AN APPROACH FOR SEMG-BASED VARIABLE DAMPING CONTROL OF LOWER LIMB REHABILITATION ROBOT

Most control methods for rehabilitation robot lack human active participation during gait rehabilitation. They cannot guarantee the patient's maximum voluntary motion ability and satisfy the physiological gait trajectory requirement meanwhile. Therefore, a variable damping control method based on surface electromyography (sEMG) is proposed. In this method, the patient's muscle activity level is evaluated in real time by the integral electromyography value of the sEMG signal, and the damping parameter is adaptively adjusted. Hence, the patient's active effort is stimulated through the variable damping parameter while the gait trajectory is not modified. The performance and efficiency of this sEMG-based variable damping control method were tested and validated among six healthy volunteers. The experimental results demonstrate that the variable damping controller can adaptively adjust the damping parameter through the subject's muscle activity level compared with the traditional impedance control method. Furthermore, it can stimulate the subject's active torque with the unchanged gait trajectory to make subjects actively participate in gait rehabilitation training, which is a benefit for improving the rehabilitation effect.