Tracking Control of Autonomous Underwater Vehicle Based on Sliding Mode Adaptive Optimal Feedback

To improve the tracking control of autonomous underwater vehicles, an adaptive sliding mode optimal tracking control method for linear continuous systems is proposed by combining adaptive control and sliding mode technology. The vertical state equation of an autonomous underwater vehicle is simplified according to the actual situation. Firstly, the linear sliding mode surface is designed and the state optimal feedback controller is established. Then, considering the performance index function and linear quadratic value function that meet the system requirements, the Riccati equation is linearly parameterized, and an online learning algorithm driven by parameter estimation error is introduced to approximate the optimal solution of the equation. Finally, the stability of the closed-loop system and the convergence of the error are proved by Lyapunov theory. Simulation results demonstrate that the proposed method effectively achieves depth tracking control with dynamic response, high tracking accuracy, and robustness.