Robust resonant plus proportional tracking controller for diving motion control of an autonomous underwater vehicle

A tracking control problem is addressed in this paper for the diving motion of an autonomous underwater vehicle (AUV). The primary control objective is precisely following a desired trajectory in the presence of underwater uncertainties and disturbances. A cascade control structure has been adopted, comprising an inner pitch control loop and an outer depth control loop. This cascade control framework introduces a Resonant plus Proportional control law to achieve the desired control objectives effectively. Robustness analysis is conducted by introducing parametric uncertainties into the nominal model of the diving motion system, accounting for disturbances and noise. The stability of this proposed control law is meticulously examined. This case study is based on the real-world vehicle parameters of the MAYA AUV. The effectiveness of the proposed control law is assessed via a comparative evaluation against other state-of-the-art control strategies. Through rigorous simulation studies and quantitative analysis, it becomes evident that the proposed controller excels, demonstrating its superior performance when considering both linear and nonlinear models of the diving motion system.