Research on Sliding Mode Control for Near-Surface AUV Depth Regulation in Waves Circumstance

The paper addresses the problems of depth regulation control of a torpedo-like autonomous underwater vehicle (AUV) in wave circumstance. A mathematical model of AUV's pith motion in vertical plane is established by simplifying and linearizing the nonlinear 6 degrees of freedom equations of motion at a specified operating point. Sliding mode control (SMC) is introduced for depth regulation and a second-order sliding mode controller is designed to reduce chattering and improve dynamic characteristics. The computer simulation results showed that the proposed controller was effective and satisfactory for resist wave disturbance.