ISHS Acta Horticulturae 801: International Symposium on High Technology for Greenhouse System Management: Greensys2007
DEVELOPMENT OF AN END EFFECTOR FOR A STRAWBERRY-HARVESTING ROBOT |
| Authors: | S. Yamamoto, S. Hayashi, H. Yoshida, K. Kobayashi, K. Shigematsu |
| Keywords: | strawberry, elevated substrate culture, harvesting, robot, end effector |
| Abstract:
We designed a prototype end effector for a strawberry-harvesting robot for application to an elevated-substrate culture, and then conducted a performance test. First, at a greenhouse in Ehime Prefecture in which the strawberry cultivar ‘Beni hoppe’ was grown, we investigated the difficulty of approaching the targeted fruit from below. Thirty-seven percent of target fruits had no adjoining fruits, 25% had intervening adjoining fruits when approached from below, and 38% had adjoining fruits that did not affect access from below. We also measured the maximum force needed to separate a fruit from its peduncle. When harvesting a fruit, a farmer tilts it approximately 90° and then pulls it from the peduncle. We compared measurements obtained when the fruit was tilted with those obtained when the fruit was harvested by holding it straight and pulling. The force required to separate a fruit from its peduncle was reduced by tilting and pulling the fruit, and the peduncle was also more likely to be completely removed from the fruit by this method. We then designed an end effector prototype and installed it on a robot arm with seven degrees of freedom of motion, and we prepared software that enabled us to teach the position of the targeted fruit to the robot beforehand. We evaluated the performance of the end effector with plants growing in an elevated-substrate bed. If a fruit was approached from below, the approach success rate was more than 97% and the separation success rate was more than 92%. However, 30% of fruits were damaged, and 23% of the time, other fruits were harvested as well. | |
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