Modeling and simulation of marine environmental disturbances for dynamic positioned ship

The effect of marine environment on the ship dynamic positioning (DP) systems is the foundation of performing control law design and the necessary step. In order to effectively calculate the effect acted on dynamic positioned ship by ocean environment, mathematical model of the ocean environmental disturbances include wave and wind was established. Based on the Matlab/Simulink, a simulation platform for the wind and wave disturbances was set up to calculate the effect of ocean environment wind, wave disturbances forces and moments of dynamic positioned ship, which can be used in any wind speed, wind direction, wave height and wave angle. In this paper, a supply ship was taken as an example. Using the simulation platform, based on different wind speed, wind direction, wave height and direction, the influence of wind, wave disturbances forces and moments and the positions of the ship was calculated. The results show that this mathematical model is correct and effective. This simulation platform can be used for simulation, testing and verification of the design of dynamic positioning systems controller, and has good versatility, real-time simulation and verisimilitude.