Adaptive Interval Type-2 Fuzzy Logic Control of Marine Vessels

Abstract

This thesis focuses on developing advanced strategies for dynamic positioning (DP) and tracking control of marine vessels in the harsh marine environment. For DP, an indirect adaptive interval type-2 (IT2) fuzzy logic controller (FLC) and a passive adaptive IT2 fuzzy observer are proposed. For tracking control, an indirect as well as a direct adaptive IT2 FLCs are first presented for state feedback control. To extend the state feedback control to output feedback case and improve the reliability of the control systems, an output feedback fault tolerant adaptive backstepping IT2 FLC is then designed. In all the designs, the combination of approximation-based adaptive technique and IT2 fuzzy logic system is employed to handle the time-varying hydrodynamic disturbances. Lyapunov analysis is used for the stability analyses of all the closed-loop systems. Simulation studies are conducted to illustrate the efficiency and robust of all the designs.