the first harvester ground speed 0. 62 mi/hr and its beaters position at turn buckle length 12 in ches ; the ground speed 1. 4 2 mi/hr and the beaters position at the default setting; and the ground speed 1. 4 2 mi/hr and the beaters at turn buckle length 12 in ches all on other side recorded clearly as having high significant differences on the fruit detachment percentage The other inter actions were overall recorded between having and not having significant e ffects on each other on the proportion of the detached fruit at level of significance 1 0 %.

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173 Table 4 3 0. The a verage amount of the detached f ruit ( fruits / t ree) Turn Buckle Length ( i n) Harvester Forward Speed ( m i/ h r) Ave. 0. 62 1. 42 12 64 cd 53 d 59 Default Setting 134 a 96 b 1 15 16 83 b c 88 b c 86 Ave. 94 79 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 31 The a verage of the grapef ruit detachment p ercentage (%) Turn Buckle Leng th ( i n) Harvester Forward Speed ( m i/ h r) Ave. 0. 62 1. 42 12 66.88 be 57.75 b 62.32 Default Setting 84.13 ad 74.36 dce 79.25 16 89.09 a 86.84 ac 87.97 Ave. 80.03 72.98 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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174 Effect of the Inter action Beaters Positions on the Field Harvesting Influence of the inter action between various beaters positions and beaters shaking speed s of the citrus harvester on th e amount of the detached fruits is show n in Table 4 32 As can be observed in Table 4 32 with specific beaters position determined by the turn buckle lengths at both the default setting and 16 inches turn buckle length the number of detached fruits was increased by increasing the harvester beaters shaking speed It was also observed that the number of detached fruits with the turn buckle length set at 12 inches was increased by decreasing the beaters shaking speed Moreover, t he average amount of detached fruit ranged between 53 fruits /tree as a minimum average due to the inter action of the beaters position set by turn buckle length of 12 inches and beaters shaking speed of 73 in/sec and 144 fruits /tree as a maximum average due to the inter action of the beaters shaking speed 73 in/sec and the default beaters position Statistical analysis found that the effect on the amount of detached fruits, of the inter action between the highest beaters shaking speed 73 in/sec and the beaters default position on one side and the other side of the inter actions between the other beaters shaking speeds and harvester beaters positions is recorded as having a high statistically significan ce at 0.10 level of significance. In contrast, at level of significance 10 %, the other inter actions between othe r beaters shaking speeds and the beaters positions either had or did not have a statistically significant effect on each other as measured by the amount of detached fruit. In addition, Table 4 33 refers to the influence of the inter action between the positions of the harvester beaters and the beaters shaking speed s on the fruit detachment percentage. From the results of the shaking speed s and beaters positions inter actions the maximum detachment percentage equal s 93.54 % using the inter action of 1 6 inches of the machine turn buckle length and 73 in/sec of the beaters shaking speed, while the minimum percentage 59.86 % result ed from the inter action between

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175 the shaking speed 73 in/sec and the beaters at turn buckle length of 12 inches. Al so as observed, the detachment percentage of the grapefruit increased from 82.39 % to 93.54 % by increasing the shaking speed from 56.50 in/sec to the highest beaters speed 73 in/sec at the highest beaters position at turn buckle length of 16 inches At the lowest beaters position of 12 inches of turn buckle length the fruit detachment percentage is decreased from 64.77 % to 59.86 % by increasing the shaking speed from 56.50 in/sec to 73 in/sec, while the inter action of the default position of the shakin g beaters, and the shaking speed 73 in/sec, resulted in the fruit percentage increas ing to 85.76 %. On the other hand at both shaking speeds 56.50 in/sec and 73 in/sec, the fruit detachment percentage increased by decreasing the harvester beaters displa cement via increasing the turn buckle length from 12 inches to 16 inches. Statistically, it is clear that the inter action influence between the beaters position by the turn buckle length 16 inches and the beaters shaking speed 73 in/sec on one side and t he beaters position by the turn buckle length 12 inches with the beaters shaking speed 73 in/sec; the default position of the with the lowest beaters shaking speed 56.50 in/sec ; and the lowest beaters shaking speed 56.50 in/sec with the beaters position at 1 2 inches of the turn buckle length all on the other side recorded as having significant differences on the fruit detachment percentage, at the 10 % level of significance Also, from the statistical analysis it was clear that there are no significant differences on the proportion of the detached grapefruits due to effect of the inter actions between the other harvester and the beaters shaking speeds on each other at the level of confidence 90 % since ther e were no significant differences between the first three highest percentage s of the fruit detachment as shown in Table 4 33

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176 Table 4 32 The a verage of the detached f ruit ( fruits / t ree) Turn Buckle Length ( i n) Beaters Shaking Speed ( inch/sec ) Ave. 56.50 73 12 64 b c 53 c 59 Default Setting 86 b 144 a 115 16 83 b 88 b 86 Ave. 78 95 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 33 The a verage of the grapef ruit detachment p ercentage (%) Turn Buckle Length ( i n) Beaters Shaking Speed ( inch/sec ) Ave. 56.50 73 12 64.77 b d 59.86 d 62.32 Default Setting 72.73 b c 85.76 a 79.25 16 82.39 ac 93.54 a 87.97 Ave. 73.30 79.72 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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177 Effect of the Inter action Machine Forward Speeds on the Field Harvesting The data in Table 4 34 describe influence of the inter action between forward speeds of the harvesting machine with its beaters shaking speeds on the amount of detached grape fruit s The average amount of the detached fruit ranged between the minimum amount of grape fruit 70 fruits /tree, which resulted from the inter action of the highest forward speed 1. 4 2 mi/hr with the lowest beaters shaking speed 56.50 in/sec, and the maximum amount of detached grape fruit a t 102 fruits /tree resulted from the inter action of the lowest machine forward speed 0. 62 mi/hr and shaking speed 73 in/sec. The lowest average amount of the detached fruit ( 70 fruits /tree) was obtained using the highest forward speed 1 4 2 mi/hr with lowest shaking speed 56.50 in/sec. This combination did not furnish enough time to shake the whole tree canopy at a shaking time of approximately 3.88 sec/tree In contrast, the highest average amount of detached grape fruit 102 fruits /tree was obtained with the lowest forward speed (0. 62 mi/hr) which provided enough time to shake the whole grape fruit tree canopy since the shaking time resulting from this speed was approximately 8.75 sec/tree. Also, it can be observed that for both beater shaking speeds 56.50 in/sec, and 73 in/sec, the detached grape fruit amounts are decreased by increasing the harvester forward speed from 0. 62 mi/hr to 1. 42 mi/hr. Similarly, at both harvester forward speeds 0. 62 mi/hr and 1. 42 mi/hr, increasing the beat ers shaking speed from 56 .50 in/sec to 73 in/sec, results in higher detached grape fruit amounts. It is clear that the maximum average amount s of the detached fruit s were obtained by using the beaters shaking speed 73 in/sec at both forward speeds of the harvester From the statistical analysis it was found that the inter action average amount of the detached grape fruit s does s how significant differences at the 10 % level of significance. Clearly, the inter action effect between the highest beaters shaking speed 73 in/sec

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1 78 and the lowest forward speed of the harvester 0 62 mi/hr from one side and inter action between the lowest beaters shaking speed 56.50 in/sec and h ighest machine forward speed 1 42 mi/hr recorded as having high significant difference s on the average a mount of detached fruit s Besides that, there were no further significant differences between the effect of the other beaters shaking speeds and the ha rvester forward speeds inter actions at each other on the av erage amount of detached fruits, also at the lev el of significance 10 %. In addition, from the amounts of detached fruit and fruit remaining on the grapefruit tree canopies, Table 4 35 shows the i nter action effect between the beaters shaking speed s and the machine forward speed s on the grape fruit detachment percentage. The average amount of fruit detachment percentage that resulted from this inter action ranged between 69.18 % due to the inter action of the beaters shaking speed of 56.50 in/sec and forward speed of 1. 42 mi/hr and 82.65 % that was the result of the inter action of the forward speed 0. 62 mi/hr and the shaking speed 73 in/sec. As observed from Table 4 35 at both harveste r forward speeds, the fruit detachment percentage increased by increasing the beaters shaking speed from 56.50 in/sec to 73 in/sec, while the fruit detachment percentage is decreased at all beaters shaking speed s by increasing the harvester forward speed from 0. 62 mi/hr to 1. 42 mi/hr. The highest fruit detachment percentage 82.65 % is the result of the inter action between the specific forward speed 0. 62 mi/hr and shaking speed 73 in/sec. This maximum percentage was obtained due to the operation at the highest shaking speed for a long enough period of time, which wa s acquired with the lowest forward speed 0. 62 mi/hr. The forward speed 0. 62 mi/hr allowed more time for the machine shakers to shake whole tree canopy sufficiently (8.75 sec/tree) On t he other hand, the minimum fruit detachment percentage ( 69.18 %) resulted from the inter action between the highest forward speed 1. 42 mi/hr and the lowest shaking speed 56.50 in/sec also this percentage

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179 occurred due to the lowest shaking speed operation w ith a shorter period of time Clearly this percentage occurred because t he forward speed 1. 42 mi/hr allow ed less time to shake the whole grapefruit tree canopy (3.88 sec/tree). Statistical analysis showed that, the inter action effect of the harvester f orward speeds and its beaters shaking speeds on the percentage of detachment fruit is considered as a high contributor at the 10 % level of significance. The influence on the grapefruit detachment percentage, of the inter actions between the harvester beaters shaking speed 73 in/sec with the harvester forward speed 0. 62 mi/hr the machine forward speed 0. 62 mi/hr with beaters shaking speed 56 .50 in/sec and the machine forward speed 1.42 mi/hr with beaters shaking speed 73 in/sec were not a statisti cally meaningful on each other when the level of significance was 1 0 % Similarly the influence on the grapefruit detachment percentage, at level of significance 10 %, on the inter actions between the harvester beaters shaking speed 73 in/sec with the har vester forward speed 1.42 mi/hr the machine forward speed 1.42 mi/hr with beaters shaking speed 56 .50 in/sec and the machine forward speed 0.62 mi/hr with beaters shaking speed 56.50 in/sec do n ot have significant differences on each other However, th e inter action influence between the on one side forward speed 0.62 mi/hr on the other side has a meaningful statistical influence on the fruit detachment percentage at the 10 % level of significance.

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180 Table 4 34 The average of the detached fruit ( fruits /tree) Forward S peed of the Harvester ( m i/ h r) Beaters Shaking Speed ( in/sec ) Ave. 56.50 73 0. 62 86 ab 102 a 94 1. 42 70 b 88 a b 79 Ave. 78 95 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Table 4 35 The a verage of the grapef ruit detachment p ercentage (%) Forward S peed o f the Harvester ( m i/ h r) Beaters Shaking Speed ( in/sec ) Ave. 56.50 73 0. 62 77.41 ab 82.65 a 80.03 1. 42 69.18 b 76.79 a b 72.98 Ave. 73.30 79.72 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level.

