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次条纹积分法解调位相的三维面形测量 总被引:1,自引:1,他引:0
提出一种新的条闰相分析技术用于三维面形自动测量。将光栅图案投影于物体表面上,投影像随物体三维面形变形,形变的投影像用次条纹积分算法分析,求出位相变化和相应的三维面形。 相似文献
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表面粗糙度测量的磁光位相调制和锁相干涉 总被引:1,自引:0,他引:1
提出了一种表面粗糙度测量的新方法,该方法采用了微分偏振干涉的原理,利用由法拉第磁光调制器所组成的调制系统对偏振干涉光路的位相进行调制,利用锁相干涉原理对位相进行探测,该方法可实现无参考面快速非接触测量,在普通实验条件下,也可保持良好的稳定恶性循环 ,实验装置即可给出表面的轮廓又可给出其它统计数据,其横向分辨率为1.2μm纵向为2nm。 相似文献
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采用剪切干涉和虚拟光栅的三维形貌检测 总被引:3,自引:0,他引:3
本文提出一种新型三维形貌测量方法,该方法通过投影装置将剪切干涉条纹投射到物体表面,以获取调制光栅图。采用相位法,由计算机生成虚拟接收光栅,从一幅调制光栅图重建物体形貌。文中给出了实验结果和性能分析。 相似文献
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平衡零拍探测是测量量子光场的重要方法之一. 通过对相位灵敏光学参量放大器注入的信号进行位相调制, 然后利用平衡零拍探测系统测量光学参量放大器输出的压缩光. 将相位灵敏光学参量分别运转在参量放大和参量缩小, 通过观察噪声谱中的调制信号就可确定测量的量子光场是正交振幅或位相分量. 通过解调位相调制信号可获得误差信号, 实现锁定平衡零拍探测系统本底光与待测光场相对位相为零(对应于待测光场振幅噪声分量).
关键词:
平衡零拍探测
位相锁定 相似文献
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傅里叶变换轮廓术中相位失真的预矫正方法 总被引:1,自引:1,他引:0
介绍了一种基于傅里叶变换轮廓术的三维面形测量系统中相位失真的预矫正方法。由于投影系统和成像系统的空间三角位置关系、投影仪的发散照明和两套系统蕴含的光学畸变,投影一幅相位与空间坐标成理想线性关系的标准正弦光场,拍摄到的条纹相位和空间坐标不再呈线性分布,引起相位失真,甚至会影响系统测量精度。该方法借鉴反向条纹投影的思想,计算拍摄光场的非线性相位分布与理想的线性相位分布之间的关系,预先矫正,反算出一个新的待投影光场。实验结果表明这种方法能有效地减小该类相位失真所导致的测量误差,获得了更好的测量结果. 相似文献
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In order to develop a high-speed and accurate surface inspection system of structures such as tunnels, a new surface profile measurement method using linear array sensors is studied. The sinusoidal grating is projected on a structure surface. Then, the deformed grating is scanned by linear array sensors that move together with the grating projector. The phase of the grating is analyzed by a spatial offset phase-stepping method to perform accurate measurement. The surface profile measurements of the wall with bricks and the concrete surface of a structure are demonstrated using the proposed method. The change of geometry or fabric of structures and the defects on structure surfaces can be detected by the proposed method. It is expected that the surface profile inspection system of tunnels measuring from a running train can be constructed based on the proposed method. 相似文献
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A method for accurately measuring a sectional profile of a cylinder is proposed in which a sinusoidally vibrating sinusoidal grating is used to generate a sinusoidally vibrating sinusoidal intensity distribution. A light coming from the top point of the cylinder surface is extracted with an optical system to make an image of this point. A sectional profile of the cylinder is measured by detecting a phase of a time-varying signal contained in the image intensity at a position where the amplitude of the signal is maximum. Detection of the amplitude and the phase is carried out easily and exactly. 相似文献
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The technique of phase-measuring profilometry is reviewed, whereby a sinusoidal grating structure is projected onto a diffuse three-dimensional surface, and the resulting deformed grating image is detected by a solid state array camera and processed by a microcomputer using interferometric phase measuring algorithms. The approach permits parallel acquisition and processing of large amounts of data with high accuracy and speed.Several systems are described, configured with telecentric laser light illumination or general white light diverging illumination, and capable of measurement from a single point of view or over full 360°. Each system consists of an optical projection assembly with phase-shifter, an imaging assembly with high density CCD camera and an IBM AT microcomputer with buffer and control cards.Applications to industrial inspection and medical diagnostics are presented. 相似文献
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Multi-parameter measuring method of image intensifier based on Fourier transform phase measurement 总被引:1,自引:0,他引:1
