| The Charge Coupled Device (CCD) is a device of the formation of image of semiconductor, which can shift, store, transmission and deal with the picture of the scenery in the form of photoelectric signal with the aid of the essential optical system and suitable driving circuit. In the past 20 years, the CCD technology applies military and civil fields widely. The applications of measuring and monitoring are more and more popular especially with the improvement of the industrial automation and need of the industry condition.This paper studies and designs a precise photoelectric measurement device for dimension integrated with optics and signal proceeding technology. Using narrow-spectrum of high brightness LED as lamp-house, even parallel light comes into being when passing special optical structure. Adopting high resolution linear CCD sensor and subdivision technology and integrated with digital signal proceeding technology, the system has achieved steady micron-grade dimension measure. The time order driving circuit of CCD is designed and debugged with CPLD, which make the whole driving circuit's volume smaller, shorter design, modify design at any time, and enhance reliability and agility of circuit. The video signal processing circuit is designed by differentiating amplifier, second Butterworth low-pass filter and in-phass proportion amplifier, that realizes the primary catching, filtering and signal amplifying. The data acquisition system is designed using TLC5510, CY7C199, 74F579 and PDIUSBD12, that realizes the sampling, store and transmission of the video signal. In order to improve the precision of the measurement, the data processing adopts multiple algorithm of smooth processing and edge detecting in digital image processing.The experiment of CCD driving and signal processing circuit shows that the drivers can assort with CCD well, take advantage of the characteristic of CCD photoelectric transition and output steady and reliable electric signal. Video processing circuit can restrain the main noise, enhance SNR and obtain high quality video signal for further signal processing. Software program and debug of data processing are completed, and system error is analyzed.Principle analysis, practicality design and experiment result indicate that the application of the whole system is feasible, and has merits of high precision and non-contact measurement relative to traditional measuring methods. |
