Integral sliding mode control of cable-driven rehabilitation robot based on nonlinear extended state observer

Abstract

Cable-driven robots have been applied to the field of rehabilitation, to improve the rehabilitation effect of patients during passive training, an integral sliding mode control method based on nonlinear extended state observer (ISMC-NESO) is designed. Firstly, considering the movement of the cable winders along the rail brackets, the moving platform model and driving model of the robot are established by Lagrange method. Then, the NESO is used to estimate the reaction force of human joints and external interference, and the inverse hyperbolic sine function is used to select the parameters in the initial stage to suppress the differential peak phenomenon. Finally, the error feedback rate is designed combined with integral sliding mode control to improve the trajectory tracking performance of the system, the stability is analyzed by Lyapunov function. The simulation results show that the designed ISMC-NESO method has good tracking effect and can be applied to the rehabilitation training of patients.