Fixed‐time non‐singular terminal sliding mode control with globally fast convergence

Abstract

This paper investigates a fixed-time terminal sliding mode (TSM) control scheme of second-order non-linear uncertain systems. A globally fast fixed-time stable system is proposed, and the convergence time is established with the Lyapunov method. Then, a novel non-singular TSM utilising the proposed fixed-time stable system and an auxiliary polynomial function is constructed. Meanwhile, a fixed-time disturbance observer technique is employed to estimate the matched lumped perturbation. Globally fast fixed-time convergence of the closed-loop system is guaranteed with the phase plane analysis and Lyapunov tools, and the upper bound of the settling time independent of the initial conditions can be predefined by the controller parameters. Finally, the simulation results of a single inverted pendulum system are included to confirm the validity of the proposed methodology while comparing with some popular TSM control strategies.