绳牵引康复机器人的工作空间分析与运动学研究

Workspace analysis and kinematics study of a wire-driven rehabilitative robot

针对在康复训练过程中如何协调控制患者的骨盆运动轨迹问题,设计了由4根绳牵引的3自由度绳牵引并联康复机器人。基于力/位混合控制的思想,给出了一种基于矢量封闭原理和特定的力/力矩条件的可控工作空间分析方法;用影响系数方法建立了绳牵引康复机器人的运动学方程,得出骨盆运动与绳运动的映射关系;并采用Matlab软件和Simulink工具对骨盆在步态运动过程中的运动轨迹进行了仿真研究。结果表明:该工作空间分析方法可以直观地判断绳牵引康复机器人的机构参数是否满足设计目的要求,绳的速度值和加速度值与骨盆的速度值和加速度值是同数量级的。

A wire-driven 3DOF parallel rehabilitative robot was designed with the aim of realizing coordination and control of the trainer pelvis movement during the course of rehabilitative training. Based on the idea of force/position hybrid control, an analytical method of controllable workspace based on the principle of vector closure and the condition of given force or moment was presented. The kinematics equations were established by the influence coefficients so that the mapping relations between pelvis-motion and wire-motion could be obtained. Pelvis＇ trajectory in walking was simulated and analyzed by Matlab/Simulink. The results show that the workspace analytical method can directly judge whether the machine parameters of wire-driven parallel robots would meet the design requirements or not and that the values of velocity and acceleration of the wires are of the same order of magnitude as that of the end-effectors.