Proximal Policy Optimized Tube MPC Fault-Tolerant Control for Thrusters in AUV

This paper investigates a fault-tolerant control (FTC) method for underwater vehicles, specifically focusing on small autonomous underwater vehicles (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{S}-\text{AUVs}$</tex>) experiencing thruster faults. We propose a novel control strategy that combines Proximal Policy Optimization with Tube Model Predictive Control (PPO Tube MPC) to enhance system performance under fault conditions. By leveraging PPO-trained policy to adaptively adjust the auxiliary feedback control law parameters in Tube MPC, this method reduces controller conservativeness while maintaining system stability during fault handling. Simulation results demonstrate that our PPO Tube MPC method significantly outperforms traditional control methods in reducing tracking errors. The PPO-trained policy exhibits strong generalization capability, maintaining effective control across diverse tasks and varying fault occurrence times.