Stabilizing ship's dynamic fin-roll using the comparativesliding mode controller

In this article, the designing of comparative-sliding mode controller for ship’s dynamic fin-roll stability in the presence of disturbances is presented. For designing the controller, at first non-liner model of desired system is studied, then the uncertainty is entered into the system model and by using the designing of sliding mode methods, the desired controller is designed. As the disturbance range information is not always available, selecting an appropriate rate coefficient foe sliding mode controller is very difficult. To solve this problem, in this article, the comparative method for setting the controller is presented. To prove the stability, the Liapanov method is used. To study the function of the loop system, the performed simulation and its obtained results from the comparative-sliding mode controller by PID control method are compared. The results show that the suggested methods have better function than PID ones.