并联式踝关节康复机器人的运动学分析及其优化

Kinematics analysis and optimization of parallel ankle rehabilitation robot

针对踝关节损伤患者的康复训练需求,提出了一种基于2-RURU/RR并联机构的新型人体踝关节康复训练机器人。首先,利用螺旋理论分析了机构运动输出特性和自由度计算,推导出了机构的姿态角位移和角速度方程,并基于数值搜索法求解出了机构的工作空间;然后,利用运动/力传递性能指标对机构进行了运动性能分析,绘制出了机构的性能分布图谱,借助全域传递性能指标对机构进行了优化设计;最后,基于ADAMS进行了运动学仿真,搭建了踝关节康复机器人物理样机,并进行了康复运动试验。实验结果表明:该踝关节康复机器人的转动中心可调,并且具有无耦合的运动学特性;经过优化后机构的优质传递工作空间占比提高了10.8%。运动学仿真和物理样机研究结果表明:康复机器人的运动范围完全能够满足人体踝关节的康复训练要求,该研究可以为此并联式踝关节康复机器人的研发提供理论参考。

Aiming at rehabilitation training requirement for patients with ankle injury,a novel human ankle rehabilitation robot was designed based on 2-RURU/RR-type parallel mechanism.Firstly,motion output characteristic of the mechanism was analyzed and degree of freedom was computed by using the screw theory.The posture angular displacement and angular velocity equations were derived.The workspace of the mechanism was solved based on the numerical search method.Then,kinematic performances were analyzed by using the motion/force transmission index,and the performance distribution map of the mechanism was described.Optimal design of the mechanism was carried out based on the global transmission index.Finally,kinematics simulation was carried out based on ADAMS software,the physical prototype was built and rehabilitation test was performed as well.The results indicate that the rotation center of the designed ankle rehabilitation robot is adjustable,and it has uncoupled kinematic characteristics.After the optimization design,the ratio of the well transmission workspace of the mechanism is improved by 10.8%.The kinematic simulation and physical prototype experimental research show that the motion range of the rehabilitation robot can fully meet the rehabilitation training requirements of human ankle.The paper provides the key theoretical basis for the development of the parallel ankle rehabilitation robot.