Application of Numerical Control Machine Simulation in NC Teaching
Keywords: virtual CNC machine tool numerical control teaching and training virtual reality simulation With the wide application of CNC machining in the mechanical manufacturing industry, a large amount of training for CNC operators has become an urgent problem. In the traditional operation training, the effective training of NC programming and operation must be carried out on the actual machine tool, which takes up the processing time of the equipment and has risks. Misoperations in the training often lead to damage of expensive equipment. With the development of computing technology, especially the development of virtual reality technology and concepts, a computer simulation training system that can simulate the actual equipment processing environment and its working state is generated. It uses computer simulation training system for training, which not only can quickly improve the quality of the operator, but also is safe, reliable and low cost. Similar to science fiction, the combination of imagination and technology creates virtual reality. Bacon’s sci-fi story of a horseless car and powered machinery written in the 13th century is an early testimony to this combination. Verne wrote the prophetic science fiction of rockets and submarines in the 19th century, especially some sci-fi writers. The various assumptions that have been made to take advantage of the basic concepts of virtual reality are gradually becoming concrete. Several technical milestones built in the last century made virtual reality possible, telephone, radio, television, semiconductor triodes and integrated circuits (microprocessor chips) and liquid crystal displays. Especially the rapid development of computer technology. Some early simulation attempts (such as the first flight simulator, stereoscopic movies, video games, etc.) have become the pioneers of today's virtual reality simulation. Of course, the development of virtual reality technology is inseparable from the booming of electronics and the computer industry. At present, there are a few institutions of higher learning in China that have initially applied computer simulation to the teaching of numerical control operation personnel training, and also produced various simulation teaching systems. These teaching systems can run independently on a stand-alone system and online. The independent operation means the machine model. The training facility only needs one microcomputer. The simulation operation of the CNC machine is performed on the simulation panel displayed on the display screen. The part cutting process is simulated by the machine model three-dimensional animation. The initial training in this way is Cost-effective; online operation means the machine tool. In this way, the teaching system will be connected with the actual machine tool, and the hardware will realize the part cutting process. In addition to the operator operating with the simulation panel, the actual situation with the actual machine tool. Similarly, simply using a computer and other specialized hardware software to generate a simulation of a real scene, participants can experience a feeling close to the real scene by interacting with the simulation scene. Therefore, the actual work skills of the operator can be further trained. The core of the CNC simulation system is the virtual CNC machine tool, and the virtual CNC machine tool is an execution unit in the virtual manufacturing technology. It not only provides manufacturability analysis for product design in the NC machining process, but also learns in the CNC system. During the training, we provided comprehensive learning and training for all types of schools and enterprise technicians. This type of system completely simulates the cutting process of the part, can verify the correctness of the NC command, and provides a full set of functions such as debugging, editing, modification and tracking execution. 1 virtual CNC system function The virtual CNC machine is actually a model of a CNC machine in a virtual environment. Compared to real machine tools, virtual CNC machines should have the following features: • The virtual CNC machine should have exactly the same structure as the real machine. Virtual CNC machines can mimic any function of a real machine without causing distortion or loss of certain structures and information due to some approximate substitution. It should have the same interface style as the real machine tool, and guarantee the learning and training of the technicians. · The powerful network function of virtual CNC machine tools provides possibilities for distance education. · Complete graphics and standard data interfaces. Users can run virtual machines in real-world environments, observe various travel parameters, and interface with other CAD/CAM software. 3 platform purchase and construction How does a virtual CNC machine implement these functions? It is generally implemented through the following build platform. 1Nc Interpretation Platform The NC Interpretation Platform includes an NC interpreter and an NC validator. The task assignment database accepts the NC code from the task schedule and translates it into information about the motion of the virtual machine's components, tools, etc., and simulates the machine's response through the calculation module. The NC interpreter can be freely configured to simulate any A CNC controller for CNC machine tools. 2NC verifier, able to verify the grammatical correctness of the NC code. 3 Tool magazine tool magazine should include the tools required for a CNC machine tool, and can freely configure the tool number in the tool magazine. This allows you to simulate the tool change form of any CNC machine. 4 Simulation platform The simulation platform includes tool path simulation, cutting force simulation, machining accuracy simulation, 3D animation simulation, and processing time statistical analysis. The simulation platform is the core technology of virtual CNC machine tools. The operator can simulate the machine movement and cutting process in a virtual environment, and obtain relevant processing data. Such as the amount of displacement of the feed axis, tool change status, spindle speed, acceleration, feed amount, machining time, etc. Through the simulation of the machining process, the machiningability of the designed workpiece is known, the correctness of the NC code is verified, and the machining process is evaluated and optimized, and the NC code is optimized by modifying the NC code online. 5 computing platform computing platform is used to complete various calculations in virtual CNC machine tools, such as calculating the new geometry of the machined parts according to the NC code, and calculating the compensation amount of the tool according to the material of the tool, the running time, the material properties of the parts and the properties of the lubricating medium. And the amount of thermal compensation. These calculations are necessary for the evaluation of the machining scheme and the manufacturability analysis of the virtual CNC machine tool in the virtual manufacturing process. 6 Design and Development Platform The design platform of the virtual CNC machine tool is an object-oriented CNC software library and its development environment. Through the standardization, standardization research of CNC software and other CAD/CAM software data exchange, and typical parts are packaged, it is designed as a reusable software with stable and universal interface. 7 Operational operation platform and monitoring platform Fully realize the operation of the real machine in the virtual environment, let the user fully feel the running characteristics of the real machine. Monitoring hardware and software based on these, used to control simple machine tools. Increase the realism of virtual CNC machine tools. And you can carry out experimental trial cutting of typical parts, so that users have a feeling of being in the air. Especially in the process of CNC teaching and training, beginner CNC programmers need a lot of programming exercises and actual debugging. It is obviously unreasonable to test the NC machining program with the trial cutting method, and it is also difficult to implement. If you use simulation technology, these problems can be easily solved to avoid artifacts caused by human error or unreasonable process during programming. 4 Summary In view of the functions of virtual CNC machine tools, the number of students in CNC teaching courses and participating in CNC internships is increasing, and the numerical control equipment is more sophisticated and expensive. Introduce CNC machining simulation software into teaching for CNC machine tool operation and programming training, which can avoid the damage of expensive CNC machine tools caused by misoperation, and enable operators to produce on-site during the operation of simulated CNC machine tools. Feeling and realism. Moreover, the students can get familiar with and understand the working process of CNC machining more quickly, and master the basic operation of each CNC machine tool. The greater benefit is to minimize processing errors and accident rates while achieving the same results. The current hardware facilities of our company are basically available, including computer room, local area network and various CNC machine tools. In the near future, after the campus network is connected, this teaching method is indeed likely to become a reality. Especially after the opening of the distance education course at the Beihang Engineering Training Center, I believe that this teaching method will become a necessary teaching method.
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