A Diagnoser-Based Approach to Diagnosis and Diagnosability of Repeated Faults of Discrete-Event Systems
João Carlos Basilio, Guilherme M. O. Silva · IEEE Transactions on Automatic Control · 2025
Studies carried out in real plants have shown that repeated and/or intermittent fault events occur frequently during the operation of a system. Regarding the occurrence of repeated fault events, the problem becomes that of determining the number of occurrences of the fault event, namely, for a given$\kappa \in \mathbb {Z}_+^{*}$, and based on the observation of events, be sure that the fault event has occurred at least$\kappa$times ($\kappa$-diagnosability). In this article, the problem of repeated fault diagnosability is revisited, and a new algorithm that relies on a diagnoser-based automaton is proposed for the verification of$\kappa$-diagnosability. Based on the proposed test automaton, a necessary and sufficient condition for$\kappa$-diagnosability is presented. As a by-product of the proposed method to verify$\kappa$-diagnosability, a diagnoser that can be used for online diagnosis is also developed.