Dissertation
SEMI-AUTOMATED END-EFFECTOR CONCEPTS FOR LOCALIZED REMOVAL AND CATCHING OF FRESH-MARKET APPLES IN FRUITING WALL ORCHARDS
Doctor of Philosophy (PhD), Washington State University
01/2014
Handle:
https://hdl.handle.net/2376/118417
Abstract
Mechanizing the fruit removal operation during fresh-market apple harvesting is essential for labor use and cost savings for fruit growers. This study introduces a semi-automated mechanical fruit harvesting system that uses a fruit removal technique based a unique limb shaking mechanism called a Dual Motor Actuator (DMA). A manipulator arm, positioned by a human, held a fruit catchframe and an end-effector. The system was mounted on a mobile orchard platform. The dual motor actuator was developed as an infinitely variable pattern end-effector that applies rhythmic motions to a fruiting limb to remove fruit. The novelty of the DMA design is the use of two eccentrics mounted to electric motors that are pinned together to form a triangle with an adjustable base. Pattern, rhythm, and actuation time, were varied to characterize the removal efficiency and fruit damage rates in a formally trained `Gala' orchard. Removal efficiency averaged 35% across the fruiting section (limb) but averaged 88% within the actuation zone of the fruiting section, showing potential for a semi-selective harvesting technique to localize fruit removal on branches trained to trellis wires. A circular pattern using a 200 cycles min-1 rhythm achieved the lowest overall damage rate (10%) for any combinations of the patterns and rhythms tested. Bruise rate was also the lowest (4%) using the same pattern and rhythm setting. Rhythm and actuation time were significant factors that influenced the fruit removal condition. No fruit was removed outside of the targeted actuation zone when using a single limb grasper. This localized limb actuation method shows a great potential for removing apples from a limb while maintaining fresh-market quality fruit.
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Details
- Title
- SEMI-AUTOMATED END-EFFECTOR CONCEPTS FOR LOCALIZED REMOVAL AND CATCHING OF FRESH-MARKET APPLES IN FRUITING WALL ORCHARDS
- Creators
- Mark E. De Kleine
- Contributors
- Manoj Karkee (Advisor)R. Troy Peters (Committee Member)Qin Zhang (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 164
- Identifiers
- 99900581842301842
- Language
- English
- Resource Type
- Dissertation