关节型果蔬采摘机械臂优化设计与试验

Optimization Design and Experiment of Fruit and Vegetable Picking Manipulator

针对现有采摘机械臂存在的问题,研制了四自由度的关节型果蔬采摘机械臂。为使机械臂能够灵活高效地收获目标空间果实,同时尽量减少机械臂的操作空间和结构尺寸,提出了一种应用于采摘空间为任意立方体,通用的关节型机械臂结构参数优化方法:以工作空间为约束条件,建立优化设计的数学模型,并利用Matlab优化工具箱来实现。为验证优化方法的合理性,以温室环境下黄瓜采摘作业为例,对研制的采摘机械臂进行了结构参数优化;并对优化后的机械臂进行了运动规划试验。结果表明:优化后的机械臂能包容黄瓜采摘所要求的全部目标空间,并能到达目标空间的极限点和其他采摘点,在x、y、z方向上的最大定位误差分别为:4.3、5.6、6.8 mm,基本能满足黄瓜采摘作业的要求。

In view of the existing problems of current picking manipulator,an articulated picking manipulator with four degree of freedom was developed.In order to harvest fruits and vegetables of the target space flexibly and efficiently,meanwhile to reduce operating space and structure size of the manipulator as much as possible,the general structure optimization method of the articulated manipulator for picking fruits and vegetables was proposed,which was applied in random cube of the picking space.The mathematical models were constructed by taking the workspace for constraints,and the Matlab optimization Toolbox was applied to realize the proposed method.For verifying the availability of the method,the structure parameters of the designed articulated picking manipulator were optimized by referring to the example of the cucumber picking operation in greenhouse;and the motion planning experiments of the optimized manipulator were carried out.Experimental results showed that the optimized manipulator could cover the whole required target space of the cucumber harvesting operation,and also could reach the limit points and other picking points of the target space,the maximum positioning errors of the x,y,z axis were respectively 4.3mm,5.6mm,6.8mm,so it could basically satisfy the requirement of the cucumber picking operation.