FAULT-TOLERANCE IN AUTOMATED MANUFACTURING SYSTEMS

The high level of automation, the high level of interrelationship between components, and the productivity demands to which automated manufacturing systems are subjected are causing considerable increases in both the frequency and significance of faults and, as a consequence of this, the real availability of machines is low, the product quality uneven, and the reliability of systems insufficient. The simplicity, precision, and generality of the graphs mean that they are very useful tools in the representation of manufacturing systems. At the same time, any system modelled by means of graphs is an ideal candidate for coding with AI tools. The physical and functional models of manufacturing systems can be represented by means of petri nets, status diagrams, decision trees, logic graphs, grafcets, fault diagnosis graphs, and so on. In this work, the results of two projects initiated by the European Community are presented: ESPRIT 504 (1985-1988) and ESPRIT 2349 (1989-1992).