Petri net diagnoser for DES modeled by finite state automata

Fault detection and isolation is an essential task in automated manufacturing systems and, as such, has received considerable attention in the literature. We propose in this paper a Petri net approach to online diagnosis of a discrete event system (DES) modeled by a finite state automaton. The diagnosis method requires, in general, less memory than other methods proposed in the literature and relies on the computation of a Petri net diagnoser (PND). In addition, a method for the conversion of a PND into a ladder diagram for implementation on a programmable logic controller (PLC) is presented. The conversion method leads to a ladder diagram that preserves the structure and represents the evolution of tokens of the PND.