Nonlinear Robust Sliding Mode Control for Dynamic Positioning of a Surface Vessel

Offshore explorations and operations are increasing day by day looking for ocean resources and dynamic positioning (DP) systems are incorporated with these offshore vessels. DP controllers send appropriate signals to thrusters in order to maintain its location and heading or to follow a predetermined path at slow speeds. Since the ocean environment is dynamic and nonlinear, it is necessary that a robust controller achieve desired objective. This paper focus on the design and numerical simulation of a robust Sliding Mode Controller (SMC) for dynamic positioning fully actuated surface vessel under input saturation and time varying unknown environmental disturbances.