Active fault diagnosis of discrete event systems subject to safety constraints

A method for the active fault diagnosis of discrete event systems subject to safety constraints is presented. The behavior of the system under different faults is modeled by a set of deterministic input/output automata, where each automaton contains some forbidden transitions. The main result is a characterization of the set of input sequences whose application to the faulty plant allows the identification of the fault. Furthermore, a procedure for determining such a set of input sequences is presented. The applicability of the developed method is demonstrated by means of an example featuring a simplified chemical plant.