Research on the sliding mode control for underactuated surface vessels via parameter estimation

This brief proposes an adaptive sliding mode control law for an underactuated vessel via parameter estimation to follow a desired path. An adaptive continuous PI sliding mode scheme is devoted to enhancing the robustness of the control system and reducing the system oscillation in presence of unknown plant parameters and environmental disturbances. To address model uncertainties and unknown environmental disturbances, an adaptive parameters estimation and an upper bound estimation scheme are incorporated with the control scheme. In addition, a novel virtual control approach based on backstepping and adaptive dynamical sliding mode control is designed to relax the assumption of passive boundedness in sway motion. Under this kind of consideration, a certain nonlinear scheme is proposed to guarantee sway velocity uniformly ultimately bounded by Lyapunov direct method. Finally, numerical simulation results are given to demonstrate the effectiveness of the proposed method.