Disturbance Observer-Based Global Sliding Mode Control for Uncertain Time-Delay Nonlinear Systems

Abstract

ABSTRACT This paper proposes a novel adaptive disturbance observer-based fast terminal global sliding mode tracking control for uncertain time-delay nonlinear systems in the presence of parameter uncertainties, multiple delayed state perturbations and external disturbances. The suggested fast terminal sliding mode disturbance observer guarantees the disturbance approximation error converges to zero in finite time. Under the proposed method, the tracking error trajectories converge to the sliding surface in finite time and the zero-tracking error is achieved. A new tracking control law is introduced and has the salient features such as no requirement of a priori knowledge of the upper bound of uncertainties as well as disturbances and the elimination of the undesirable chattering and reaching phase. Simulation results illustrate the effectiveness and advantages of the proposed control method.