What is a fuzzy logic system (FLS)?
An FLS is depicted in Figure 1. It contains four components rules, fuzzifier, inference engine, and output processor that are interconnected. When the rules have been established, an FLS can be viewed as a mapping from inputs to outputs (the solid path in Figure 1, from crisp inputs to crisp outputs), and this mapping can be expressed quantitatively as y = f(x). This kind of FLS is very widely used in many engineering applications of FL, such as in FL controllers and signal processors. It is also known as a fuzzy controller, fuzzy system, fuzzy expert system, or fuzzy model. Rules are the heart of an FLS. They have membership functions associated with them. Each rule can be thought of as a subsystem. Unless inputs are applied to the rule, that rule does nothing, in much the same way that until the ignition is turned on and the gas pedal is depressed, a car does nothing. The inference engine maps each rule’s fuzzy input sets into each rule’s fuzzy output set, analogous to a car’s engine
