Conjunctive Decentralized Diagnosis of Discrete Event Systems*

In this paper, we study conjunctive decentralized diagnosis of discrete event systems. A notion of conjunctive codiagnosability which guarantees that any failure is detected by a conjunctive decentralized diagnoser within a uniformly bounded number of steps has been defined in literature. We propose an algorithm for verifying conjunctive codiagnosability based on a necessary and sufficient condition for the system not to be conjunctively codiagnosable. To construct a conjunctive decentralized diagnoser for a conjunctively codiagnosable system, we need to compute the delay bound within which the occurrence of any failure can be detected by conjunctive decentralized diagnosis. We show how to compute the delay bound.