Polynomial-time verification of diagnosability of fuzzy discrete event systems

A fuzzy approach to perform diagnosis of fuzzy discrete event systems (FDESs) is proposed by constructing diagnosers, which may more effectively cope with the problems of vagueness and fuzziness arising from failure diagnosis of fuzzy systems. However, the complexity of constructing this kind of diagnosers is exponential in the state space and the number of fuzzy events of the system. In this paper, we present an algorithm for verifying the diagnosability of FDESs based on the construction of a nondeterministic automaton called F -verifier instead of diagnosers. Both the construction of F-verifiers and the verification of diagnosability of FDESs can be realized with a polynomial-time complexity.