干涉条纹自动计数系统的设计与研制

利用集成电路芯片结合光敏晶体管等器件设计并成功制作了一种自动化测量的干涉条纹计数仪器,以实现干涉条纹的自动测量、可逆计数显示等功能。设计方案包括基于光敏晶体管RPM-075PT获取光电信号,以集成电路ST288A准确判别干涉条纹的凹进冒出方向以反映等厚或等倾干涉中光程的变化情况,使用集成电路ICM7217A进行条纹可逆计数。进一步的,使用自带整形滤波功能芯片ST288A以简化方向判别电路及提高抗干扰能力。最后,实验测试结果表明本计数器全面满足干涉条纹的计数要求,可取代人工观测条纹计数,可广泛应用于高校实验、企业检测等应用干涉条纹计数的场景中。     

干涉条纹可逆计数的控制信号处理

干涉条纹可逆计数的控制信号处理杨庆芬（石家庄铁道学院基础部０５００４３）《物理实验》１９９２年第２期刊发了许祖华等同志“干涉条纹可逆计数系统”．文中利用计算机处理双光纤束装置的输出信号，做成了干涉条纹可逆计数系统，解决了一般光电接收器只记录条纹的数量...     

基于单片机的迈克耳孙干涉仪自动计数装置

选用AT89C51单片机,为迈克耳孙干涉仪设计了干涉条纹自动计数装置．用程序来控制计数和步进电动机的运行;用光电转换器使明暗变化的条纹转化成脉冲电流,作为计数脉冲信号;用步进电动机带动迈克耳孙干涉仪的微调手轮,使其慢速可控转动,完成脉冲信号采样;并用数码管直接显示计数结果．     

莫尔(干涉)条纹计数细分和辨向技术的研究

提出了一种双阈值计数法与正切细分法结合使用的莫尔(干涉)条纹计数细分和辨向技术。通过阈值的设置,实现了整周期信号的辨向和计数,消除了直流电平漂移和高频噪声引起的计数误差;采用正切细分法,对不足一个信号周期的条纹位移,实现了正确的辨向和高倍数细分。该方法同时具有双阈值计数法和正切细分法的优点,具有强的环境适应性和抗干扰能力。     

基于脉冲计数的零相位差跳变补偿外差干涉信号处理方法

在基于脉冲计数的外差干涉信号处理中,提出了一种零相位差跳变补偿的大小数相位结合处理方法,可实现外差干涉信号处理中大小数的准确结合。大数测量采用对两路干涉信号进行脉冲计数同步对减的方法实现,小数测量采用混频降频方法来提高测量分辨率,并采用锁相环对拍频信号跟踪产生用于混频降频的动态基准信号,解决外差信号拍频变化的问题,以提高小数测量分辨率的稳定性。基于信号发生器对实现的外差干涉信号处理方法进行了验证,包括测量精度、大数计数、小数相位测量。构建了双通外差干涉位移测量光路,通过对精密导轨位移的测量来验证大小数结合处理方法的有效性和信号处理方法在外差干涉位移测量应用中的可行性。     

基于Arduino单片机的双光纤双向干涉条纹计数器

介绍了一种基于Arduino单片机的双光纤双向干涉条纹计数器.该装置可根据干涉条纹的涌出和陷入实现条纹的双向计数.在干涉法测量金属热膨胀系数实验中,使用此计数器对条纹计数,具有成本低廉、操作简易、计数精度高、抗干扰能力强、反应时间短等优点.     

莫尔条纹软件计数法

针对常规莫尔条纹计数法中的缺陷 ,设计了一种软件计数法。软件计数具有可靠性高、适应性强、智能化程度高等特点。介绍了莫尔条纹软件计数的原理 ,以及基于 DSP的莫尔条纹信号软件计数的实现     

干涉条纹智能计数器的研制

设计了干涉条纹智能计数器,结合线胀系数测量实验验证了该仪器可实现干涉条纹的自动计数,具有计数准确、抗干扰能力强、价格低廉等优点.     

基于Matlab的迈克尔逊微小位移测量

传统迈克尔逊干涉条纹人工计数,测量方法稳定性差,人为误差较大。现提出一种基于CCD进行干涉条纹采集,利用Matlab中Waved Ruler（波尺）对干涉条纹进行图像处理。根据干涉条纹明暗周期性变化,通过对干涉条纹去背景噪声、二值化阈值滤波、去小噪声、条纹优选等步骤,对干涉条纹处理并计数,从而测得物体微小位移。实验结果表明,该方法优化了迈克尔逊干涉法测物体微小位移,测量最小误差达到0.4%,减小测量过程中的误差,提高测量稳定性。     

等倾干涉条纹的采集与处理

迈克尔逊干涉仪是测量微小长度的精密仪器。实验中,测量等倾干涉条纹个数是重要环节。为了实现单片机自动计数,对干涉条纹的采集和处理是前提条件。本文详细介绍了等倾干涉条纹,以及对它的采集与处理方法。     

Two color interferometry with nonlinear refractive properties

Using nonlinear refractive properties of salt-water solution at two wavelengths, numerical analysis has been performed to extract temperature and concentration from virtual interferometric fringe data. The theoretical study, using a commercially available equation solving tool, starts with critical fringe counting needs and the role of nonlinear refractive properties in such measurements. Finally, methodology of the analysis, developed codes, and fringe counting accuracy needs are described in detail.     

