并联机器人中柔顺关节代替传统关节可行性分析

Feasibility Analysis of Compliant Joints Instead of Traditional Joints in Parallel Robot

在3-RRR平面并联机器人中,驱动杆和连杆之间的传统关节被柔顺关节代替,形成含有柔顺关节的并联机器人。基于含有柔顺关节的并联机器人动力学模型和传统关节并联机器人动力学模型,从理论上求解并对比了在并联机器人中加入柔顺关节前后动平台的轨迹、驱动力矩以及驱动杆的转角变化,同时通过实验对比了两者的动平台轨迹,验证了大范围宏观运动的3-RRR并联机器人中柔顺关节代替传统关节的可行性,为柔顺关节并联机器人的进一步研究打下了基础。

A parallel robot with compliant joints was formed by compliant joint substituted for the traditional joints between the driving rods and the connecting rods in a 3-RRR planar parallel robot.Based on the dynamics models of the parallel robot with compliant joints and the traditional-joint parallel robot,the trajectories of the moving platform and the angles change of driving rods were solved theoretically and compared with each other,and the results showed that both of theoretical calculation curves were very close,but there were high-frequency low-amplitude vibrations in the parallel robot with compliant joints and the maximum relative difference of trajectories of moving platform and of the angles change of driving rods were 1. 02% and 1. 6%,respectively. At the same time,the maximum driving torques of both robots were compared,and the result was that the maximum driving torques of the parallel robot with compliant joints were less than that of the conventional-joint parallel robot. Simultaneously,the trajectories tracking experiments of the parallel robot with compliant joints and the traditional-joint parallel robot were made respectively,which were compared with the ideal circular path,the result showed that the two experimental trajectories changed both basically consistent,but the magnitudes were different.The two experimental trajectories were compared with each other,and the relative difference was 3. 91%.The theoretical and experimental studies proved that it was feasible and effective that the traditional joints were substituted by compliant joints in the parallel robot,which laid foundation for further study of parallel robot with compliant joints.