Trajectory Tracking Controller Based On Command Filter And Twisting Algorithm For Marine Vessel

With the rapid development of marine transportation industry in recent years,the vessel's motion control has also aroused more attention.However,the marine vessel trajectory tracking control has also attracted many domestic and foreign scholars to start research.Vessel trajectory tracking gradually plays an increasingly important role in the exploration of marine resources,unmanned ships and other military and civilian areas.For marine vessel trajectory tracking control system,we mainly 'consider two cases about full actuated and underactuated ship with unknown external disturbance,and construct controller to realize the trajectory tracking control by backstepping and sliding mode control in this thesis,respectively.And by using Lyapunov stability and matlab simulation,we prove the correctness of the marine vessel's trajectory tracking controller.The thesis mainly includes the following parts:(1).For the full actuated vessel control system,first of all,a finite time disturbance observer based on the Super Twisting is constructed,then a finite time backstepping controller is designed using the backstepping technology.But it is necessary to calculate the virtual control derivation,which will lead to the controller singularity problem.In order to avoid this problem,the finite time filter based on Levant differentiator is used to replace the derivation of virtual control.To eliminate the filtering error,we introduce the filtering error compensation mechanism in this thesis,which can improve the system's steady-state performance.Finally,a nonsingular finite time controller is designed,and the correctness of the proposed algorithm is proved by finite time stability theory and matlab simulation experiment.(2).For underactuated vessel control system,surge controller and yaw controller based on the backstepping technology is constructed.In the process of surge controller design,the virtual control's denominator consists the heading-angle tracking error's cosine.In order to overcome the singularity problem,prescribe performance algorithm is adopted in the process of vessel sway controller design to meet the requirements of controller design.Then the filter and the filtering error compensation mechanism are used respectively in the design of the two controllers.And finite time trajectory tracking controller is verified by matlab simulation.(3).In order to improve the robustness of vessel control system,vessel motion controller is designed by sliding mode control method.Firstly,a new PID non-singular fast sliding mode surface is proposed,then RBF neural network is used to approximate the unknown disturbance,and the adaptive law is used to obtain the maximum estimation error to reduce chattering.However,to further improve the controller robustness,a second order sliding mode controller is designed based on Twisting algorithm.In order to reduce chattering phenomenon,an improved vessel trajectory tracking controller based on Twisting algorithm is proposed.Through theoretical analysis and matlab simulation,the effectiveness of proposed algorithm is demonstrated.