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利用调焦方式可以实现焦距的连续变化从而对不同物距下的光学组件进行在线检测,但是调焦过程操作复杂且对调焦位移精度要求较高,景深内光学元件缺陷无法区分,难以实现真正意义上的在线检测。因此,本文提出了基于相机阵列的光学组件缺陷在线检测方法。首先建立了相机阵列的成像模型并给出了数字重聚焦表达式以及空间分辨率的表达式。接着利用MATLAB模拟相机阵列成像过程和数字重聚焦过程。最后进行实验验证,通过二维位移台带动相机对不同物距下的多个光学元件表面缺陷进行成像获得阵列相机图像,通过数字重聚焦算法得到不同物距下的光学元件表面缺陷分布信息。实验结果表明,基于相机阵列的光学组件缺陷在线检测技术能够同时对位于景深范围内的光学组件进行在线检测。该方法在光学元件缺陷在线检测方面有着一定的应用价值。 相似文献
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为快速准确检测球粉板表面缺陷,对球粉板表面光学特性不一致性和缺陷类型的多样性等关键问题进行了分析,以利于有效地解决关键问题;论文提出采用基于模板图片创建矫正模板来解决被测板材表面光学特性变动的均化问题、自适应萃取二值化阈值解决二值化阈值整定问题,以提高软件的执行鲁棒性;通过自定义算法实现了细线型缺陷修补,有效地提高了划痕类缺陷检测的精度和可靠性;提出了筛查模型实现了符合缺陷检测精度要求的噪点筛除;通过大量现场实验验证了本系统能够正确高效实现球粉板表面缺陷检测定位标识和面积测量功能,以及达到了目标检测精度;本系统能很好地胜任球粉板在线表面缺陷检测;实验证明检测系统非常高效精准,极大地提高了生产线自动化能力。 相似文献
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高精密轴承是一种圆柱型零件,针对圆柱型零件高曲率表面缺陷及外形尺寸不能同时进行在线检测的问题,设计并实现了基于机器视觉的在线检测系统。检测时,为了解决金属件表面反光的问题,设计了专用的光源系统和照明方式,通过光学系统和机械旋转平台的配合,圆柱型零件在旋转的过程中被光学系统成像,从而可以采集到完整的圆柱面图像;经过快速的图像处理技术,可以检测到微米级的轴承表面缺陷及外形尺寸。检测结果表明系统具有高效率、精度高、易于使用等特点,可有效解决高精密轴承表面缺陷及尺寸在线检测的问题。 相似文献
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针对皮革表面类缺陷用机器视觉在线检测时,某些缺陷成像质量对照明方向呈现各向异性甚至无法显现而形成检测盲区的问题,研究设计了一套可消除该类检测盲区的在线检测系统。基于缺陷处的散射和信息采集机理得出缺陷特征光强随照明方向的变化规律,并以压印和油墨类缺陷为例进行实验研究,发现2类缺陷特征光强分布均与照明方向相关,缺陷的检测盲区与有效区呈正交态。据此,采用自主设计的侧入式均匀照射离轴面光源,设计出线阵和面阵正交复合的在线检测系统,采用垂直目标面采集信息、45°角暗场正交照明,线阵相机和线光源组成主检测系统,面阵相机和离轴面光源辅检测系统,对随机出现的各向异性缺陷进行上百个样本检测,实验证明,缺陷检测盲区被有效消除,缺陷识别率提升了近22%,检测效率也得到大幅度提高。 相似文献
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产品表面缺陷检测是工业自动化生产的重要环节,准确率是评价自动检测系统可靠性的主要指标。基于复杂纹理表面缺陷检测的特殊性以及对检测方法的实时性、通用性等要求,提出了优化骨干网络并使用迁移学习特征映射构建复杂纹理表面缺陷的检测方法。该方法通过优化残差网络模型并建立仿真数据集的方式进行迁移学习,以解决实际情况中复杂纹理表面产品数据集样本数量少、数据集制作困难、相似问题难以互相兼容等问题。实验结果表明,提出的方法可以准确地检测随机复杂纹理的人造木质板材表面缺陷,平均准确率可达99.6%。现有实验条件下单张人造木质板材的检测时间为305 ms,可以满足在线检测的实时性要求。研究结果可为基于深度学习的复杂纹理表面缺陷检测提供新的思路与理论参考。 相似文献
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零件缺陷检测是保证零件使用安全的重要手段。传统的零件缺陷检测法需要有操作人员参与其中,易受主观因素影响,检测的效率及精度得不到良好的保证。而采用机器视觉技术的检测法可实现实时在线的自动检测,无需人工参与,这就极大的提高了生产效率。本文以小轴承表面为研究对象,针对微小轴承的表面结构、尺寸、检测精度和缺陷特征,设计了基于BP神经网络的零件缺陷机器视觉在线自动检测系统,其采用机器视觉技术,构建了BP神经网络检测识别模型,采用进行图像特征提取的间接识别方法,对微小轴承缺陷进行实时检测。实验结果证明了人工神经网络模型的检测能力的可靠性。 相似文献
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通过对脉冲耦合神经网络(pulse coupled neural network,PCNN)和拉曼光谱定性分析的研究,提出了基于PCNN的拉曼光谱定性分析方法.首先,利用PCNN神经元的疲劳与不应期特性将拉曼光谱数据进行编码;然后,基于改进的Horspool算法将检测样品对应编码与基码数据库中的所有基码逐一匹配,并得到各对应的匹配相似度,进而判定样品类别.相关实验和数据分析证明了该文方法的准确性和有效性.同时,该文方法避免了目前基于谱模版定性分析方法中待测样品拉曼光谱特征谱峰难以确定以及匹配分析冗余度高等不足,且对存储空间的要求仅为后者的5.8%. 相似文献
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J.Apolinar Muñoz Rodríguez 《Optics & Laser Technology》2011,43(3):491-500
An automatic calibration technique for three-dimensional vision is presented. This technique determines the vision parameters by means of approximation networks and image processing of a laser line. Also, the network performs the three-dimensional vision based on laser scanning and a mobile camera. The network is built based on the behavior of a laser line and the camera position. Here, an electromechanical device moves the camera during the vision task and the network provides an automatic re-calibration. Thus, the vision is carried out via mobile camera and extrinsic parameters are not passed to the system. Therefore, the accuracy and the performance of the vision procedure are improved. It is because the physical measurements of references are avoided. Thus, a contribution for the calibration of lighting methods is achieved. Additionally to it, the mobile setup provides a high sensitivity and avoids occlusion. The proposed technique is tested with real objects and its results are evaluated based on laser projection methods. To carry it out, a root mean square of error is computed using a contact method as reference. Also, the time processing is described. 相似文献
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The problem of obstacle detection and recognition or, generally, scene mapping is one of the most investigated problems in computer vision, especially in mobile applications. In this paper a fused optical system using depth information with color images gathered from the Microsoft Kinect sensor and 3D laser range scanner data is proposed for obstacle detection and ground estimation in real-time mobile systems. The algorithm consists of feature extraction in the laser range images, processing of the depth information from the Kinect sensor, fusion of the sensor information, and classification of the data into two separate categories: road and obstacle. Exemplary results are presented and it is shown that fusion of information gathered from different sources increases the effectiveness of the obstacle detection in different scenarios, and it can be used successfully for road surface mapping. 相似文献
