Presented in this thesis is a systematic approach to constructing a Petri net model of AMS (automated manufacturing system). Mainly because of its modeling power and theoretical generality, Petri net is gaining more popularity in modeling AMS. The major drawback of Petri net (and other modeling tools) is that it is not easy at least for FA engineers to build a comprehensive Petri net model of a non-trivial AMS.
Typical AMSs such as FMS, FAS, and AS/RS are built from a set of standardized components or resources such as machining centers, robots, AGVs, conveyors, and stacker cranes. In the proposed modeling scheme, "modular approach", a set of "primitives" (standardized resourcess of the system) is predefined and then the entire system is described with relevant primitives by specifying "relations" among them. The network representation of this relation is termed a JR-net (job resource relation net). The resulting JR-net can be converted automatically into a comprehensive Petri net model.
This thesis consists of three phases: (1) Definitions of JR-net primitives and JR-net modeling scheme of AMS with primitives; (2) Constructing schemes for sub-PN (sub Petri net) of each JR-net primitives and conversion rules for translating a JR-net to Petri net using sub-PN; (3) Program implementation procedure for general Petri net model. In the first two phases, examples of AMS such as FAS, PFS, FMS, AS/RS are presented for illustration of the proposed modeling scheme. As the result of last phase, a simple PNE (Petri net executor) is developed and tested with FAS case. Proposed modeling scheme is found to be a very usefull and effective tool for modeling and simulation of AMS. The JR-net simulator ("not" Petri net simulator) of AMS can be developed with automatic conversion of JR-net to Petri net.