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181 Effect of the Inter action Positions, and the Machine Forward Speeds on the Field Harvesting The analysis which c an lead to a sound decision about adjusting the harvesting machine operation al variables shaking speed, an d displacement ), comes from the inter action analysis done using the different operating variables. Table 4 36 shows the inter action effect between the three operating variables on the average amount of the detached grapefruit s. It is observe d that the detached fruit quantity ranged between 47 fruits /tree due to the inter action between the highest beaters shaking speed ( 73 in/sec), second machine forward speed (1. 42 mi/hr), and the beaters turn buckle length 12 in ches and the highest detach ed grape fruit average amount 165 fruits /tree was obtained due to the inter action between the initial forward speed 0. 62 mi/hr with the in/sec and the beaters at the default t u rn buckle length Also, as observed from the fi eld data, the lowest amount 47 fruits /t ree may mean that the shaking time available at the highest machine forward speed (3.88 sec/tree) is significantly less than the shaking time at the lowest machine forward speed (8.75 sec/tree) and thus negatively affects fruit detachment. So, the minimum detachment is obtained due to an inadequate shaking time and shaking beaters penetration at turn buckles length 12 in ches while the maximum detachment wa s obtained due to sufficient shaking tim e and shaking beaters penetration at the default turn buckles lengths The statistical analysis revealed that the inter action forward speed 0.62 mi/hr, and the default position of the shaking be aters from one side and all the other harvester operation variables on the other side o n the amount of detached fruits is an arbitrary significant difference at the 10 % level of significance. Secondly, there is a significant effect as a result of the i nteraction forward speed 1.42 mi/hr, and the beaters default lengths of the turn buckle from one side and

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182 all the other harvester operation variables on the other side despite the interactions between the other harvester operation variables which provided the amount of detached fruit s of 103, 95, and 86 fruits /tree respectively, o n the amount of detached fruits, also at a 0.90 confidence level. Thirdly, there is a significant difference between the interaction 56.50 in/sec, machine forward speed 0.62 mi/hr, and the beaters default lengths of turn buckle from one side and the interactions between the other harvester operation variables which provided amount of detached fruits of 165, 59, 60, and 47 fruits /tree respectively, from the other side on the detached fruit s amount at level of significance 10 %. In contrast, there were no significant effects found due to interaction between other operating variables of the citr us harvester on the amount of detached grapefruits at the 10 % level of significance a s shown in Figure 4 1 0 Additionally the scientific decision about the appropriateness of the selected operating variables (two machine forward speeds, two king speeds, and three shaking beaters positions ) of the original prototype of the fruit harvesting machine may be taken from the calculation results of the percentage of the detached grapefruit. Table 4 37 shows the effect of the interaction between the t hree operating variables (machine forward speed, beaters shaking speed, and the harvester beaters position ) on the average amount of fruit detachment percentage. The result of that interaction reveals that the highest percentage of the detached fruit is 93.56 % as a result of interaction between the second beaters shaking speed 73 in/sec, first machine forward speed 0. 62 mi/hr, and the 16 inches turn buckle length This high percentage of detached fruit may have resulted due to the lowest forward speed 0.62 mi/hr which provi d ed a sufficient shaking time to shake the whole tree canopy synchronously w ith an adequate shaking speed 73 in/sec. The second highest percentage of the detached fruit 93.52 % w as a result of inter action

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183 between the second beaters shaking speed 73 in/sec, second machine forward speed 1.42 mi/hr, and the beaters position at 16 inches turn buckle length Th is second high percentage of detached fruit may have resulted from the inter action of the highest shaking speed and more beaters penetration by the 16 inches turn buckle length which provided a deep enough beaters penetration into the grapefruit tree canopy with the adequate shaking speed of 73 in/sec to shake the whole tree canopy regardless of the different shaking time due to the shaker speed Furthermore data demonstrates that the lowest percentage of detached grape fruit is 55.26 % as a result of inter action between the second shaking speed 73 in/sec, second machine forward speed 1. 42 mi/hr, and the 12 inches turn buckle length This lowest percentage of detached fruit s may have resulted due to the maximum machine forward speed which does not provide an enough shaking time (3.88 sec/tree) to shake the whole tree canopy, when associated with the lowest shaking beaters pene tration into the grapefruit canopy (12 inches turn buckle length) As observed from the data that w as obtained at forward speed s of 0. 62 and 1.42 mi/hr and the two beaters positions of 16 inches and default turn buckles lengths by increa sing the beaters shaking speed from 56.50 in/sec to 73 in/sec, the proportion s of detached fruit s increased On the contrary, with the beaters position at 12 inches turn buckle length at both of the harvester forward speeds of 0.62 and 1.42 mi/hr the de tachment percentage of grapefruit decreased from 69.30 % to 64.46 % and 60.24 % to 55.26 % respectively, by increasing the shaking speed from 56.50 in/sec to 73 in/sec. Finally, the high est percentages of the detached grape fruit s were obtained with t he first machine forw ard speed 0.62 mi/hr and the second machine forw ard speed 1.42 mi/hr , and maximum beaters penetration position (16 inches turn buckle length).

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184 Statistically, there are significant differe nces for the inter action effects between the and the inter actions between the other harvester operation variables whi ch provided the percentages of the detached grapefruits of 69.30, 67.14, 64.46, 60.24, and 55.26 % from the other side on the detached fruit percentage at level of significance 10 %. Similarly, the inter action effects between the forward speed 1.42 mi/hr and the inter actions between the other harvester operation variables which provided the percentages of the detached grapefruits of 69.30, 67. 14, 64.46, 60.24, and 55.26 % from the other side on the detached fruit percentage at the 10 % level of significance. Also, there are obvious significant differences for the inter action speed 73 in/sec, and the beaters position at and the inter actions between the other harvester operation variables which provided the percentages of the detached grapefruits of 69.30, 67.14, 64.46, 60.24, and 55.26 % from the other side on the percentage of detached grapefruit at the 10 % level of significance. Also, there are noticeable differences from the effect of the inter action between the forward speed 0. and the forward speed 0.62 mi/hr, at turn buckle length of 12 inches ; the forw ard speed 1.42 mi/hr, shaking speed 56.50 in/sec, and the beaters position at turn buckle length of 12 inches ; and the forward speed 1.42 mi/hr, shaking speed 73 in/sec, and the first beaters at 12 inches turn buckle length all from the other side on the fruit detachment percentage at the 10 % level of significance. Finally, there were no significant effects found by

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185 the other operating variables inter actions on the fruit detachment percentage as shown in Figure 4 11 In conclusion, should be noted that for both harvester forward speeds 0.62 and 1.42 mi/hr, in increasing the beaters penetration into tree canopy from 12 inches to 16 inches at both shaker speeds 56.50 in/sec and 73 in/sec, have favorable inter actions of grapefruit detachment percentage s So, the sound decision from the final test results as shown in Table 4 37, is operating the new prototype of a self propelled over the top citrus harvesting machine using shaking speed 73 in/sec, and beaters position at 1 6 inches turn buckle length, where 93.56 % and 93.52 % maximum grapefruit detachment percentage s were obtained.

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186 Table 4 36 The a verage of the detached f ruit ( fruits / t ree) Turn Buckle Length ( i n) Harvester Forward Speed ( m i/ h r) 0. 62 (Mfd1) 1. 42 (Mfd2) Canopy Shakers Speed ( in/sec ) Canopy Shakers Speed ( in/sec ) 56.50 (Shs1) 73 (Shs2) 56.50 (Shs1) 73 (Shs2) Ave. 12 (Bp1) 69 c de 59 ce 60 ce 47 e 59 Default (Bp2) 103 b d 165 a 70 c de 123 b 115 16 (Bp3) 86 bc e 81 c de 80 c de 95 bc 86 Ave. 86 102 70 88 Shakers Speed 78 95 Harvester Speed 94 79 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Figure 4 1 0 Comparison results for the effect of the inter action between the three operating variables on the amount of the detached grapefruit ( fruits / t ree)

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187 Table 4 37 The a verage of the f ruit beads detachment p ercentage (%) Turn Buckle Length ( i n) Harvester Forward Speed ( m i/ h r) 0. 62 (Mfd1) 1. 42 (Mfd2) Canopy Shakers Speed ( in/sec ) Canopy Shakers Speed ( in/sec ) 56.50 (Shs1) 73 (Shs2) 56.50 (Shs1) 73 (Shs2) Ave. 12 (Bp1) 69.30 bc d 64.46 cd 60.24 ce 55.26 c 62.32 Default (Bp2) 78.32 abde 89.94 a 67.14 bc d 81.58 a d 79.25 16 (Bp3) 84.62 ab 93.56 a 80.17 abde 93.52 a 87.97 Ave. 77.41 82.65 69.18 76.79 Shakers Speed 73.30 79.72 Harvester Speed 80.03 72.98 Averages, which have been followed by the same letter in each row and column, do not have significant differences among them statistically at a 0.90 confidence level. Figure 4 11 Comparison results for the effect of the inter action between the three o perating variables on the grapefruit detachment percentage (%)

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188 Effect of Length of the New Canopy Shakers on the Citrus Harvesting Additional experiments on the final prototype of the citrus harvester were carried out on Jan uary 15, 2014 to investigate t he effect of additional beaters, which were attached to the final shaker design along with the original main beaters on the grape fruit detachment rate These tests were conducted with a beater length longer than the beaters length utilized for the final field experiments (i.e., experiments of the Jan uary 6, 2014). The new beaters ( extra long beaters) were 48 inches long while the previous extra beaters had a length of 30 inches (Figure 4 12 ). The machine operating variables that were used for this test w ere harvester forward speeds of 0. 62 mi/hr as a slow speed and 1. 87 mi/hr as a fast speed, the shakers shaking speed of 63.74 in/sec (the two flow control valves were set on number 3 ) and the be aters penetration was constant at 16 inches for each turn buckle length The shaking results are presented as shown in Table 4 38 Table 4 38 shows the effect s of the forward speeds of the final harvesting machine design (additional final test) on the amount of the grapefruits that were harvested from the frui t tree and the f ruit detachment percentage Practically, it was found that the average amount of detached grapefruit decreased from 89 fruits /tree to 70 fruits /tree and the fruit detachment percentage decreased from 93.29 % to 92.89 % by increasing the harvester forward speed with the extra long beaters Consequently by operating the canopy shaker harvesting machine with either t he harvester forward speed 0. 62 mi/hr ( as a slow speed ) or 1. 87 mi/hr ( as a fast speed ), 63.74 in/sec shak ers shaking speed the beaters penetration at 16 inches turn buckle length, and the extra long beaters yielded an equivalent f ruit detachment percentage as was realized by operating the m achine with either forward speed 0. 62 mi/hr or 1. 4 2 mi/hr 73 in/se c shakers shaking speed beaters penetration at 1 6 inches turn buckle length, and the extra short beaters (93.56 % and 93.52% respectively). B y applying statistical analysis to the field data as shown in Table 4 38 by the small letters, it was found that with 10 % level of significance there is an

PAGE 189

189 obviously significant difference between the influence of the low and high forward speed on the amount of detached grapefruits while there is no significant difference at the 10 % level of significance for the influence of the harvesting machine forward speeds and the length of the new extra beaters on the average percentage of the detached grapefruit s In fact, it is possible to obtain a high er detached grapefruit percentage more than 93.29 % by utilizin g the harvester with forward speed 0. 62 mi/h r, 63.74 in/sec shakers shaking speed and 16 inches turn buckle length The experimental result shown in Table 4 38 ( replicate number 3) has affected the final average of the detached grapefruit percentage due to fact that the tree canopy size (wide and h eight of canopy) was greater than the dimensions of the internal harvesting tunnel of the shaking machine (69 104 inch es ) A lmost all of the tree branches were strong branches that could not be shake n by the shakers, and almost all of the grapefruit remaining in the tree canopy were found at the central top of the canopy and lower part of the grapefruit tree canopy

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190 Figure 4 12 The Final new extra long shaking be aters ). [Photo courtesy of Naji A l Dosary ]

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191 Table 4 38 The a verage s of the detached grape f ruit s ( fruits / t ree) and the grape f ruits detachment p ercentage (%) Shaking S peed (Flow Control No. 3) Replicated T reatments Harvester Forward Speed (mi/hr) Slow 0.62 Fast 1.87 Detached Fruits ( F ruits ) Fruit Detachment Rate ( % ) Detached Fruits ( F ruits ) Fruit Detachment Rate ( % ) High Shaking S peed 6 3. 74 (in/sec) 1 97 98.98 55 98.21 2 75 97.40 66 77.65 3 108 72.97 72 96 4 67 97.10 77 97.47 5 99 100 78 95.12 Ave. 89 a 93.29 a 70 b 92.89 a S.D. 17.36 11.42 9.45 8.60 Averages, which have been followed by the same letter in each two similar columns, do not have significant differences among them statistically at a 0.90 confidence level.

