A synthesis method for Petri net modeling of automated manufacturing systems with shared resources

摘要

A general approach to synthesizing a class of Petri nets that model shared-resource automated manufacturing systems is proposed. The approach imposes minimal restrictions on the interactions among the subsystems initially so that the modeler is given more freedom. To modularize the synthesis procedure, a shared-resource system is formulated as the processes, i.e., the subsystems, that control the system resources and the interactions among the processes. For modeling the processes, resource control nets are defined as the generic modules. The system model is built by merging these modules through their common transitions and common transition subnets, which denote the interactions among the processes. The merged net is proved to be conservative and thus bounded. An algorithm is also developed for checking two sufficient conditions for structural liveness of the net. This algorithm examines only the net's structure, and appears to be more efficient than state enumeration techniques such as the reachability graph method.