A comb-type end-effector for inflorescence thinning of table grapes

Abstract

Inflorescence thinning of table grapes is a crucial step in the production management to enhance grape yield. In order to reduce labor dependency and improve the efficiency of inflorescence thinning, a comb-type end-effector is designed to achieve precision mechanical thinning of grape inflorescences. Firstly, the two-finger end-effector is designed based on the principle of bionic hand inflorescence thinning. Then, the comb-tooth made of silicone is designed at the two-finger end of the end-effector to protect the inflorescence peduncle. In addition, the rotating device is designed to adjust the angle of thinning for more precise inflorescence thinning of table grapes. Finally, the end-effector is installed on the inflorescence thinning robot for field experiments. Field experiment results show that the success rates of thinning inflorescence in four categories (different angles) are 93.33 % (45°–60°), 86.67 % (30°–45°), 80 % (60°–90°) and 73.33 % (0°–30°), respectively. The average time of thinning inflorescence is 7.65 s and the inflorescence damage rate is 5 %. The comb-type end-effector effectively prevents damage to the inflorescence. Therefore, the comb-type end-effector for inflorescence thinning of table grapes proposed in this study exhibits superior thinning accuracy and efficiency in field environment, providing hardware support for the development of table grape thinning machinery.