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192 Distribution of Acceleration Magnitude in the Grapefruit Tree Canopy Two experiments of acceleration distribution were conducted on grapefruit trees to evaluate the final prototype citrus harvesting machine with 13 beaters on each shaker unit Fifteen USB accelerometer sensors ( model X16 1C) were placed at various branches locations i n the tree canopy (Ray Ruby grapefruit). The same trees were used as these shaken in the summer harvest of 2013 with sensors at approximately the same locations. The acceleration magnitude data (g) for the X16 1C sensor s were r ecorded at a sample rate of 50 Hz and sample size 30,000 ( counts) The results of the distribution of the acceleration during the shaking were obtained using a constant beaters penetration of 12 inches turn buckle length, 63.74 in/sec, slow machine forward speed tunnel width fixed at 69 inch es Shaking Acceleration Distribution for the Final Design of the Shaking Beaters on One Grapefruit Canop y The results of Table 4 39 show the maximum magnitude of the ac celeration (g) and the average magnitude of each acceleration period (g) that were gained by operating the harvester beaters on one grapefruit tree canopy ( 0.97 mph average of the harvesting machine speed ) where 15 sensors were attached i n the grapefruit tree canopy The distribution of the acceleration upon shaking operation was non uniform with differences in the magnitudes of the acceleration as shown in Figure 4 13 The branches behavior was changed along the tree canopy perimeter (laterally and verti cally). The maximum magnitude average was 15.253 g The maximum magnitude was achieved by the left bea ters squad on the left side of the grapefruit tree while the maximum magnitude recorded by the right bea ters squad on the right side of the grapefruit tr ee was equal to 11.35 g At the top of the tree canopy, the maximum magnitude average wa s recorded between 4.427 g caused by the left bea ters squad and 8.138 g caused by the right bea ters squad. The minimum magnitude average (4.063 g) was recorded at the lower central part

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193 of the canopy near the trunk ( F igure 4 13 ). The acceleration (g) has a higher maximum magnitude (15.253 g) at the left and right side of the tree perimeter ( 40 inches to 65 inches above ground ), than the branches at the central top o f the tree canopy (8.138 g). Generally, comparison results based on the sensors location showed that the acceleration magnitude was substantially higher (average, 9.791 g) at the lower branches on the tree canopy ( up to 40 inches to 65 inches from the gro und ) than the branches at the central top of the tree canopy (average, 6.867 g) or the limbs along the central band of the tree canopy and trunk ( 4.158 g wa s average of sensor s 3 and 15). Also, the average magnitude of the acceleration (g) increased disti nctly when moving from inside the tree canopy to the perimeter of the canopy.

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194 Table 4 39 A p recise average magnitude of the acceleration (g) among the tree canopy branches depending on the delimited accelerometer sensors locations and the final machine operating variable into one tree canopy No. of Accel. Sensor Accelerometer Sensors Locations Branch Dia. a t the Posted Sensor (in) First Trial (12 inches of turn buckle linkage) Into the Tree Canopy From Main Trunk (in) From G round (in) Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) 1 Right central edge, Top Back 20 75 0.93 6.468 1.373 2 Right central edge, Top Front 16 75 0.85 7.933 1.373 3 Central trunk, Down 6 32 2.50 4.063 1.154 4 Left edge, Top Back 36 58 0.90 11.661 2.002 5 Back edge, Right 31 50 0.75 6.211 1.532 6 Central edge, Top, Left, Back 16 62 1.42 4.636 1.209 7 Left edge, Front 22 41 0.65 13.344 2.183 8 Central edge, Top, Left, Front 8 72 0.73 7.369 1.461 9 Central edge, Top, Left, Back 30 75 0.93 4.427 1.294 10 Right edge, Front 31 40 0.95 11.35 1.744 11 Right central edge, Front, Top 37 72 0.87 8.138 1.715 12 Left edge Back 33 43 0.78 15.253 2.440 13 Left edge, Top 15 58 0. 70 6.088 1.411 14 Left edge, Front 24 36 0.92 10.01 1.624 15 Central edge, Back, Down, Rear of the main trunk 20 27 0.90 4.252 1.222 Ave. (g) 8.08 0 1.582 S.D. (g) 3.537 0.376

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195 Figure 4 13 Acceleration magnitude distributions int o one grapefruit tree canopy by the highest beaters shaking speed (front view) [Photo courtesy of Naji A l Dosary ] Normalized acceleration (g/max.g)

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196 Acceleration Distribution by the Final Design of the Shaking Beaters into Three Harvested Grapefruit Canopies For this experiment, 1 5 USB accelerometer sensors (model X16 1C) were placed on various branches at different locations on three random tree canopies (Ray Ruby grapefruit), where 5 sensors were attached to each individual tree canopy. The results of the acceleration magnitude d istribution i n the tree canopies were obtained by various shaking speeds of the referenced in Table 4 40 The results of Table 4 40 show the average maximum magnitude of the acceleration (g) and the average magnitude of each acceler ation period (g) that were achieved by operating the shaking beaters o n three different grapefruit canopies ( 0.85 mph of machine forward speed, 12 inch es turns buckles length beaters shaking speed of 6 3. 74 in/sec ) The distribution s of acceleration upon shaking the tree s canop ies were uneven as shown by the diversity in the magnitudes of the acceleration (g) in Figure 4 14 As was observed, the tree branch behavior changed along each tree canopy perimeter (laterally and vertically). The maximum average of the acceleration mag nitude was 14.09 g, which wa s obtained at the left side of the tree perimeter using the left shakers and the minimum magnitude average was 6.27 g at the right side of the tree perimeter using t he right shakers. At the top of the tr ee canopy (more than 52 inch es above the ground), averages of the maximum magnitude were recorded between 6.270 g and 10.34 g The averages of the maximum magnitude at the lower tree canopy that is less than 52 inches from the ground were recorded betwee n the values of 7.152 g and 14.09 g. Also the maximum acceleration magnitude is increased from the center of the tree canopy (average of 6.928 g) to the grapefruit tree perimeter (average of 9.80 g) The lowest sensor on the grapefruit canopy (sensor numb er 3, 15 inch es rear of the main trunk ) showed 7.544 g as the maximum magnitude while the highest sensor (sensor number 7) on the top of the tree canopy showed 6.367 g maximum acceleration magnitude In general, as shown in

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197 Figure s 4 14 the comparison re sults depending on the sensors location s showed that the shaking beaters acceleration magnitude was substantially higher at the lower branches on the tree canopy ( 55 inches from the ground and less ) than the branches on the central top of the tree canopy or the limbs on central band of the tree canopy (sensor 3). At the lateral branches ( height of 4 0 inch es and more from the ground ), the left side of the tree canopy ha d more acceleration magnitude (Ave. of 9.366 g) than the right side (Ave. of 8.249 g) Finally, from the two field experiments of the shaking acceleration effect, t he differences in the acceleration magnitude distribution from the left and right shakers may have occurred due to a pair of variables: the misa djustment of the two flow control valves causing the two operated crank shafts to lack the same rotational speed or the not maintaining center of the machine harvesting track ( the main trunk of the grapefruit tree was not centered). Statistically, the total averages of the maximum acceleration magnitude that are shown in the Tables 4 39 and 4 40 confirmed that there was no significant difference at the 10 % level of significance for the influence of the shaking trials, ( one tree canopy or various grapefruit trees canopies at a high ) on the average amount of the acceleration magnitude of the tree branches

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198 Table 4 40 A p recise average magnitude of the acceleration (g) among the tree canopy branches depending on the delimited accelerometer sensors locations and the final machine operating variables at three different tree canopies. No. of Trees No. of Accel. Sensors Accelerometer Sensors Locations Branch Dia. at the Posted Sensor (in) First Trial (12 inches of turn buckle linkage) Into the Tree Canopy From Main Trunk (in) From G round (in) Ave. of the Max. Accel. Mag. (g) Ave. Accel. at each Shaking Period (g) 1 1 Left edge, Front 36 43 0.83 13.08 2.278 2 Central edge, Left, Top 6 70 0.60 7.114 1.609 3 Central edge, Back, Down 15 29 0.91 7.544 1.358 4 Right edge, Down 16 34 1.41 7.152 1.708 5 Central edge, Right, Top, Back 12 53 0.65 7.297 1.501 2 6 Left edge, Back 32 47 1.00 14.09 2.414 7 Central edge, Left, Top 3 75 0.95 6.367 1.666 8 Right edge, Top, Back 20 62 0.63 10.34 1.819 9 Right edge, Top, Back 25 53 0.75 8.932 1.752 10 Right edge, Front 17 52 0.58 6.270 1.342 3 11 Left edge 20 47 0.81 9.003 1.752 12 Central edge, Left, Front 15 54 0.75 6.308 1.517 13 Left edge, Back 24 40 0.87 9.603 1.782 14 Right edge 16 40 0.86 9.718 2.051 15 Central edge, Right, Top 8 65 1.20 6.938 1.679 Ave. (g) 8.651 1.749 S.D. (g) 2.647 0.307

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199 Figure 4 14 Acceleration magnitude distribution int o three diverse grapefruit trees canopies by the highest beaters shaking speed (front view) [Photo courtesy of Naji A l Dosary ] Normalized acceleration (g/max.g)

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200 CHAPTER 5 C OMPARISON RESULTS DEPENDING ON THE IMPROVEMENT OF THE SHAKING SHAKERS DESIGN The shaker design of the citrus canopy shaking machine was improved from the original 7 beaters per shaking unit to 13 beaters per shaking unit in the fall of 2013 (Figures B 6 and B 7) It was felt that increasing the number of beaters would have a significant effect on the e fficiency of the h arvester m achine where the more beaters penetrati ng into the tree canopy, the more engagement with the tree branches and fruit This turned out to be a significant improvement in fruit detachment efficiency. Effect of the Harvesting Machine Forward Speed on the Field Harvesting Figure 5 1 shows effect s of the forward speed of the two canopy shaker design s on the average percentage of the detached grapefruit F rom the two field trials at low forward speed it was found that increasin g the beaters number will increase the detached grapefruit percentage from 29.54 % to 80.03 %. Also, using the highest forward speed showed that, by decreasing the beaters number the detached grapefruit percentage will be decreased from 72.98 % to 18.71 % So, the modification of increasing the number of beaters from 14 beaters to 26 beaters with altered beater material, increased the a verage percentage of f ruits detachment from 24.13 % to 76.51 %. In general, the two shaker unit designs showed similar resu l ts that by increasing t he harvester forward speed, the detached grapefruit percentage will be decreased Statistical ly, it was found that with 10 % level of significance there is an obviously significant difference between the influen ces of the the harvesting machine forward speeds on the percentage of the detached grapefruits

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201 Figure 5 1 Effect of the changing in the shakers design with the shaking machine speed on the grapefruit detachment percentage. Effect of the Beaters and Tree Canopy Engagement on the Field Harvesting The effect of varying position either by changing the turn buckle length or by changing the harvester tunnel width is showing in Figure 5 2. Figure 5 2 shows that for the preliminary shaker s design, the percentage of grapefruit detachment is increased from 23.64 % to 27.31 % by increasi ng the beater s penetration into the grapefruit tree canopy T he final shakers modification reveals that increasing the beater s penetration into the grapefruit tree canopy increased the grapefruit detachment percentage from 62.32 % to 87.97 %. In addition by increasing the beater s penetration into the tree canopy, the final shakers design gave higher grapefruit detachment percentage (76.51 %) than the preliminary shaker design (25.48 %). In general, incre asing t penetration into the grapefruit tree canopy, the detached grapefruit percentage will increase. According to the statistical analysis at the 10 % level of significance, it was found that there is a Harvester Speed Grapefruit Detachment Percentage ( % ) 24.13 76.51 72.98 18.71 80.03 29.54

