Specification of FMS real-time control based on Petri nets with objects and process failure monitoring

This paper presents an approach for control and monitoring of discrete events systems. We show how it is possible to preserve the advantages of a hierarchical control structure for process monitoring purposes. The limitations of the monitoring system induced by the tools classically used for the specification of the control sequences are exposed. A new approach of knowledge representation is proposed: a database model is associated to the hierarchical control and monitoring structure. In this context, the main monitoring functions become more powerful and are able to treat most of the erroneous situations following from a process failure