Fuzzy Systems
This book is intended to present fuzzy logic systems and useful applications with a self- contained, simple, readable approach. It is intended for the intelligent reader with an alert mind. The approach, the organization, and the presentation of this book are also hoped to enhance the accessibility to existing knowledge beyond its contents. The book is divided into twelve chapters. In Chapter 1 Gaussian membership functions (MFs) are proposed as an alternative to the traditional triangular MFs in order to improve the reliability and robustness of the system. Gaussian MFs provide smooth transition between levels and provides a way to fire the maximum number of rules in the rule base and hence a more accurate representation of the input-output relationship is achieved. Chapter 2 describes robust H∞ control problems for uncertain Takagi-Sugeno (T-S) fuzzy systems with immeasurable premise variables. A continuous-time Takagi-Sugeno fuzzy system is first considered. The same control problems for discrete-time counterpart are also considered. Chapter 3 deals with the control of T-S fuzzy systems using fuzzy weighting-dependent lyapunov function. In Chapter 4, the digital fuzzy control system considering a time delay is developed and its stability analysis and design method are proposed. The discrete Takagi- Sugeno(TS) fuzzy model and parallel distributed compensation(PDC) conception for the controller are used. The proposed control system can be designed using the conventional methods for stabilizing the discrete time fuzzy systems and the feedback gains of the controller can be obtained using the concept of the linear matrix inequality (LMI) feasibility problem.
