共查询到19条相似文献,搜索用时 125 毫秒
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温度场的精密测量对机械、航空航天、生物医学、食品化工、电力、能源和环境等诸多行业都有重要意义。提出了一种基于多步相移法和偏振干涉光学层析光路的三维温度场测量方法。首先,结合马赫-曾德尔干涉光路结构与光学层析技术设计偏振干涉光学层析测量系统,并利用偏振器件的旋转实现多步相移以实现高精度信号检测。然后,通过指数型滤波反投影算法还原得到被测介质的三维折射率分布,进而获得三维温度场分布。最后,推导了测量公式并搭建了实验系统。误差分析表明,现有实验条件下的系统测量不确定度约为0.8℃。测量实验和比对结果表明,所测得的温度场与实际情况吻合,与铂电阻温度计的标定温度比对结果小于2℃。 相似文献
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卷积反投影法重建温度场 总被引:1,自引:0,他引:1
电子散斑干涉技术是近年发展起来的一门新兴的测量技术,它由光干涉原理测量物理场的密度、温度分布等,这种测量技术是由物理场在不同截面、不同方向上的投影值反求场分布,这非常类似于CT技术。简述二维重建的基本原理,着重介绍卷积反投影重建算法。依此原理,模拟了双高斯分布函数的投影,并由平行束卷积法重建出模拟的温度场。为了指导电子散斑干涉实验,模拟了三种可能实验误差,并分别给出了重建结果。由于电子散斑干涉测量(投影)的方向个数小,提出了双线性滤波算法,使在测量值稀疏的条件下得到较好重建结果。 相似文献
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电子学全息干涉术用于温度场测量 总被引:11,自引:4,他引:7
探讨了用电子学全息干涉术(双称数字全息干涉术)测量温度场分布及其变化的可行性,利用所设计的全息干涉实验光路,对一电烙铁头部周围温度场分布进行了实时全息记录,进而利用一维快速傅里叶变换及数字滤波处理再现出了反映温度场分布的全息干涉条纹图样,实验结果表明,与传统的光学全息干涉术相比,电子学全息干涉术借助于高分辨率CCD记录及高速计算机数字处理技术,从而可实现光学全息图的数字化记录、存储和重现。同时,利用再现物场相位倍增原理还可实现对干涉条纹数目的倍增,或利用物场相位分布的直接计算精确获取任意两点间的相位差,从而提高测量精度。此外,由于能够在不改变光路的前提下以较高的重复频率完成光学全息图的记录,电子学全息干涉术可以用于记录三维物场的变化并接近实时地再现和测量三维物场的变化规律,因此是一种极有发展前途的新型实时全息干涉计量技术。 相似文献
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船体三维角度变形的自准直干涉测量方法 总被引:8,自引:0,他引:8
以自准直原理基础,将光栅干涉原理引入,提出了一种能对船体三维变形测量的自准直干涉法。分析了测量三维角度变形的自准直干涉原理,并根据该原理设计了光学系统,系统主要包括两个主光路,自准直光路和光栅干涉光路,并且两路光部分共光路。自准直光路可以实现船体的二维测量;自准光栅的像和反射光栅干涉可测量船体的另一维变形,从而实现了船体三维变形的测量。给出了计算三维角变形的理论公式,最后进行了精度分析。试验结果表明,在±30′的视场范围内,系统精度达到2″,该方法不仅适用于船体也适用于其它物体三维角度变形的测量。 相似文献
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针对现有点衍射三维坐标测量系统中的坐标高精度解调问题,提出了一种基于Levenbery-Marquardt(LM)算法的点衍射干涉测量方法。基于L-M算法的点衍射测量技术是以点衍射干涉理论为基础,在实现干涉场相位分布信息解调的基础上运用基于L-M算法的二重迭代算法重构出点衍射源的三维坐标。为验证所提出测量方法的可行性,同时进行了计算机仿真和测量实验,并与三坐标测量机的测量结果进行了对比。结果表明:该测量方法可在xyz三维方向上100mm×100mm×300mm空间范围内实现优于微米量级的测量精度。该测量方法具有不依赖算法迭代初值、测量精度高、运算速度快、抗噪声能力强等诸多优点,在三维坐标测量及测量系统的校准中具有较好的实用性。 相似文献
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The temperature field in combustion chamber of spark ignition engine is measured using laser shearing interferometry and high-speed photography in this paper. A set of experimental facility is set up. The relationship equation between the interference fringe image and temperature distribution is deduced. Changing the shearing interferometry quantity, the two-dimensional temperature field of engine combustion chamber and flame propagation can be measured quantitatively by image processing. The test results indicate that the shearing interferometric method has a strong vibration resistance, and a simple and reliable optical path. The temperature distribution and the temperature gradient are different in different zones. The temperature is highest in the burning zone and the temperature gradient is large. The temperature is lower in the burned zone and the temperature gradient is smaller. The temperature is lowest in the unburned zone but the temperature gradient is large. At the initial period of combustion, the flame propagation velocity is low. In the combustion process, the flame front in the approximate spherical shape pushes toward the unburned zone, and the flame propagation velocity starts to decrease. It rapidly increases until it reaches the maximum value as the combustion process going on, and then it gradually decreases until it has burned in the entire combustion chamber. 相似文献
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Robert Windecker Matthias Fleischer Klaus Krner Hans J. Tiziani 《Optics and Lasers in Engineering》2001,36(2):3272
Optical sensors are very suitable for the analysis of microscopic structures and micro devices. We compare two very promising methods: the white-light interferometry and the fringe projection technique for the application to this task. The fringe projection is very useful for fast measurement of objects with vertical dimensions of some μm. White-light interferometry is especially useful for highly resolved 3-D measurements. Furthermore, we present a new technique, the scanning fringe projection (SFP), which enables absolute 3-D measurements with one single grating period. 相似文献
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The development of full field interferometry as a velocimetry technique in experimental fluid mechanics from its inception in 1977 to the present is discussed. In 1977, holographic interferometry (HI) was applied for the first time to measure the velocity field in a liquid flow. It was not until 1998 that the first application to a gaseous flow was reported. The only kind of speckle interferometry that has been applied to measure velocity fields so far is digital speckle pattern interferometry (DSPI). It was in 1999 that DSPI was demonstrated both in a liquid and a gaseous flow. 相似文献
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A phase-shifting interferometer with a tunable external-cavity laser diode has been constructed for forming three-dimensional (3-D) phase profiles. The interference phase is shifted equally in four steps by varying the source wavelength. Profilometry is achieved by measuring the phase shifts that are extracted by the Carré algorithm. The linear regression of the distance measurement from 40 μm to 13mm has been experimentally demonstrated by phase-shifting interferometry. A laser-diode interferometer has been applied to 3-D profile measurement for a step-mirror object at a deep depth. 相似文献
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研究发展了一种计算高超声速三维热化学非平衡电离流动的数值方法。真实气体热力学状态是通过平动-转动温度和电子-振动温度来模拟。对零攻角轴对称钝锥体和有攻角钝锥体的高超声速电离流动,采用隐式有限体积法NND格式,数值求解NS方程。 相似文献
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