绝对距离测量技术综述

本文从非相干测量和干涉测量两方面综述了绝对距离测量技术方法。重点介绍了干涉测量法中的半导体激光调频干涉测量技术在绝对距离测量中的一些新应用和新方法。     

白光相移干涉中频谱对测量精度的影响

在相移干涉中有时采用白光干涉来扩大深度测量范围,白光光源的使用,缩短了光束的相干长度,降低了测量精度。本文从干涉理论出发推导了白光相移干涉法测量三维表面形貌的计算公式,通过数值积分的方法分析了干涉光频谱对测量精度的影响。分析表明,在白光相移干涉测量中表面形貌的测量精度与中心波长和频谱宽度有关,白光频谱越宽,测量精度越低,中心波长越大,测量精度越高。     

全视场外差白光干涉测量技术

为了解决传统白光干涉测量技术中对线性位移机构的位移精度要求过高的问题,本文提出了一种全视场外差白光干涉测量技术。该技术主要通过使用存在差频的白光干涉信号作为光源来实现在大扫描步长和低扫描精度条件下相干峰位置的高精度检测。本文首先建立了白光外差干涉的数学模型,再根据数学模型提供的光强信号特性提出了整体系统设计方案,然后对测量方案的可行性进行了实验验证。最后针对多种误差对算法计算精度的影响进行了理论分析和数据对比。误差分析的结果表明:白光外差干涉测量技术提供更高的测量精度和更好的抗干扰性能,有效地降低了传统白光干涉测量对线性位移机构精度的严苛依赖,为光学自由曲面检测技术提供了更多的可选解决方案。     

动态三维面形测量

简述三维测量必要性和要求性，提出用光栅莫尔三维测量，激光全息干涉计量和计算机全息干涉计量的工作原理。     

新型高精度激光干涉小角度测量仪的研究

在分析小角度测量基本原理和特点的基础上，介绍了光波干涉小角度测量的方法和一种新型双参考镜激光干涉小角度测量仪的测角原理，功能特点及具体应用方法。     

高精度大长径比圆柱轴孔内外径测量系统研制

介绍一种非接触式测量大长径比精密圆柱轴孔内外径的方法,该方法基于移相干涉测量技术,研制的高精度内径及外径测量系统以一等量块作为标准,采用白光干涉定位、激光干涉测长与移相干涉技术相结合,实现精密圆柱件长轴外径及深孔内径的高精度非接触自动测量。     

半导体激光端点干涉长法原理探讨

阐述利用半导体激光的频率变化和波长变化测量干涉仪光程差的基本原理，探讨一种在长度的两个端点干涉测量长度的新方法，即端点干涉测长法的原理，推导这种方法测量长度的公式，指出这种方法区别二其它干涉测长方法的独特优点，最后讨论测量中的注意事项以及需要深入的研究的问题。     

螺纹跨线测量干涉问题的探讨

本文建立了对称的阿基米德螺纹(蜗杆)跨线测量时发生干涉的数学模型,并导出干涉发生的判定公式。论证了干涉的发生不仅与螺纹(蜗杆)的参数有关而且与选用的量针直径有关的观点。     

表面粗糙度干涉图像处理系统

介绍了表面粗糙度干涉图像处理和该系统以静态干涉图像处理技术对表面粗糙度检测的过程。该系统通过对一帧白光干涉图像的处理，可对Ｒａ值≤０．２μｍ的多刻线样板，试件表面粗糙度绝对、非接触、快速、自动地测量；该系统通过对白光和纳光二帧干涉图象的联合处理，以白光定位、纳光定度可对沟槽深度Ｈ≤５μｍ的标准单位刻线深度绝对，非接触，准确地测量。     

溶液扩散系数自动测量系统

结合实时法全息干涉计量和数字图象处理技术，提出了一种溶液扩散系数的自动测量系统。在干涉图的处理中，采用了相位检测和曲线拟合技术，得到了亚象素的测量精度。     

ESPI Measurements of Strain on a CFRP‐Reinforced Bending Beam1

Abstract: This paper presents 3D electronic speckle pattern interferometry (ESPI) measurement results of strain components at the end of a carbon‐fibre reinforced polymer (CFRP) plate adhesively bonded to a reinforced concrete beam. To minimise speckle decorrelation because of the inevitable rigid‐body motion of the measured specimen, the load was increased in small increments. Two evaluation schemes are compared: the step‐by‐step addition of the measured displacement components and regain of the correlation by image shifting. Strain is evaluated by interpolating the in‐plane displacement measurements along selected lines, and is compared with results from finite element analysis (FEA). An uncertainty estimate is given.     

散斑干涉条纹图的总变分去噪方法

去除散斑条纹图中的噪声是电子散斑干涉测量技术的关键问题.提出将总变分图像去噪方法应用于电子散斑干涉条纹图滤波过程中,并对保真系数进行了改进.用总变分模型定义图像的能量函数,利用变分法求得满足能量函数的最优解,将图像去噪过程转化为求解偏微分方程的过程.分别对计算机模拟的条纹图和实验获得的条纹图进行了测试,定性和定量分析的结果表明该技术能够在显著滤波的同时保持条纹的对比度.     

