Abstract Since a slight variance in production processes can make the entire production run defective, defect inspections are indispensable procedures in manufacturing processes to ensure high quality of each item before entering the next manufacturing step. Three-dimensional (3D) optical shape measurement technologies are widely applied for surface defect inspection of complex workpieces because of its high-accuracy and digitization. However, the complex surface structure and position of the test object can pose serious challenges, making inspections still relatively slow, expensive, and complicated in implementation and maintenance. In this work, we propose a real-time 360∘ 3D surface defect inspection approach based on fringe projection profilometry without any auxiliary equipment for position control. Firstly, a multi-view 3D measurement based on geometric constraints is employed to acquire high-accuracy depth information from different perspectives. Then, a cycle-positioning-based registration scheme with the establishment of the pose-information-matched 3D standard digital model is proposed to realize rapid alignment of the measured point cloud and the standard model. Finally, a minimum 3D distance search is driven by a dual-thread processing mechanism for simultaneous scanning and detecting to quantify and locate 3D surface defects in real time. Experimental results show that our method can accurately identify the surface defects of complicated objects in real time in an extremely simple (hand-held) manner, saving a lot of operational expenses on precision alignment and position-orientation adjustment. The proposed method holds tremendous potential for quality control in many facets of industry, such as product development, testing, and manufacturing.

中文翻译：

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使用条纹投影轮廓测量法进行高分辨率实时 360∘ 3D 表面缺陷检测

摘要 由于生产过程中的微小差异都会导致整个生产过程出现缺陷，因此缺陷检查是制造过程中必不可少的程序，以确保每个项目进入下一个制造步骤之前的高质量。三维（3D）光学形状测量技术因其高精度和数字化而被广泛应用于复杂工件的表面缺陷检测。然而，复杂的表面结构和测试对象的位置会带来严峻的挑战，使得检查仍然相对缓慢、昂贵且实施和维护复杂。在这项工作中，我们提出了一种基于条纹投影轮廓测量法的实时 360∘ 3D 表面缺陷检测方法，无需任何用于位置控制的辅助设备。首先，采用基于几何约束的多视图 3D 测量，从不同角度获取高精度深度信息。然后，提出了一种基于循环定位的配准方案，建立了位姿信息匹配的3D标准数字模型，实现了被测点云与标准模型的快速对齐。最后，最小 3D 距离搜索由双线程处理机制驱动，用于同时扫描和检测以实时量化和定位 3D 表面缺陷。实验结果表明，我们的方法可以以极其简单（手持）的方式实时准确识别复杂物体的表面缺陷，节省了大量的精密对准和位置定向调整的运营费用。