Petri Net Based On Behavior Of Token And Its Applications

Production scheduling is an important aspect of studying discrete event dynamic systems. Petri net provides a powerful tool to describe and research discrete event dynamic systems characterized by parallelism, asynchronism, distributive, uncertainty. Traditional Petri nets describe the behavior of system by place-marking. Most of the previous literatures usually add many new "units"(sets or maps) to enrich property and behavior of place. The place-marking only shows the distribution of the number of tokens, and it can't describe location, mechanism and microcosmic information of token. In this paper, a domain of tokens is introduced, and a complex Petri net model with several state machines on the class of token is proposed, which are useful to research complex modeling, distributed monitoring and dynamic scheduling problem about discrete event dynamic systems.1) The behavior of token includes discrete marking (location of Token) and hybrid marking (location and continuous information of Token). A Petri net based on behavior of token is proposed in this paper. In a complex Petri net, the token aggregate exists a class partition. The complex Petri net can be described as a complex with several state machines. It gives a detailed analysis of enabling mechanism of transition, enabling mechanism of event, migrating mechanism of token and evolutionary mechanism of continuous information.2) A controlled Petri net based on behavior of token is established by introducing the set of controlling model. In this paper, it also studys scheduling rules of first come first served and minimized the total waiting time.3) Taking scheduling problem of bell-type annealing process as an example, this article describes scheduling rules of first come first served and minimized the total waiting time. This example shows that, complex Petri net model with several state machines can effectively resolve modeling, analysis and scheduling problem about complex DEDS systems. This new model is suited to be used in the actual engineering and provides a new way to research complicated discrete event dynamic system.