ABSTRACT
In the sixties, Zaheh introduced the concept of fuzzy sets. Since its inception more than 30 years ago, the theory and methods of fuzzy sets have developed considerably. The concept of the fuzzy set is a generalization of the concept of the ordinary set. It introduces vagueness by eliminating the clear boundary, defined by the ordinary set theory, between full nonmembers and full members. Problems in engineering could be very complex and involve various concepts of uncertainty. The use of fuzzy sets in engineering has been quite extensive during this decade. The area of fuzzy control is one of the most developed applications of fuzzy set theory in engineering. Fuzzy controllers have been created for the control of robots, aircraft autopilots, and industrial processes, among others.
