A Modular Approach for Deadlock Avoidance in FMS

In Petri net models of FMS, deadlock avoidance policies based on siphon control may require an excessive computational load and result in over-sized control sub-nets. In this work, a simple approach is proposed for the design of sub-optimal but compact controllers. The approach is based on the separate control of two sub-sets of resources, and an anticipated booking mechanism for one of the two sets of resources that decouples the two sub-models. An illustrative example is provided, which shows how the partition design influences the control quality and performance.