Ship Course Control Study Based On Sliding Mode Variable Structure

In the modern ship moving system, an autopilot for a ship (also known as an automaticoperation navigating instrument) is an important device in the core part of ship control system.The performance of the ship autopilot determines the safety and efficiency of the voyage, andthe feasibility of dynamic position of ships, automatic obstacle avoidance and the automaticobstacle avoidance and ship tracking track, and the study of the ship autopilot is always thefocus in the field of ship control system and the worldwide basic topic in the field of shipstudy. The performance of the ship autopilot’s maneuvering on the motion of the ship is oneof the indexes that are used to evaluate the performance of the ship maneuvering capability.With the emergence of advanced navigation equipment, people’s demand on the controlrequirements of the ship becomes also higher, and ship track control will be the maindevelopment direction. Because the movement of the ship has a large inertia, large delay andnonlinear characteristics, the speed and load changes lead to the model parameter perturbation;disturbance caused by the flow of wind and waves can produce ship dynamic uncertainty, and,therefore, the main consideration of ship course study controller will be strong robustness.Fuzzy control and sliding model variable structure control has strong robustness, and thecombination of them can achieve reciprocal advantages. So in this paper, the fuzzy slidingmode variable structure control is applied to ship course control and the hybrid intelligentcontroller and its simulation are researched.First of all, the ship control technology background, the history of control technologydevelopment and its current situation, and the situation of the control strategy of the automatichelm are reviewed in this paper. After the analysis of the dynamic equations of the shipmaneuvering movement, the nonlinear model of ship heading control and wind, wave andflow of interference model are established. Second, briefly introduce the basic principle of thecontrol of the ship’s course, and study the variable structure control system’s mathematicalmodel and design process. On the analysis of flaws of the variable structure control, putforward a kind of fuzzy sliding mode control algorithm, according to the requirements of theship’s course changes in different sea states. cirst, the basic theory of sliding mode control isdiscussed, on the basis of which this paper analyzes the characteristics of ship course control,a special kind of controlled objects, and thus the ship’s course sliding mode controltechnology is put forward and the ship’s course variable structure control system is designed.Through the simulation this controller has more robust than the traditional PID control, and,in order to further improve the control performance of the sliding mode controller, and, to a certain extent, chattering phenomena, the fuzzy sliding mode controller is designed.Combining the respective advantages of the fuzzy control and variable structure control,improve the accuracy and efficiency of the ship’s course control system. Finally, thesimulation results are presented for the controller, which shows that the designed controllercan achieve good control effect.