Adaptive trajectory tracking control of space manipulator with fast fixed-time convergence

This paper investigates the problem of fixed-time tracking control for a space manipulator subject to internal uncertainties and unknown disturbances. To shorten the system’s response time, a novel globally fast fixed-time stable system is first developed. Based on this system, a novel non-singular terminal sliding mode surface is designed, which ensures fast and fixed-time convergence regardless of the initial states. A robust fast fixed-time sliding mode controller is then constructed by combining an adaptive mechanism, which can guarantee the tracking errors converge quickly to small regions around the origin within a bounded time. With the proposed control method, there is no required to know prior information about the bound of the lumped uncertainty. The suggested scheme is analysed using the Lyapunov stability theory, and the effectiveness is demonstrated through numerical simulations.