绳索牵引康复机器人的动力学建模与控制

Dynamic modeling and control of a wire-driven rehabilitation 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根绳索牵引的三自由度绳索牵引并联康复机器人.基于力/位混合控制的思想,利用牛顿-欧拉法建立了绳索牵引康复机器人的动力学模型.以轨迹控制为目标,用计算力矩法设计了基于刚性模型的位置控制器,就绳索的刚度对机器人系统性能的影响进行了仿真分析;以刚度控制为目标,推导了机器人系统的刚度矩阵,并对康复机器人进行了仿真验证.理论分析和仿真结果表明,系统的刚度与绳索的张力有关,调整绳索的内张力可以改变系统刚度,实现对机器人系统的柔顺性控制.

A wire-driven parallel robot was designed to coordinate and control a subject＇s pelvic movements during the course of rehabilitative training. Based on the idea of force/position hybrid control, using the Newton-Euler equations, a dynamic model was established. Taking trajectory tracking as the aim of control, a positional controller based on the stiffness model was designed by the calculation of moments method. The impact of wire stiffness on robot system performance was simulated and analyzed. Taking stiffness control as the goal, a stiffness matrix of the robotic system was derived. The rehabilitative robot was then simulated and validated. The results show that systematic stiffness of the robotic trainer is related to wire tension. This can be changed by adjusting wire tension, allowing compliant control of the robot system.