Petri Nets in a Knowledge Representation Schema for the Coordination of Plant Elements

Abstract This paper is focused on the real-time coordination of manufacturing systems. A software architecture for real-time control of complex manufacturing systems is presented. The architecture follows a hierarchical approach for control ranging from real-time coordination to long term scheduling, where the different layers are sharing a common knowledge base. With this purpose, a knowledge representation schema for manufacturing systems is also proposed. This schema integrates knowledge representation techniques based on frames, high level Petri nets to describe plant behavior and it follows an object oriented programming methodology. The coordination function is materialized by making a coordination model evolve (a Petri net based representation is underlying in that model).