圆孔几何参数的图像测量方法

为了快捷方便地测量圆孔的直径和深度,提出了圆孔几何参数的图像测量方法。首先,将相机模型简化为针孔成像模型,并对相机的焦距进行精确标定;然后,根据同一相机在不同物距下两次对同一物体成像的大小不同这一特性,在不同的两个物距下分别对所测圆孔成像;最后,对图像进行畸变校正和边缘提取等图像处理工作,并由图像信息计算出所测圆孔的直径和深度。实验结果表明,所提出的图像测量方法的测量误差小于0.15mm,能够满足圆孔的一般精度测量要求,适用于测量精度要求不高的在线测量以及接触式测量方法无法完成的测量任务中。

Image Measurement for Geometric Parameters of Circular Hole

A image measurement method is proposed in order to measure the diameter and depth of circular holes con- veniently and rapidly. First of all, the camera model is simplified as a pin-hole model, and an accurate calibration is carried out for the camera＇s focal length. Then two different images are shot respectively under two different object dis- tances according to the speciality thai the size of the images under different object distances are unlikeness. Finally, the diameter and depth of the circular hole are calculated out by the image informmion after a series of work such as dis- tortion correction and edge detection of the images. Experimental results indicate that the error of this measurement method is less than 0.1,5 millimeter and it can suffice for the requiring of ordinarily measurement precision, and it is ap- plicable for some on-line measurement without requiring of high precision. And it is also applicable for the measuring tasks in which the contact measuring methods are noneffective.