高精度自动贴片机视觉对准系统及其图像处理

Vision alignment system in automatic high precision chip mounter and its image processing

阐述了高精度自动贴片机视觉对准系统的构成和原理。介绍了利用模式识别理论和图像的不变矩实现定位标志存在性判断的原理及算法和定位标志对准的原理及相关的图像处理算法,以及其中的点模式匹配算法。试验结果表明,定位标志存在性判断算法可以有效地区分不同的定位标志和判断定位标志是否在视场之内;定位标志对准算法在输入图像旋转、平移、定位标志被部分遮挡时,能精确地得到定位标志的位置偏差。

Accurate alignment is very crucial in the process of chip mounting. The structure and principle of vision alignment system in automatic high precision chip mounter are introduced. A method to judge the presence of fiducial by means of pattern recognition and moment invariants is presented.A method to align the two fiducials in chip and substrate is presented, and the related point pattern algorithm is detailed. Experiment results demonstrate that the proposed method to judge the presence of fiducial can effectively distinguish different fiducials, and judge whether the fiducial is in camera's field of view , and that the method to align fiducials can accurately get position offset between fiducials in chip and substrate even when the input image is rotated, translated, and fiducial is partly occulted.