Failure components detection in discrete event systems modeled by Petri net

This paper addresses the problem of fault diagnosis in discrete event systems (DES) modeled by Petri nets with outputs, i.e., Petri net (PN) with place sensors and transition sensors. The PN is used in order to give a functional and dysfunctional modeling of the system studied. In the dysfunctional modeling, places represent the failure mode and transitions represent the conditions that led a system to a failure mode. These Places and transitions are modeled as unobservable places and transitions. Therefore, a new method based on an Unknown Input Observer (UIO) is proposed to detect the failure mode functioning as well as the instants of the occurrence of these faults in DES modeled by PN. The sufficient conditions for the existence of the observer are also given. Finally, a simple photovoltaic system will be considered as an example to show the effectiveness of the proposed approach.