Design for Sequential Control System Using Petri Nets with Hierarchical Expression(I) - Division of Petri Nets Based on SFC

J. Ocean Eng. Technol. 1999;13(Suppl DB Error: no such field):106-115.

Jeong, Seok-Kwon;Yang, Joo-Ho;

페트리네트의 계층화를 통한 시퀀스제어계의 설계(I) - SFC에 근거한 페트리네트의 분할

정석권;양주호;

부경대 해양산업개발연구소;부경대 제어기계공학과;

Keywords: Petri Net, Sequential Control, PLC(Programmable Logic Controller), SFC(Sequential Function Chart), Hierarchical Expression

핵심용어: 페트리네트, 시퀀스제어, PLC(Programmable Logic Controller), SFC(Sequential Function Chart), 계층화표현

Abstract

Modeling a discrete event system such as a sequential control system is difficult compared with a continuous system. Petri nets have been introduced as an analyzing and design tool for the discrete systems. One of the problems in its applications is that the model can not be analyzed easily in the case of large scale or complicated systems because of increase of the number of components of the system. To overcome this problem, some methods for dividing or reducing Petri nets have been suggested. In this paper, an approach for a hierarchical expression of Petri nets based on Sequential Function Chart(SFC) is proposed. A measuring tank system will be described as a typical kind of discrete systems. The system is modeled by sub Petri nets based on SFC in order to analyze and visualize efficiently about the dynamic behaviors of the system. Some numerical simulations using state equations are performed to prove the validity of the proposed method.