Waypoints tracking for USVs employing fixed-time prescribed performance fuzzy inverse optimal control with marine...

This paper presents a fixed-time control framework for underactuated Unmanned Surface Vehicles (USVs) to track waypoint trajectories under large initial position errors. A Fixed-Time Prescribed Performance (FTPP) guidance law is designed to ensure predefined tracking accuracy. Considering that the Hamilton-Jacobi-Bellman (HJB) equation cannot be directly solved, an optimal control output is derived through a fuzzy inverse optimization approach, while ensuring fixed-time stability. Although fixed-time stability theory ensures that the steady-state time is independent of the initial condition, satisfactory convergence remains difficult to achieve under large position errors. To address this issue, a Dynamic Virtual Guiding Ship (DVGS) mechanism is introduced to replace the original reference trajectory. Finally, the effectiveness and feasibility of the proposed approach are validated through numerical simulations and sea experiments with a 4.9-meter underactuated USV.