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202 visible significant differenc e of the final shakers modification on the fruits detachment percentage (%). Figure 5 2. Effect of the changing in the shakers design with the shaking beaters position on the grapefruit detachment percentage. In terms of the beater speed influence, Figure 5 3 displays the influence of the two machine beater s design ( 14 beaters and 26 beaters ) on the average grape fruits detachment percentage By increasing the beaters shaking speed ( with the first design ) the fruits detachment percentage is increased from 17.90 % to 35.77 % and similarly the final shakers design provides fruit detachment percentage between 73.30 % and 79.72 % when the shaking speed increased. Also, at all shaking speeds, by increasing number of beater s from 1 4 to 26 beaters, the average grape fruit detachment percentage increased from 26.62 % to 76.51 % respectively. Generally, w hen the beaters shaking speed is increased from low speed to high shaking speed Grapefruit Detachment Percentage ( % ) First Second Third Average Shaking Beaters Position 2 5.48 76.51 87.97 27.31 79.25 23.64 62.32

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203 the average amount of the grapefruit detachment percentage is increased as the final and initial shakers design had agreed. From the statistical analysis at the 10 % level of significance it was found that there is a significant difference between the influences of the two shaker designs in terms of t he average amount of grape fruit s detachment. Figure 5 3 Effect of the changing in the shakers design with the shaking speed on the grapefruit detachment percentage. Effect of the Machine Beaters Number on the Citrus Canopy Shaker Harvesting Machine Efficiency Obviously, Figure 5 4 shows that the highest fruit detachment percentage (by individual tr ee) was achieved by increasing the number of the shaking beaters. The maximum average of fruit detachment percentage using the preliminary design of the shaker (14 beaters) was 41.58 %, while the final shaker design (26 beaters) provide d a maximum average fruit detachment percentage of 93.56 % During the preliminary shaker design operation, t he two highest Beaters Shaking Speed Grapefruit Detachment Percentage ( % ) 2 6 62 76.51 35.77 79.72 26.20 73.30 17.90

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204 detachment percentages were obtained by the lowest machine forward speed with different beater shaking speed s however, using the final shaker design, the two highest fruit detachment percentages were obtained with the same beaters shaking speed but via both the lowest and highest harvester forward speeds. Finally, from the statistical analysis it was found clearly that there is a significant differen ce due to effect of the 14 beaters of the initial harvester design and the 26 beaters of the final harvester design on the citrus canopy shaker harvesting machine efficiency at the level of confidence 90 %. Figure 5 4 Final e ffect of the changing in the shaker design on the grapefruit detachment percentage (the highest and second highest detachment percentage) Grapefruit Detachment Percentage ( % ) Highest Efficiency of the Harvester Machine 93.52 93.56 38.05 41.58

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205 Acceleration Magnitude Distribution on the Grapefruit Tree Canopy by the Two Shaker Design s C omparison results were taken from an experiment using the 15 USB accelerometer sensors that were attached on various branches on three grapefruit tree s canopies, with 5 sensors mounted on diverse branches o n each canopy. The results of the acceleration magnitude distribution on the tree canopies were obtained by operati ng the shaking beaters at high shaking speed ( 65.90 in/sec for preliminary design and 6 3 .74 in/se c for final design ) penetration into random three grapefruit trees canopies were determined by 12 inches length of the turn buckles for the beaters and 69 inches of internal tunnel width for the harvester machine Figure 5 5 shows that the highest accel eration magnitude ( 14.09 g ) was obtained by the final shaker design using 26 beaters while in contrast, the initial design of the canopy shaker with 14 beaters provided 8.00 g as a maximum magnitude value Also, the minimum value of the acceleration mag nitude by the final design (6.27 g) was still substantially more than the minimum acceleration magnitude that was obtained by the initial shaker design (1.93 g). Evidently, by increasing the number of shakers on each canopy shaker unit from 14 beaters to 2 6 beaters the average of the acceleration magnitude increase d from 5.04 g to 8.65 g as shown in Figure 5 5 Statistically, the small letters in Figure 5 5 confirm that there is an obvious significant difference at the 10 % level of significance between the influence of the initial and final canopy shaker design on the average of the maximum acceleration magnitude on the grapefruit tree branches and thus more effective shaking of grapefruit tree canopies will result

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206 Figure 5 5 An acceleration magnitude result on the grapefruit tree canopy by operating the two shaker models with a high beater shaking speed. Acceleration Magnitude (g) Acceleration Magnitude 5.044 8.651 8.00 14.09 1.93 6 .27

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207 CHAPTER 6 ECONOMIC ANALYSIS OF THE NEW CANOPY SHAKER MACHINE The Economic Performance A preliminary analysis of the economic influence of the citrus harvesting m achine performance and the resulting harvesting efficiency were used to estimate the effect on citrus fruit harvesting cost previously show n in Table 3 5 The outputs of Table 3 5 show several economic variables of the harvester operations, which may affect the result of the har vesting cost s For the economic calculation in this study, some potential econ omic impacts from the operation of the new citrus harvester were estimated hypothetically such as : the citrus harvester capacity, yearly operated hours, the harvester life, the yearly harvested area, and the harvester purchase price and maintenance. So, by operating th e new harvester prototype for citrus harvesting the harvester cost will be decreased significantly by increas ing either the harvester efficiency or the fruit recovery rate. Therefore, by applying the recommended operation variables (i.e., h arvester forward speed s 1.42 or 0.62 mi/hr, and the default harvesting width 69 inch es ) and 94 % of the fruit detachment percentage which would be obtained by operating the final citrus tree canopy shaker design with an attached catch frame ( effectively deliver ing almost 100 % of the detached fruit to the accompanying trailer ) to the equation 3 3 3 the total cost of this h arvester operation as shown by the results in Table 3 5 was estimated as 152.3 8 $/hr for the final canopy shaker design To emphasize th e result of equation 3 3 3 Table 6 1 disp lays the anticipated harvesting c ost of the mechanical harvester and two trucks per hour by applying the coefficients in Table 3 5 to determine the e stimated costs of the new mechanical harvester and trucks (i.e., ownership (fixed) and operating costs (variable) ) So, from Table s 6 1 the total cost of the new citrus harvest ing concept is calculated as 1 51.1 7 $/hr as well as the labor cost is 1.66

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208 $/box The field efficiency which includes the exact harvesti ng time, and the time that lo st during the harvester adjustment and movement between orchard lines is estimated to be 70 %. Th rough the operation al development of building a new more efficient citrus harvester, mechanical harvesting h as the further eco nomic advantage of higher produc tivity. T he new prototype of citrus canopy shaker operated at either low or high forward speed was estimate d to harvest approximately 36 6 to 800 boxes per hour respectively This estimate applies with 70 % field efficiency and 94 % fruit recovery via an attached catch frame which will deliver almost 100 % of the detached fruit to an accompanying truck as shown in Table 6 2 Also, the new prototype of citrus canopy shaker was estimate d to shake and harvest, when o perated at t he recommended operating settings, between 293 and 641 trees per hour when the field efficiency is 70 % So this new design as well as other mechanical harvesters will decrease the field labor cost and intensity impact. The innovative canopy shaker is expect ed to harvest between 1. 47 and 3 29 acres per an hour with one harvester operator and two truck operators resulting in a harvest cost of 151.1 7 $/hr Also, from Table 6 3, the total grapefruit mechanical harvesting cost by the new mechanical shaker is expected to range between 260.64 and 340.28 $/acre with the machine recovery 94 % and 70 % field efficiency S ubsequently if the harvest rate is 238 box/acre, 94 % fruit recovery, and 70 % field efficiency applies, the predictable co st of each grapefruit box will be between 0. 72 and 0. 94 $/box while the grapefruit manual harvesting cost is 1.66 $/box. Accordingly, grapefruit yield harvested by the new mechanical harvester (366 800 box/hr) was found to be between 3 6 and 80 times great er than the productivity of manual harvest ing (8 1 0 box/hr Futch et al., 2005 ) This result is consistent with the reduce d cost of citrus f ruit harvest by more than 50 %, which has referred by Brown, 2005. Also, as the mechanical harvesting can improve the labor productivity from 8 to 10 box/hr to more than 30 box/hr (Futch et al., 2005),

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209 the entire harvesting time by mechanical harvesting seems to be decreased to as little as one third (1/3) of the manual harvesting time Also, from Table 6 3, the total mechanical harvesting cost for each orange box, by the new mechanical canopy shaker is expected to be between 0.55 and 0.73 $/box, if the harvest rate is 49 4 box/acre, when the orange recovery is 94 % and 70 % field efficiency, while the manual harvestin g cost is estimated as 1.99 $/box. In general, continuing with t he machine improvement may present a desired result of decreasing the mechanical harvesting cost. Table 6 1. Estimated costs of the ownership (fixed) and operation (variable) Hourly Costs of the Mechanical Harvester with two trucks Classification Cost Fruit detachment rate by the machine (%) 94.00 Grapefruit f ield yield of the season 2013 2014 (box/acre) 362 Ownership price ($) 250,000.00 Life expectancy (years) 10.00 Yearly operation hours (hr/year) 873 Salvage value ($) 20,000.00 Fixed costs Depreciation ($/hr) 26.35 Interest ($/hr) 10.54 Tax ($/hr) 17.90 Insurance ($/hr) (i.e., 0.25% of purchase price/873) 0.72 Total relevant fixed ownership cost ($/hr) 55.51 Variable cost Fuel expense ($/hr) 2.41 Lubrication ($/hr) 0.98 Maintenance ($/hr) 57.27 Harvester operator wage ($/hr) Truck operator wage ($/hr) 15 10 2 Total relevant variable cost ($/hr) 95.66 Total expense of the new mechanical harvester ($/hr) 151.17

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210 Table 6 2 Estimated the unit costs ($/box) of the new mechanical harvester Classification Expected Cost Grapefruit Orange Harvester cost ($/hr) 151.17 Fruit recovery (%) 94.00 Field efficiency (%) 70.00 Predicted number of trees in intended orchard (trees/acre) 272 375 New mechanical harvester performance F ield yield (box/acre) 362 750 Average productivity of the grapefruit orchard (fruits/tree) 113 F ield yield (box/ tree) 1.33 2 If the field efficiency 100 (%) Harvester low speed (trees/hr) 418 Harvester high speed (trees/hr) 915 Harvester low speed (box/hr) 556 747 Harvester high speed (box/hr) 1216 1712 Harvester low speed (acre/hr) 1.47 Harvester high speed (acre/hr) 3.29 If the field efficiency 70 (%) and 94 (%) fruit recovery Harvester low speed (box/hr) 366 491 Harvester high speed (box/hr) 800 1126 Expected cost to repair grove included repairing of the irrigation system, tree pruning and skirting ($/acre) 80 0 0 1 Harvest cost ($/box) By harvester low speed (0.62 mi/hr) By harvester high speed (1.42 mi/hr) 0.41 0.19 0.31 0.13 Orchard service cost ($/box) 0.22 0.11 Table 6 3 C omparison of harvest cost: new mechanical harves ter versus manual harvesting. Method Expected Cost ($/box) Grapefruit Orange The New Mechanical H arvester with Fruit Recovery 94 % and Efficiency 70 % Harvester cost By harvester low speed 0.41 0.31 By harvester high speed 0.19 0.13 Orchard repairing cost 0.22 0.11 6 % fruit gleaning with roadsiding charge 0.21 0.21 Debris cost 0.10 2 0.10 2 Total mechanical harvesting cost 0.72 0.94 0.55 0.73 The Hand Harvesting when Fruit Recovery 100 (%) Fruit picking 0.71 3 1.008 3 Fruit roadsiding 0.95 3 0.989 3 Total manual harvest cost 1.66 1.997 1 Roka et al., 2009; 2 Roka, 2010; and 3 Muraro, 2012.

