On-line multiple-fault-detection of fuzzy controllers

In this paper we propose the on-line multiple-fault-detection of fuzzy controllers. The membership functions in each antecedent part are divided into at most four groups. The faults in each group are detected by observing calculations concerning degrees of the functions in it. Our test forms two output fuzzy sets per function, and observes the calculations concerning areas of the sets. It has the advantage of being valid for the case where the number of overlapped functions is three or more.