CCD测量误差的研究

Research on the error of CCD

为了提高CCD的测量精度,对CCD的测量误差进行了深入分析。以单CCD和双CCD错排,对直径为5.000mm、8.000mm、12.000mm的三个标准杆件直径的测量数据为基础,对CCD测量误差的大小及其影响因素展开研究,重点对测量误差、像素间距间的关系进行了深入分析。对N个像素间距为H的CCD错排进行测量,其最大误差减小为H/N,当被测对象大小刚好是像素间距的整数倍时,测量值以很高的机率靠近真实值,检测零件尺寸时,在极值处分别设置一列CCD像素,调整零件极值刚好位于CCD两相邻像素的中间,能准确地判别零件的合格性。

For higher measurement accuracy, the error of CCD is analyzed. In an early experiment, three standard pole＇s diameter is measured by single CCD and two-inclined CCD, these poles diameter are 5. 000 mrn, 8. 000 mm and 12. 000mm. Base on the experiment, the size and infection of measurement error is discussed; the relationship of pixel space-between and measurement error is investigated. The results show that several CCD are fit together by the distance of H1= H/N （His pixel space-between, and N is CCD amount）, and the maximum error is reduced to H/N, as the part＇ s size is times of pixel spacebetween, the measurement value will close to the true value greatly. When test the part size, by use a CCD at each extremum, adjust the extremum lie to the middle of two pixels, the eligibility will be gained accurately.