基于3-UPS/RRR的并联踝关节康复机构及其性能分析

基于踝关节的生理解剖结构和运动特性分析，提出了一种适用于踝关节康复的3自由度3-UPS/RRR并联机构.该机构采用三个主动支链倾斜布置避开了机构的奇异位形，能满足踝关节康复运动需要，同时约束支链和动平台的设计使机构的转动中心与患者的踝关节转动中心重合.应用解析法得到了机构的位置反解，建立了速度雅可比矩阵和静力雅可比矩阵，求解了机构的工作空间.基于雅可比矩阵，仿真分析了机构的运动学性能和静力学性能.结果表明在规定的工作空间内机构具有良好的可操作性、运动灵活性、刚度特性和力矩传递性能.最后运用牛顿-欧拉法建立了机构的逆动力学方程，得到了驱动力、约束力与运动参数的关系，并给出了仿真实例.

A Parallel Ankle Rehabilitation Mechanism and Its Performance AnalysisBased on 3-UPS/RRR

Based on the physiological anatomical structure and movement characteristics analysis of human ankle joint, a 3 degree of freedom (DoF) 3-UPS/RRR ankle rehabilitation parallel mechanism is presented. Its three active branched chain inclination arrangement avoids the singular configuration of the mechanism and meets the required ankle rehabilitation workspaces. By means of constraint branches and the moving platform, the mechanism center of rotations matches the patient's ankle center of rotations. Inverse kinematics is solved analytically velocity Jacobian matrix and statics Jacobian matrix are established, and mechanism workspace is coped with. Moreover, in view of Jacobian matrix, kinematics performance and statics performance of the mechanism are analyzed and simulated. The result shows that the mechanism is of favorable operability, flexibility, and stiffness characteristics, and its torque transmission is within the specified workspace. Lastly, inverse dynamics equations of the mechanism are modeled by Newton-Euler formulation; the relationship among driving forces, constraint forces and motion parameters are obtained. A computational example is provided.