페트리네트의 계층화를 통한 시퀀스제어계의 설계 (II) - Bottom up에 의한 서브PN의 분할과 합성 -

Design for Sequential Control System Using Petri Nets with Hierarchical Expession(II) - Composition of Sub Petri nets by Bottom up Oriented Method-

Petri nets(PN) have been introduced as a poweful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can not be analyzed easily when we deal with large scale systems because of increase of the number of components of the systems. To overcome this problem, some methods for dividing or reducing of PN have been suggested. In this paper, an approach for hierarchical expression of PN based on Sequential Function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definition and rules are defined in order to divide and compose sub PN. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub PN based on the SFC and BUM by the proposed method in this paper.