基于Zernike矩的保持架直径测量方法

Measuring Method of Cage Diameter Based on Zernike Moment

摘要:

为了解决轴承保持架人工抽检费时费力等问题,同时提高工业生产自动化水平,简述了一种基于Zernike矩的保持架直径测量方法;以型号32007E的圆锥滚动轴承筐形保持架为例,提出了基于视觉的直径测量方法,分析CCD相机采集到的轴承保持架大小端面图像,进行图像预处理后,对Sobel算子边界点阈值进行重新设定,快速检测出保持架两端圆面可能存在的边缘点集,增加了有效圆检测算法,剔除部分偏离有效圆的点,再利用 Zernike 矩算子对有效的边缘点进行重新定位,检测出保持架两端圆面的亚像素边缘并计算其精确位置,最后对所得到的亚像素边缘点集进行最小二乘法拟合,获取保持架两端直径具体尺寸;实验表明,该方法测量结果与人工测量精度接近,甚至更高,具有良好的效果和实用价值。

Abstract:

In order to solve the time-consuming and laborious problem of manual inspection of bearing cages, and to improve the level of industrial production automation, a method of measuring the diameter of cages based on Zernike moments is presented. Taking the 32007E cylindrical roller cage as an example, a vision-based diameter measurement method is proposed to analyze the image of the bearing cage size captured by the CCD camera. After image preprocessing, the threshold of the Sobel operator is changed and is used to detect the possible edge point set, after the effective circle detection, remove part of the interference point, and then using Zernike moment operator on the edge of these re-positioning to detect the image sub-pixel edge and calculate the exact location. Finally, these exact positions are fitted by using the least squares method to obtain the specific dimensions of the diameter of the cage. The actual operation shows that this method can achieve the expected accuracy, with good results and practical value.