扭梳式油茶果采摘末端执行器设计与试验

Design and Experiment of Twist-comb End Effector for Picking Camellia Fruit

为了解决油茶果采摘过程中采净率低、花苞损伤率大的问题,通过研究不同品种油茶果结合力和油茶枝条特性,设计了一种扭梳式油茶果采摘末端执行器,在采摘作业时该执行器可以对油茶果产生多种作用力。阐述了该末端执行器的结构和工作原理,并对关键部件进行了设计,分析了末端执行器的作业过程和油茶果脱落的影响因素。对不同品种油茶果的结合力和枝条扭转进行测试,得出抗拉力主要集中在10~25 N之间、抗剪力主要集中在5~15 N之间、抗扭力矩主要集中在0.015~0.030 N·m之间,不同品种油茶枝条扭转模量在2~7 MPa之间。单因素试验表明,在扭梳组件转速为25~35 r/min、梳辊转速为75~85 r/min、作业时间为8~12 s工况下,采摘性能较优。试验表明,最优工作参数组合为扭梳组件转速35 r/min、梳辊转速85 r/min、作业时间12 s,此时油茶果采净率平均值为93.37%,花苞损伤率平均值为13.16%。

In order to solve the problems of low net recovery rate and large bud damage rate during the picking process of camellia fruit,by studying the binding force and branch characteristics of different varieties of camellia fruit,a twist-comb type camellia fruit picking end effector was designed. It produced a variety of forces on the camellia fruit during operation. The structure and working principle of the end effector were described,the key components were designed,the operation process of the end effector was analyzed,and the factors that affected the shedding of the camellia fruit were obtained. By measuring the binding force of different varieties of camellia fruit,it was concluded that the tensile force was mainly concentrated between 10 N and 25 N,the shear resistance was mainly concentrated between 5 N and15 N,and the torsion moment was mainly concentrated between 0. 015 N·m and 0. 030 N·m. The measured torsional modulus of different varieties of camellia branches was between 2 MPa and 7 MPa. The results of single factor test showed that the performance was better when the rotating speed of the torsion component was 25 ~ 35 r/min,the rotating speed of the comb roller was 75 ~ 85 r/min,and the working time was 8 ~ 12 s. The results of test showed that the optimal working parameter combination was35 r/min of torsion component,85 r/min of comb roller,and 12 s of operation time. Under this working condition,the average net recovery rate of camellia fruit was 93. 37%,the average damage rate was13. 16%.