Fuzzy Control of Oceanic Structures Subjected to External Force

A mathematical model considering an oceanic environment, in which the wave-induced flow fields cause structure surge motion, was built. The solutions corresponding for the mathematical model are derived analytically. The structure vibration might be mitigated in virtue of a set fuzzy controller. In the design procedure of the controller, parallel distributed compensation (PDC) scheme was utilized to construct a global fuzzy logic controller by blending all local state feedback controllers. A stability analysis was carried out for a real structure system using Lyapunov method. The corresponding boundary value problems include scattering and radiation problems. Based on separation of variables, solutions describing the interaction between the wave motion and structure response are thus obtained. The surge motion of the structure depends on the wave characteristics and structure properties. A parametric approach shows its effect whilst others parameters are hold constant. The vibration of the floating structure is discussed in order for resulting in the decay of surge motion. The numerical results indicated that the decay including displacement and velocity is significant due of the fuzzy controllers.