Modeling and Applied Research in Petri Net of Virtual Assembly Program Control

The conventional method of PLC program design is difficult to analysis and solve the complicated control system. Based on examples, the model of Virtual Assembly System is established through by Petri Net (PN), ordinal, parallel and synchronous relationship among events is described directly and accurately. And the Petri net transfers the PN model into LAD of PLC, which improves the efficiency in programming the LAD program of PLC.