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211 Observations of the Grapefruit Orchard Damages Grapefruit Orchard Damage s by the Preliminary Canopy Shaker Design The h s which deliver the shaking motion to the tree canopy, is the major source of canopies damages (Figure 6 1 was essential to the efficiency of fruit harvesting. The beaters design (i.e., 7 round metal pipes and flexible PVC pipes on each shaker unit as shown in Figure 6 2 ) helped to minimize the tree canopy da mages The rounded design allowed the trees branches to slip up or down when the branches and beaters coll ide. H owever branch splits have occurred as a result of entanglement of inflexible branches in the lower canopies, especially branches with crotch angles (Figure 6 3 ). Also, the tree canopies with non uniform (non concentric) shapes were another source of branch damages where split branch es occurred on one side of the canopies at each trial So, as the trunks of the grapefruit tree s were inclined toward one side more than the other the canop ies were extended farther horizontally on on e side than the other As a result, the operator could not take the main trunk of the grapefruit tree as the center of the harvesting direction which resulted in injuries to the trees branches by the canopy shaking machine. Generally, canopy shak ing cause d many leaves to drop off the tree yet without excessive tree defoliation especially during longer duration s of sha king time D uring the harvesting trials some leaves were dropped as seen in Figure 6 4 Also as observed, the main tree trunks were unaffected by the shaking beaters so there were no visible injuries to t hem and not many grapefruits near the trunk had fallen Also, despite these issues, after harvesting trials by the preliminary machine design (pre test trials) were completed, the grapefruit trees seem to be in perfect health (Figure 6 5 ). Thus, this result will help to reduce the required field mainten ance cost.

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212 Figure 6 1 The preliminary citrus harvesting machin e during its operation [Photo courtesy of Naji A l Dosary ] Figure 6 2 The preliminary the green part is a solid round steel pipe and the gray part is a flexible round PVC pipe ). [Photo courtesy of Naji A l Dosary ]

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213 Figure 6 3 Some injured branches due to the shaking beaters treatment. [Photo s courtesy of Naji A l Dosary ] Figure 6 4 Tree defoliation due to the shaking beaters treatment s on May 2013 [Photo courtesy of Naji A l Dosary ]

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214 Figure 6 5 Grapefruit trees after the May 2013 harvesting trials seem to be in good health [Photo courtesy of Naji A l Dosary ]

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215 Grapefruit Orchard Damage s by the Final Canopy Shaker Design Additional d evelopment of the citrus harvesting machine included attaching extra beaters (30 inches of a flexible 1 inch (OD) UHMW polyethy lene white pipe) to the main beaters (25 inches of curved steel pipe and 30 inches of a flexible 1 inch (OD) UHMW pol yethylene white pipe) on the two shakers system s of the preliminary shaker design The result was the h shaking beater s deliver ed more shaking acceleration to the tree canopy So the consequence of operating the 26 beaters of the final design at a fixed tunnel width of 69 inches may have been the main cause of the canopies branch damages as shown in Figure 6 6 Furthermore, the main beaters design (i.e., curved metal pipes with attached UHMW polyethylene white pipes shown in Figure 6 7 ) could hav e help ed minimize the tree canopy damages However as stated previously, some grapefruit canop y splits occurred due to some inflexible branches in the lower tree canop y as shown in Figure 6 8 The first beater at the bottom of each shaker unit is 28 inche s above the ground exactly where the strong lower branches of the trees canopies (almost 2.50 inches of diameter) were located So as observed, the trees trunks were unaffected by the shaking beaters but two trees out of the total trees tested with the improved harvester ha d trunks broken at the base as shown in Figure 6 8 The se b reak s may have occurred because the main trunk of each tree was divided laterally in to two strong crotches that could not avoid the strong beating by the lowest shaking beater Another possible cause for the broken trunks may have been the impacted the right trunk crotch when operator unintentionally missed the main trunk alignment with the cen tral track of the harvester This incident could have been resolved if a catch frame had been attached underneath the harvester centering main trunk on the main track. According to the harvesting results 2 7 tree s out of 70 treated trees had a broken crotch branch (large branch) on at least one side of the tree canopy T he broken branches diameters ranged between 0.65 and 2 15

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216 inches T he broken branches concentrated inside the trees canopies between 26 and 58 inches above the ground. Addi tionally, 16 trees out of the 70 treated trees had at least one small sub branch broken at one side of the tree canopy or both side s (Figure 6 9 ). Rarely, s ome tree branches received bark damage (Figure 6 1 0 ). Furthermore as previously described, canopy shakers can cause many leaves to drop off the tree without excessive tree defoliation especially during longer duration shaking time s, so during the harvesting trials some leaves ha d been dropped as shown in Figure 6 1 1 and some grapefruits had dropped with their stems (Figure 6 1 2 ). Also, after harvesting trials were completed, the irrigation system in the field seems to have been unaffected by the shaker machine (Figure 6 1 3 ) This result will also help to reduce the required fiel d maintenance cost O bviously, the d amages to tree branches and trunks of t h e non uniform canopies and crotches splitting can be resolved by proper utilization of the hydraulic system to control the machine internal tunnel width and the resulting shaking beaters penetration into the tree canopy as well as establishing a new load level and body suspension system that will be developed for the shaking be aters vertical height mechanism. Finally t o showcase the operation and the optimal p erformance of the prototype of an inno vative, self propelled over the top citrus harvesting machine using canopy shakers the Object 6 1 show s the video of the canopy shaking machine in grapefruit orchard during the season of 2013 14 harvest trials, while the video in Object 6 2 shows the harmonization of the shaking speed of the harvester's beater design. Object 6 1. Video of innovative citrus canopy shaker per formance (.mp4 file 10.4MB) Object 6

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217 Figure 6 6 The final citrus harvesting machin e during its field operation in the winter of 2014. [Photo courtesy of Naji A l Dosary ] Figure 6 7 The Final the gray part is the flexible UHMW polyethylene white pipe at the default position ). [Photos courtesy of Naji A l Dosary ]

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218 Figure 6 8 Broken trees occurred unintentional ly due to moving the shaking machine in a zigzag where trunks ha d beaten by the lowest shaking beater. [Photos courtesy of Naji Al Dosary] Figure 6 9 Some injured branches due to treatment of the new shaking beaters. [Photos courtesy of Naji A l Dosary ]

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219 Figure 6 1 0 Bark damage occurred on some branches due to treatment of the new shaking beaters. [Photo courtesy of Naji A l Dosary ] Figure 6 1 1 Tree defoliation due to January 2014 treatment s of the improved shaking beaters. [Photo courtesy of Naji A l Dosary ]

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220 Figure 6 1 2 Some grapefruits with their stems due to treatment of the new shaking beaters. [Photo courtesy of Naji A l Dosary ] Figure 6 1 3 Grapefruit trees irrigation system a fter the harvesting trials. [Photo courtesy of Naji A l Dosary ]

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221 The Harvesting Process M ay H a ve Been Affected by the Field Conditions As has been observed from the field experiments with the two machine shakers design s there are many reasons for the disparity of results of either the detachment percentage of the harvested fruit or shaking distribution of the harvester beaters on tree canopies It may have occurred due to the mis adjustment of the flow control valve between both harvester units (two operated crank shafts) resulting in different rotational speed s of the beaters the accuracy of the harvester operator in maintaining the center of the machine harvesting track with the main trunk of the grapefruit tree or due to the grapefruit tree shape which may not have had a concentric and homogenous vegetation canopy Homogenous canopy was defined as those trees that ha d been trimmed and skirted to clear trunk and lower branches to 24 to 30 inches (height of the grapefruit canopy off the ground ) but in practice, some sides were 1 5 to 4 0 inches (Figure s 6 1 4 and 6 1 5 ) However, as shown in Figure 6 1 6 some trees had their trunks distorted and inclined toward one side more than the other side thus the grapefruit canop ies were extended horizontally to on e side more than the other side. T ree canopy pruning may have also affect ed grapefruit detachment per centages The canopy pruning was completed before harvesting time. Pruning underneath the tree canopy resulted to the grapefruits dangled down close to the ground (the lowest beaters were 25 inches above ground for the preliminary design and 28 inches for the final design test ) Thus almost all of th os e grapefruits close to the ground were out of the shaking beaters range as shown in Figure s 6 1 7 and 6 18 Also, variability in average yield per grapefruit tree (78 fruit s per tree for the preliminary harves ter test and 113 fruit s per tree for the final test ) may have been the main reason affecting the total grape fruit detachment rate Finally, in terms of the observed injur ies to the grapefruit trees, splits have occurred to some canopy branches as a resu lt of the branches entanglement with the harvester beaters and

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222 operating the two machine designs on the internal harvesting width of 69 inches. In other words, this injury (split s ) occurred due to the engagement of the solid part (metal) of the shaking b eaters with the branches underneath the grapefruit canopies especially the branches with large woody crotch angles. Figure 6 1 4 Uniform g rapefruit tree canopy involved by the harvesting machine tunnel of the final design [Photos courtesy of Naji A l Dosary ]

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223 Figure 6 1 5 Heterogeneous g rapefruit tree canopy forced by the internal tunnel of the final shaking machine design [Photos courtesy of Naji A l Dosary ] Figure 6 1 6 Some misshapen grapefruit trunks [Photo s courtesy of Naji A l Dosary ]

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224 Figure 6 1 7 Grapefruits hanging down close to the ground due to the tree canopies pruning of summer 2013 [Photo s courtesy of Naji A l Dosary ] Figure 6 18 Grapefruits hanging down close to the ground due to the tree canopies pruning of winter 2014 [Photos courtesy of Naji A l Dosary ]

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225 Future Studies of the New Representative Citrus Canopy Shaker Modification Th e citrus harvesting concept that wa s used in this research employ ed two shaking beaters units (one each on the left and right side of the machine) to reap the citrus fruit from tree canopy Movement is transferred to the shaking beaters through the use of the crank shaft, where the rotational motion is translated to lin ear motion by the turn buckles which then transfers the motion to the harvester beaters. The new prototype of citrus harvesting machine consists of two main systems: the machine hydraulic system and the shaking beaters The machine hydraulic system also consists of four main hydraulic circuits: transmission to drive t he harvester wheels, retracting and extending of the internal tunnel width o f the harves ter, steering system, and the shaking beaters speed hydraulic system In addition, the tree canopy sha king system ha d a pair of 7 shaking beaters and a pair of 6 additional beaters on each side which received their movement from the crank shaft. Accordingly further development that can be done to improve t he harvesting efficiency of the new canopy shaker design is indicated in the following practical points: 1 Investigate the operator safety during the machine field operations is inevitable. 2 Establishing new load level and body suspension system s where the two flange bearings of each beaters pivot shaft (beaters holder) are fixed on the machine body to obtain better penetration of the m echanical removal unit s ( harvester beaters) into citrus tree canopy and to shake the adjacent fruit that may be hanging by stems underneath the canopy This can be accomplished by b uild ing a new flexible frame with its hydraulic system to hold only the mechanical removal units ( the shaking beaters) or build ing a new suspension system on each wheel frame to manage the height of the citrus harvester from the ground which will ass ist in i ncreas ing the beaters penetration without retract ing or expand ing the entire machine body 3 Modify ing the beaters to be strong enough to avoid the fatigue, which may have been the result of employing the PVC pipe or the UHMW polyethylene white pipe or adding more extra beaters on each beaters holder shaft to increase shaking that should be transferred to the citrus tree canop ies Also, the short sleeve rod that was us ed to join the solid part and the PVC pipe or the UHMW polyethylene pipe of the shaking beaters to the metal beaters part should be taken in to consideration. Also, proper shielding to cover the two shaft units and employ ing proper eccentric shaft s instead of the used

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226 crank shaft s on the machine may p rovide a smooth er beaters shaking speed with more safety to the harvester handlers. Each eccentric shaft h as an eccentric bearing (e.g., two eccentric beari ngs) attached to the drive shaft (motor shaft) instead of having the cranks at equal distances which may have cause d to the harvester beaters to vibrate when it spins ( i.e., a rotary shaft with an eccentric bearings) 4 Retest the prototype of harvesting machine after the new amendments to assess the optimal performance under the citrus field con ditions or by operating this new prototype with a chem ical application e specially the citrus abscission agent CMNP obviously enhanced. In addition as a following phase, by attaching a new ca tch frame with conveyor belt s to this new citrus canopy shaker, the har vesting time will be maintained

