Discrete event diagnosis using labeled Petri nets. An application to manufacturing systems

In this paper an approach to on-line diagnosis of discrete event systems based on labeled Petri nets is presented. The 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 called Basis Reachability Graph.Finally, the effectiveness of the proposed procedure is analyzed applying a MATLAB diagnosis toolbox we developed to a manufacturing example taken from the literature.

Research highlights► We present an approach to on-line fault diagnosis based on labeled Petri nets. ► We consider both silent events and undistinguishable events. ► Basis markings and justifications avoid an exhaustive enumeration of the state space. ► In the case of bounded net systems, the procedure can be significantly simplified. ► A manufacturing system is considered to show the effectiveness of the procedure.