Diagnosability of discrete event systems: a Petri net based approach

Abstract

Abdmci-This paper deals with model based fault diagnosis of Discrete Event Systems. The model of the system, expressed as an Interpreted Petri Net ( I P N ) describes partially observed events and states, and includes all possible faulty states. Based on a modular modelling methodology, the input-output diagnosability property is introduced and structurally characterized. Then a diagnoser scheme is proposed allowing fault detection and location in polynomial time. K e y w o d s -Model-based fault diagnosis, diagnosability discrete event systems, modelling methods based on intarpreted petri nets. 0-78w-8232-3/04/$17.00 a 2 0 0 4 IEEE 541

Multi-steps diagnosis of discrete event systems with Petri net models

“…Two diagnosis approaches have been developed: a state based one (Chung et al, 2003;Sampath et al, 1995;Ushio et al, 1998) and a structural one (Alcaraz-Mejia et al, 2003;Lefebvre and Delherm, 2006;Ramirez-Trevino et al, 2004). For both approaches, diagnosers design is strongly related to sensor selection (Darabi et al, 2003;Jiang et al, 2003;Liu and Darabi, 2004).…”

Fault Diagnosis in Discrete Event Systems Using Interpreted Petri Nets

“…Such diagnoser can detect a fault and locate faulty markings reached by an IPN. The proposed scheme for diagnosis (Ramírez-Treviño, et al, 2004) handles a copy of the normal behavior model which must evolve similarly to the system; the outputs of both the system and the model are compared and, when there is a difference, a procedure is started to compute the faulty marking. Example 2.…”

Diagnosis of Discrete Event Systems with Petri Nets

“…Another diagnosis approach for DES has been developed according to event detectability of interpreted PN (Alcaraz-Mejia et al, 2003;Ramirez-Trevino et al, 2004). An interpreted PN is event detectable when any pair of transitions can be distinguished from each other by the observation of the input -output symbols of the interpreted PN (inputs are defined according to the events associated with the transitions and outputs are defined according to the measurements of the observable markings).…”

“…An interpreted PN is input -output diagnosable in r steps if any marking M resulting immediately from the firing of a fault transition is distinguishable from any other marking M' by firing any sequence with r transitions (Alcaraz-Mejia et al, 2003;Ramirez-Trevino et al, 2004). Several structural characterizations of input -output diagnosability have been provided: necessary and sufficient conditions related to inputoutput relationships between places, sufficient conditions when the normal behaviour of the interpreted PN is event detectable (Alcaraz-Mejia et al, 2003;Ramirez-Trevino et al, 2004;Ramirez-Trevino et al, 2007). In order to illustrate event diagnosability, let us consider again PN2 in figure 2.…”