Underactuated Ship Track Control Based On Fuzzy Sliding Mode PID

Ship motion control can shorten sailing time and save energy by designing reasonable control algorithm,so it has important research significance.This paper aims at the characteristics of non-linearity and susceptibility to external disturbance of underactuated ships,and also the physical meaning of parameters in PID control is not obvious,easy to influence each other and is not conducive to parameter adjustment.So the fuzzy sliding mode PID control algorithm is proposed combining the advantages of sliding mode control and fuzzy control.The algorithm can simplify the controlled system without establishing a complete mathematical model of the controlled object,and the parameters are less influenced by each other in the process of fuzzy tuning,as well as less affected by external disturbance.On this basis,the control of ship’s straight track can be well optimized.In the design process of ship track control,by analyzing the physical meaning of the parameters of hyperbolic tangent function,a control algorithm using fuzzy control to optimize hyperbolic tangent function is proposed,which can adjust the ship running curve continuously according to the feedback signals,so as to shorten the sailing time.In this paper,the experiments are carried out on the MATLAB Simulink simulation platform,the establishment of the ship model choosing MMG model for more fitting the navigation reality.Through the comparative simulation analysis of the experiment,it can be proved that the proposed fuzzy sliding mode PID controller has the advantages of faster response rate,no overshoot,smaller steering frequency and certain anti-interference ability through the verification of heading control,it provides favorable conditions for the next step of ship track control.In the stage of ship track control,compared with the condition of using the hyperbolic tangent function directly,the simulation results of using the fuzzy control to adjust the hyperbolic tangent function have a faster response rate,shorter time to complete the position convergence and course convergence,and better robustness,and the control advantage is relatively obvious.