基于最小二乘拟合的PCB板焊点定位

Locating of PCB Solder Joint Based on Least Squares Fitting

在PCB板的生产过程中,为了满足实时性检测和快速准确定位的要求,根据PCB板的颜色特征和焊点的形状特征,论文提出一种基于最小二乘法拟合圆的快速定位方法。首先对图像进行校正;然后利用背景和焊点区域颜色的明显差异,选择其单通道显示并进行形态学操作,从而突出显示焊点区域;最后针对焊点轮廓为圆形这一关键特征,采用最小二乘法对其进行拟合,从而确定圆心和半径。实验测量结果表明了文中算法的的有效性。

In order to meet the requirements of real-time detection and accurate location in PCB production process, ac- cording to the color features of the PCB and the shape feature of the solder joint, a kind of fast locating method is put forward in this paper, which is based on the least squares fitting. The PCB image is firstly calibrated for its angle distortion. Then according to the obvious color difference of the solder ioint zone and background zone, morphological operations are per- formed on the red channel of the PCB image, thus to highlight the solder joint zone. Finally the center and radius are deter- mined by using the least squares fitting method to fit the round shape of the solder joint. The experimental results show the effectiveness of the proposed method.