Adaptive Backstepping Sliding Mode Control for Rudder/Fin Joint Roll Stabilization System

Considering the influence of wind and waves disturbance, the 4 degrees of freedom nonlinear mathematical ship motion model including roll, yaw, sway and surge is established, which can more fully reflect the nonlinear essence of ship motion. In view of the unknown upper limit of uncertainties such as the change of the model parameters and the external disturbances, the adaptive backstepping sliding mode controller is designed for rudder/fin joint roll stabilization system. The stability analysis of the control system is carried out by using the Lyapunov stability theory. The simulation results show that the algorithm has good robustness under different sea conditions and the control system can achieve better performance on roll stabilization while maintaining the accuracy of course control.