无铅焊点鲁棒定位的灰度积分投影算法  

Robust Positioning Algorithm of Lead-Free Solder Joints Based on Gray-Level Integration Projection

作　　者：吴福培[1] 张宪民[1] 邝泳聪[1] 欧阳高飞[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2009年第9期98-102,116,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家杰出青年科学基金资助项目(50825504);粤港关键领域突破项目(东莞专项200816822);广州市科技攻关项目(2008A010300002)

摘　　要：针对自动光学检测系统因焊点定位不准确而导致的误判问题,基于灰度积分投影技术提出了一种焊点定位的鲁棒算法.首先对无铅焊点图像进行预处理,利用焊点的颜色特征对图像进行二值化,将焊点从印刷电路板图像中分割出来;然后分别利用焊点特征的水平和垂直灰度积分投影曲线,以焊盘窗内焊点像素的面积最大化为目标,获得焊点的定位坐标,以实现准确的焊点定位.此外,通过引入Blob评价函数区分焊点与噪声,从而有效地减少了噪声的干扰,提高了定位算法的鲁棒性.实验结果表明,采用所提出的算法对变化多样的Chip元件焊点进行定位时,定位误差小于1个像素,具有较高的定位精度.In order to avoid the misjudgement of automatic optical inspection system due to the positioning error of solder joints,a robust positioning algorithm of solder joints is presented based on the gray-level integration projection.In this algorithm,first,solder joints are segmented from the printed circuit board（PCB） image after the binarization of the pretreated image of lead-free solder joints according to the color feature of the joints.Then,with the help of gray-level integration projection curves of solder joint features in both horizontal and vertical directions,the positioning coordinates of the joints are obtained and the accurate positions of the joints can be determined by maximizing the pixel area of solder joints within the solder-land windows. Moreover, by introducing a Blob evaluation function, the solder joint and the noise are differentiated, thus effectively reducing the disturbance of noise and improving the robustness of the algorithm. Experimental results show that the proposed algorithm is of a high positioning precision less than 1 pixel for various solder joints of a Chip component.

关 键 词：自动光学检测 无铅焊点 焊点定位 灰度积分投影 鲁棒性 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]