Study Of The Intelligent Control In Course Keeping And Course Turning Of Ship

Ship motion control is very boring, especially for long distance shipping and the bad weather condition. On one hand the high fuel price increase the shipping cost, so the owner has the requirement of the economic shipping. On the other hand the traffic became very busy now, so it's necessary to take accurate control strategy. For the seaman, they don't want to turn the parameter of the controller. All of this call for new autopilot design.Ship course control can be divided into two modes each of them has its own control target. In course keeping, we hope to control the ship in the desired direction, at the same time we want to save fuel cost. But for course turning, to control the ship turn from the current direction to the desired direction, smoothly, quickly, and no overshoot. We should also mention that there will always have disturbance from the environment, such as wind, wave and current. The changing of load and ship velocity and water depth will also influence the dynamic characteristic of ship.First the mathematic model was introduced and proved. Then the traditional PID controller and an improved PID autopilot based on the closed-loop gain shaping method were introduced. Course form algorithm was designed to improve the performance of turning. The linear quadratic optimal autopilot was designed. To suit the variance of environment, an improved neuron adaptive PID autopilot was designed based on the optimal performance index. At last, an integrated autopilot was designed, which contain course keeping and course turning controller. The transform of them was based the change of the desired direction and course error.To verify the performance of the design, simulation system based on MATLAB was designed. A wave simulation algorithm and the index moving average filter were designed. The 5446TEU cargo ship was used as the ship model. The results of simulation show that the autopilot has good performance.