Distributed diagnosis using predetermined synchronization strategies

We consider distributed fault diagnosis in a discrete event system modeled as a nondeterministic finite automaton that is observed, at multiple observation sites, through distinct natural projection maps. The majority of previous work in this setting has focused on local observers (diagnosers) that are separately implemented at each observation site, without exchanging any information among themselves and relying exclusively on communicating their decision (fault or no fault) to a coordinator that is responsible from making the ultimate diagnosis decision (co-diagnosability). In this work we extend recent techniques that allow local observers to communicate their state estimates to a coordinator by considering strategies that also allow the exchange of local diagnostic information among different observation sites and by analyzing their diagnosability.