Fault-resilient prescribed performance cooperative control for fully actuated unmanned surface vehicles with sensor-fault-induced cooperative abnormalities

This paper develops a fault-resilient prescribed performance cooperative control scheme for multiple fully actuated unmanned surface vehicles (USVs) subject to unknown nonlinear dynamics, ocean disturbances, and sensor-fault-induced cooperative abnormalities. Faulty pose measurements may contaminate the cooperative errors generated by the coordination layer and consequently invalidate conventional prescribed performance constraints. To address this problem, a sensor-fault-induced cooperative abnormality model is first established, followed by a multilayer flexible prescribed performance control (MLF-PPC) mechanism. Two boundary-approaching rates are introduced to evaluate the feasibility of the active performance constraint. When the original boundary is threatened, the admissible region is temporarily enlarged; when the flexible boundary is critically approached, the barrier-type constraint is switched off to avoid transformation singularity and is smoothly recovered after the abnormality subsides. A post-cooperative channel regulator further attenuates severe transformed cooperative signals. Based on the regulated errors, a multilayer feedforward neural-network adaptive controller with a high-frequency robust compensator handles unknown nonlinear dynamics, residual approximation errors, and external disturbances. Lyapunov analysis establishes uniform ultimate boundedness of all closed-loop signals. Comparative and robustness simulations demonstrate the effectiveness of the proposed scheme.