Fixed-time trajectory tracking control for unmanned surface vessels in the presence of model uncertainties and external disturbances

Abstract

This paper proposes a fixed-time sliding mode control scheme for the rapid and accurate trajectory tracking of a fully actuated USV in the presence of model uncertainties and external disturbances. First, a novel fixed-time nonsingular sliding mode manifold is developed based on the bi-limit homogeneous theory. Then, a fixed-time sliding mode controller is designed to track the desired trajectory of the USV based on the fixed-time sliding mode manifold. Rigorous theoretical analysis for the global fixed-time stability of the whole closed-loop system is provided. The proposed fixed-time sliding mode control scheme can guarantee the position and velocity tracking errors converge to zero in fixed time with strong robustness against lumped uncertainties. To the best of the authors’ knowledge, there are really limited existing controllers can achieve such excellent performance under the same conditions. Numerical simulations illustrate the effectiveness and superiority of the proposed control scheme.