共查询到19条相似文献,搜索用时 46 毫秒
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白光频闪散斑干涉术的研究 总被引:1,自引:1,他引:0
在利用白光对振动物体进行测量时,由于白光的相干性较差,难以得到质量较好的图像,为了克服这一缺点,本文提出了一种用白光光源照明进行振动测量的新方法-白光频闪散斑干涉术.阐述了白光频闪散斑干涉术的基本原理,分析了提高图象质量的主要原因,采用了相干性较好的白光光源和合理的光路,使系统的时间相干性和空间相干性得到提高,从而提高了图像的质量.实验结果表明,该方法用于振动的测量,能给出物体在任一瞬时的振动信息,得到清晰的、高对比度的全场干涉条纹图,图像的质量得到大大提高. 相似文献
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将WLSI技术横向放大率M作为可变量,建立由此引起的误差关系,因此,在实际工程测量中可以充分利用成象系统景深扩大测量范围,以2m长砼梁一次成象加以验证,首次获得砼结构的全场变位分布图。 相似文献
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本建立了一套相移激光数字散斑干涉自动测量系统,运用一系列的图象处理方法,实现了高精度的自动测量,显地提高了数字散斑干涉计量技术的可靠性、实用性及自动化程度。该计量系统被应用于变形、振动等参数的测量中,取得了较为理想的结果。 相似文献
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本文用统计学方法对散斑参考束型散斑干涉计量中阴影滤波技术进行了理论分析。在提出计量过程的描述、统计学方法的采用及信息表征形式的基本观点的基础上,建立了信息分布的统计模型,导出了变形信息的可测条件,并通过与传统实验结果的比较验证了本文的结论。 相似文献
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就散射光的偏振性对剪切电子散斑干涉术中的影响进行了研究,文中给出了理论分析及实验结果,得出了消偏振效应不改变计量条纹调制度,但降低光能利用率的结论。 相似文献
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N. G. Vlasov S. G. Kalenkov A. E. Shtan’ko A. V. Kritskii 《Measurement Techniques》2006,49(7):664-665
A simple method for studying the time-dependent coherence of laser radiation by speckle interferometry is proposed and tested
by experiment.
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Translated from Izmeritel’naya Tekhnika, No. 7, pp. 25–26, July, 2006. 相似文献
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Bruno Pouet Tom Chatters Sridhar Krishnaswamy 《Journal of Nondestructive Evaluation》1993,12(2):133-138
In this paper, a video-based speckle interferometric method using a continuous reference updating technique is presented. Unlike conventional ESPI techniques, this methodsynchronizes the optical interferometric detection system with the acoustic stressing of the test object, and includes continuous renewal of the reference image. It is shown that the susceptibility of the method to environmental noise caused by vibration, temperature gradients, or thermal currents is substantially lower than that of conventional techniques. The application of this technique to the detection of defects in adhesively bonded structures is demonstrated. 相似文献
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Yasuhiko Arai 《Journal of Modern Optics》2013,60(15):2329-2345
A high resolution new fringe analysis method for ESPI with only one camera is proposed by using features of speckle interferometry in a deformation process of a measured object. The profile of intensity of each speckle of the speckle patterns in the deformation process is analyzed by the Hilbert transform. A virtual speckle pattern for creating a carrier fringe image is produced artificially by using the information of profiles of intensities of speckles. The deformation map of the measured object can be detected by the virtual speckle pattern in an operation based on the spatial fringe analysis method. Experimental results show that the difference between the results by the new and the ordinary methods is 0.1 rad as standard deviation. From the results, it is confirmed that the high resolution measurement can be performed by this method the same as compared to the ordinary measurement method which needs to employ three speckle patterns. 相似文献
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Orthognatic surgeons have a requirement for the measurement of stress distribution within the human lower jaw, in order to aid and improve surgical procedures. Validation of finite element modelling data describing mandible behaviour which has previously been attempted using holographic interferometry. Electronic speckle pattern interferometry (ESPI), a whole field non-contact optical technique has been applied to the study of a dry human mandible under load. This technique improves over previous methods by generating discrete quantitative displacement and strain components. The optical analysis of a dry mandible is described, with the results viewed in 'real time' as progressively greater forces were applied on the lower border of the chin, in the upwards (impact) direction with biting boundary conditions included in the experimental model. This has shown that the bone tissue holding the front teeth transmits the forces impacting on the chin, which are absorbed by the basal bone of the mandible. 相似文献
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Yasuhiko Arai 《Journal of Modern Optics》2013,60(4):297-306
