Design of fuzzy logic controllers for Takagi-Sugeno fuzzy model based system with guaranteed performance

A new fuzzy logic controller (FLC) for the Takagi-Sugeno (TS) fuzzy model based systems is proposed in this paper. This new FLC has two consequents in each rule. They are a numerator part and a denominator part. It can be shown that on applying this FLC, the number of fuzzy sub-systems will remain the same as the number of fuzzy rules of the plant model. Besides, the overall closed-loop system can be designed such that it behaves like a linear system. Comparing with the FLCs in the existing design approaches for TS fuzzy model based systems, the proposed FLC has two major advantages. First, it does not require the complex process of finding a common Lyapunov function for a large number of fuzzy sub-systems in order to guarantee the system stability. Therefore the design procedure of the proposed FLC is much simpler. Second, by employing the proposed FLC, the closed-loop system performance can be designed. Illustrative examples will be given to demonstrate the ability and merits of the proposed FLC. (C) 2002 Published by Elsevier Science Inc.