共查询到19条相似文献,搜索用时 234 毫秒
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基于三角法测量原理设计了光学三维传感实验系统.实验系统光源采用数字光学投影仪,并用计算机生成电子光栅.将电子光栅投影到被测物或参考面后,使用CCD进行图像采集,并通过视频采集卡将采集的图像数据传到计算机中保存.通过相应算法对保存的数据进行考查、处理,最终得到解调后的三维信息. 相似文献
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利用线阵CCD自动测量航空相机镜头的焦距 总被引:6,自引:0,他引:6
提出了一种以线阵CCD固态传感器取代读数显微镜的航空相机镜头焦距测量系统。论述了系统的工作原理、软件和硬件的设计及系统的测量误差。结果表明 ,利用线阵固态图像传感器取代读数显微镜 ,把特定物体经透镜成像的大小转换为电信号的脉宽 ,并利用计算机技术自动处理测量数据 ,从根本上克服了用读数显微镜进行测量的缺陷 ,实现了航空相机镜头焦距的实时精确地在线测量 相似文献
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利用高速CCD 可见光相机系统研究了EAST 上的边缘局域模(ELMs)细丝动力学特性。采用Tsai 两步标定法对CCD 相机进行标定,以实现将CCD 图像坐标转换为真实空间坐标。选取CCD 图像中与边缘局域模细丝垂直方向上的图像灰度值,绘制了灰度分布图。灰度分布图中的一个凸起的尖峰代表了一条边缘局域模细丝结构,细丝的位置坐标由尖峰顶点确定。运用Sobel 边缘检测算子检测细丝边缘轮廓,从而得到细丝的宽度。通过对边缘局域模细丝宽度特性的分析,发现边缘局域模细丝在从最外层封闭磁面向外传播的过程中宽度不断减小。这表明细丝在向外传播的过程中其能量和粒子不断耗散。I-型边缘局域模的细丝宽度比III-型边缘局域模细丝的宽度更大。 相似文献
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针对太赫兹直线加速器,开发了基于EPICS分布式系统的横向截面尺寸测量系统。该系统采用束斑检测器完成束斑到光斑的转换,并通过远心镜头将光斑成像到CCD相机,完成对光斑图像的采集,之后基于ADAravis将相机采集的图像数据汇入到EPICS数据库。由于暗电流以及环境辐射的影响,在采集到的图像中会存在椒盐噪声,因此使用卷积神经网络(CNN)对图像中的椒盐噪声进行抑制,最后对图像进行高斯拟合计算出束流截面尺寸。实验结果表明,CNN可以有效地消除椒盐噪声,并且系统的分辨率达到15.8μm,满足系统设计要求。 相似文献
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针对现有光栅测量方法不能兼顾高速与高精度的问题,为适应电子制造装备高速运动和高精密定位的位移反馈要求,提出基于增量式光栅尺的纵横转换细分测量原理和相应的图像快速处理算法。为了提高光栅图像采集处理速度,搭建基于FPGA的硬件测试平台,先将采集到的图像进行滤波和二值化处理,然后对图像先进行纵横坐标相加,求取像素点最小值得到交点位移值。实验结果表明:应用纵横转换算法并搭载FPGA测试系统,能够达到0.029 μm的分辨率,精度达到0.3 μm。 相似文献
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A method based on inverse photogrammetry and fringe analysis is presented for 3D coordinate measurement. Measurement system mainly consists of a micro-camera fixed on one end of a measuring rod, a measuring probe on the other end and a liquid crystal display screen for displaying 2D fringe pattern in the measurement. In the measurement process, the probe contacts the surface of the measured object, and the CCD camera captures the stripes image on displays screen. The coordinates of camera principal point in the world coordinate system may be determined by the phase information carried in the fringe pattern. The coordinate relations between the principal point of the camera and the measuring probe can be determined with a least square optimization technique in camera coordinate system. This method has the advantage of large measurement range, good flexibility, and portable, which is suitable for field measurement. A result of our method is compared with that of the Coordinate Measuring Machine (CMM), which shows that the measurement accuracy of this method can meet accuracy requirement of the field measurement in large dimension. 相似文献
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Aimed at the problems of inferior precision and bad maneuverability for three-dimensional (3D) measurement by projected fringe pattern, a flexible new 3D technique for performing system calibration and measuring was proposed. First, we analyzed the principle of conventional 3D measurement with projected fringe pattern, and pointed out the shortcoming of measurement system. Then, the CCD camera calibration technique is analyzed and we set up the perspective projection model which transforms the computer image coordinate to 3D world coordinate, and we get the coordinate of the CCD camera image lens. Third, the position of projection lens optical center can be obtained using the above model. At last, some experiment results presented show that this technique is more simple and robust in engineering than conventional measurement method. 相似文献
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在大型设备自动对接系统中,需要CCD摄像头对一设备截面的圆目标进行图像获取,并找出图像的中心点坐标,用于两设备的中心对准。为了满足实时性测量和高精度定位要求,提出一种CCD摄像头圆目标中心定位方法。先对图像使用中值滤波方法进行图像增强,利用广义数字形态学中的多结构抗噪膨胀腐蚀型算子提取单像素宽图像边缘,用多项式插值法对图像边缘进行亚像素定位,用半径约束最小二乘圆拟合法对圆中心进行精确定位。实验测量结果表明,该方法测量时间短、精度高、稳定性好,亚像素定位精度优于1/20像素,中心点总标准偏差小于0.01,可满足设备自动对接系统要求。 相似文献
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Fourier transform profilometry: : a review 总被引:4,自引:0,他引:4
Fourier transform profilometry is one of the popular non-contact 3-D measurement methods, where a Ronchi grating or sinusoidal grating is projected onto a diffuse three-dimensional surface, and the resulting deformed grating image is detected by a CCD camera and processed by a computer. This method requires only one frame (or two frames) of the deformed fringe pattern in some algorithms to retrieve the surface of measured object, so it has obvious advantage for real time data acquisition and 3-D measurement of dynamic process. In this paper, we review some algorithms in FTP, discuss some important problems, including frequency spectra overlapping, phase unwrapping, sampling, and 3-D measurement of dynamic process. With the development of computer hardware and software and availability of high-resolution image grabber, FTP method will be a promising one for acquiring 3-D data of object, and more and more researchers pay attention to it. 相似文献