PPRRRP和RRRPU肩关节康复外骨骼机构运动性能的分析比较

基于外骨骼机构的构型综合和优选原则，提出PPRRRP和RRRPU两种外骨骼构型.在优选的构型中，通过在人机连接处引入被动关节，使外骨骼机构和人体上臂形成的人机闭链转化为3-DOF（自由度）运动学恰约束系统，实现人机运动学相容.从人机闭链整体的角度，分别建立PPRRRP和RRRPU人机闭链运动学模型，通过对被动关节的合理分解及运动学特征分析，推导其运动学约束方程，并分别求得两闭链的速度雅可比矩阵，该方法降低了人机闭链运动学分析的复杂性.通过对速度雅可比矩阵的数值仿真，在冠状面、矢状面和水平面对2种外骨骼构型进行条件数倒数、可操作度椭球以及灵巧操作速度的分析比较.结果表明：在上述3个面内，PPRRRP构型的运动灵活度、运动各向同性和速度操作灵巧性的运动学性能要优于RRRPU.在此基础上，研制了PPRRRP构型的上肢康复外骨骼样机.

Analysis and Comparison of the Kinematic Performance of PPRRRP andRRRPU for Shoulder Rehabilitation Mechanisms

Based on the configuration synthesis and optimum principles of exoskeleton mechanism, PPRRRP and RRRPU exoskeleton configurations are proposed. In preferred configurations, the two human-machine closed chains which both consist of the exoskeleton mechanism and the human upper limb are translated into an 3-DOF (degree of freedom) exact kinematic constraints system by introducing passive joints at the connection position of the human and the exoskeleton, in order to realize kinematic compatibility. From the perspective of the whole human-machine closed chain, the kinematics models of the human-machine closed chains of PPRRRP and RRRPU are established. Through the reasonable decomposition and kinematic characteristics analysis of passive joints, the equations of kinematic constraint are deduced, and the velocity Jacobian matrices of the two human-machine closed chains are derived, and the complexities of the human-machine closed kinematic chains are reduced by this algorithm. Through the numerical simulation of velocity Jacobian matrices, reciprocal of condition number, manipulability ellipsoid and dexterous operating velocity of the two mechanisms mentioned above are analyzed and compared in the coronal plane, sagittal plane and horizontal plane. The results show that the dexterity, isotropy and dexterity of operating velocity of the PPRRRP mechanism are better than those of the RRRPU in the above three planes. On this basis, an upper limb rehabilitation exoskeleton of PPRRRP is designed.