An autonomous strawberry‐harvesting robot: Design, development, integration, and field evaluation

Xiong, Ya, Ge, Yuanyue, Grimstad, Lars and From, Pal (2020) An autonomous strawberry‐harvesting robot: Design, development, integration, and field evaluation. Journal of Field Robotics, 37 (2). pp. 202-224. ISSN 1556-4959

Full content URL: https://doi.org/10.1002/rob.21889

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An autonomous strawberry‐harvesting robot: Design, development, integration, and field evaluation
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Abstract

This paper presents an autonomous robot capable of picking strawberries continuously in polytunnels. Robotic harvesting in cluttered and unstructured environment remains a challenge. A novel obstacle‐separation algorithm was proposed to enable the harvesting system to pick strawberries that are located in clusters. The algorithm uses the gripper to push aside surrounding leaves, strawberries, and other obstacles. We present the theoretical method to generate pushing paths based on the surrounding obstacles. In addition to manipulation, an improved vision system is more resilient to lighting variations, which was developed based on the modeling of color against light intensity. Further, a low‐cost dual‐arm system was developed with an optimized harvesting sequence that increases its efficiency and minimizes the risk of collision. Improvements were also made to the existing gripper to enable the robot to pick directly into a market punnet, thereby eliminating the need for repacking. During tests on a strawberry farm, the robots first‐attempt success rate for picking partially surrounded or isolated strawberries ranged from 50% to 97.1%, depending on the growth situations. Upon an additional attempt, the pick success rate increased to a range of 75–100%. In the field tests, the system was not able to pick a target that was entirely surrounded by obstacles. This failure was attributed to limitations in the vision system as well as insufficient dexterity in the grippers. However, the picking speed improved upon previous systems, taking just 6.1 s for manipulation operation in the one‐arm mode and 4.6 s in the two‐arm mode.

Keywords:active obstacle separation, agricultural robotics, cable?driven gripper, field evaluation, strawberry?harvesting robot
Subjects:H Engineering > H671 Robotics
D Veterinary Sciences, Agriculture and related subjects > D400 Agriculture
Divisions:College of Science > Lincoln Institute for Agri-Food Technology
ID Code:44053
Deposited On:17 Feb 2021 10:56

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