人机相容型肩关节康复外骨骼机构的运动学与灵活性分析

For the rehabilitation needs of shoulder joint movement disorder, a 3R-PU serial shoulder rehabilitation exoskeleton mechanism is proposed to realize the movements of abduction/adduction, flexion/extension, internal/external. To realize human-machine kinematic compatibility, the human-machine closed chain which consists of the exoskeleton mechanism and the upper limb is translated into an exact kinematic constraints system with three degrees of freedom by introducing a passive sliding pair P and a hooke hinge U in the human-machine interface. Based on the kinematic coupling analysis of related joints in shoulders, the position changes relationship of the center of glenohumeral joint (CGH) relative to the location of the sternum are obtained. The angular displacement curves of kinematic pairs of the exoskeleton mechanism are acquired by establishing the model of the human-machine closed chain and solving the position inverse solution. Furthermore, the velocity Jacobian matrix of the human-machine closed chain is derived and the kinematic dexterity is analyzed. The results show that the motion amplitude of passive joint P and U are larger in the rehabilitation training process, passive joints introduced are beneficial to release motion constraints of human-machine interface, and then the constraint intensity of human-machine is reduced. Meanwhile, this exoskeleton mechanism has better kinematic dexterity when the upper arm is elevated at 0°, 45°, 90° and 135° lifting surface. The above research results will provide analysis basis for the exoskeleton mechanism motion planning and control.