Nonsingular fixed-time terminal sliding mode trajectory tracking control for marine surface vessels with anti-disturbances

Abstract In this paper, we investigate an accurate trajectory tracking control of marine surface vessels (MSVs) under external disturbances. First, introducing an auxiliary velocity vector, a complicated MSV models can be further simplified. Then, a fixed-time disturbance observer (FDO) is employed to identify external disturbances to enhance the tracking performance of the system. The estimation errors can achieve the origin within a finite time independent of the initial conditions. On the basis of the FDO, in the context of fixed-time sliding mode manifold, a novel nonsingular fixed-time terminal sliding mode (NFTSM) scheme is formulated, by which MSVs can track the reference trajectory with all states globally stabilized in a fixed time. The effectiveness of the developed scheme is validated by numerical simulation results.