Research And Design On The Control System Of A Four-Axis CNC Engraving Machine Based On AVR Microcontroller

With the rapid development of CNC and CAD/CAM technology,CNC engraving machine emerges as the times require,which has shown a vigorous vitality in the engraving industry.With advanced CNC system and powerful manufacturing ability,Germany,America,Japan and other developed countries have been in the leading position in carving technology.After more than ten years of development,China's carving technology changes with each passing day and has achieved very gratifying results.However,the common engraving machines in the domestic market are still deficient in interpolation types,machining accuracy and number of linkage shafts.In view of the above situation,the control system of a four-axis CNC engraving machine based on differential interpolation principle is studied comprehensively and systematically in this paper.The main research contents are as follows:(1)The software and hardware of the engraving machine control system are planned,and the control scheme of PC+AVR microcomputer is determined.According to the plan,the hardware control circuit is designed based on AVR microcontroller,and the software function of the control system is planned and studied.(2)In the host computer of the control system,the development environment of Qt5.0 is used to complete the decoding of CNC system based on regular expression,the emulation of interpolation machining path based on Open GL,and the development of convenient human-machine interaction and other main functions.(3)In the slave computer of the control system,a set of differential interpolation motion controller is developed based on AVR microcontroller.The motion controller realizes the direct interpolation of the plane conic curve and the cubic polynomial curve,the multidimensional linear interpolation based on differential principle and the special cylindrical interpolation mode etc.At the same time,a step motor acceleration /deceleration control strategy adapted to the differential interpolation principle is proposed to achieve accurate and efficient motion control.(4)The experiment platform of a four-axis CNC engraving machine is built.A series of tests have been carried out on the platform,such as direct interpolation of the plane conic curve and cubic polynomial curve,relief machining,interpolation of spiral line and conic curve on the surface of rotary body etc.Finally,a four-axis NC code is programmed with Power Mill,and the circular carving test is completed on the rotating coordinate axis of the experimental platform.Through the above research,a special motion controller of differential interpolation based on AVR microcontroller and the host computer of the control system.The control system of four-axis NC engraving machine is developed.Finally,a series of machining experiments carried out on the experimental platform of four-axis CNC engraving machine show that the control system of the four-axis CNC engraving machine designed in this paper meets the initial design requirements.It has laid a good foundation for the research and development of the control system of high-end multi-axis CNC engraving machine.