基于USB的数控系统直接数字通信研究-电气工程专业论文.docx

Abstract NC machine tools have a wide range of applications in various fields of industrial production and occupy an important position in national economy. With the development of computer technology, microelectronic technology, automatic control and communication technology, the NC technology and NC machine tool also constantly upgrade ， and develop to high-speed, multi- functional, open. After the 1990s, the emergence of a new control technology, that is, computer digital control PC-based, achieve the main control functions by standard PC. Not only powerful computing capabilities have, but also get the support of the majority operating system. It represents development direction in the future. Its emergement made a tremendous leap forward of the traditional numerical control system in the structure and the performance. On the basis of modern numerical control technology, combined with the development of USB technology in recent years, the paper designed a direct digital communications structure of NC system which modular, reconfigurable and can be expanded. Functions such as servo control, USB communications, encoder signal control, analog-digital conversation control and digital interface control were achieved in a integrated FPGA. Realize the direct digital communications between computer digital control devices, drive systems and other peripherals equipment by USB interface. Control functions such as high- speed, multi-point data transfer and data monitoring are achieved, the interface design of the NC system are simplified, improve the performance of the NC system is improved. Study on USB2.0 protol, combined with the requirement of NC system, in accordance with the design process of the IP core, USB IP was designed. Firstly USB was devided by its features, and then the physical layer module and the protol layer module were designed. Designning process of USB IP core was introduced, and the design flow and simulation waveform were given. Because of the IP