Intelligent Course Control For Large Twin-propeller Twin-rudder Ship

With the rapid development of shipbuilding industry and waterway transportation, Maersk 3E class container ship equipped with twin propellers and twin rudders starts to be used in ocean transportation. Research of modeling, maneuverability and course control for very large twin-propeller twin-rudder ship becomes a very significant project in this area.In this thesis, based on modelling mechanism of MMG modelling ideas, mathematical model of twin-propeller twin-rudder ship has been established considering the hydrodynamic force and moments acted on hull, twin propellers, twin rudders respectively, as well as the influence of environment disturbances such as wind, wave, current.Based on above mathematical model of twin-propeller twin-rudder ship of Maersk 3E class and using Matlab simulation software, the author complete the ship motion simulation. In ship loaded condition, the simulation of turning tests and Zig-zag tests is finished. By comparing simulation data with real ship test data, the validity of twin-propeller twin-rudder ship model is proved. Under the condition that the ship is at high speed and loaded state, the simulation of twin-propeller individual control is tested. Compared with twin-rudder synchronous control, individual twin-propeller control can make a ship turn on a smaller area and if we make one propeller rotate positively and the other propeller rotate oppositely, we can find that this control pattern make the decrease of turning track area more obvious to prove that twin-propeller twin-rudder ship has good maneuverability and flexibility.Based on mathematical model of twin-propeller twin-rudder ship, the author studies the intelligent course control of twin-propeller twin-rudder ship. The author mainly designs three types of course control algorithms, which are linear and nonlinear active disturbances rejection controller (LADRC and NLADRC) based on active disturbances rejection control theory and variable parameter PID controller for comparison. In different sea condition, ship course and rudder angles under the action of three types of controllers are simulated and investigated to compare and analyze the quickness, stability and robustness of three types of controllers and verify the effectiveness of intelligent course control algorithms.