Path following and stabilization of underactuated surface ships

To solve the path following and stabilization problems for underactuated surface ships with nonintegrable acceleration constraint, a nonlinear feedback algorithm is presented using decoupling control method and iterative nonlinear sliding mode designing approach. The saturations on actuators and unknown environmental disturbances are also explicitly considered. Integrating with simple increment feedback control laws, a dynamic control strategy is developed to fulfill the underactuated following and stabilization objectives with only surge force and yaw movement available. Numerical simulation results on a full nonlinear hydrodynamic model of a training ship are presented to validate the effectiveness and robustness of the proposed controller.