The Research Of Experimental Teaching Open-NC Platform Base On Embedded Technology

With the development of CNC technology lead to the rapid demand of NC talent for social.For the traditional training model of talent exists many Malpractices, the thesis developed a set of open-NC experimental platform,which is suitable to primary education,in order to train CNC technicians better and more economical.The platform is suitable for universities and vocational colleges’ students to carry on CNC technology teaching experiment,which is simple, modular open and easy to control.The system is consists of PC, SCM control board, stepper motor drives, feedback devices, X-Y table and other components. The modular design, manufacture and test debugging of the SCM control board and stepper motor driver circuit were finished in the thesis.And the driving principle of stepper motor and control methods were analysied in-depth.To verify the feasibility of the CNC simulation system that is based on the Matlab/Simulink simulation platform, the mathematical model of closed-loop control system was built, which is consists of stepper motor, PID control algorithm and PWM pulse width modulation technology.The hardware of the open-NC simulation system with STC89C54 chip was designed based on the Altium Designer software platform, which included the master chip circuit,power circuit, motor drive circuits, limit circuits, key circuit, encoder interface circuit,RS485 communications and auxiliary circuits. And the PCB board of SCM control board was designed with the schematic library and device packaging library of Altium Designer.The thesis had developed the operating system of X-Y table base on ARM’s integrated development tools keil C51, which is designed for software. The study of communication technology, interpolation technology, stepper motor control technology and the C language compiler technology had been completed. The C language control program was constrcted to carry on X-Y table to go full circle trajectory by comparison circular interpolation, and simulation debugging was operated by using keil C51 circuit debugging module.The operating parameters of the control system had been established through integration and commissioning. The C language control program derived from circular interpolation algorithm was compiled based on keil C51. The coincidence degree between running track under the driven of C language control program and interpolation track under NC rule of X-Y table was analysied.The practical value of open-NC experimental platform had been verified.