过驱动并联机器人驱动力矩的特解构造法

Driving torque special solution constructive approach of redundant actuated manipulator

以一种平面三自由度过驱动并联机构为研究对象,分析其运动学方程,并采用虚功原理和等效力方法推导了该机构的动力学模型.讨论过驱动机构的容错性,给出了故障前后驱动关节力矩突变的定义.分析过驱动机构逆动力学方程解的不确定性,从提高机构的可靠性以及容错性角度出发,提出一种新的过驱动机构驱动力矩分配思路,以驱动器集可靠度作为系数乘子,采用故障后力矩分配的确定解构造过驱动机构输入力矩的不确定解.将这种方法与传统的力矩分配方法所得到的各关节力矩突变之和进行比较,数据计算结果表明该方法具有更好的容错性能.

Taking redundant actuated manipulator with planar 3 degree of freedom as subject investigated, the kinematics model was deduced. Based on the virtual work principle and the equivalent force theory, the dynamic model was built. After the fault tolerant performance of redundant actuated manipulator was discussed, the force abrupt change of driving joint before and after fault occurrence was defined. Furthermore, the uncertainty of redundant actuated manipulator dynamics inverse solution was analyzed. To improve the reliability and fault tolerant performance, a new force allocation approach was brought forward. By taking the reliability of actuator as coefficient multiplier, the uncertain solution was constructed from the certain force allocation solution after failure. The sums of force abrupt change got calculated with traditional approach and this new method were compared. Data simulating result indicates this approach has an outstanding fault tolerant performance.