JIANG Mei-hua, FU Lu-hua, WANG Zhong, SONG Yu-hang
（State Key Laboratory of Precision Measuring Technology and Instrument, School of Precision Instrument and OptoElectronics Engineering, Tianjin University, Tianjin 300072, China）
Abstract： Defect inspection of specular curved surface is a challenging job. Taking steel balls for example, a new method based on reflected pattern integrity recognition is put forward. The specular steel ball surface will totally reflect the patterns when it is placed inside a dome-shaped light source, whose inner wall is modified by patterns with certain regular. Distortion or intermittence of reflected pattern will occur at the defective part, which indicates the pattern has lost its integrity. Based on the integrity analysis of reflected pattern images, surface defects can be revealed. In this paper, a set of concentric circles are used as the pattern and an image processing algorithm is customized to extract the surface defects. Results show that the proposed method is effective for the specular curved surface defect inspection.
Key words： specularity; curved surface; defect inspection; reflected pattern; computer vision
CLD number： TP391.4 Document code： A
Article ID： 1674-8042（2016）03-0221-08 doi： 10.3969/j.issn.1674-8042.2016.03.003
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基于图案完整性的高反射曲面缺陷检测新方法
姜美华， 付鲁华， 王 仲， 宋宇航
(天津大学 精密测试技术及仪器国家重点实验室， 天津300072)
摘 要: 高反射曲面零件的表面缺陷检测是一项具有挑战性的工作， 以钢球为例， 提出了一种通过识别反射图案的完整性进行表面缺陷检测的新方法。 该方法基于钢球表面的反光率极高且达到镜面成像的特性， 将钢球置于穹顶形光源内部， 光源罩内壁修饰有规则、完整的图案。 若钢球表面存在缺陷， 则其反射形成的修饰图案的像将在缺陷部分发生扭曲变形或间断缺失。 采集钢球表面图像， 检测修饰图案所成像的完整性即可实现表面缺陷的检测。 设计了内壁修饰同心圆图案的新型光源， 利用上述方法， 对钢球表面缺陷进行了有效提取与分析， 取得了良好效果， 验证了该方法对于高反射曲面零件表面缺陷检测的有效性。
关键词: 高反射； 曲面； 缺陷检测； 反射图案； 计算机视觉
引用格式： JIANG Mei-hua, FU Lu-hua, WANG Zhong, et al. A new method for specular curved surface defect inspection based on reflected pattern integrity. Journal of Measurement Science and Instrumentation, 2016, 7(3)： 221-228. ［doi：10.3969／j.issn.1674-8042.2016.03.003］
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