Research of Station Keeping Controller of Dynamic Positioning Vessel in Varying Sea States Based on State Observer

Abstract

Station keeping is the most fundamental operating mode of many offshore operation ships, such as deep ocean drilling ship, submarine pave cable ship and so on. In the practical application, due to the time-varying characteristic of the sea states, the dynamic positioning vessel is difficult to achieve the desired position. So in order to solve the problem mentioned above, a new control solution based on state observer (SO) which could estimate the unknown environmental forces online, is proposed according to the estimated unknown environmental forces by SO, the controller could compensate the environmental forces in time to achieve good disturbance rejection performance. A simulation scenario on an offshore supply vessel is provided based on the proposed controller and the traditional PID controller, and the comparative results demonstrate that the proposed controller has better control performance in varying sea states.