Time Optimal Synthesis Based Upon Sequential Abstraction and Its Application to Cluster Tools

The Ramadge-Wonham supervisory control paradigm has been shown effective in dealing with logic control. Nevertheless, time-related performance is always one of the major concerns in industry. Current methods for synthesizing time optimal supervisors are incapable of dealing with large discrete-event systems (DESs) with massive state spaces. This paper proposes an approach for finding a time optimal accepting trace for large DESs based upon sequential language projection, and pruning. The algorithms are tested on a linear cluster tool to show their effectiveness.