FPGA-based Diameter Measurement System

Diameter is a very important physical quantities, for measuring diameter in many different areas all have an important role, for example, precision machining, screw machine rails or drive the diameter is to ensure that the important parameters of precision parts and indicators to facilitate the construction and site safety, the deformation of the truss or bridge diameter test, is also very important means of detection. Therefore, the diameter of such high-precision parts and components has a very important test.This paper studies coupled with CCD photoelectric sensor to the rail, the diameter of shaft-line measurements, to ensure that the shaft parts factory to meet the accuracy requirements. In different applications and testing different shaft products, the CCD driving frequency have different requirements:the need for high-speed measurement, the larger the case of external interference, the use of high-frequency measurements CCD driver can achieve higher measurement accuracy, and there will be a higher detection efficiency, high-end CCD line for diameter detection apparatus, the CCD with adjustable frequency drive system, the instrument has a wider range of applications;in the environment is stable, measuring less demanding circumstances, use of low-end CCD-line detection equipment can meet the requirements, so in order to reduce development costs, the use of low-end processor chips (such as 8051, etc.) of the CCD to capture low-frequency signals. The system is simple, reliable, easy to operate, can be measured continuously.FPGA design using the CCD drive timing, and control TLC5510A/D converter chip CCD analog signals into digital signals, stored in the FIFO inside the FPGA, the main use of FIFO buffer as the data processing, digital signal will be analyzed and calculated to get the required diameter of the system, and this number into ASCII code sent to the LCD liquid crystal display module for display. RS232 interface can also convert the data to the PC, at any time to monitor the sampling points of each signal.