AbstractSpeckle interferometry is an important deformation measurement method for an object with a rough surface. In this paper, a novel fringe analysis method is proposed that uses a new optical system, which uses a plane wave as the reference beam of the speckle interferometer. When the optical system is employed in fringe analysis, the deformation information and the bias components of the speckle patterns are clearly separated in the frequency domain. Therefore, the deformation information can be readily extracted using a Fourier transform, which gives a pair of real and imaginary components concerning the information. The specklegram is calculated using such a pair of components, and the phase map is obtained from the specklegram. Experimental results confirmed that the resolution power of this measurement method is higher than 1/261 of the wavelength of the light source of the optical system. 相似文献
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Gaojianyong Wang 《Journal of Modern Optics》2013,60(13):1090-1098
Ideal low-pass filtering methods were studied in detail and adaptive elliptical ideal low-pass filters proposed for the first time. The proposed adaptive elliptical ideal low-pass filters can be used effectively for denoising of digital speckle interferograms obtained in phase-shifting digital speckle pattern interferometry. The shape of adaptive elliptical ideal low-pass filters is determined according to the spectrum distribution of interference fringes by using the adaptive method. Theoretical analysis, simulation calculation, and experimental results are presented, and are in good agreement. 相似文献
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John B. Deaton Jr. James W. Wagner Robert S. Rogowski 《Journal of Nondestructive Evaluation》1994,13(1):13-22
An electronic speckle pattern interferometer that incorporates a commercial, long-working-distance microscope is described which provides new opportunities to perform nondestructive inspection for applications in fields such as microelectronics. The long-working-distance microscrope was attached directly to the CCD camera to form a compact, portable system with a field of view that was variable over several mm in width. Alignment was greatly simplified because the skewed Michelson interferometer configuration used a speckled reference beam imaged from a diffusely reflecting reference surface that was positioned adjacent to the test object. To demonstrate the performance of the micro-ESPI instrument, fringe patterns were recorded for the quasi-static cantilever deflection of a 1 mm-wide interconnect clip from an electronics socket. 相似文献
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A. Dávila S. Márquez E. Landgrave Z. Vázquez K. Vera C. Caudillo 《Journal of Modern Optics》2013,60(11):937-942
A computerized system for real-time displacement visualization using carrier fringes in an electronic speckle in-plane sensitive interferometer allows force calibration for micro-displacement analysis of rat bones and verification of axial loading conditions. Once the force has been calibrated and the load is applied along the bone axis, the difference-of-phase method is used to obtain the phase map, which after phase unwrapping, allows the evaluation of the displacements produced by the bone deformation. The proposed method avoids common loading mistakes using first carrier fringes to assure that the loads are within the measuring capabilities of the in-plane interferometer and the Carré phase-stepping method to compensate for linear phase step miscalibration. The experimental results obtained with the calibration of loading forces and axial loading verification show the advantages of the system proposed here over a system which uses a cantilever configuration to make a similar bone deformation analysis. 相似文献
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Yasuhiko Arai 《Journal of Modern Optics》2013,60(15):1223-1228
Electronic speckle pattern interferometry is employed in many industrial fields as a useful deformation measurement method. However, two speckle patterns obtained before and after the deformation are necessary for measurement. Furthermore, at least three speckle patterns are required for high resolution measurement using ordinary fringe scanning technologies. In this paper, a novel method that can measure high speed deformations using a limited number of speckle patterns without using high speed cameras is proposed. The method enables application to dynamic deformation analysis because the method involves analysis using only two speckle patterns obtained before and after the deformation. A novel optical system that can record some spatial information into each speckle is set up for the method. In experimental results, it is confirmed that the out-of-plane deformation measurement can be precisely performed by the method and that the resolution power is almost equivalent to that of the ordinary method. 相似文献