滚珠丝杠副内螺纹的图像测量

Image Measurement on Internal Thread of Ball Screws

为了在一个系统中对滚珠丝杠副内螺纹进行无损探测及几何参数测量,提出了基于工业CT技术及图像处理技术的滚珠丝杠副内螺纹的非接触测量方法。工业CT机采集的图像经过图像预处理、二值化、轮廓提取及细化等处理后,图像信息转变成宏观图形信息。借助图像处理中提取的滚珠丝杠副内螺纹的边界,使用自编程序测量和计算螺母的齿形圆弧、珠心径、滚道跳动及螺距,测量误差分别为0.017mm、±0.015mm、0.013mm和±0.025mm。测量结果能够满足产品技术要求。

In order to realize non-destruction detection and parameter measurement on internal thread of ball screws in one system, this paper proposed a non-contact measurement method, which was based on image processing technology and industrial CT technology. Original gray level image collected by industrial CT device was changed into macroscopical drawing information after processed by pre-processing, threshold selection, bivalency image, edge detection and contour extraction etc.In measuring, based on the segmented contour line of internal thread of ball screws, compiled measurement program to calculate and measure such geometrical parameters of the internal thread of ball screws as tooth shape arc, radius of ball center, ball way jumpiness and pitch, and the reason of errors was analyzed. Errors of tooth shape arc, radius of ball center, ball way iumpiness and pitch can reach 0.017ram,!0. 015ram,0. 013ram and ±0. 025ram respectively. The results satisfy with the technical requirements of production.