Design of a robust ship fin stabiliser control system

Traditional optimal PID controller of ship fin stabilisers can not keep good roll reducing effectiveness when ship status or seaway disturbance is varied. A optimal robust PID controller was set up to adapt the variation of ship speed, load etc and different encounter waves. In the design, a new cost function and an engineering PID model were proposed, a restrained non-linear dynamic programming was used to seek the optimal coefficients of the PID controller. From simulation results it can be seen that the performance of the robust PID controller is good in different encounter waves when ship roll model is varied.