The Control In The Course And Speed Of High Speed Ship

The high speed planning craft belong to a kind of very important and common high speed ships. Due to its advantages of small size, high speed, strong maneuverability and flexibility of operation, the high speed planning craft is well applied in military and civil aspects. The most research has not considered the change of navigation status and uses the single hydrodynamic model for high speed planning craft. In fact, hydrodynamic will change along with the change of navigation status, and the difference will be big. There are obvious limitations with only one hydrodynamic model at different speeds of the planning craft. The major objectives of this study are to establish the motion mathematical model of planning craft in the calm water and under the sea wind disturbance, research its open-loop motion feathers, and design course and speed controller.At first,this paper establishes inertial coordinate system and body-fitted coordinate system for high speed planning craft, and gives coordinate transformation relation. In the horizontal body-fitted coordinate, the paper derives the six freedom motion equation of planning craft. Based on ideas of the MMG separation model, this paper divides external forces of planning craft into inertial hydrodynamic force,viscous hydrodynamic force,restoring force(gravity, buoyancy), lift force, damping force, propeller propulsion force and rudder force. After studying the mechanism of the hydrodynamic forces, this paper gives the estimating formulas of hydrodynamic forces directly. At the same time the paper gives the mathematical calculate models of the propeller propulsion force and rudder force. Hereto, a motion mathematical model of planning craft in calm water and in different sailing states is established.Then, under the assumption of stationary wind, the paper researchs the sea wind disturbance model and adds it into the motion equation of planning craft in calm water. So the motion equation of planning craft under sea wind disturbance is established, and the maneuvering of planning craft under the wind disturbance can be studied.At last, the five degree motion equation of planning craft is established by simplifying the above model. The paper uses S-Function to establish simulink model and uses 4th order Runge-Kutta method to solve the equation. The paper predicts open-loop moving features of planning craft in calm water and in sea wind environment respectively, and gains satisfactory simulation results. Due to strong nonlinearity of the model, the paper designs and improves course sliding mode variable structure controller and speed fuzzy controller. Compared with the simulation results of the conventional PID controller, we can find clearly that the improved course sliding mode controller and speed fuzzy controller have faster dynamic response and better stability.