METHOD OF EVALUATION OF A SET OF LINGUISTIC RULES

摘要

The present invention provides a method forgenerating an output for a fuzzy controller by evaluating aset of linguistic rules prepared according to a methodincluded in the invention. According to the presentinvention, for each input signal the linguistic hedge isformed to be a fuzzy information system; each linguistic ruleis formed with a premise consisting of a multitude oflinguistic statements about pairwise different input signals,linked by AND, or consisting of one statement about one inputsignal, and a conclusion consisting of a linguistic statementabout the output signal of the fuzzy controller; the set ofrules is built such that it forms as a complete and consistentset of linguistic rules. Then, for every linguistic rule themembership function associated with the linguistic statementabout the output signal in the conclusion of the rule isdefuzzified to produce a first signal for each rule. Forevery linguistic rule, second signals are produced, one secondsignal for each linguistic statement in the premise of therule, by determining the degree of membership of the currentvalue of the input signal referred to in the linguisticstatement to the fuzzy set characterized by the membershipfunction associated with the linguistic statement. For eachlinguistic rule, the second signals are multiplied to producea third signal for the rule. For each of the linguisticrules, the first and third signals are multiplied to produce afourth signal representing the weighted recommended actioncorresponding to the rule. Finally, the fourth signals of allthe rules in the set of linguistic rules are added to producethe output signal.