MATERIAL FLOW AND CONTROL SEQUENCE SPECIFICATION OF FLEXIBLE PRODUCTION SYSTEMS USING COLORED PETRI NETS

Starting with the specification of each resource and the whole structu re of a flexible production system, in this approach a special kind of coloured Pt tri nets is used for performing the modelling and the val idation of the coordination control structure of the systems. in a sec ond phase, it is proposed to modify the first models to synchronised! Petri net schemas to facilitate the supervision and the interaction of the coordination model with the physical components of the system as well as the development and maintainability of the discrete-event cont rol structures. The final result is a formal specification of coloured Petri net based coordination control of resources of the system, and logic control structures for control sequencing based on the use of sy nchronised subPetri net structures derived from the first one by refin ing transitions, i.e., their occurrence. Based on the proposed approac h, the coordination control model of resources and a first skeleton of the logic control structures of a flexible assembly cell located at t he institute of Manufacturing Automation and Production Systems at the University of Erlangen-Nuremberg, Germany is elaborated and then the correctness of the obtained models with regard to material flow and co ntrol sequence specifications is validated by means of the structural analysis of the coloured Petri net-based models.