Research On Ship Movement Prediction And Anti-roll Control Method

The movement of ships which is affected by the disturbance such as sea wave and sea wind will give rise to six-dimension complex perturbation. Since the perturbation is stochastic and nonlinear, the movement prediction and anti-roll control are very difficult. So it is important to study ship movement nonlinear prediction and anti-roll control method.The ship movement control is always uncertain, there are the problems of model parameter changing and model structure changing. In view of that, a control system which have the capability of parameter adaptation and structure adaptation should be designed, the multi-level recursive method can well cope with this situation.The multi-level recursive (MR) method has greatly developed the study of the nonlinear control system and achieved accomplishments in both academic study and practical engineering. The multi-level method includes multi-level identification, multi-level prediction and multi-level control. The multi-level identification is used to identify the system model which helps ship movement prediction. The multi-level control has been developed into model free adaptive control (MFAC) for ship movement anti-roll control.This dissertation first applies multi-level recursive method to the ship movement prediction and the ship anti-roll control .In this dissertation, the main study contents are:putting forward ship movement prediction and ship anti-roll control based on MR (multi-level recursive) method.Making further study to the MRP. Simulation comparing study is carried on by taking respectively the traditional AR method and the new type MR method to the same system. The results indicate that the AR method have its limitation to a certain extent resulting from using a fixed parameter model to predict a time changing parameter system. On the contrary, since the MR method use a time...