Design of Deadlock Prevention Supervisors Using Elementary Siphons

This paper proposes a methodology to synthesize deadlock prevention supervisors for a class of sequential resource allocation system for flexible manufacturing systems (FMSs). Since all minimal siphons should be controlled, the controlled nets are very complexity when the systems are large. In this article, a concept of the elementary siphon is used to reduce the number of control places. We further present a new siphon-based policy of deadlock prevention for the type of Petri nets. This policy is consisting of two main stages. Compared with the existing approaches, the new deadlock prevention policy can obtain a structurally compact deadlock prevention supervisor by adding only a few of control places