摘要
针对可编程逻辑控制器(Programmable Logic Controller,PLC)控制系统中,传统的程序设计框图难以描述并发事件、协调事件及竞争事件等控制问题,利用Petri网图形化的性质和对并发事件的建模能力,对液化天然气(Liquefied Natural Gas,LNG)钢瓶生产线控制系统进行建模。通过层次化建模和仿真分析,消除了系统设计中潜在的死锁、冲突和冲撞等问题。根据Petri网的变迁触发条件和托肯变化规则,列出逻辑表达式,将表达式中的"与"、"或"关系与PLC梯形图的"串"、"并"相对应,快速设计出清晰、可读性好及修改容易的PLC程序,通过实际运行,系统稳定可靠。
In complex Programmable Logic Controller （PLC） control system, traditional flow sheet is very hard to describe complex events such as concurrent, coordination and competition. It constructs models of Liquefied Natural Gas （LNG） cylinder line produc- tion control system by using the ability of Petri nets in graph and model. Through hierarchical model and analyzes, potential prob- lems are eliminated such as deadlock and conflict. Logic expression is listed based on Petri net＇ s condition of transition and change of place. It makes a connection between logic expression and PLC Ladder Logic Programming Language （LAD）. According to the Petri net＇ s model, PLC program can be designed clearly and readably. Through practical operation, the system is stable and reliable.
出处
《现代制造工程》
CSCD
北大核心
2017年第1期24-28,135,共6页
Modern Manufacturing Engineering
基金
国家自然科学基金资助项目(61070058)
江苏大学研究生创新基金资助项目(CXLX13_665)
