基于LabVIEW的Petri网控制器实现

Implementation of Petri nets controller based on LabVIEW

为使Petri网更易应用于测控系统,提出一种基于图形化编程工具LabVIEW、组件化的时延C/E Petri网系统实现方法.在LabVIEW中,用布尔控件表示Petri网的库所(布尔控件值为TRUE表示库所中有token),用子VI控件表示Petri网的变迁.变迁被触发时,变迁VI控件通过布尔控件的控件引用修改库所的值,并把4种具有不同输入输出库所数量(单进单出、单进多出、多进单出和多进多出)的变迁VI封装成一个多态的变迁元件VI.实现Petri网时,只要简单地组合库所与多态变迁元件即可在LabVIEW里构建一个时延C/E Petri网.构建了一个特定的Petri网,并进行测试.结果表明,控制器的前面板直观反映了系统的运行状态,而后面板程序框图与Petri网具有类似的拓扑结构.通过结合LabVIEW、Petri网这两种图形化语言,使基于Petri网的测控系统的实现更为简单、直观.

To apply the Petri nets on measurement and control system widely,a component-based implementation method of time delay C/E Petri nets system was proposed,in which a graphical programming language LabVIEW was adopted.In LabVIEW,the places of Petri nets were represented by Boolean controls（＇TRUE＇ of boolean control means place contains token）,and the transitions of Petri nets were represented by subVIs.Transition subVI would change the value of places by the Boolean controls reference when it was fired.Four transition subVIs with different number of input/output places（SISO,SIMO,MISO,MIMO） were bound together to set up a polymorphic transition VI.Based on this method,a time delay C/E Petri net was set up by combining the place and polymorphic transition components in LabVIEW,so that the process was simplified.A specific Petri net was completed and tested.The results show that the system operating state is reflected by the front panel of the controller directly,and the topo-logy of block diagram is similar to that of the original Petri net.Due to the combination of two graphic languages,LabVIEW and Petri net,the implementation of measurement and control system based on Petri nets becomes simpler and more visualable.