AN INTELLIGENT DIAGNOSTIC SYSTEM BASED ON PETRI NETS

An intelligent event-oriented diagnosis methodology and diagnostic sys tem architecture is proposed in this paper. The dynamic behaviour of t he process system in different faulty modes is described by cause-cons equence event sequences represented by coloured Petri nets (CPNs). The dynamic model of the system is assumed to be partially unknown and it is refined using the observed event sequences by a learning method. T he real-time diagnosis operates on the CPN model of the system and on the expected operating procedures comparing observed event sequences t o the model-based prediction.The diagnostic system architecture consis ts of an event archivator, a data structure generator, a real-time dia gnostic monitor and a learning subsystem.