Monitoring of flexible production systems using high-level Petri net specifications

The degree of reliability in the operation of flexible production systems depends not only on the operation of the individual components, but also on the structure and evolution of the embedded supervisory control system. Monitoring of operations and of the behaviour of the components and of the system as a whole is an essential function of such a supervisory control system. This paper focuses on the development and implementation of feature- and model-based monitoring methods using high-level Petri net specifications of flexible production systems and of the embedded discrete-event controllers. The combination of machine-human interface concepts with the developed monitoring methods leads to a user-friendly representation of monitoring information. An application at industrial level is shown by means of a case study, i.e., a sample flexible assembly cell, situated at the Institute for Manufacturing Automation and Production Systems, Germany. (C) 1999 Elsevier Science Ltd. All rights reserved.