密封圈自动测量技术研究

发布时间：2018-10-08 09:42

【摘要】：为了实现对O形密封圈的尺寸测量与缺陷检测,设计了双工位自动测量系统,研究了尺寸测量与缺陷检测集成方法,以及图像采集路径规划算法。针对利用机器视觉技术检测O形密封圈表面缺陷时,存在成像一致性差的难题,研究了 O形密封圈曲面成像理论以及缺陷检测方法。首先,针对O形密封圈曲面外形和尺寸跨度较大的特点,提出构建基于多视场协同测量原理的双工位自动测量系统的方案,介绍了该系统集成方法。当O形密封圈外轮廓尺寸大于大视场成像视野范围时,规划大视场序列图像采集路径,并开发了基于公共特征的图像拼接算法。根据O形密封圈在大视场图像中的位置信息,推导了小视场图像自动采集的路径规划方法。为实现自动测量,建立空间测量坐标与图像坐标之间的映射关系。然后,为了避免框架结构的固有频率与动力系统的频率相近发生共振而影响测试精度,研究了框架结构的有限元建模及计算模态分析方法,并通过模态实验验证了该仿真分析方法的有效性,为自动化设备上大量使用的该类型结构的模态分析提供了方法。建立O形密封圈在任意方向光源辐照条件下的成像亮度计算方法,提出利用三套相机-镜头组从三个不同的角度对O形密封圈表面缺陷成像检测方案。最后,评定了 O形密封圈尺寸测量结果的不确定度,定量的说明了 O形密封圈尺寸测量结果的可靠程度。实验结果表明,所提出的尺寸测量与缺陷检测集成方法可以实现对O形密封圈自动测量,O形密封圈表面成像实验表明:理论亮度计算结果与实际亮度分布趋势基本一致,所提缺陷检测成像方案能可靠检测出O形密封圈表面缺陷的位置。
[Abstract]:In order to realize the size measurement and defect detection of O-shaped seal ring, a dual-station automatic measuring system is designed, and the integrated method of dimension measurement and defect detection, as well as the algorithm of image acquisition path planning are studied. In order to solve the problem of poor imaging consistency when using machine vision technology to detect the surface defects of O-shaped seal rings, the theory of curved surface imaging of O-ring seals and the defect detection method are studied. Firstly, in view of the large surface shape and size span of O-shaped seal ring, a scheme of automatic measurement system based on the principle of multi-field cooperative measurement is proposed, and the integration method of the system is introduced. When the size of the outer contour of the O-ring is larger than that of the large field of view, the image acquisition path of the large field of view sequence is planned, and an image mosaic algorithm based on common features is developed. Based on the position information of O-ring in large field of view image, a path planning method for automatic acquisition of small field of view image is derived. In order to realize automatic measurement, the mapping relationship between spatial measurement coordinates and image coordinates is established. Then, in order to avoid resonance between the natural frequency of the frame structure and the frequency of the dynamic system, the finite element modeling and the computational modal analysis method of the frame structure are studied. The effectiveness of the simulation analysis method is verified by modal experiments, which provides a method for modal analysis of this type of structure which is widely used in automation equipment. The imaging luminance calculation method of O-shaped seal ring under any direction light irradiation is established. Three sets of camera lens sets are used to detect the surface defect of O-shaped seal ring from three different angles. Finally, the uncertainty of measurement results of O-ring size is evaluated, and the reliability of O-ring size measurement is quantitatively explained. The experimental results show that the integrated method of dimension measurement and defect detection can be used to automatically measure the surface of O-shaped seal rings. The experimental results show that the theoretical luminance calculation results are basically consistent with the actual luminance distribution trend. The proposed defect detection imaging scheme can reliably detect the surface defect position of O-shaped seal ring.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH136;TP391.41

【相似文献】