Diagnosis of Petri nets

This chapter focuses on on-line fault diagnosis of labeled Petri nets, i.e., place/transition nets where a labeling function assigns to each transition either a symbol from a given alphabet or the empty word. Some important contributions in this framework are first recalled. Then particular attention is devoted to an approach proposed by the authors that is based on the notion of basis markings and justifications, that presents the main advantage of not requiring an exhaustive enumeration of the system state space. Moreover, in the case of bounded net systems, the most burdensome part of the approach may be moved moved offline, computing a particular graph called Basis Reachability Graph. Some results concerning problems related to on-line fault diagnosis are also recalled, such as diagnosis via fluidification, diagnosability analysis and decentralized diagnosis.