State Observer for DES Under Partial Observation with Time Petri Nets

This paper deals with a state observation approach for Discrete Event Systems with a known behavior. The system behavior is modeled using a Time Petri Net model. The proposed approach exploits temporal constraints to assess the system state and therefore detect and determine faults given partial observability of events. The goal here is to track the system state and to identify the event scenarios which occur on the system. Our approach uses the class graph of the Time Petri Net which models the complete system behavior to develop a state observer which is a base to perform online fault detection and diagnosing.

Pascal YimEmail:

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Mohamed Ghazel   is a researcher in ESTAS (Evaluation and Safety of Automated Transport Systems) research team of the INRETS (The French national institute for transport and safety research) institute. Born in Mednine (Tunisia) in 1978, he obtained in 2005 his PhD in Automatic control and industrial computer sciences at the LAGIS – Ecole Centrale de Lille/University of Lille. (France), in 2002 the Master’s degree in automatic control and industrial computer sciences from the same establishment, and in 2001 the engineer diploma in productics–logistics from the ENSAIT de Roubaix (France). Dr. Ghazel works on safety and security and develops methods of behavioural modelling, state estimation, fault detection and diagnostic from a discrete point of view while using formal (Petri Nets, State finite Automata, etc.) and semi-formal (UML, etc.) models. The main applications of his research are in manufacturing and transportation systems, with a special interest in railways (ERTMS, SELCAT, etc.). He has several publications in international journals and conferences. Armand Toguyéni   is a Professor of Computer Sciences and Discrete Events Systems (D.E.S.) at the Ecole Centrale de Lille (France). He has in charge the Department of Computer Sciences of the “Institut de Génie Informatique et Industriel de Lens”. Born in Dakar (Senegal) in 1964, he obtained in 1988 the Engineer Diploma of the “Institut Industriel du Nord” (French “Grande Ecole”) and the same year his Master Degree in Computer Sciences. He obtained a Ph.D. in Automatic control for Manufacturing and Discrete Events systems in 1992 and his “Habilitation à Diriger des Recherches” in 2001. Pr. Toguyeni’s research area is the Quality of Service (QoS) of D.E.S. More particularly one of its topic research is the design and the implementation of dependable controls for Automated Production Systems. He works more particularly on Fault Detection and Isolation techniques for Flexible Manufacturing Systems (FMS). He has developed different approaches for the diagnostic of faults based on plant items reports or the analysis of the production flows in an FMS. Pascal Yim   is Professor at the Ecole Centrale de Lille. His research are based both on concepts from discrete automatics and software engineering with a special interest on Petri Nets, constraint programming and information systems. The principal applications of his work come from design and optimisation of transport systems, in particular railways. He published several papers in international journals and conferences and was in charge of numerous industrial projects (SNCF, port fluvial de Lille, 3 Suisses France...). Pascal Yim was coordinator of francophone team on Petri Nets and responsible of the regional pole of transport security (ST2). He is also correspondent of the European excellence research network on railways (EURNEX).