Design And Implementation Of Virtual PLC Control System In Salt Product Packaging Pipe Line

With the rapid development of computer technology, the virtual reality involved becomes more and more wide, and the virtual reality becomes more popular in the users and there are a wide range of applications in the education field and the demand for virtual training are more strong. Constrained by the relevant conditions, the students can't go to industrial production lines site to learn and master the components of the production lines or the functions and control methods of each module, so the industrial production line of virtualization emerges. Because the domestic industrial production line of virtualization starts late, the current system only often focus on how to show the equipment of the production lively with little attention to the behavior of the production line equipment and operation of the logic, so the virtual system like that can not make students understand the working process of industrial production line very well even can't train students how to do the work in the real equipment. Aim at the flaws which exists in the virtual industrial production lines for the current system, taking the virtual salt packaging production line for example, this paper achieves manipulating the conduct and the behavior logic of the virtual production line equipment by the virtual PLC technology which simulates the programmable logic controller.This paper, with the object-oriented thinking, divided the virtual production line PLC control system into five major modules according to the functions of them. It includes the scene display module, PLC control module, PLC programming module, tasks list loaded module and the tasks scene editing module.Regarding the structure of the salt packaging production line and controlling method as virtual object and combine with the relevant standards of the virtual PLC, the passage extracts the collection of virtual PLC ladder instruction sets about the system. At the same time, it discusses the modeling strategy about the production line model and the hierarchy of the model control.Secondly, the paper builds the program skeleton of the system, after the study of the system modules and utilizing the BCGControlBar frame to encapsulate each module according to the function. In the realization of the process of virtual PLC editing, it designs the ladder and instruction list corresponding to the data structure and explores ideas and concrete steps about the ladder data conversion to the instruction list data, meanwhile research out the specific PLC logical analytical process. In the process of the preparing for realizing scene display module, explore the specific method of modeling and propose the key steps of definition about model behavioral properties, meanwhile design a virtual PLC logical drive 3d model method in the scene through the research of the virtual scene and the model of hierarchical relationship.Finally, it achieves a common virtual environment platform, the platform can construct virtual scenes of different functions by adding different models to the scene. In the experiment, by adding to the scene, filling the boxes with packing model of group behavior to form a packing box control tasks scene, according to a mission statement, according to the control ladder logic design, select the PLC output interface control three-dimensional model, and then run the PLC. Experiments show that the PLC control system in the packaging production can visually and accurately display the control process of equipment according to the PLC logic designed.