Fuzzy Control for an Oceanic Structure: A Case Study in Time-delay TLP System

In this paper, a Takagi-Sugeno (T-S) fuzzy model approach combined with a parallel distributed compensation (PDC) scheme is proposed for time-delay control of the response of a tension leg platform (TLP) system subjected to an external wave force. A global PDC-based fuzzy logic controller is constructed by blending all local state feedback controllers. A fuzzy-model-based control is thereby developed which can attenuate the influence of the external wave force. The controller is evaluated in terms of stability analysis, and the linear matrix inequality (LMI) conditions guaranteeing the stability of the TLP system derived via Lyapunov theory. A simulation example is given to show the feasibility of the proposed fuzzy control approach. The example shows the concept of half-circle fuzzy number can be used in fuzzy control and the proposed control method can be employed in practical engineering problems of oceanic structure.