PCB基准点的探针式鲁棒定位方法  

Robust Probe Type Positioning Method for the PCB Mark Point

作　　者：曾友[1] 高健[1] 岑誉 

机构地区：[1]广东工业大学机电工程学院机械装备制造与控制技术教育部重点实验室,广州510006

出　　处：《组合机床与自动化加工技术》2016年第6期30-34,共5页Modular Machine Tool & Automatic Manufacturing Technique

基　　金：国家重点基础研究发展计划项目(973计划)(2011CB013104);广东省高等学校科技创新重点项目(2012CXZD0020);广东省战略性新兴产业专项资金(2012A080303004;2011A081301001)

摘　　要：为了提高印刷电路板(PCB)基准点的定位鲁棒性与定位精度,减少因基准点损坏而定位不准或者不能定位现象,提出了探针式基准点定位方法。该方法分粗定位与精定位两步,粗定位阶段首先采用区域增长法进行图像分割,通过圆度阈值筛选出圆形区域,运用所提出的探针定位方法建立探针法数学模型,实现基准点的粗定位。基于粗定位所得基准点区域图像,提取其图像亚像素边缘,提出基于稳健估计算法的几何距离法圆拟合方法,实现基准点的精定位。实验结果表明:在复杂背景下该探针式定位法的基准点识别结果的正确率达100%,可有效降低基准点误定率;定位方法对基准点污损不敏感,在基准点损坏50%的情况下定位精度还能达到0.021个像素。In order to improve the robustness of localization and positioning accuracy of PCB（ Printed circuit board）,reduce the phenomenon of wrong location or unable location for the damaged mark point,a probe method is proposed. The method is divided into the coarse positioning and the accurate positioning. About the coarse stage： First,using the region growing algorithm to segment the image. Then choose the circular region with roundness threshold. At last the probe detection method is proposed and a mathematical model is set up to complete the coarse positioning. At the accurate positioning stage, the sub-pixel edge of the image should be obtain first. Then using the geometry method and combining the robust estimation method, the circle of the mark point is fitted, so the accurate positioning is completed. The experimental results show that the probe method is effective, its right positioning rate is as high as 100% under the complicated background.This means that the wrong positioning rate is highly decreased. The results also shows that the circle fitting method is not sensitive with the damage and stains. The positioning accuracy can reach 0. 021 pixel even though the mark point is damaged 50%. Its effect is far superior to the other method described in this paper.The requirements of mark point positioning of stable, reliable,high accuracy and low sensitivity of damage and stains are reached.

关 键 词：PCB基准点 计算机视觉定位 探针法 边缘检测 几何法圆拟合 

分 类 号：TH16[机械工程—机械制造及自动化] TG506[金属学及工艺—金属切削加工及机床]