Advancing Over the Top Citrus Harvesting Equipment for Fresh Markets: Harvesting Arm Development

Numerous challenges face the Florida and U.S. citrus industries, including global market pressure, urban and environmental pressures, labor issues, and emerging diseases and pests, thus underscoring the need for new production approaches. Over the last decade, over 200,000 acres of Florida citrus production has been lost due to the citrus canker eradication program and citrus greening known as HLB. HLB is now considered endemic in Florida and hundreds of thousands of acres are in step decline, with minimal hope of finding remediation solutions. Long term hope rests on finding HLB resistant varieties, and developing advanced management strategies that can control the psyllid population, repel them from groves, and manage trees in an optimal economic framework. One approach being considered is Advanced Production Systems (APS) that use high density semi-dwarfed trees, and open hydroponics with optimized nutrient and water availability, which accelerates plant growth. When combined with HLB tolerant rootstocks, the concept seeks to increase yield production per acre, while simultaneously shortening the time to return on investment, which means that grove life can be shortened by disease pressure and still remain viable economically. However, this new grove architecture will require new equipment systems to manage production and harvesting. The concept proposed by GeoSpider, Inc. will offer a broad range of production and harvesting implements, such as mass and selective harvesting, spraying, hedging, and mowing.In this Phase I project, we will advance a strategic aspect of selective harvesting which will improve harvestability of fresh market fruit. An integrated hybrid harvesting arm will be developed to selectively remove fruit on the canopy surface or within the canopy interior. We believe that a hybrid arm that takes advantage of the speed, strength and accuracy of an articulated manipulator, coupled with the dexterity improvements of hyper-redundant manipulators will have unique performance characteristics. Scalability must be kept in mind since it is likely that each mobile harvester will carry 4 to 8 harvesting arms, thus multiplying the harvesting throughput, but at the same time increasing the complexity of workspace planning and collision avoidance. Leveraging prior research by the University of Florida PI's, GeoSpider, Inc will further develop a serial link maco-positioning manipulator equipped with a hyper-redundant forearm. Foundational controls will be developed for this Phase I prototype to demonstrate proof of concept in a laboratory setting at the UF citrus harvesting laboratory. Appropriate experimental methods will be implemented to evaluate the hybrid manipulator's performance in terms of; 1) workspace reach, 2) dexterity, 3) harvesting cycle speed, 4) stability, and 5) end point precision.