腕部康复机器人助动训练的力反馈控制

Force Feedback Control for Assistive Mode Training of the Wrist Rehabilitation Robot

研制了一种3自由度腕部康复机器人并设计了具有力反馈功能的助动训练控制系统.采用力传感器及转矩传感器检测人腕部施加的力或力矩,根据作用力确定电机需要提供的助动力,以使患者腕部保持可承受范围内的压力,充分发挥患者已恢复的运动能力并实现康复机器人助动训练.电机控制系统中的电流环和速度环采用比例-积分调节器,位置环采用滑模变结构控制,具有控制精度高、稳定性强的特点.与采用脑电信号或肌电信号作为反馈控制的方式相比,采用力反馈控制的可操作性更强、精度更高且稳定性更强.同时,通过模拟实验验证了所提出的助动训练控制系统的有效性.

A three degrees of freedom(DOFs)wrist rehabilitation robot and the assistive control system with the force feedback function are designed.The assistive force provided by motors is determined according to the force/torque detected from the patient.The system ensures the patient can keep the same force/torque in assistive training.Compared with the electro-encephalogram(EEG)or surface electromyography(sEMG),the force feedback possesses many advantages such as high operability,accuracy,stability and low cost.Three closed loops with current,velocity and current system are applied in the control system.Proportional-integral(PI)regulator is applied in both current and velocity loops,and sliding variant structure regulator is adopted in the position loop,which effectively improves the accuracy and robustness of the system.System simulation has proved the validity of this control system.