A Control Method for Assisted Stair Climbing Exoskeleton Robot

Aiming at the demand of assisting power during stair climbing in human attachment, a control strategy of active assisting power in support phase and passive following in swing phase based on force feedback is proposed according to the structural characteristics of lower limb exoskeleton robot. Based on the human-robot interaction force information, a PID control algorithm is applied to realize the passive following control of the swing phase. Aiming at the requirements of the active assist of the support phase on the joint angle and the size of the assist, a composite control method with PID control as the outer loop and sliding mode control as the inner loop is proposed. In order to solve the sliding mode vibration problem, the equivalent sliding mode control algorithm is used, and the sign function in it is replaced by the saturation function. On this basis, the experimental system was built and the experimental study was completed, and the experimental results show that the proposed method can reduce the energy consumption during the human weight-bearing staircase.