The Research Of Oblique Rudder Ship Comprehensive Tabilization Control And Prediction Method

The ship stabilization and prediction is one of important topics about naval architecture and ocean engineering. On the basis of the tenth five-year national defence advanced foundation program-the control research of shipping rudder stabilization, this thesis, from the perspective of modeling and control, discusses the ship motion control and researches the methods of ship motion model prediction, adopting the oblique rudder as stabilization equipment.Firstly, it sets up the equation of the oblique rudder ship movement based on the strip theory, which provides the mathematics model for the research on stabilization of ship oblique rudder. Secondly, it utilizes the improved algorithm of minimum recursive square method to model wave disturbing force and disturbance torque, and analyses the estimation method of wave disturbing force and disturbance torque.Combining wave disturbing model and oblique rudder motion model, the outward shipping motion model with white noise as the new system interference is shown. For the new expanded system, the method of linear quadratic Gaussian control is used to calculate expanded Kalman filtering gain matrix and the optimal expanded random control gain matrix and the influence caused by the angle of oblique rudder is provided. The simulation result indicates that utilizing classical LQG control on the basis of oblique rudder method to realize ship's reducing vertical and horizontal shake control is feasible.The hydrodynamic parameter of shipping model is obtained through test under certain sea circumstance, thus the robust feature research of ship motion and disturbing stance that Kalman estimates is needed when the hydrodynamic parameter changes near the normal value. Therefore, the thesis sets up the probability model of oblique rudder ship motion and disturbing stance Kalman estimates, further makes robust statistic feature analysis on disturbing Kalman filter, and displays the analysis results on the effect on horizontal and vertical shaking when there is error of steering.When the systematic hydrodynamic parameter changes obviously and frequently, its hydrodynamic parameter matrix appears singular. For the shipping parameter uncertainty of regular perturbation, singular perturbation and wave disturbance, this thesis proposes the robust control method of singular system, which can reduce the control system's dependence on the model to a great extent. The robust control method of singular system is utilized to simulate ship's reducing vertical shake course, which proves the validity of this method.Finally, for the modeling prediction of ship motion stance under the random wave disturbing, the thesis adopts the improved smooth cyclic graph method, makes modeling prediction of ship motion stance, gets the predicting curve, analyzes and summarizes the predicting result. This thesis also compares the precision between smooth cyclic graph algorithm and direct cyclic graph algorithm and analyzes the complexity, realization and practicability of the two algorithms.