面向静态稳定的外骨骼机器人阻抗自动化动态控制

Automatic Dynamic Control of Exoskeleton Robot Impedance for Static Stability

针对外骨骼机器人阻抗不稳定、静态与动态的协调控制效果误差较大的问题,为了更好地模拟人的运动技能,该文提出一种面向静态稳定的外骨骼机器人阻抗自动化动态控制方法。分析外骨骼机器人在运动过程中的静态稳定性,计算不同姿态对应的稳定程度,采用sEMG信号组建新型人机技能传递系统,提取人的阻抗信息,将其映射到外骨骼机器人关节空间或者笛卡尔空间,通过力矩控制模式,进行力矩对应的刚度估计,自动化控制目标末端运动轨迹收敛过程。实验结果表明,阻抗控制器的运动轨迹和期望轨迹更加接近,阻抗控制系数均值误差为0.072,均方根误差为0.065,平均误差为0.044,能够更好地完成外骨骼机器人阻抗自动化动态控制。

Aiming at the problems of unstable impedance of exoskeleton robot and large error of static and dynamic coordination control effect,in order to better simulate human motion skills,an automatic dynamic control method for static stability of exoskeleton robot impedance is proposed.Analyze the static stability of the exoskeleton robot in the process of motion,calculate the degree of stability corresponding to different postures,use sEMG signal to build a new human-machine skill transfer system,extract human impedance information,map it to the joint space or Cartesian space of the exoskeleton robot,estimate the stiffness corresponding to the torque through the torque control mode,and automatically control the convergence process of the target end motion trajectory.The experimental results show that the motion trajectory of the impedance controller is closer to the expected trajectory,and the average error of the impedance control coefficient is 0.072,the root mean square error is 0.065,and the average error is 0.044,which can better complete the impedance automatic dynamic control of the exoskeleton robot.