In engineering systems there is generally two classes of knowledge: objective knowledge,\ud which can be quantified using the laws of traditional mathematics, and subjective or\ud intelligent knowledge, that cannot be modeled mathematically but can be expressed in\ud linguistical terms. Fuzzy Logic (FL) is a method that combines these two forms of\ud knowledge, and as such provides a powerful tool for solving real engineering problems.\ud A fuzzy logic system (FLS) is the methodology of applying FL to engineering systems.\ud In general, a FLS can be considered as a non-linear mapping of crisp (firm) input data to\ud crisp output data. It is the inclusion of subjective knowledge in a FLS that leads to a\ud plethora of mapping possibilities, ...