A Complete Tuning Procedure and Root Locus Stability Evaluation for Fuzzy Logic Control Systems

A complete tuning procedure of designing a fuzzy logic controller (FLC) and a new stability evaluation using root locus criterion for fuzzy dynamic systems are presented. The importance of FLC in industrial applications arises from the fact that a nonlinear mapping between inputs and outputs of the process that leads to a preferred controller performance which can be easily described by fuzzy linguistic variables and fuzzy rules. However, tuning a FLC based on trial-and-error basis is usually a tedious and timeconsuming task. Stability issues of FLC systems still remain unknown as well. All of these bring over criticisms and attacks in fuzzy logic technology. In this paper, we developed a complete tuning guideline for FLC parameters (membership functions, scaling factors, rules) to simplify the tuning process. Moreover, we introduced a novel stability evaluation criterion for FLC systems based on root locus technique to design a stable fuzzy control system. Finally, simulation results ..