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227 CHAPTER 7 CONCLUSION In this research study, the effectiveness of a new prototype citrus harvesting machine which shakes trees by surrounding the tree canopies with two shaking units wa s studied on high density dwarf trees c onditions. Operationally, the harvester beaters were thrust into the tree canopies Th ree sets of operating variables were studied: two different beaters shaking speeds, three various positions of the machine and two forward speeds of the canopy shaker machine for the final performance test Experiments were carried out on a field of grapefruit at the Plant Science Research and Education Center in Citra (PSREC), which is located 20 miles southeast of the city of Gainesville Florida. The harvesting times were May and June 2013 the fruit of season 2012 2013, for the prete st of the preliminary design, and the harvesting time for the final design experiments was January 6 th and 15 th of 2014 during the fruit of season 2013 2014. The fruit under this study were the variety Ray Ruby grapefruits. Also, the average yield of the g rapefruit field during the 2012 2013 season w as 55,14 3 fruits /h ectare (78 fruits /tree) while the 2013 2014 season yielded 76,020 fruits/hectare (113 fruits/tree). The results of testing the two prototype s of the canopy shaker machine on citrus tree harves ting are listed in the following sections. The e ffect of the varying the forward speed s on the harvester field performance was shown by different fruit harvest yields. By increasing the harvester forward speed, the average per centage of detached grapefru its decreased from 29.54 % to 18.71 % with the preliminary design and from 80.03 % to 72.98 % with the final design. I ncreasing the harvester forwar d speed reduced the required canopy shaking time Operating at higher forward speed, the preliminary design averaged 4.30 sec/tree and the final design averaged 3.88 sec/tree. Operating

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228 at the machines lower speed increased total shaking time for the preliminary design to an average 6.49 sec/tree, and final design shaking time also increased to 8.75 sec/tree For the e ffect of the internal harvesting tunnel width and the shaking beaters penetrations on the harvester field performance, increasing the swath width of the preliminary design from the default width 69 inch es to 75 inch es leads to a decrease in the pe rcentage of fruits detachment from 27.31 % to 23.64 % The reason for that decrease may be that the machine is working at swath width greater than the lateral width of the trees canop y, or the operating width did not provide enough penetration depth for the machine beaters, which in turn decrease d the amount of detached fruits. By increasing the turn buckle length on the final design machine, the grapefruit detachment percentage increased from 62.32 % to 87.97 %. The reason for that increase may have b een that the machine was operating with greater penetration of the shaking beaters into the grapefruit tree canopies. The e ffect of the beaters shaking speed on the field performance of the two canopy shaking machine designs showed that with an incr ease in the harvester shaking speed increased performance. With the preliminary shakers design, an increase in shaking speed from 40 to 73 in/sec resulted in an increase in detached grapefruit from 17.90 % to 35.77 %. In the final design, with an increas e in shaking speed from 56.50 to 73 in/sec, the percentage of the grapefruit detachment increased from 73.30 % to 79.72 % In general, as it was calculated, the maximum percent age of the detached grapefruits when operating the preliminary shakers design w as 58.06 % as a result of interaction between the first beaters shaking speed of 40 in/sec, first machine forward speed of 0.90 mi/hr, and first harvesting tunnel width of 69 i nches O perating the final shakers design with different parameters, resulted in several 100 % detached grapefruit s harvests. On the other hand, the

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229 highest average of detached grapefruit by the preliminary citrus canopy shaker design was 41.58 % as a result of interaction between the third beaters shaking speed of 73 in/sec, firs t machine forward sp tunnel width of 75 in ches Moreover, the highest average grapefruit detachment percentage by the final citrus canopy shaker design were 93.52 %, as a result of interaction between the beaters shaking speed of 73 in/sec, high machine forward sp eed of 1.42 mi/hr, and beaters position at turn buckle length of 16 inches; and 93.56 %, as a result of interaction between the beaters shaking speed of 73 in/sec, machine forward sp eed of 0.62 mi/hr, an d beater turn buckle length of 16 inches. Also, operating the final design with the extra long beaters provided grapefruit detachment percentage equal to 93.29 %, as a result of interaction between the beaters shaking speed of 63.74 in/sec machine forwar d sp eed of 0.62 mi/hr, and beaters position at turn buckle length of 16 inches. As observed from the preliminary harvester design performance the distribution of the shaking vibrations i n the tree canopy was uneven with large diversity in the magnitu des of the acceleration. So depending on the sensors location, by increasing the beater penetration into the grape fruit tree canopy from 10 to 12 inches, the average magnitude of the acceleration on trees bra n ches increased from 3.40 to 3.85 g Also, by in creasing the beaters shaking speed from 45.30 in/sec to 65.90 in/sec, the average magnitude of the acceleration (g) on the grapefruit tree bra n ches was increased from 3.65 g to 5.04 g In addition, when operating the final harvester design, the average of the magnitude of the acceleration (g) on the grapefruit trees bra n ches were 8.08 g when the harvester machine operated at the forward speed of 0.97 mi/hr, 12 inches turn buckle length, and 63.74 in/sec beaters shaking speed; and 8.651 g when the harv ester machine operated by the forward speed 0.85 mi/hr, 12 inches turn buckle length, and 63.74

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230 in/sec beaters shaking speed. It was also observed that the acceleration magnitudes were more evenly distribution in the final design performance. The number o f laborers in the citrus fields has been reduced by using the mechanical harvesting approaches over manual harvesting (CCSC requires 6 labor er s while TSC requires 3) (Roka et al. 2009) With this new prototype self propelled canopy shak er machine, the des ired goal is to have one harvester operator and two fruit transport operators. In conclusion, a self propelled over the top citrus harvester for high density citrus was developed, which achieved fruit detachment percentage of 94 % on average and as high a s 100 % fruit removal on some trees. Consequently, this s tudy r ecommend s o perating the new prototype citrus harvesting machine at either forward speed 0.62 mi/hr or 1.42 mi/hr, with turn buckle length 16 inches and higher grapefruit detachment percentage with average 94 % Although, the initial prototype does not have a catch frame and material handling system, these results are very encouraging for the future of high density citrus mechanical harvesting. Gran ted these results were based on grapefruit rather than orange, but these result s demonstrate the potential. In addition, although some limited tree damage s did occur during testing, they were mi nimal and it is believed that with better shielding and shaker head control, the damage can be reduced even further. In this study, operational parameters were identified which improved harvest performance and form the basis for future harvesting trials. There are numerous opportunities for improvement, but this work has de monstrated concept feasibility.

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231 APPENDIX A H YDRAULIC S Y S T EMS Hydraulic Control Systems of the Innovative Continuous Canopy Shaker harvesting Machin e The developed citrus canopy shaking machine as mentioned in chapter three typically includes three effective hydraulic control systems; the hydraulic control system for the canopy shaker travel speed, the hydraulic control system for the beaters shaking speed, and the hydraulic control system for the harvesting tunnel width of the canopy shaker. So, the fulfilled components of the harvesting machine hydraulic systems are presenting in the following figures The H ydraulic C ontrol S ystem of the Bea ters S haking S peed Figure A 1. Major components of the hydraulic system of the two canopy shakers units

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232 The H ydraulic C ontrol S ystem of the C anopy S haker T ravel S peed (Preliminary Design) Figure A 2. Major components of the hydrostatic drive of the preliminary self propelled shakers machine

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233 The H ydraulic C ontrol S ystem for the H arvesting T unnel W idth of the C anopy S haker and the Steering System (Preliminary Design) Figure A 3. The hydraulic system components of the harvesting tunnel width extension and the steering drive system of the preliminary shaker machine

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234 The Modified Hydraulic Control System of the Beaters Shaking Speed with a Shaker Brake System The hydraulic brake circuit of the previous hydraulic shakers motors ( that have brake ports ) has been excluded due to the new hydraulic motors of the shakers movement do not require brake ports. Figure A 4. Previous hydraulic system components of the two canopy shakers units with the eliminated shakers motors brake ports (two on/off solenoid valves)

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235 APPENDIX B A PROTOTYPE OF THE SELF PROPELLED CITRUS CANOPY SHAKING MACHINE The O verall A ppearance of the Preliminary C itrus H arvesting M achine D esign Figure B 1. The f inal view of the preliminary design of the continuous citrus canopy shaking machine. A) The machine front view, B) rear view of the machine, C) the machine right side view and D) left side view of the citrus harvester design [Photos courtesy of Naji A l Dosary ]

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236 The O verall A ppearance of the Final C itrus H arvesting M achine D esign Figure B 2 The f inal view of the final design of the continuou s citrus canopy shaking machine. A) The machine right side view, B) left side view of the citrus harvester design, C) rear view of the machine and D) t he machine front view [Photos courtesy of Naji A l Dosary ]

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237 T he New C itrus H arvesting M achine Transportation Figure B 3 Easy machine transportation [Photo courtesy of Naji A l Dosary ]

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238 The Machine Orientation Control System The Hydraulic Cylinders for the Machine Steering Control System Figure B 4 Two hydraulic cylinders utilized for the machine orientation system mounted on the front wheels frame of the citrus canopy shaking machine. A) The front right wheel and B) t he front left wheel [Photos courtesy of Naji A l Dosary ]

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239 The Hydraulic Steering Control Valve for the Machine Steering Cont rol System Figure B 5 A steering control valve with its steering wheel utilized for the machine orientation system placed on the front top of the citrus canopy shaking machine. [Photo courtesy of Naji A l Dosary ]

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240 The Improvement of the Canopy Shaker System s Basic Components of the Initial and Final Shaker System s Figure B 6 Basic components of the preliminary canopy shaker units Figure B 7 Basic components of the final canopy shaker units

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241 APPENDIX C THE ACCELERATION MAGNITUDE Effect of the Shaking of the Preliminary C itrus H arvesting M achine on the Acceleration Magnitude Distribution i n the Grapefruit Tree Canopy Table C 1. A p recise average magnitude of the acceleration (g) among the tree canopy branches depending on the delimited accelerometer sensors locations and the machine operating variables i nto one tree canopy (the pre test results) No. of Accel. Sensor Accelerometer Sensors Locations Branch Dia. at the Posted Sensor (in) First Trial (10 inches of turn buckle linkage) Second Trial (11 inches of turn buckle linkage) Third Trial (12 inches of turn buckle linkage) Into the Tree Canopy From Main Trunk (in) From G round (in) Ave. of Max. Accel. Mag. (g) Ave. of Gravi. Accel. (g) Ave. of Max. Accel. Mag. (g) Ave. of Gravi. Accel. (g) Ave. of Max. Accel. Mag. (g) Ave. of Gravi. Accel. (g) 1 Right edge 36 54 0.56 5.559 1.298 6.151 1.268 4.07 1.17 2 Right edge, Top 8 73 0.74 2.74 0.988 4.319 0.989 1.988 0.963 3 Right edge, Down 20 35 1.19 3.782 0.996 3.516 0.973 3.13 0.992 4 Left edge, Top 29 57 0.72 4.604 1.110 4.799 1.063 7.804 1.181 5 Back edge, Right 28 50 0.66 3.343 1.106 2.999 1.081 4.23 1.104 6 Central edge, Left, Back 15 58 1.25 1.884 1.045 1.691 1.03 2.588 1.044 7 Left edge, Front 31 52 0.82 4.427 1.155 3.763 1.113 5.041 1.154 8 Central edge, Top, Left, Front 8 72 0.55 1.91 1.034 2.228 1.029 2.561 1.033 9 Central edge, Left, Back 30 75 0.68 2.823 1.089 2.464 1.075 3.45 1.095 10 Right edge, Front, Down 31 38 0.90 6.074 1.181 7.255 1.301 6.457 1.274 11 Central edge, Front, Top 33 58 0.71 2.877 1.057 2.217 1.053 2.169 1.050 12 Left edge 33 40 0.63 4.07 1.236 3.348 1.163 6.207 1.264 13 Left edge, Top 15 58 0.69 2.361 1.027 2.677 1.021 3.292 1.052 14 Left edge, Front 24 36 0.85 2.622 1.068 2.592 1.063 2.738 1.075 15 Central edge, Back, Down, Rear of the main trunk 20 27 0.9 0 1.971 0.986 2.207 0.975 1.994 0.985 Ave. (g) 3.403 b 1.092 3.482 ab 1.08 3.848 a 1.096 S .D. (g) 1.772 0.100 1.717 0.096 1.879 0.096

