Modeling And Adaptive Backstepping Sliding Mode Control For Rudder/Fin Joint Roll Stabilization System

Rudder/fin joint control is a new type of anti-sway control strategy on the development based on the fin and rudder roll stabilization.It can make the ship to ensure the accuracy of the heading control at the same time to achieve the purpose of reducing the ship roll when sailing on the sea.Based on the nonlinear mathematical model of ship motion established in this paper,the application of adaptive backstepping sliding mode control is designed for rudder/fin joint control system.The paper's main contents include the following aspects:First of all,based on the idea of MMG modeling,refer to the theory of additional mass and additional inertia moment produced by the movement of the fluid following the ship proposed by Sun Jinhao,the ship mathematical model of four degrees of freedom is established,which can reflect the characteristics of the ship.In addition,considering the complex marine navigation environment,the wind and waves disturbance model is established including wind and wave.According to actual ship data,the simulation of the ship maneuvering test is carried out to verify the correctness of the model.Secondly,an adaptive backstepping sliding mode controller is designed and applied to the rudder fin joint roll reduction control system.Considering the complexity of system and the convenience of designing the controller,the mathematical model of the rudder fin joint system with strict feedback is established.A sliding mode term is introduced to overcome the poor robustness of traditional backstepping,which improve the robustness of the controller.Meanwhile,aiming at the unknown upper bound of the disturbances such as uncertainties of the model parameters and external disturbances,the adaptive algorithm is added to estimate the bound of system uncertainties.What's more,the control system is stable analyzed by Lyapunov stability theory.The results of simulations of the integrated control of roll and course under different conditions show that the controller has excellent robustness to ensure the accuracy of the ship course control,while achieving a better effect of roll reduction.Finally,a nonlinear disturbance observer is designed based on the adaptive backstepping sliding mode control,which estimates the interference terms directly to compensate effect of disturbance of the system.The simulation results show that the proposed algorithm improves the control performance and achieves better control effect.