Fuzzy Control and Approximate Reasoning

Abstract

Traditional control techniques are possible only in the case of complete understanding of the physical nature of the problem and only after a suitable mathematical treatment leading to a usable model. This enables us to obtain a numerical function f whose intended meaning is that f(x) is the correct control given x. Unfortunately, this is not the case for a majority of real systems. Difficulties can arise, for instance, from poor understanding of the underlying phenomena (and therefore from a lack of theory), or from the complexity of the resulting mathematical model. In such cases fuzzy control, as devised in Zadeh [1965], [1975]a, [1975]b and in Mamdani [1981], is a very useful tool. To explain the idea, we can distinguish two phases in the building of a fuzzy controller.