Sliding mode controller by using adaptive exponential reaching law based on nonlinear disturbance observer

Abstract

Aiming at the position tracking control problem of flexible jointed manipulator in the uncertainties and external disturbances, this paper proposes an integrated nonlinear disturbance observer (NDOB) and a non-singular fast terminal sliding mode (NFTSM) control method based on adaptive exponential reaching law (AERL). The NDOB is designed to ensure that the time-varying disturbance is suppressed in finite time. The AERL is designed to improve the track tracking speed and reduce the chattering of the control input. Simulation results show that compared with the optimal ARL, the proposed method reduces the trajectory tracking error by 1.3 %, improves the trajectory tracking convergence speed. Experimental results show that the proposed method reduces the trajectory tracking error by 0.545 %.