关键词: CCD；齿形链；亚像素；集成；误差

Abstract: The measurement system on chain board of tooth shape chain was established based on computer vision, and a new kind of sub-pixel algorithm for edge orientation of beeline and circle was put forward.Pinhole diameter, roundness error, chain board pitch and angle between two right sides of chain board were calculated, then the error analysis to measurement results was performed.The whole course containing image process, parameter calculation, and calibration etc. was integrated.Coordination transmission was performed,measurement area was confirmed, and the calibration for part image to be measured was finished through standard sample. Experimental results show that the orientation error of improved least-square linear fitting method is one quarter of ordinary least-square linear fitting error under small difference of orientation time. The sub-pixel orientation of circle makes resolution of CCD increase 42 times, which enhances greatly orientation precision of image edge. Pinhole ,pitch, angle between two right sides and roundness are respectively 2.563mm, 6.296mm, 60.453° and 14.7μm, while taking sub-pixel method. The whole measurement course for one chain board spends less than one second.

Key words: CCD, tooth shape chain, sub-pixel, integration, error