The real issues in fuzzy logic applications

Abstract

The transition from Boolean Logic to Fuzzy Logic is shown by modifying a ladder diagram consisting of discrete variables with values of 0 and 1 to include intermediate values. Properties of membership functions are discussed as they influence the control output. The concept of compromise and output blending is shown. Important observations regarding the presence of rules are presented. The notions of “gain” and “time” are introduced, and a PID controller using Fuzzy Mechanisms is shown. In one example, the level and temperature of a tank are controlled; in another example the engine power and the turning of the wheels of an automobile are controlled as a function of the gas pedal and the steering wheel excitation.