Study On Modeling Of Ship Motion And Controlling Of Ship Course Considering The Various Speeds

Ship maneuverability processes complicated and changeful characteristics.The varieties of ship speed directly affect ship maneuverability.Therefore,these issues should be taken into account in the control research on ship steering.With the rapid development of international shipping,the ships are getting larger,more high-speed and maritime transport and the fiver traffic has become increasingly busy and crowded. often navigate in port,the narrow waterway or dangerous waters.Thinking of them,this article discusses the rudder effect of the ship and the intelligent control algorithm of the course in different speeds.Thinking of the characteristics of the ship in different speeds,such as constant speed,low speed and the rotation of the engine,this paper adopts MMG modeling ideas, combined with constant speed and low-speed,large drift angle,taking into account the continuity of the ship movements,and establish the mathematical model.The models are verified via turning simulation calculation compared with the data from the trial voyage condition in different speed.The result indicates that the datas of the simulation is consistant with the ones of the trial voyage condition and the models are valid.Based on the models,this paper verifies the rudder effect of the ship in different speeds.At the mean time,it includes the rudder effect of the ship in different engine speed.The results of simulation indicates that the higher the speed is and the faster the engine is,the better the rudder effect is.When the ship sails at the low speed,we can increase the engine speed to improve the rudder effect.For the Control algorithm,this paper derives the algorithm of BP networks and combines neural network and PID controller to establish BP neural network-based intelligent PID controller.Using Matlab,this paper established various parts of the system with S-function modules in simulink.Combining the controller and the models above,realizes the simulation of the turning cycle and course-controlling at low speed. From the simulation,we can find that neural network PID controller can adjust the parameters of PID on line and it can be manipulated to improve the performance of the ship's autopilot in different speeds,specially in low speed.