Adaptive State Feedback Shared Control for Unmanned Surface Vehicle With Fixed-Time Prescribed Performance Control

Unmanned surface vehicles (USVs) often encounter unknown obstacles, adverse weather, and emergency situations during missions, especially external disturbances such as wind, waves, and ocean currents at sea, which pose challenges for operators to respond promptly. To solve this issue, a Fixed-time prescribed performance adaptive state feedback shared control method for unmanned surface vehicles is proposed in this paper. The method comprises two parts: autonomous control based on Fixed-time prescribed performance adaptive state feedback for unmanned surface vehicles and shared control with adaptive state feedback, combining direct control commands with autonomous control. To ensure the convergence of tracking errors, a predefined performance control function is designed to guarantee transient error of the tracking error. Subsequently, an error transformation function is introduced for convenient controller design, and a nonlinear filter is used to compensate for boundary errors. Finally, utilizing the backstepping method, a controller is designed, and a Lyapunov function is formulated to verify the stability of unmanned surface vehicles using the designed transformation error. A state feedback shared control function is also designed to implement the shared control algorithm. Experimental results demonstrate the feasibility and effectiveness of this approach.