Fuzzy Sets Theory and Process Control: Past, Present and Future

Abstract It is now some 15 years since the first “fuzzy controller” was implemented as an experimental system by one of the the authors and his associates. Today this work occupies a prominent place within the larger areas of both control systems and fuzzy sets theory and there is an extensive and growing literature on the subject. In this paper we take a retrospective look at that original study and describe how and why it came about. It is not the intention here to present a survey of current blossoming work on fuzzy control. However, we present some reflections on the importance and the nature of this work. Finally, the paper indulges in some projections concerning fruitful avenues of future research. One key point put forward in this paper is that the original study was aimed more at control engineering than at fuzzy sets research, and so the projections in this paper also address the same control engineering community.