干涉条纹场成像的目标重建

分析环状条纹干涉成像的信号提取方式,用计算机模拟目标二维图像的重建方式,研究干涉环中心在照明场中心的位置对点扩展函数的影响,并用实验论证上述影响。     

非球面检测中最佳入射球面波和最佳参考球面波的确定

为了能够对非球面光学元件面型进行高精度的干涉检测,提出了一种确定最佳入射球面波和最佳参考球面波的新方法。该方法通过计算分析入射球面波与非球面反射波干涉条纹密度,确定最佳入射球面波的波源位置;通过计算分析在干涉图记录平面CCD上干涉条纹的密度,确定非球面检测时参考球面波波源的最佳位置。应用该理论与方法,不仅可明确非球面检测时CCD等光路元件选型的具体策略,而且可用于指导非球面检测调试过程,并能够通过对干涉图的深入分析,获得更多被测非球面的信息。     

Surface profilometry based on polarization analysis

We report a novel algorithm for the analysis of interferometric images for surface profiling. The algorithm can be used with any interferometric system in which the two interfering beams are orthogonally polarized. The algorithm is based on a measurement of the polarization state and gives a unique value for the path difference that is not subject to the ambiguities associated with fringe counting or phase unwrapping. A detector array allows the polarization state and hence the height of every pixel in the image to be determined simultaneously. The concept is easily extended to enable one to obtain the profiles of moving surfaces from a single pulse of illumination.     

Signal processing scheme for central position identification in a white-light interferometric system with a dual wavelength source

A signal processing scheme using a curve fitting algorithm to determine the central position of the digitized fringe pattern output of a white light interferometric (WLI) system is discussed. An analytic result for the resolution obtained in the central fringe position measurement using a specific curve fitting scheme has been given and a simulation of the measurement of the central position of a computer generated fringe pattern has been carried out. The results from the simulation show good agreement with those from the theoretical analysis. A supporting experiment to investigate this effect has also been carried out and the short term repeatability of the central position measurement using the curve fitting scheme gives close agreement with the theoretical results.     

Sensitivity and optimization in the determination of deformations by holographic interferometry

The use of a fringe-counting holographic interferometric technique for measuring small superficial displacements can present difficulties in determining the measurement inaccuracy. A useful general method is given here for the analysis of errors in displacement measurements. The optimum number and type of observation directions are determined and correspond to counting in the four semi-diagonals of the holographic plate. The technique, as applied to skull experiments, makes it possible to measure directly displacements of up to 20 μm, in the object plane parallel to the holographic plate. The associated errors range from 0.1–0.3 μm, for a counting inaccuracy of of a fringe and increments of traction of 100 g to 1 kg of force.     

自适应统计滤波的单幅干涉条纹图相位解调研究

基于统计信号处理技术的最大后验估计原理 ,提出一种新的自适应滤波方法。该方法能有效减少干涉条纹图中的噪声 ,仅估计一幅非载波条纹图上每一点的空间频率向量的幅值和方向 ,通过解系数阵为正定阵的方程组 ,就能获得准确的条纹相位分布。通过实例说明了此方法的处理过程。     

Position Sensing Grating Interferometer for a Specular Object

A position sensing interferometer is described which is able to sense the position of a specular object from a normal distance. The interferometer consists basically of a diffraction grating, a focusing lens and two plane mirrors. The grating acts as a tool to divide the incident beam and also to combine the reflected beams from an object so that they interfere with each other. An experiment was carried out to verify the principle. Interference fringe patterns caused by variation in the object position were obtained. The sensitivity obtained theoretically was confirmed by measuring the width of the fringes. As a result of theoretical comparison with conventional techniques, it was determined that this interferometric method has the advantage of the high sensitivity and the wide dynamic range being compatible with each other. The setting for sensing is simple and the analysis of the fringe patterns is easy.     

Test of a conical lens using a two-beam shearing interferometer

We describe a two-beam shearing interferometric technique for testing refractive conical lenses. The optical configuration requires two mutually coherent plane wave fronts transmitted through the conical lens under test. The method can also be considered as an interferometric fringe projection technique in which a fringe pattern produced by the two interfering wave fronts is projected through the optical elements. We describe the principle of the method and present application of the technique for determining the angle formed by the flat surface and the conical surface of a refractive conical lens.     

Application of the FFT method for the quantitative extraction of information from high-resolution interferometric and photoelastic data

This paper describes the application of a digital Fourier transform to phase encoded intensity distribution. Attention is drawn to a method of extracting quantitative information automatically from the interferometric fringe data. To achieve this, a set of carrier fringes has been added to interferometric fringe data. This has made it possible to form a phase map using a FFT (fast Fourier transform) algorithm. A minimum spanning tree (MST) phase unwrapping strategy has been used to create a contiguous map of the whole fringe field. Finally, the measurement parameter related to the fringe field has been calculated from one single image. Experimental results are given for the burner flames, a compressible flow and photoelastic fringe data. It has been shown that the methods developed have the potential for use as reflection analysis systems suitable for applications to non-stationary objects and complicated fringe fields.