Abstract: In view of the low efficiency of artificial harvesting and the slow development of mechanized harvesting equipment, the lotus picking end‑effector was designed. In order to determine the mechanical parameters of lotus stem, the mechanical properties of lotus stem in mature stage were tested by texture instrument. The experiment indicated that when the shear speed was within 500 mm/min, the shear speed and stem diameter had no significant impact on the shear strength of lotus stem, while the shear position had the greatest influence on it. The closer the shear position was to the lotus pods, the smaller the shear force was required. The shear force required for stem cutting of mature lotus was 10.29-132.17 N, and the shear stress was 0.20-2.71 MPa. Then, the optimal picking range and the required shearing force of the lotus picking end‑effector were determined, and the lotus picking end‑effector was designed according to the test results.The results showed that the cutting success rate of the device was 100%, but the whole picking success rate was 92% because of the falling from the end‑effector.

Key words: lotus stem, picking robot, mechanical properties, end?effector

摘要： 针对目前人工收获莲蓬效率低，莲蓬机械化收获设备发展缓慢的问题，对莲蓬采摘末端执行器进行设计。为确定莲蓬茎秆的相关力学参数，以成熟期莲蓬茎秆作为试验材料，使用质构仪对莲蓬茎秆进行剪切力学特性试验。试验表明，剪切速度在500 mm/min以内时，剪切速度、茎秆直径对莲蓬茎秆剪切强度影响不显著。剪切位置对莲蓬茎秆剪切强度影响最大，剪切位置越靠近莲蓬，所需要的剪切力越小。成熟莲蓬的茎秆剪断所需的剪切力为10.29~132.17 N，剪切应力为0.20~2.71 MPa。由此确定莲蓬采摘末端执行器的最佳采摘范围及所需剪切力，并根据试验结果设计莲蓬采摘末端执行器。采摘试验表明，所设计的莲蓬夹持剪切装置的莲蓬剪切成功率为100%，但由于莲蓬从末端执行器滑落，导致整体采摘成功率为92%。

关键词: 莲蓬茎秆, 采摘机器人, 力学特性, 末端执行器