Determination of distinguishing input sequences for the diagnosis of discrete-event systems

The paper deals with the determination of input sequences for which the faults occurring in discrete-event systems described by deterministic I/O automata can be detected and identified. The basis for this method is provided by diagnosability criteria that show that faults can be found whenever the automata describing the faultless and the faulty system do not have equivalent initial states. The absence of equivalent states implies that there exist finite input sequences for which the output sequences distinguish for all faults. The paper describes a method to find these input sequences.