电子摄像式刀具预调测量仪的调焦方法研究  

Focusing Evaluation Method of Tool Presetting and Measuring Machine Based on CCD Imaging

作　　者：刘力双[1] 吕乃光[1] 

机构地区：[1]北京机械工业学院电子信息工程系,北京100085

出　　处：《制造技术与机床》2008年第7期116-119,共4页Manufacturing Technology & Machine Tool

基　　金：北京市自然科学基金/北京市教委科技发展计划重点项目(KZ200511232019);北京市属市管高等学校人才强教计划资助项目(PXM2007_014224_044674)

摘　　要：电子摄像式刀具预调测量仪中,测量图像具有背景部分灰度值高、刀具部分灰度值低、边缘部分处于中间灰度值的特点。由于图像越正焦,边缘梯度越大,处于中间灰度值的像素数越少,因此提出了一种基于中间灰度值像素数统计的粗调焦评价方法,当值达到极小值时认为图像正焦。该方法简单,只统计像素个数,所以具有较快的处理速度,实验结果表明该方法对于透射式照明图像测量系统来说具有较大的调焦范围,适合于粗调焦。In the tool presetting and measuring systems, the background has higher gray levels and the image of the workpiece has lower gray level. Correspondingly, the gray levels in the edge area are between those of the workpiece and the background. When the image is in focus, the gradient at edge reaches its maximum and the number of pixels with median gray levels reaches its minimum. Accordingly, a fast coarse focusing method based on the counting pixel number with median gray levels is proposed for rough focusing evaluation. The advantage of the method is that it is simple and fast. The experimental results show that the proposed method allow a large focusing range for the transmission illumination image based measurement systems, so that it has superiority over other methods in coarse focusing applications.

关 键 词：刀具预调测量仪 自动调焦 调焦评价 图像测量 

分 类 号：TN948.41[电子电信—信号与信息处理] TB851.1[电子电信—信息与通信工程]