Phase-shifting algorithms for electronic speckle pattern interferometry

A set of innovative phase-shifting algorithms developed to facilitate metrology based on electronic speckle pattern interferometry (ESPI) are presented. The theory of a phase-shifting algorithm, called a (5,1) algorithm, that takes five phase-shifted intensity maps before a specimen is deformed and one intensity map after a specimen is deformed is presented first. Because a high-speed camera can be used to record the dynamic image of the specimen, this newly developed algorithm has the potential to retain the phase-shifting capability for ESPI in dynamic measurements. Also shown is an algorithm called a (1,5) algorithm that takes five phase-shifted intensity maps after the specimen is deformed. In addition, a direct-correlation algorithm was integrated with these newly developed (5,1) or (1,5) algorithms to form DC-(5,1) and DC-(1,5) algorithms, which are shown to improve significantly the quality of the phase maps. The theoretical and experimental aspects of these two newly developed techniques, which can extend ESPI to areas such as high-speed dynamic measurements, are examined in detail.     

Vibration measurement by the time-averaged electronic speckle pattern interferometry methods

Three different image-processing methods based on the time-averaged technique were compared by the electronic speckle pattern interferometry (ESPI) technique for vibration measurement. The three methods are the video-signal-addition method, the video-signal-subtraction method, and the amplitude-fluctuation method. Also, errors introduced by using the zero-order Bessel function directly into the analysis of the fringe pattern were investigated. The video-signal-addition method has been the most generally used ESPI technique for vibration measurement. However, without additional image and/or signal-processing procedures, the fringe pattern obtained directly by the video-signal-addition method is rather difficult to observe. The reason for poor visibility of the experimentally obtained fringe pattern with this method is explained. To increase the fringe pattern's visibility without additional image and/or signal processes, we tried two video-signal-subtraction methods. One of the two methods is the video-signal-subtraction method that has normally been used in the static applications. The other method, called the amplitude-fluctuation method, and its associated theory are reported here.     

散斑检测技术及其应用

综述了散斑计量中的主要检测技术。主题包括散斑照相技术、散斑干涉技术、电子散斑干涉技术、数字散斑相关技术和时间序列散斑检测技术。介绍了散斑计量在科学和工程研究中的一些重要应用。     

Multiplicative electronic speckle-pattern interferometry fringes

A theoretical analysis of fringe patterns and its experimental corroboration obtained by multiplication of two speckled images with electronic speckle-pattern interferometry (ESPI) are reported. A specifically designed digital filter is used to enhance the contrast and visibility of the inherently noisy multiplication fringes. Phase retrieval is achieved by a phase-stepping technique. Experimental results are presented for the in-plane-sensitive optical ESPI setup; however, out-of-plane and shearing setups may be used as well. The method represents an alternative to the subtraction and addition techniques in ESPI.     

Phase extraction from electronic speckle pattern interferometry addition fringes

Addition fringes are obtained in real time from electronic speckle pattern interferometry (ESPI) by use of a twin-pulsed laser when two pulses are fired during a single field of a CCD camera. This enables object deformations to be studied in harsh environmental conditions. However, the fringe patterns have poor visibility because optical noise is additive. To our knowledge automatic phase extraction from addition fringes has not previously been achieved: Low-pass filtering to suppress random speckle noise also eliminates the fringes because of their low visibility. Two phase-stepping algorithms that calculate phase from ESPI fringes without the need for a preprocessing filter are presented. In the first ESPI subtraction fringes are considered, for which an improvement in accuracy is seen, and in the second ESPI addition fringes are considered, which, we believe, has enabled the phase to be extracted for the first time. The algorithms are demonstrated with theoretical data and with experimental ESPI fringepatterns recorded with a cw laser. As presented, they form the first step toward a procedure that can beused with twin-pulsed ESPI.     

双脉冲ESPI中高速图象采集的同步控制方法

双脉冲ＥＳＰＩ技术中的高速图象采集同步控制系统是实现双脉冲ＥＳＰＩ的关键之一,提出并实现了一种新的高速图象采集同步控制方法,此法比传统方法的误采率大大降低。     

Additive-subtractive phase-modulated electronic speckle interferometry: analysis of fringe visibility

Fringe-visibility issues of additive-subtractive phase-modulated (ASPM) electronic speckle pattern interferometry (ESPI) are explored. ASPM ESPI is a three-step method in which additive-speckle images are acquired rapidly in an analog fashion in every frame of a video sequence, a speckle phase modulation is intentionally introduced between frames, and a digital subtraction of consecutive pairs of additive-speckle images is performed. We show that this scheme has the good high-frequency noise immunity associated with additive-ESPI techniques as well as the good fringe visibility associated with subtractive-ESPI techniques. The method has better fringe visibility than can be obtained with purely additive ESPI and also does not suffer from the fringe distortions that can occur with subtractive ESPI in the presence of high-frequency noise. We show that even if full speckle decorrelation were to occur between the two additive speckle images that are to be subtracted, the visibility of ASPM ESPI fringes can be made to approach unity by suitable adjustment of the reference-to-object beam-intensity ratio.     

Retrieving ESPI Map of Discontinuous Objects via a Novel Phase Unwrapping Algorithm

Abstract:  This work presents an effective scheme for the phase unwrapping of electronic speckle pattern interferometry (ESPI) map of discontinuous objects. ESPI is a highly effective measurement approach for industry and academia. However, due to the speckle noise, its unwrapping job is quite difficult, especially, when treating ESPI maps obtained from the deformation field of an object containing height discontinuities. The minimum L^p norm method developed by Ghiglia and Romero can treat the aforementioned problem with acceptable accuracy, but takes a long time to run. Therefore, this study presents a novel method based on a hybrid of the regional algorithm proposed by Gierloff, the branch cut method presented by Goldstein et al . and the (spatially) parallel unwrapping method with region-referenced algorithm developed by Huang and He. The proposed algorithm can retrieve ESPI maps with height discontinuities within acceptable accuracy and effectiveness.