冗余驱动并联机构预防故障的力矩分配法

分析冗余驱动并联机构的动力学方程可知,通过合理的分配各驱动器的输出力矩,可以避免部分驱动器过载,有效地延长机构的首次故障时间.从各驱动器的承受能力出发,提出输出裕度的概念,并据此构造了驱动力矩优化模型,以输出裕度来构造加权系数的选择准则,实现对各驱动器的单独调解.推导了输出裕度均衡及部分驱动器输出裕度取均值两种情况下的力矩分配方法,协调系统中各驱动器的承载情况.以一种平面3自由度过驱动并联机构为研究对象,数据计算及分析结果表明所提出的方法对于调节各驱动器输出裕度均衡及防止部分驱动器过载有一定的作用.

Method of torque distribution of redundant actuation parallel manipulator for fault prevention

Through the analysis for the kinetic equation of over-actuated parallel manipulator, it is proved that the partial actuator failure can be avoided by reasonably distributing torque output of each actuator, thus the first occurrence of failure can be deferred. The capacity of each actuator is first discussed in this paper, and then the concept of the output margin is proposed. The drive torque optimization model is accordingly put forward. With the selection criteria of the weighted coefficient constructed from output margin, independent mediation of each drive is achieved. The torque distribution method under balanced output margin and mean output margin of partial actuator is conducted, so the loading of each actuator is coordinated. With a planar three DOF redundant actuated parallel manipulator, the result of calculation and analysis shows that the proposed method is helpful to regulate the balanced margin output of each actuator and thus prevent partial actuators from over loading.