Model-Based Control and Stability Analysis of Underactuated Autonomous Underwater Vehicles Via Singular Perturbations

This paper presents the control design and stability analysis for path-following of underactuated autonomous underwater vehicles (AUVs), with dynamics restricted to the horizontal plane. As illustration, the time-scale separation caused by different rates of numerous variables is exploited via a singular perturbation model formulation. On the basis of that, a time-scale decomposition method is used to decompose the full system into three-time scale subsystems. The three-time scale structure allows independent analysis of dynamics in each time scale. Therefore, control strategies are designed in each subsystem separately, leading to a reduction of control complexity and a relatively simple control law. This paper also demonstrates the asymptotic stability of the closed-loop system with a composite Lyapunov function candidate and provides alternative, simple but generic mathematical bounds on the singularly perturbed parameters. Finally, the simulation results are presented to illustrate the effective performance of proposed controller.