一种基于条纹相位特征的印刷电路板三维重建方法  

A Printed Circuit Board Three-Dimensional Reconstruction Method Based on Fringe Phase Characteristics

作　　者：吴福培[1] 彭俊龙 叶玮琳[1] 郑志丹[1] 李昇平[1] Wu Fupei;Peng Junlong;Ye Weilin;Zheng Zhidan;Li Shengping(Department of Mechanical Engineering,College of Engineering,Shantou University,Shantou 515063,Guangdong,China)

机构地区：[1]汕头大学工学院机械工程系,广东汕头515063

出　　处：《光学学报》2024年第14期144-153,共10页Acta Optica Sinica

基　　金：广东省自然科学基金(2021A1515010661);广东省普通高校重点领域专项(2020ZDZX2005);广东省普通高校创新团队资助项目(2020KCXTD012)。

摘　　要：重建印刷电路板(PCB)表面元器件的三维形貌对确保其贴装质量具有重要意义。为提升PCB表面三维重建的精度和可靠性,本文提出了一种基于条纹相位特征的PCB三维重建方法。首先,基于自适应权重法建立多曝光图像的融合规则,进而合成高质量的条纹图像,并构建异步多频相移法以求解视场内各像素点的相位值;其次,针对结构光三角立体模型因标定误差而影响PCB重建精度的问题,由相机和结构光发生器视线映射关系建立高度重建模型;在此基础上,基于标准量块的测量值标定并拟合出最终的三维重建参数。实验结果表明,所提方法可有效提升高动态范围复杂表面的三维重建效果;在精度评价实验中,采用所提三维重建方法测量陶瓷标准球的平均直径误差为0.0188 mm,且能准确可靠地恢复PCB表面元器件的三维形貌,进一步检验了所提方法的有效性。Objective Printed circuit board(PCB) is a crucial component of electronic products, and its mounting quality directly affects the stability and reliability of electronic products. Therefore, three-dimensional(3D) reconstruction of PCB is essential for accurately detecting solder joint defects and component mounting positions, etc., which is vital for ensuring PCB mounting quality. At present, the structured light method is widely used in PCB 3D reconstruction due to its simple operation, versatility, and high precision. However, the accuracy of PCB 3D reconstruction is compromised by two main factors. First, the varying reflectivity of the PCB surface can lead to abnormal and missing fringe phase information.Second, calibration errors of the structured light system can further affect accuracy. We propose a PCB 3D reconstruction method based on fringe phase characteristics, which effectively addresses the issue of missing 3D point clouds when measuring high dynamic range surfaces and improves the accuracy of 3D reconstruction.Methods The structured light system consists of a structured light generator and a camera. Initially, a multi-exposure image fusion rule based on adaptive weights is established, which calculates the weight map through sample images captured at different exposure time and synthesizes the fringe image sequences. The weight map is determined by two factors: the relationship between each pixel's intensity value and the overall brightness of the current image, and the variation of the same pixel between neighboring exposure images. Next, the phase value is solved using an asynchronous multi-frequency phase shift method. To improve the calibration accuracy of the structured light system, we build a height reconstruction model based on the perspectives of the camera and the structured light generator. The optimal function is formulated by examining the offset between the measured value and the actual value of the gage blocks. Subsequently, the Levenberg-Marquardt algorithm is used to fit and optimi

关 键 词：三维重建 条纹结构光 印刷电路板 参数标定 图像融合 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]