FUZZY-LOGIC IN CONTROL-SYSTEMS - FUZZY-LOGIC CONTROLLER .1.

During the past several years, fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the realm of industrial processes, which do not lend themselves to control by conventional methods because of a lack of quantitative data regarding the input-output relations. Fuzzy control is based on fuzzy logic—a logical system which is much closer in spirit to human thinking and natural language than traditional logical systems. The fuzzy logic controller (FIX) based on fuzzy logic provides a means of converting a linguistic control strategy based on expert knowledge into an automatic control strategy. A survey of the FIX is presented; a general methodology for constructing an FIX and assessing its performance is described; and problems that need further research are pointed out. In particular, the exposition includes a discussion of fuzzification and denazification strategies, the derivation of the database and fuzzy control rules, the definition of fuzzy implication, and an analysis of fuzzy reasoning mechanisms. © 1990 IEEE