Robust Practical Prescribed‐Time Trajectory Tracking Control for ASVs With Mismatched Disturbances Based on Dual Disturbance Observer

ABSTRACT To address the persistent challenge of time‐constrained high‐precision trajectory tracking for autonomous surface vehicles (ASVs) operating in complex ocean environments, this article proposes a robust practical prescribed‐time (PPT) trajectory tracking control strategy. Unlike existing methods that primarily focus on matched disturbances, the proposed approach explicitly considers mismatched disturbances arising from model reduction and simplification. A dual prescribed‐time disturbance observer (PTDO) framework is developed to simultaneously estimate and compensate for both mismatched and matched disturbances. Based on this framework, a prescribed‐time filtering backstepping control (PTFBC) law is developed. By introducing a continuous and smooth prescribed‐time adjustment function, the proposed controller ensures PPT stability while effectively avoiding the over‐conservative settling‐time estimation inherent in fixed‐time and predefined‐time approaches. Furthermore, a prescribed‐time nonlinear filter is incorporated to eliminate the explosion of complexity problem without degrading convergence performance. Rigorous Lyapunov analysis proves that both the tracking and observation errors converge to an adjustable neighborhood of zero within a user‐specified settling time. Numerical simulations demonstrate the effectiveness and advantage of the proposed control strategy.