5-UPS/PRPU冗余驱动并联机构的内力分析与协调

摘要/Abstract

摘要：

基于全雅可比矩阵和伪逆法求解了5-UPS/PRPU冗余驱动并联机构的内力，并提出了一种基于冗余驱动变刚度的协调内力的方法。通过求解机构的变形协调方程，得到机构的全雅可比矩阵的加权广义逆，从而求得该5-UPS/PRPU冗余驱动并联机构的内力表达式，通过有限元软件验证了该方法的正确性。以相应的5-UPS/PRPU冗余驱动并联机床为例，分析了冗余分支驱动刚度的变化对各个分支内力幅值的影响，进而提出了一种协调内力的方法。通过分析其内力随冗余分支刚度的变化分布情况可知，非冗余分支各个驱动螺旋以及冗余分支约束螺旋所对应的内力幅值可以通过在一定程度上增大冗余分支的驱动刚度来降低。该方法对机械结构设计人员以及控制系统搭建人员在提高系统精度、降低系统内力方面有重要的参考价值。

关键词: 并联机构, 冗余驱动, 变刚度, 内力

Abstract:

By combining the overall Jacobin matrix and pseudo-inverse matrix method, the internal forces of each driving limb of a 5-UPS/PRPU redundantly actuated parallel mechanism were derived,and a novel internal force coordination method was presented.By using compatibility equation of deformation, the pseudo-inverse of the overall Jacobian of the mechanism could be obtained.The internal forces of the 5-UPS/PRPU parallel mechanism were solved as well,which was verified by finite element method.To investigate the influences of stiffness of the redundant actuator on the internal forces of each driving limb,the 5-UPS/PRPU redundantly actuated parallel machine tool(PMT) was used to illustrate the method mentioned above,and a method to coordinate internal forces was proposed.The analyses show that the actuation wrench of the non-redundant limb and the constraint wrench of the redundant limb can be reduced by increasing the stiffness of the redundant actuator to some extent. The method may be used by mechanism designer and programmer to improve the systems precision and reduce the internal forces of the mechanisms.

Key words: parallel mechanisms;redundant actuation;variable stiffness;internal , force

中图分类号:

周鑫, 许允斗, 姚建涛, 郑魁敬, 赵永生, . 5-UPS/PRPU冗余驱动并联机构的内力分析与协调[J]. 中国机械工程, 2016, 27(06): 711-717.

Zhou Xin, Xu Yundou, , Yao Jiantao, Zheng Kuijing, Zhao Yongsheng, . Internal Force Analysis and Coordination of a 5-UPS/PRPU Redundantly Actuated Parallel Mechanism[J]. China Mechanical Engineering, 2016, 27(06): 711-717.

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