A new quality parameter measuring method of image intensifier based on Fourier transform phase measurement is proposed. A standard sinusoidal fringe pattern is projected into the measuring system by spatial light modulator and the corresponding reference pattern and deformed pattern are captured by CCD. The Fourier transform and inverse Fourier transform are applied in order to extract the phase distribution of deformed pattern. The magnification, pillow-shaped distortion, barrel-shaped distortion, snake-shaped distortion and shear distortion of image intensifier are obtained at the same time. Experiment has proved its feasibility with real-time performance and without manual intervention. 相似文献
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A method using entire modulation information of the measured object itself for pixel matching is proposed in online phase measuring profilometry (PMP). Only one fixed sinusoidal grating is projected onto the moving measured object and then five deformed patterns are captured by the imaging system (CCD). Because the contrast of the sinusoidal grating is a constant, the modulation distribution of each deformed pattern reflecting the gray of the measured region can be extracted. The entire modulation of the object cut from one of them is regarded as a template, and then the distance of the measured object's movement between each two adjacent deformed pattern can be calculated by the correlation operation so that we can cut the corresponding parts containing the measured object's information from five deformed patterns. Then the discrete phase can be calculated with Stoilov algorithm. By the phase unwrapping and the mapping algorithm, the object can be reconstructed exactly. A series of simulations and experiments confirm its feasibility and validity. 相似文献
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In this paper, the surface profile of objects is determined by using a grating projection system. The method is based on the concept of self-imaging, namely, the Lau effect. Periodic fringe patterns are generated from the projection of a grating illuminated by multiple mutually incoherent quasi-plane wavefront. The fringe patterns are then projected on to the object surface and the deformed grating image is captured by a CCD camera for subsequent analysis. Phase shifting techniques have been employed to determine the phase value. With suitable calibration of the system and the phase value obtained, the surface profile of the objects can be determined. The phase variation is achieved by using a linear translation stage incorporated to the grating. In this study, two specimens are tested to demonstrate the validity of the method. One is a spherical cap with a height of 4 mm, and the other is a coin. The experimental results are compared with results obtained by mechanical stylus method. In the case of the spherical cap the results are also compared with fringe projection method based on Talbot effect. 相似文献
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提出一种基于数字信号处理器(DSP)的嵌入式三维数字成像系统设计方案。该方案的硬件平台由条纹投影模块、数据采集模块、条纹自动分析模块及储存器等其他辅助电路组成。条纹投影模块将DSP输出的正弦光栅条纹, 经视频编码后用DLP投射到物体表面; 数据采集模块通过CCD相机采集被物体表面三维信息调制后的变形条纹图, 并进行视频解码; 条纹自动分析模块中利用相移算法计算折叠相位, 再结合相位展开算法求绝对相位分布。系统软件采用多线程技术并行控制三个模块。在相位解调过程中以软件流水线为主综合运用了循环展开、数据预取和内联函数等多种方法优化解调程序。实验结果表明, 该系统可以高速、准确地实现三维轮廓测量,优化后相位展开程序速度是优化前的7倍。 相似文献
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Qican Zhang Qingfeng Wang Zhiling Hou Yuankun Liu Xianyu Su 《Optics & Laser Technology》2011,43(4):801-805
In this paper, a practical method using phase tracking and ray tracing algorithms is proposed for measuring the three-dimensional (3D) shape of an underwater object. A 2D projected sinusoidal fringe goes through the water and illuminates the tested object. Firstly, the phase tracking algorithm is employed to identify homologous points in phase distributions of the deformed fringe captured by the camera and these of the fringe pattern projected by the projector. The projector is regarded as a special camera as regards the stereovision principle. In the calibrated system, both ray directions of the homologous points can be easily figured out. Secondly, the ray tracing algorithm is used to trace the propagation path of each ray and to calculate the 3D coordinates of each point on the tested object's surface. Finally, the whole shape of the tested object can be reconstructed. 相似文献