关键词: 柑橘, 采摘机器人, 末端执行器, 夹持机构, 简支梁式

Abstract: It is an important means to improve the harvesting ability of the harvesting robot by improving harvesting success rate of end-effector. The simply supported beam shear method can cut the carpopodium more easily than the cantilever beam shear mode with same cutting speed and diameter, and the simply supported beam shear mode can be achieved by clamping the citrus. Therefore, the harvesting success rate of the harvesting robot could be increased by adding a clamping mechanism to the end-effector. Through ultimate squeeze test of citrus, the ultimate load that citrus could stand was 14.0 N under the condition of pressure surface diameter of 14.12 mm. Based on the results and citrus parameters, the fingers of clamping mechanism were designed, and the maximum ultimate clamping force for citrus was determined under 102.41 N. According to the previous research results and force analysis of the carpopodium, the minimum clamping force of clamping mechanism was determined more than 3.79 N. The control system design was completed by the movement characteristics of clamping mechanism, the 3-dimensional model of clamping mechanism was established and finite element analysis and verification were performed. The prototype of the clamping mechanism was made and gripping experiments for different citrus varieties were carried out. The clamping mechanism was installed on the end-effector, the picking comparative experiment between the non-clamping mechanism and with clamping mechanism were performed under natural conditions. The experimental results showed that the clamping mechanism could achieve the non-destructive clamping of various citrus varieties. The harvesting success rate of end-effector was increased from 70% to 85% after adding the clamping mechanism. The harvesting success rate of end-effector was significantly improved, thereby improving the harvesting operation ability of harvesting robot.

Key words: citrus, harvesting robot, end-effector, clamping mechanism, simply supported beam mode