A CAD tool for simulation of fuzzy controllers

This paper presents a user-friendly, menu-driven simulation tool for fuzzy user-defined controllers. Fuzzy controllers as well as other fuzzy systems are normally used when adequate crisp mathematical models for the process u nder control are not available because of process complexity and non-linear ities, and when the system variables can naturally be fuzzified. The hardes t part in the design of a fuzzy control system lies in the assignment and a djustment of input and output membership functions, the inference rules and also in the selection of a suitable defuzzification strategy. The software package allows the user to systematically design, save the description of, simulate, test, evaluate, and improve the performance of any fuzzy control ler. This can be accomplished through an easy to implement trial-and-error methodology whereby the fuzzy model can be tuned to yield the desired outpu t response. The paper also compares the results of a new defuzzification st rategy with the minimax weighted average formula which has been utilized as a defuzzification method in many fuzzy control situations.