自对准人工膝关节的人机匹配设计

Human-robot matching design of self-aligning artificial knee joint

针对膝关节处人-机系统错位的问题,提出两自由度自对准人工膝关节机构.为了模拟生物膝关节的屈伸运动,该装置采用2个电机对自对准人工膝关节进行驱动.对机构进行运动学分析,建立人-机耦合的运动学模型,将人工膝关节与生物膝关节间的错位定量地描述为机构绑带点与小腿参照点的摆角偏差和位置偏差.以缩小偏差为目标,提出基于粒子群优化的人-机系统运动匹配方法优化关键部件参数,在绑带点趋近参照点的过程中,人工膝关节摆角趋近小腿屈伸角度.采用高速相机测量个体小腿的运动数据,以测量结果为参考进行人机匹配操作.建立数字虚拟样机,开展仿真实验.通过MATLAB-Adams联合仿真,对动态过程中人工膝关节与个体小腿运动的匹配效果进行验证.结果表明,该人工膝关节在其工作空间内可以实现运动匹配与摆角自对准.

A self-aligning artificial knee mechanism with two degrees of freedom was presented aiming at the problem of human-robot system misalignment at the knee joint.The mechanism was driven by two motors to simulate the flexion and extension movements of the biological knee joint.A kinematic model of human-robot coupling was established to quantify the misalignment as the deviation of the swing angle and position of the mechanism’s connecting point from the reference point of the calf.A particle swarm optimization(PSO)-based endmatching method for human-robot systems was proposed in order to reduce deviations and optimize the parameter of the key component.The swing angle of the artificial knee joint approaches the knee flexion and extension angle in the process of the bandage point approaching the reference point.A group of high-speed cameras was used to measure the movement data of individual lower leg,and the human-robot matching operation was conducted with the results as a reference.A digital virtual prototype was developed to conduct simulation experiments.The matching effect of the artificial knee joint and individual calf motion was verified through a joint simulation of MATLABAdams.Results show that the artificial knee joint can achieve motion matching and self-alignment of the swing angle.