Adaptive fixed-time control for uncertain surface vessels with output constraints using barrier Lyapunov function

This paper proposes a fixed-time control for trajectory tracking of a marine surface vessel with model uncertainties and prescribed position tracking constraints. The vessel tracking is achieved with fixed-time backstepping using a universal barrier function to constrain the position tracking error. We develop and analyse the controller for a general single-input single-output (SISO) system before extending to the multiple-input multiple-output marine surface vehicle (MIMO MSV) control. Numerical simulations based on a physical test system are provided to demonstrate the efficacy of the solution. We show the proposed controller can provide lower tracking error for the position states and also show that the barrier Lyapunov function (BLF) type control provides to some degree capability to maintain tracking in the presence of unknown disturbance.