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Zewei Liu Dongming Lu Weixian Qian Guohua Gu Kan Ren Jun Zhang Xiaofang Kong 《Optical and Quantum Electronics》2018,50(12):447
Laser and visual imagery have been broadly utilized in computer vision and mobile robotics applications because these sensors provide complementary information. Since the single-point laser range finder can provide depth information of a single pixel in the observed image, its price and size is very suitable for handheld devices or very lightweight robotic platforms. So the combination of a single-point laser range finder and a camera has become increasingly useful in recent report and industrial applications. In this paper, we propose two accurate calibration methods for determining the position and direction of the laser range finder relative to the camera. Furthermore, we can accomplish calibration even without observing the laser spot in camera image. We evaluate the two methods through experiments which demonstrate their efficiency and high reliability. 相似文献
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基于同心圆合成图像匹配的双目视觉标定 总被引:6,自引:1,他引:5
分析了双目视觉传感器的数学模型,提出了一种基于同心圆合成图像匹配的双目视觉传感器的标定方法。在测量范围内任意多次摆放同心圆靶标,由两台摄像机拍摄靶标图像。根据摄像机模型与已知同心圆在靶标坐标系上的位置关系,构造合成图像,将合成图像与观测图像进行相似度匹配,通过优化定位得到靶标上每个圆的圆心点图像坐标。利用左右图像对应的圆心图像坐标和双目视觉的约束关系,对双目视觉传感器参数进行非线性优化,并得到最优解。所提出的标定方法是在张正友方法的理论基础上,利用了图像的整体性进行的优化。实验结果表明,该方法提高了标定精度。 相似文献
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Wavelet-based enhancement for detection of left ventricular myocardial boundaries in magnetic resonance images 总被引:1,自引:0,他引:1
MRI is noninvasive and generates clear images, giving it great potential as a diagnostic instrument. However, current methods of image analysis are too time-consuming for dynamic systems such as the cardiovascular system. Since dynamic imagery generate a huge number of images, a computer aided machine vision diagnostic tool is essential for implementing MRI-based measurement. In this paper, a wavelet-based image technique is applied to enhance left ventricular endocardial and epicardial profiles as the preprocessor for a dynamic programming-based automatic border detection algorithm. Statistical tests are conducted to verify the performance of the enhancement technique by comparing borders manually drawn with 1. borders generated from the enhanced images, and 2. borders generated for the original images. 相似文献
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单摄像机虚拟立体视觉测量技术研究 总被引:6,自引:0,他引:6
以双目立体视觉传感器三维测量模型为基础,提出了一种用于测量空间三维点坐标的低成本单摄像机模型。该模型利用光学成像,把单摄像机镜像为一对虚拟摄像机,在一个CCD像面上采集到同一物体存在视差的两幅图像,从而恢复空间点的三维信息。讨论了单摄像机传感器测量空间三维点坐标的基本原理,建立了单摄像机传感器的测量模型,克服了双摄像机系统中成本高、切换采集左右摄像机的图像使检测速度减慢等诸多缺陷,为空间三维点的精密测量提供了经济、快速、有效的测量途径。实验表明.传感器可实现约0.8%的相对测量精度.证明了本方案合理、有效。 相似文献
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In the paper machine vision, laser interferometer and coordinate measuring machine (CMM) are combined to develop a vision inspection system. The measurement capability of the developed system is investigated by measuring the distances between the lines on a standard line scale. The vision camera is used to replace the probe of the CMM to take the images of the interested lines on a line scale at two different positions. Meanwhile, the displacement of the CCD camera is measured using laser interferometer. Using subpixel edge localization and outlier-excluding least-squares regression, the distance between two interested lines is computed under an image plane coordinate system. By adding the displacement of the CCD camera measured using laser interferometer, the line space can be determined. Experiments have been performed repeatedly to measure the line space on the 1.00 and 300.0 mm line scales. Results indicate that the measured data only have a little fluctuation and are close to those obtained by the NML (National Measurement Laboratory, Taiwan). 相似文献