$\mathbf{H}_{\boldsymbol{\infty}}$ Fault-Tolerant Tracking Control of Autonomous Underwater Vehicles based on HOFAS Theory

This paper proposes a fault-tolerant tracking control method for autonomous underwater vehicles (AUVs) operating in complex underwater environments. The primary objective of this method is to address the challenges posed by actuator failures and external disturbances, which are prevalent in such environments. The proposed approach utilizes a high-order fully actuated system (HOFAS) as the foundation for its fault-tolerant tracking control mechanism. Firstly, the HOFAS model is established, and the controller is designed according to the principles of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H} \infty$</tex> control theory. Then employing the minimax theory formulates an optimal control strategy, thereby ensuring the system's capacity to track a stable trajectory in the face of the worst disturbances. Finally, the results of the simulation demonstrate the efficacy of the method in suppressing faults and disturbances, thereby significantly enhancing the system's anti-interference capability.