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242 s of the Preliminary C itrus H arvesting M achine on the Acceleration Magnitude Distribution i n the Grapefruit Trees Canopies Table C 2. A p recise average magnitude of the acce leration (g) among the tree canopy branches depending on the delimited accelerometer se nsors locations and the machine operating variables at three different tree s canopies (the pre test results) No. of Tree s No. of Accel. Sensor s Accelerometer Sensors Locations Branch Dia. at the Posted Sensor (in) First Trial (first beaters shaking speed) Second Trial (second beaters shaking speed) Into the Tree Canopy From Main Trunk (in) From G round (in) Ave. of Max. Accel. Mag. (g) Ave. of Gravi. Accel. (g) Ave. of Max. Accel. Mag. (g) Ave. of Gravi. Accel. (g) 1 1 Left edge 18 37 1.28 2.674 1.066 4.28 1.16 2 Left edge, Top 12 65 0.74 3.47 1.011 4.216 1.074 3 Central edge, Back 21 27 0.91 2.088 0.935 1.933 0.955 4 Right edge 24 34 1.41 7.387 1.242 7.52 1.529 5 Right edge Top, Back 12 56 0.73 3.8 1.041 4.698 1.097 2 6 Left edge 32 45 1.00 3.188 1.176 4.884 1.317 7 Left edge, Top 15 57 0.78 3.01 1.022 5.907 1.126 8 Right edge, Top, Back 20 62 0.57 4.32 1.229 6.947 1.411 9 Right edge, Down 13 31 0.83 3.995 1.113 5.74 1.212 10 Right edge, Top, Front 17 52 0.58 2.66 1.036 4.759 1.086 3 11 Left edge 20 44 0.71 3.756 1.08 4.667 1.19 12 Central edge, Right, Front 15 56 0.69 2.286 0.997 3.425 1.07 13 Left edge, Back 24 40 0.87 2.409 1.037 4.024 1.194 14 Right edge 16 40 0.71 6.168 1.176 8.004 1.3 15 Central edge, Right Top 8 64 0.89 3.54 1.055 4.652 1.143 Ave. (g) 3.65 a 1.081 5.044 a 1.191 S .D. (g) 1.708 0.091 1.883 0.156

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243 APPENDIX D THE SHAKING BEATERS POSITIONS The New Shakers Penetrations into the Grapefruit Tree Canopy For the final citrus harvester design, the shaking beaters are still dragged within the tree canopy, but th e intimate engagement between the canopy and shaking beaters will be increase d by increasing the length s of the turnbuckles. The s haking beaters penetrations into the grapefruit canopy depending on the turn buckle length s and also based on no load by the tree branches are show n in Table D 1 Moreover, the l owest shaking beaters height from the ground is 28 inches as well as the h eight of the top shaking beaters from the ground is 76 inches and 28 inches from top of internal tunnel of the machine (Figure D 1) Table D 1. The shaking beaters penetrations into the grapefruit canopy depending on the turn buckle length. The Main Beaters The Extra Beaters Crank Position (one full cycle) The Beaters Penetration Based on the Turn Buckle Length (in) Distance Between the Internal Body of the Harvester and a Free End of Beater (in) Di stance Between Free Ends of Two Beaters (in) Distance Between the Internal Body of the Harvester and a Free End of Beater (in) Distance Between Free Ends of Two Beaters (in) Retraction Position 12 12 4 5 19 .50 30 15 20 29 23 23 16 2 2 25 24 .50 20 Extension Position 12 2 9 11 27 15 15 36 Interaction as 3 inches 29 11 16 37 Interaction as 5 inches 30 9

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244 Figure D 1. Dimensions of the new self propelled canopy shaker machine

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245 APPENDIX E THE DEVELOPMENT TEAM A N ew C itrus H arvesting Concept This project was funded by GeoSpider, Inc. through a research award funded by the USDA NIFA SBIR program grant number 2011 33610 30458. The concepts developed were the results o f GeoSpider, Inc Patent Pending established in 2004. Correspondingly, the b asic elements of the citrus canopy harvester with the b asic c ontributions of its design are presented in Table E 1. Table E 1. Directory of the b asic contribution of the citrus har vester elements design Series Citrus Harvesting Machine Structures Design Perspectives Technical Services 1 Harvesting Machine Frame Design Naji Al Dosary, T h om as Burks and M ike Zingaro Michael Zingaro 2 Two Shaking Units Design Naji Al Dosary, T h om as Burks and M ike Zingaro Naji Al Dosary and Michael Zingaro 3 Harvester Wheel Frame Design Michael Zingaro and T h om as Burks Michael Zingaro 4 Principle of the Hydraulic System Design T h om as Burks and Naji Al Dosary T h om as Burks, Naji Al Dosary and Michael Zingaro 5 Principle of the Electrical System Design T h om as Burks and Naji Al Dosary T h om as Burks, Naji Al Dosary, and Michael Zingaro 6 Funder and Purchase of Materials GeoSpider, Inc. T h om as Burks and Michael Zingaro 7 Machine Performance Tests Naji Al Dosary and T h om as Burks Naji Al Dosary and Michael Zingaro

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246 In addition, t he University of Florida development team posing with their accomplished construction of the first prototype of the self propelled citrus canopy shaking machine for Florida citrus trees harvesting ( Figure E 1 ) are from right to left Dr. T h om as F. Burks, Naji M. Al Dosary, and Michael J. Zinga ro Considerately, t he intellectual property contained within this dissertation is managed concepts, without the express consent of the University of Florida D r. T h om as F. Burks and Naji M. Al Dosary are prohibited. Figure E 1 The self propelled canopy shakers machine development team [Photo courtesy of Naji A l Dosary the end of year 2013 ]

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247 APPENDIX F PERFORMANCE OF THE NEW CITRUS CANOPY SHAKER T he F inal R esult s of the N ew C itrus H arvesting M achine P erformance Practical experiments o n the final prototype of the citrus harvester were carried out at the Plant Science Research and Ed ucation Center in Citra (PSREC) during the winter harvest of 2014 The results are shown in t he following tables for the various test parameter combination s ( Table s F 1, F 2, F 3, and F 4 ) Table F 1. A mount of the detached grapef ruit ( fruits / t ree) Detached Grapef ruit ( fruits /tree) Beaters Position (Turn Buckle L ength) (in ch ) Harvester Forward Speed m i/hr Sl ow (0.62) Fast (1.42) Shakers Speed inch/sec Shakers Speed inch/sec Low (56.50) High (73) Low (56.50) High (73) Default (12, 14, and 15) 97 192 56 124 68 163 86 122 109 168 58 114 130 141 81 129 111 160 67 124 37 56 55 30 75 55 57 34 80 73 65 28 72 78 74 47 80 31 47 96 80 61 52 104 101 103 83 111 79 53 69 46 70 88 91 84 98 101 107 131

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248 Table F 2 Amount of remaining grapef ruit on trees ( fruits / t ree) Remaining F ruit on the T ree ( fruits /tree) Beaters Position (Turn B uckle L ength) (in ch ) Harvester Forward Speed m i/hr Sl ow (0.62) Fast (1.42) Shakers Speed inch/sec Shakers Speed inch/sec Low (56.50) High (73) Low (56.50) High (73) Default (12, 14, and 15) 20 14 21 42 23 24 27 15 20 30 52 33 38 18 28 15 43 7 45 37 12 11 39 50 11 29 45 36 42 31 39 42 76 52 43 12 35 41 30 40 4 0 13 14 25 6 24 1 11 6 24 4 30 4 18 8 11 14 18 4

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249 Table F 3 Grapef ruit detachment p ercentage s (%) Fruit Detachment Percentage (%) Beaters Position (Turn B uckle L ength) (in ch ) Harvester Forward Speed m i/hr Sl ow (0.62) Fast (1.42) Shakers Speed inch/sec Shakers Speed inch/sec Low (56.50) High (73) Low (56.50) High (73) Default (12, 14, and 15) 82 .91 93.20 72.73 74.70 74.73 87.17 76.11 89.05 84.50 84.85 52.73 77.55 77.38 88.68 74.31 89.58 72.08 95.81 59.82 77.02 75.51 83.58 58.51 37.5 0 87.21 65.48 55.88 48.57 65.57 70.19 62.5 0 40 48.65 60 63.25 79.66 69.57 43.06 61.04 70.59 95.24 100 80 88.14 80.16 94.50 77.57 99.11 87.78 89.83 74.19 92 70 95.65 83.49 91.30 89.91 87.83 85.6 0 97.04

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250 Table F 4 A verage s of the grapef ruit detachment p ercentage (%) Fruit Detachment Percentage (%) Beaters Position (Turn B uckle L ength) (in ch ) Harvester Forward Speed m i/hr Sl ow (0.62) Fast (1.42) Shakers Speed Shakers Speed inch/sec inch/sec Low (56.50) High (73) Low (56.50) High (73) 69.30 64.46 60.24 55.26 Default (12, 14, and 15) 78.32 89.94 67.14 81.58 84.62 93.56 80.17 93.52

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251 LIST OF REFERENCES AWC, American Wood Council. 2007. DA 6 Beam design formulas with shear and moment diagrams. Available at: http://www.awc.org/pdf/DA6 BeamFormulas.pdf. Retrieved on October 18, 2011. Bedford, Anthony M. and Wallace L. Fowler. 1995. Statics: Engineering M echanics. Addison Wesley Publishing Company, Inc. USA. P:39. BEI International, LLC. 2010. BEI harvesters. Available at: http://www.beiinternational.com/Harvesters.html. Retrieved on July 15, 2010. Blanco Rolnd, G. L., J. A. Gil Ribes, K. Kouraba, and S. Castro Garc a. 2009. Effects of trunk shaker duration and repetitions on removal efficiency for the harvesting of oil olives. Applied Eng. In Agric. ASABE 25 (3): 329 334. Bohannon, J. D. 1969. Mechanical citrus fruit harvester. U.S. Patent No. 3485025 Brown, G. K. 2002. Mechanical harvesting systems for the Florida citrus juice industry. An ASAE meeting presentation. Paper No. 021108, ASAE, St. Joseph, Michigan., U.S.A. Brown, G. K. 2005. New mechanical harvesters for the Florida citrus juice industry HortTechnology 15 (1):69 72. Briesemeister, R. A., C. M. Schloesser, and M. Woodruff. 2006. Vehicle stabilizer system. U.S. Patent No. 0123763 A1 and No. 7082744 B2. Briesemeister, R. A., C. M. Schloesser, M. Woodruff, and A. E. Russell. 2008. Vehicle st abilizer system. U.S. Patent No. 7407166 B2. Briesemeister, R. A. 2002. Tree harvester trunk seal. U.S. Patent No. 6463725 B1. Buyanov, A. I. and B. A. Voronyuk. 1985. Physical and Mechanical Properties of Plants, Fertilizers and Soils. Amerind Publishin g Co. Pvt. Ltd., 66 Janpath, New Delhi. India. P: 82. Castro Garca, S., G. L. Blanco Roldn, J. A. Gil Ribes, and J. Agera Vega. 2008. Dynamic analysis of olive trees in intensive orchards under forced vibration. Trees 22 (6):795 802. Christie, D. E., and K. E. Winquist, Prtland, Oreg. assignors to OECO Corporation, Prtland, Oreg., a Corporation of Oregon. 1967. Berry harvester. U.S. Patent No. 3325984. Coppock, G. E., and J. R. Donhaiser. 1981. Conical scan air shaker for removing cit rus fruit. Transactions of the ASAE 24 (6):1456 1458. Crunkelton, W. S. 1992. Mechanical citrus and other fruit picker. U.S. Patent No. 5161358. Daniels, M. A. 1999. Fruit harvesting device. U.S. Patent No. 5946896.

