Optimal sensor choice for observability in free-choice Petri nets

Abstract

This paper studies the optimal sensor choice for observability problem in discrete event systems (DES) modeled by interpreted free-choice Petri nets (IFCN). Taking advantage of the fact that, event-detectability is a necessary and sufficient condition for observability in live, cyclic and bounded IFCN, a structural characterization of event-detectability and a simple polynomial algorithm to choose a minimal cost sensor configuration for observability in this claw of nets are provided. This algorithm is successfully applied to an illustrative example.