PLC Simulation Control Towards3D Virtual Production Line

With the rapid development of society, product is updating faster and faster. Automatic production line needs to update and adjust in time. Programmable Logic Controller (PLC) is one of the most effective tools to control automatic production line. How to develop an efficient and reasonable automatic production line controlled by PLC quickly becomes the key to the enterprises. In order to solve this problem, a3D virtual production line based on PLC simulation control system which combined automatic production line virtual simulation technology and virtual PLC technology is developed. It enabled automatic production line based on PLC Editor to be designed and simulation operated. The main contents were as follows:Firstly,3D equipment library was built for automatic production line. The geometry model of each equipment was created. Then, it analyzed the equipment’s movement behavior which was expressed by mathematically model, such as the trajectory equation. According to the behavior of the equipment trigger condition and performance, this paper defined the PLC program control of input and output ports, and used script to create the equipment behavior model. The behavior model of each equipment was created, it used Access database to store the virtual equipment in order to establish a3D equipment library for automatic production line.Secondly, geometric models assembly and behavior models configuration of automatic production line were completed. A virtual assembly environment was constructed, and studied interaction control technology, collision detection and constraint-based bounding box positioning technology of virtual equipment, then geometric models assembly was implemented. Using ADO database access technology to reads each equipment PLC control input and output port information and behavioral models script program that defined the entire automatic production line PLC control input and output ports and behavioral models script.Thirdly, an external operating device was designed. The communication between the external operating device and PLC Editor was studied. Then interface circuit and associated program were designed, and the external operating device input control signals were acquired and delivered. So the external operating device could simulate and control virtual automatic production lines.Finally, the development of simulation PLC control system faced to the3D virtual production line was completed, and the system was verified by instances. Then an automatic production line for processing rough mechanical parts was built. It ran based on PLC control program, and controlled by the input signals from external operating device.