Research On The Subdivision Method Of Linear Array CCD

CCD(Charge Coupled Device-the Optical Charge Coupled Device) has been applied in all the industry areas, the application of linear array CCD in measurement system is getting more and more attention. Subdivision is one of the most effective ways to improve measurement accuracy of linear array CCD system.Through analysis and comparison of a large amount of data about CCD, its features and advantages are concluded. The universal linear array CCD measurement system is designed. Discussion and analysis of the subdivision methods is the main foucs and new subdivision methods are also proposed: the integrated subdivision and the subsection division, and verified by experiments. The main contents of this paper are as follows:(1) Introduction of the structure and principle of CCD, highlighting its superiority by comparison with CMOS. Analysis and contrast of linear array CCD and area array CCD, pointing out the advantages of linear array CCD in measurement applications.(2) Design of the universal linear array CCD measurement system and introduction of every module function.(3) Proposes some module optimization suggestions .Through comparison of the IC drive circuit, the EPROM drive circuit, the SCM drive circuit and the CPLD drive circuit etc, C8051F320 is taken as the core and AD9826 for data acquisition and conversion, the linear array CCD data collection system based on USB interface is designed. Detailed study is given on the CCD subdivision method, the classic algorithm can hardly meet the accuracy requirement and the sub-pixel subdivision algorithm consisting of the edge subdivision and the image point positioning subdivision is gradually becoming mature. The image point positioning subdivision includes the binary method, the gravity center method, one dimensional linear interpolation, centroid interpolation, the figure center method, the cut-off voltage method, the proportional center method, the ladder method, the gray scale centroid subdivision and frequency doubling interpolation, and also the weighted polynomial interpolation and the multi-threshold proportional center method. The edge subdivision includes the modem subdivision, the space fitting subdivision, the polynomial interpolating subdivision and the dynamic probability subdivision. On this basis, the methods of integrated subdivision and the subsection subdivision are given research to.(4) The experimental system with the core of MSPCCD-060101 linear array CCD collection device is constructed. The measurement data is acquired by experiment and data fitting is done in Matlab, finally the result is obtained through subdivision process verifying the subdivision algorithm.