Straight-path Following Control Of Underactuated Ship

With the rapid development modernization and intellectualization of underactuated ship, traditional automatic course control can not meet the actual needs. Therefore, the ship straight-path following control is becoming a common and traditional control strategy, has begun to attract more and more attention;To the complexity and nonlinearity of underactuated surface vessels, the paper considering the wind, wave and current disturbance and ship's horizontal drift, established a straight-path following nonlinear mathematical model;To the nonlinearity of ship straight-path following control system model and the lateral drift problem of ship motion,the paper combines backstepping with sliding mode method, simple and practical, realistic, a global asymptotic convergence control law is presented;To the actual situation of the control law, the paper uses MATLAB Simulink toolbox to establish a nonlinear hydrodynamic model of 3 degrees of freedom,and takes advantage of the Sever/Lient simulation platform to validate the control law;The simulation results validate that the control law can effectively solve the the lateral drift of ship. The controller is not sensitive to outside disturbances, the control law is able to steer a ship on the prescribed straight path. Numerical simulation shows the effectiveness and strong robustness of the control law proposed in this paper;This research in theory and practice has its significance, the algorithm can be used in the actual works, lay the foundation for the application of a real ship; it also provides a theoretical foundation to navigation simulator research and development.