Resource Configuration Analysis for a Class of Petri Nets Based on Strongly Connected Characteristic Resource Subnets

Most existing deadlock prevention studies on flexible manufacturing systems (FMSs) resort to Petri nets (PNs) by designing controllers for them. PNs are an effective tool for analyzing and modeling the dynamic behavior of FMSs. As an important subclass of PNs, the system of simple sequential processes with resources (S
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PR) can be used to model many FMSs. This paper proposes a novel resource configuration method based on structural analysis to ensure the liveness of an S
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PR. The restrictive relation between the initial marking of the process idle places and a special PN structure called strongly connected characteristic resource sunnets (SCCRSs) is first explored by employing the corresponding relation between SCCRSs and their related strict minimal siphons. With the structural properties of SCCRSs, functions invoked to compute the configuration marking for the resource places in an SCCRS are established. Then, an algorithm for computing a configuration marking in an S
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PR is developed, and a resource configuration tree is correspondingly generated according to the execution of the developed algorithm. Thus, the liveness of the configured system is ensured, while the siphon enumerations are avoided. It is shown that the computational complexity of the developed algorithm is polynomial, which is more efficient than other existing ones. Examples are finally provided to illustrate the mentioned results.