The Research And Realization Of Engraving Machine CNC System Based On Embedded Network

The research object of this subject is the three-dimensional engraving machine in theembedded laboratory of Xi’ An University of Science and Technology, and the engravingmachine’s open computer numerical control (CNC) system based on embedded network isdesigned and produced. Aiming at the randomness of entities’ storage in the interactivemetafile used in the automatic programming of numerical control (NC) system, a newoptimization method based on the greedy algorithm and genetic algorithm, called as the GGA(Greed and Genetic Algorithm), is proposed for the contour machining path in the mixingtracks carving. And the optimization software of CNC machining path based on the hybridprogramming of MATLAB and VC is developed. In view of the low processing efficiency andinconvenience of mobile of the lab existing PC-Base engraving machine control system, anew engraving machine controller based on the ARM microprocessor is designed andmanufactured.The engraving machine controller is implemented on the basis of the Friendly Mini2440development board, of which the SPI interface is used together with independent CANcontroller to extend the CAN interface device. In the VS2005integrated developmentenvironment, the stream interface driver for CAN bus equipment is designed and programmed,which can run under the embedded operating system Windows CE6.0. The driver is added toCNC project and is complied into Windows CE6.0kernel, in order to create the embeddedoperating system image file CNC.BIN, and the CNC.SDK file for application softwaredevelopment is also created.The image file is downloaded into Friendly Mini2440development board, and the CNC.SDK is used to development CNC engraving applicationsoftware which is based on the embedded operating system. The hardware module ofmulti-motor control system which is composed of three feed stepper motor and a main shaftcarved DC motor is designed based on the CAN bus, and the CAN bus node program forCAN bus communication and motor control is written. The DXF file is researched, which is the topic object, and the automatic programmingbased on the DXF is analyzed. The structure and storage way of DXF file is analyzed.Aimingat the randomness of pel storage in the interactive graphics file, which is used in the automaticprogramming of numerical control (NC), the greedy-genetic algorithm is proposed and theoptimization software of NC machining path based on mixed programming is developed. Thefeasibility and effectiveness of the greedy-genetic algorithm is verified by the MATLABprogram simulation result. The results of simulation and test prove that not only the empty rundistance is shortened but also the number of cutter landing is decreased through this method.Thus, the NC machining efficiency is improved. What’s more, the method has a gooduniversality to finish carving work, so it is hard to be restricted by whether it has open andclosed trajectory segment in carving patterns or not, also it is not easy to be restricted by howmany it has.After the feasibility of the engraving path optimization algorithm based on GGA isvalidated, the GGA algorithm module is compiled into the dynamic link library (DLL) whichcan run without the MATLAB environment and can be called by VC language, through theMATLAB compiler. The AutoCAD interface file DXF is taken as the resource object. TheCNC engraving automatic programming software based on the DXF is developed in the VCprogramming platform, and the GGA.DLL is called to optimize the carving path, then theefficient carving processing G code is generated.A lot of experiments and tests have been accomplished, the result of which proves thatthe expected function of the carving machine NC system based on embedded network can berealized. The CAD drawing information can be extracted from DXF files and the excellentpath carved G code can be generated. Through the TCP/IP communication network，the Gcode can be transmitted to carving controller which is based on ARM microprocessor. Thecode analysis, interpolation operation, and pulse distribution function can be completed bythis carving controller. The pulse distribution information can be transmitted from the carvingcontroller to the driver controller of each axis stepper motor through CAN bus，and then thestepper motor is driven to complete the carving task.