On concurrent tests of fuzzy controllers

In this paper, we propose concurrent tests of fuzzy controllers. We assume multiple stuck-at faults in membership functions. For tests of antecedent membership functions, we observe the sum of degrees by matching a current measured input with each function and that of degrees at several easily calculated co-ordinates. For tests of consequent ones, we observe the sum of their maximum degrees, that of degrees of applicability and that of degrees at several co-ordinates on the union of output fuzzy sets. We can find all the multiple faults except redundant ones. Our tests are superior to other tests in the number of additional membership functions and multiple fault detection