Modelling and application of ocean wind disturbance for ship dynamic positioning simulator

This work presents sea wind speed model and wind disturbance model for Dynamic Positioning (DP) simulator. There were several problems in the existing DP simulator: wind speed was constant, or wind coefficients of wind disturbance was taken as to the feedforward force wind coefficients directly, or wind speed was not filtered. It caused that the feedforward force was equal to the wind disturbance, which did not meet the actual situation of DP ship. To solve the problem, sea wind speed model is built based on combined wind speed model with ocean wind spectrum, whose simulation results correspond with the actual results. Wind speed filter was designed based on Kalman filter algorithm. Wind disturbance model and DP feedforward controller was designed. Finally, the simulation research was done on a DP offshore support vessel to verify the effectiveness and reliability of model and algorithm, which have been applied to the related subsystem of DP simulator.