The Research On Interface Of CMM Grating Signal Acquisition & Processing System

Coordinate Measuring Machine (CMM) is a high-efficiency and large-scale precision measuring instrument. It can test on-line and measure automatically three-dimensional space sizes quickly and conveniently. And so it has extensive applications in the fields of manufacture and various measurements, such as mechanism, electro-automobile, avigation and space, military industry etc. At present, grating signal acquisition and processing system of Tianjin University's is based on ISA bus. However, the two key index of ISA bus ---the max transfer rate (8.33Mbps) and data bandwidth (8/16bit) have restricted performance and velocity of the system. And it is falling into disuse. At the same time, there are also many deficiencies: laboring in fixing and especially unsuitable for moble-measuring system; high cost; hampered by amount of computer's slots, accessible address and interrupt resources and with bad expansion. So we must find a type of bus interface to replace the ISA bus. With the fast-development of computer bus, PCI bus and USB bus, as the two Currently-Prevailing bus, can solve the problem which is mentioned above, and have been widely applied in the data acquisition and processing system. the dissertation expatiates mainly the design of grating signal acquisition and processing system of CMM based on USB and PCI., which make full use of plug and play, hot plug of USB and fast transfer speed, high reliability of PCI. So the system can realize real-time and displaying of data and provide a guarantee for the stability and reliability of CMM measuring system.The main work includes:1. Designing the data acquisition hardware system of CMM grating signal acquisition and processing based on USB bus after knowing well such components as CY7C68013.2. Programming the USB firmware under the utility of Keil uVision2 and the USB device driver under the operating system of WIN 2000.3. By use of testing platform which is developed by laboratory self and simulates output signal of CMM, completing the experiment using the grating signal acquisition and processing system of CMM based on USB.4. Designing the grating signal acquisition and processing system of CMM...