Fuzzy control with input energy and state variance constraints for perturbed ship steering systems

In this paper, a fuzzy controller design problem is considered for nonlinear perturbed ship steering systems. The nonlinear perturbed ship steering system is transformed into a Takagi-Sugeno (T-S) fuzzy model, which has similar dynamics to the original nonlinear system. By using linear feedback controller design technology, a nonlinear fuzzy controller is developed for the perturbed T-S type ship steering model. Building on the nonlinear fuzzy controller, a number of most important performance constraints in fuzzy control systems are addressed. These include stability conditions, minimum control input energy, and individual state variance constraints. Finally, a numerical simulation is given to show the effects of the proposed fuzzy control methodology.