An outline of the intuitive design of fuzzy logic and its efficient implementation

A range of design elements useful in fuzzy processor or controller design is discussed. The authors consider the efficient implementation of designs, and discuss taking designs from the form most intuitively useful to the designer and translating them to a common representation, resulting in implementations for high speed and small silicon area, or efficient software. They examine the use of a VHSIC Description Language (VHDL) code as a tool for developing fuzzy logic and as a readily available route through design and simulation. The features of VHDL that make it particularly suited to fuzzy logic design are described. The suggested design approach allows the rule base to be represented in the format that the user prefers and to be simulated and refined, but to be translated to a single format for implementation. Features include: processing only active rules; independent rules that allow one rule to be tuned without affecting the others; rules of different strengths allowing the relative importance of a rule to be expressed; and precalculation of the center of area of fuzzy consequents considerably speeding defuzzification