Discrete Event Diagnosis using Petri Nets.

Abstract

This paper serves as a support for the plenary address given by the second author during the conference. In this paper we present an approach to on-line diagnosis of discrete event systems based on labeled Petri nets, that are a particular class of Petri nets where some events are undistinguishable, i.e., events that produce an output signal that is observable, but that is common to other events. Our approach is based on the notion of basis markings and justifications and it can be applied both to bounded and unbounded Petri nets whose unobservable subnet is acyclic. Moreover it is shown that, in the case of bounded Petri nets, the most burdensome part of the procedure may be moved off-line, computing a particular graph that we call Basis Reachability Graph. Finally we present a diagnosis MATLAB toolbox with some examples of application. Published as: M.P. Cabasino, A. Giua, C. Seatzu, ”Discrete Event Diagnosis Using Petri Nets,” ICINCO09: 6th Int. Conf. on Informatics in Control, Automation and Robotics (Milano, Italy), July 2009.