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252 De Mendon a Fava, J. F., E. L. Domingu es, and R. Scudder. 2005. Process and device of relative positioning between agricultural machines and crops on their planting rows. U.S. Patent No. 6959527 B2. Ehsani, Reza and Lav Khot. 2012. Over the row mechanical harvesting machine for dwarf and youn g citrus trees. CREC. Univ. of FL/IFAS Extension. Citrus Extension Trade Journals 2012. Citrus Industry, September 2012: 2 pages (10 11). Available at: http://www.crec.ifas.ufl.edu/extension/trade_journals/trade_journals2012.shtml. Retrieved on March 14, 2 013. El Gindy, A. M., M. A. Baiomy, M. M. Abdelhamed, and A. M. Sahar. 2009. Design and fabrication of a simplified mechanical handling system of rice straw baling operation to reduce environment pollution. Misr J. Ag. Eng. 26 (1): 667 686. Erdo an, D., Biosystems Eng. 85 (1): 19 28. Florida Department of Citrus. 2008. History of citrus. Available at: http://www.floridajuice.com/history_of_citrus.php. Retrieved on May 23, 2010. Futch, S. H., and F. M. Roka. 2005. Continuous Canopy Shake Mechanical Harvesting Systems. EDIS. Univ. of FL. IFAS Extension. 4 pages. (DLN: HS 1006). Available at: http://edis.ifas.ufl.edu/pdffiles/HS/HS23900.pdf. Retrieved on May 23, 2010. Futch, S. H. J. D. Whitney, J. K. Burns, and F. M. Roka. 2005. Harvesting: From Manual to Mechanical. EDIS Univ. of FL. IFAS Extension. 3 pages. (DLN: HS 1017). Available at: http://edis.ifas.ufl.edu/pdffiles/HS/HS21800.pdf. Retrieved on March 26 201 4 Hannan, M. W., and T. F. Burks. 2004. Current developments in automated citrus harvesting. An ASAE/CSAE Annual International Meeting Presentation. Paper No. 043087, ASAE, St. Joseph, Michigan., U.S.A. Harrell, R. C., D. C. Slaughter, and P. D. Adsit 1989. A fruit tracking system for robotic harvesting. Machine Vision and Applications 2 (2):69 80. Hosking, J. 2002. Fruit shaker. U.S. Patent No. 0062635 A1 & No. 6425233 B1. Hunt, D. R. 1977. Farm Power and Machinery Management, 7th edition. Iowa Stat e University Press. Ames, Iowa, U.S.A. Lng, Z. 1989. Lincoln canopy apple harvester using a continuous horizontal shaking method. J. Agric. Eng. Res. 44 :267 273. Lee, B. S., U. A. Rosa, and K. Cheetancheri. 2006. End effector for automated citrus harvest ing. An ASABE Annual International Meeting Presentation. Paper No. 061143, ASABE, St. Joseph, Michigan., U.S.A.

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253 Loghavi, M., and Sh. Mohseni. 2006. The effects of shaking frequency and amplitude on detachment of lime fruit. Iran Agric. Res. 2005 2006. 24 ( 2) & 25 (1): 27 38. Mott, R. L. 2004. Machine Elements in Mechanical Design, 4th Edition. Pearson Prentice Hall, Upper Saddle River, NJ, U.S.A. Muraro, R. P. 201 2 Estimated Average Picking, Roadsiding and Hauling Charges for Florida Citrus, 201 1 1 2 Seaso n. University of Florida/IFAS, Citrus Research and Education Center, Lake Alfred, FL. Available at: http://www.crec.ifas.ufl.edu/extension/economics/pdf/Estimated%20Average%20Picking %202011 12.pdf. Retrieved on February 15th, 201 4 NI, National Instrument s Corporation. 2010. National Instruments LabVIEW 2010 SP1 Software, Version 10.0.1 (32 bit). Austin, Texas, USA. Peterson, D. L. 1998. Mechanical harvester for process oranges. Applied Eng. In Agric. ASABE 14 (5):455 458. Peterson, D. L. 2003. Harvest m echanization for tree fruits and automated sorting systems for apples. Report to USDA, Agricultural Research Service. Available at: http://www.reeis.usda.gov/web/crisprojectpages/403832.html. Retrieved on May 23, 2010. Peterson, D. L., and B. S. Bennedsen 2005. Isolating damage from mechanical harvesting of apples. Applied Eng. In Agric. ASAE 21 (1):31 34. Peterson, D. L., T. Kornecki, and both of Martinsburg, W. Va. 1989. Shaking mechanism for fruit harvesting. U.S. Patent No. 4860529. Peterson, D. L., and S. S. Miller. 1989. Advances in mechanical harvesting of fresh market quality apples. Journal of Agricultural Engineering Research 42 (1):43 50. Peterson, D. L., and F. Takeda. 2003. Feasibility of mechanically harvesting fresh market quality eastern t hornless blackberry. ASAE, Applied Engineering in Agriculture. 19 (1):25 30. Peterson, D. L., and S. D. Wolford. 2001. Mechanical harvester for fresh market quality stemless sweet cherries. Transactions of the ASAE 44 (3):481 485. Peterson, D. L., and S. D Wolford. 2003. Fresh market quality tree fruit harvester, Part II: Apples. Applied Eng. In Agric. ASAE 19 (5):545 548. Peterson, D. L., M. D. Whiting, and S. D. Wolford. 2003. Fresh market quality tree fruit harvester, Part I: Sweet cherry. Applied Eng. In Agric. ASAE 19 (5):539 543. Peterson, D. L., S. D. Wolford, E. J. Timm, and F. Takeda. 1997. Fresh market quality blueberry harvester. Transactions of the ASAE 40 (3):535 540.

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254 Pezzi, F. and C. Caprara. 2009. Mechanical grape harvesting: investigation of the transmission of vibrations. Biosystems Engineering 103 (3):281 286. Roka, F. M. 2008. A decision aid tool to compare costs of mechanical harvesting systems. Available at: http://edis.ifas.ufl.edu/pdffiles/FE/FE75100.pdf Retrieved on Aug. 24, 2011. Roka, F. M. 2010. Harvesting with and without mechanical harvesting. PowerPoint presentation #9 delivered to the Citrus Industry and Various Trade Organizations; the Future of t he Global Juice Industry Workshop. Available at:http://www.fdocgrower.com/economics/economic research/powerpoint presentations/. Retrieved on Aug. 24, 2011. Roka, F. M. 2010. To glean or not to glean. Available at: http://www.imok.ufl.edu/docs/pdf/econ_ci _glean.pdf. Retrieved on November 2nd, 2011. Roka, F. M., J. K. Burns, J. Syversen, T. Spann, and B. Hyman. 2009. Improving the economic viability of Florida citrus by enhancing mechanical harvesting with abscission agent CMNP. Available at: http://citrusmh.ifas.ufl.edu/pdf/db/abscission_white_paper_040609.pdf Retrieved on Aug. 22, 2011. Roka, F. M., and R. E. Rouse. 2004. Tree shaping and grove design to enhance perfor mance of citrus mechanical harvesting. Proceedings of the Florida State Horticultural Society 117 :117 119. Sanders, K. F. 2005. Orange harvesting systems review. Biosystems Eng. 90 (2):115 125. .3 Graph Template Language: Reference. Third Edition. SAS Institute, Cary, North Carolina, U.S.A. Schloesser, C. M. 2005. Conveyor cleaning apparatus. U.S. Patent No. 0061623 A1. Sivaraman, B. 2006. Design and development of a robot manipulator for citru s harvesting. PhD dissertation. Gainesville, FL: University of Florida, Department of Agricultural and Biological Engineering. Srivastava, A. K., C.E. Goering, R.P. Rohrbach, and D. R. Buckmaster. 2006. Engineering Principles of Agricultural Machines. Sec ond Edition. ASABE, 2950 Niles Road, St. Joseph, Michigan, USA. Thomson, W. T. 1965. Theory of Vibration with Applications. Prentice Hall Inc., Englewood Cliffs, New Jersey, U.S.A. Torregrosa, A., B. Mart n, C. Ortiz, and O. Chaparro. 2006. Mechanical ha rvesting of processed apricots. Applied Eng. In Agric. ASABE 22 (4):499 506.

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255 Torregrosa, A., E. Ort B. Mart n, J. Gil, and C. Ortiz. 2009. Mechanical harvesting of oranges and mandarins in Spain. Biosystems Eng. 104 (1): 18 24. Udumala Savary, S. K. J. 2 009. Study of the force distribution in the citrus canopy during harvest using continuous canopy shaker. Master thesis. Gainesville, FL: University of Florida, Department of Agricultural and Biological Engineering. Udumala Savary, S.K.J., R. Ehsani, M. Sa lyani, M.A. Hebel, and G.C. Bora. 2011. Study of force distribution in the citrus tree canopy during harvest using a continuous canopy shaker. Computers and Electronics in Agriculture 76 (1): 51 58. UF IFAS Extension Service University of Florida. 20 14 Citrus greening (Huanglongbing) Available at: http://www.crec.ifas.ufl.edu/extension/greening/index.shtml Retrieved on March 7, 201 4 USDA, the United States Department of Agriculture and NASS, National Agricultural Statistic Service. March 2009. Citr us summary 2007 08. Available at: http://www.nass.usda.gov/Statistics_by_State/Florida/Publications/Citrus/cs/2007 08/cs0708all.pdf. Retrieved on May 23, 2010. USDA, the United States Department of Agriculture and NASS, National Agricultural Statistic Ser vice. August 18th, 2011. Farm labor. Available at: http://usda01.library.cornell.edu/usda/nass/FarmLabo//2010s/2011/FarmLabo 08 18 2011.pdf. Retrieved on November 1st, 2011. Visser, T. R. 2001. Single shaker head harvesting apparatus and method. U.S. Pate nt No. 6178730 B1. Whitney, J. D. 1995. A review of citrus harvesting in Florida. Transactions Citrus Engineering Conference, Florida Section, ASME 41 :33 59. Whitney, J. D. 1999. Field test results with mechanical harvesting equipment in Florida oranges. Applied Eng. In Agric. ASAE 15 (3):205 210. Whitney, J. D., and R. C. Harrell. 1989. Status of citrus harvesting in Florida. J. Agric. Eng. Res. 42 :285 299.

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256 BIOGRAPHICAL SKETCH In 1970, Naji A l Dosary was born in the City of Al Badi, south of the A l Afl aj Province. He received his Bachelor of Agricultural Engineering in 1993 from the College of Food and Agricultural Sciences at the King Saud University, Riyadh. Since then he began working with the Ministry of Agriculture at Al Aflaj Bureau of the M inistry of Agr iculture in Al Afl a j Province, Riyadh. In 2000, Naji got married to Ietemad They hav e three daughters, Sarah, Shekah, and Asla and one son, Mordi. In 2005, he got his Master of Science in the agricultural engineering program with a major in farm power and machinery from the College of Food and Agricultural Sciences at the King Saud University at City of Riyadh, capital of Saudi Arabia. In 2011, he received his second Master of Engineering with a major in the machine systems development program from the Agricultural and Biological Engineering Department at the University of Florida in Gainesville, State of Florida. Naji Al Dosary has continued to pursue his graduate education fo r getting a doctorate of philosophy in agricultural and biological engineering with a major in the machine systems development from the Agricultural and Biological Engineering Department Engineering College at the University of Florida since 2007 Accordi ngly h e received his Doctor of Philosophy from the University of Florida in the spring of 201 4