Hardware And Software Design Of Economical NC Engraving Machine Based On U-Disk Technology

The CNC system is the critical part of CNC engraving machines. Its controlling functions and performance has direct bearing on the quality and efficiency of engraving process and it is crucial for the performance vs cost ratio and the competition of the engraving machine. This thesis, based on the current state of home-made engraving machines and aiming at the requirements of users, researches and develops a new type CNC system for engraving machines based on MCUreading the message in the U-disk.Based on the market research of engraving machines and according to the required functions and performance of the CNC system, this thesis draws up a framework of the whole CNC system and designs its hardware and software. For hardware, a chip named of AT89S52 produced by ATMEL is used as CPU and a decipherer is used for extending of memory and I/Os. More importantly, in the communication interface, the original design of using a USB disk module based on the chip of CH375 accosiated with MCU system to realize the USB host function is put forward. The design takes account of the controlling function and the manufacturing cost of the system, meanwhile, improves the flexibility of design and reliability of performance. For software, Turbo C is used for programming to construct the frame of software and complete unreal-time task. Thus, not only the efficiency of programming is raised and the maintenance of the system is improved, but also the good real-time performance is provided. Moreover,in the speed control system of the stepping motor, index accelerating and decelerating algorithm is used for calculating the frequency of the pulse and comparative integral is used for interpolating the curve which well satisfy the requirements of the high-speed and stability of the engraving process. As a result, the developed prototype of the CNC system achieves the anticipated functions and performance.