一种新型农业机械臂的运动学分析

Kinematics analysis of a new agricultural robot arm

针对目前果蔬采摘时机械臂工作空间小和承载能力低的不足,提出了一种工作空间范围大且有较高承载能力的新型农业机械臂.机械臂是一种串并联混合机构,具有平面内转动和移动2个自由度,能够实现在较大活动范围内对果蔬的采摘功能.本文首先对机构的组成和自由度进行了分析,并在此基础上,基于闭式运动链子组件法对机构的运动学正反解进行了分析,从而预测机械臂在工作时的空间范围.最后,求解了5组机械臂的正反解分析数值算例,验证求解方法和结果的正确性.结果表明,机械臂的工作空间可实现较大范围内的水平移动,为此类机构的分析提供了新的设计思路和参考.

The objective of this study is to propose a new agricultural robot arm with large workspace and high bearing capacity,aiming at the shortage of small workspace and low bearing capacity of the robot arm when picking fruits and vegetables.The robot arm is a series and parallel mixing mechanism and has two degrees of freedom:a motion and a rotation in the plane,which can realize the function of picking fruits and vegetables in wide activity range.Firstly,the composition and degree of freedom of the mechanism were analyzed.And on this basis,the positive and negative kinematics solutions of the mechanism were analyzed by using the closed motion-chain module method to predict the space range of the robot arm at work.Finally,five sets of positive and negative solution analysis numerical examples of the robot arm were given to verify the correctness of the solution method and results.The results show that the workspace of the robot arm can move horizontally in a large range,which provids a new design idea and reference for the analysis of this kind of mechanism.