基于三通道并行的高反光物体三维形貌测量  

Three-dimensional Morphology Measurement of Highly Reflective Objects Based on Three Channel Parallel Processing

作　　者：韩鹤翔 高楠[1] 张国锋[2] 郭彤[3] 白雅静 倪育博 孟召宗 张宗华[1] HAN Hexiang;GAO Nan;ZHANG Guofeng;GUO Tong;BAI Yajing;NI Yubo;MENG Zhaozong;ZHANG Zonghua(School of Mechanical Engineering,Hebei University of Technology,Tianjin 300130,China;School of Mechanical Engineering,Xi′an Jiaotong University,Xi′an 710049,China;State Key Laboratory of Precision Measuring Technology and Instruments,TianjinUniversity,Tianjin 300072,China)

机构地区：[1]河北工业大学机械工程学院,天津300130 [2]西安交通大学机械工程学院,西安710049 [3]天津大学精密测试技术及仪器全国重点实验室,天津300072

出　　处：《光子学报》2024年第7期181-193,共13页Acta Photonica Sinica

基　　金：国家自然科学基金(No.U2341275)。

摘　　要：传统条纹投影技术测量高反光物体时因过度曝光导致相机失真,而常用的多重曝光时间法采集图像数量过多、耗时过长,为此提出了一种基于三通道并行的条纹投影强度预测与图像融合的方法。该方法根据被测物体的光强直方图分布计算条纹最佳投影光强比例关系,投影对应的红绿蓝条纹。利用彩色相机在多光通道下对投影条纹的不同响应,分离对应条纹图像并选择其中不饱和并且调制度最大的像素生成各自通道的图像掩膜,根据三通道下的掩膜图像和条纹图像合成高动态范围条纹图。通过相位解算与系统标定,最终恢复出高反光金属平面与球面零件的三维形貌。实验结果表明,该方法测量误差减小至传统方法的61.2%,同样采集12张条纹图像,仅增加1张预投影图像,提高系统适应性的同时也提升了测量精度。Currently,optical 3D measurement technology is widely applied in various fields including industrial inspection and reverse engineering,due to non-contactness,high speed,and high precision.However,traditional fringe projection methods face challenges for the measurement of highly reflective surfaces.In such cases,the projected images may experience overexposure in bright regions,which may result in camera distortion.Currently,commonly used methods such as the multiple exposure time method and the intensity adjustment of projection patterns have issues such as requiring a large number of images to be captured and having poor algorithm adaptability.Therefore,to ensure both the measurement efficiency and accuracy while adapting to varying surface reflectivity of highly reflective objects has become a challenging research topic.With respect to the three-dimensional surface measurement of highly reflective objects,this investigation presents an approach for fringe projection intensity prediction and image fusion based on three�channel parallel acquisition of color camera.In the first place,a uniform gray image is pre-projected onto the object′s surface.Based on the histogram distribution of light intensity of the object being measured,regions with similar surface reflectivity are grouped into clusters.The specific values for either three significant clusters or two significant clusters plus one minor cluster are calculated.By considering the scattering effects of light of different wavelengths,the optimal projection intensity ratio for the three channels specific to the object is determined.The corresponding RGB fringes are then re-projected onto the surface of the object.Secondly,the corresponding RGB fringes are re-projected onto the object′s surface,and a color 3CMOS camera with three independent sensors captures images in parallel.Under multi�channel illumination conditions,the camera exhibits distinct responses to fringe patterns projected the projector with varying intensity ratios,subsequently isolating

关 键 词：测量 三维形貌 条纹投影 高反光物体 三通道 高动态范围 

分 类 号：TH741[机械工程—光学工程]