Adaptive fuzzy control with backstepping for surface ships

This paper addressed the problem of adaptive fuzzy logic systems with backstepping for surface vessels with input dead-zone. The combination of approximation-based adaptive techniques and fuzzy logic systems is used for approximating the nonlinear function from the ship plant. Through backstepping and Lyapunov synthesis, an indirect adaptive fuzzy logic controller is derived for dynamic positioning ships without dead-zone property. In order to improve the control effect, a dead-zone compensator is derived using the fuzzy logic to handle the dead-zone nonlinearity. The main advantage of the proposed controller is that it can be designed without explicit knowledge about the ship motion model, and dead-zone nonlinearities are well compensated. A set of simulations are carried out to verify the performance of the proposed controller.