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1.
应用空间解析几何方法,从理论上对由于超长导轨直线度引起的角锥棱镜空间位置变动而最终导致的激光光程的变化进行了分析,并据此建立了相应的数学模型;结合实际测量中使用的超大量程激光测长机导轨直线度的实际测量数据分析了直线度对激光测长示值的实际影响,得出符合阿贝原则的测长机在26 m内由导轨直线度误差引起的激光测长误差小于0.1 μm的结论。  相似文献   

2.
本文介绍一种用于激光准直高精度直线度测量的高灵敏度光电信号检测器,该检测器根据激光束腰处聚焦光斑点小的特点,采用一种四棱镜光点会聚式检测器来接收激光束信息,它的检测灵敏度比传统的四棱镜式四象限位敏传感器高出一个数量级以上;该检测器对激光束平行漂移与角漂移表现出不同的检出特征,因而尤适合于做为激光束漂移补偿检测和直线度误差检测;该检测器还具有结构简单、使用方便等优点。  相似文献   

3.
本文介绍了一种新型的自适应双频激光同轴度测量系统,该系统利用两个完全对称的渥拉斯顿棱镜,一个作为测量元件,另一个作为补偿元件,采用比相技术处理测量信号,因而测量元件可以暂时移出光路,能够进行同轴度的测量,系统的光学设计使激光光束的平衡和角漂不影响测量结果,对激光的漂移有自适应性,两束干涉光基本符合共光路原则,因而对大气湍流,空气扰动的影响具有更强的适应性,可用于长距离直线度,同轴度的测量。该系统与  相似文献   

4.
激光束角漂移对双频激光直线度测量的影响   总被引:2,自引:0,他引:2  
利用惠更斯关于波面传播的理论,分析计算了双频激光渥拉斯顿棱镜直线度测量系统中激光束角漂移以及渥拉斯顿棱镜和双面反射镜倾角对测量精度的影响,得到了相应的结论。  相似文献   

5.
激光束角漂移对频激光直线度测量的影响   总被引:1,自引:0,他引:1  
于瀛洁  张之江 《光电工程》1998,25(4):55-61,72
利用惠更斯关于波面传播的理论,分析计算了双频激光渥拉斯顿棱镜直线度测量系统中激光束角漂移以及渥拉斯顿棱镜和双面反射镜倾角对测量精度的影响,得到了相应的结论。  相似文献   

6.
程真英  梅寒冰  刘欣  雷英俊  李瑞君 《计量学报》2021,42(11):1409-1417
线性导轨广泛应用于精密机床和仪器,其运动精度直接影响所在设备的空间定位精度。针对团队前期研制的可以测量导轨直线度、俯仰角和偏摆角的收发分体式四自由度激光测量系统,其直线度与角度测量结果间存在的耦合干扰问题,提出了一种误差建模与补偿方法。根据激光测量系统的原理和结构,分析并确定了耦合误差的主要来源,利用矩阵光学及齐次坐标变换的方法建立了耦合误差的补偿模型。以雷尼绍XL-80型激光干涉仪为基准,对所建立的误差补偿模型进行了实验验证,结果表明:利用所建模型补偿后的直线度和角度测量误差均降低了75%以上。所提出的误差建模与补偿方法不但有助于提高四自由度激光测量系统的精度,同时也有助于降低其成本。  相似文献   

7.
设计了一种基于激光准直原理的运动平台激光五自由度运动误差测量系统,该系统基于双平行光束的准直原理对水平直线度、垂直直线度、偏摆角、俯仰角和滚转角误差进行同步测量。进行了系统直线度、偏摆角和俯仰角误差测量核心器件参数的自标定,针对双光束难以调平影响滚转角误差测量的问题,利用水平仪对滚转角误差进行补偿修正。对整套系统进行准确度比对实验,结果表明系统所测直线度、偏摆俯仰角和滚转角误差的准确度可分别达到0.8 μm,0.8″和1.5″,为机床几何误差测量技术发展提供借鉴。  相似文献   

8.
正激光测距仪选用棱镜测量模式时,棱镜的装配位置是影响测距误差的主要因素,若用反射靶球代替棱镜,可以明显减小测距的误差。常见的靶球误差为0.1mm,仅用于中、低精度的测量,设计一种误差优于0.05mm的反射靶球,可用于高精度距离测量,且明显提高靶球互换性。一、关键技术的实现光线在角锥棱镜中反射时,其等效反射光路如图  相似文献   

9.
激光干涉仪测量超长导轨直线度时,因导轨长度超出干涉仪直线度测量范围,需分段测量后拼接,测量数据易受噪声和激光漂移等因素影响,导致拼接可能引入较大误差。通过分析拼接过程中的影响因素,结合长导轨结构特性,提出了一种将拼接公共点分布在相邻两节子导轨上,利用相邻两节子导轨夹角的稳定特性来实现长导轨直线度拼接的方法。通过仿真与实验,对比了30m范围内的直接测量法与坐标变换拼接法的测量结果,2种方法的直线度结果相差<10μm,表明所提出的方法能有效减小拼接误差。将此方法应用于72m导轨的直线度测量,并与电子水平仪测量方法比较,2种方法结果相差10μm,表明所提出的方法可实现高精度的直线度拼接。  相似文献   

10.
欧阳健飞  闫勇刚 《计量学报》2006,27(Z1):197-199
介绍了SI型激光跟踪仪及安装有角锥棱镜的球形固定反射器(SMR)的工作原理和特性,从实际应用角度分析了SMR因摔落或磕碰造成的误差.提出了校验SMR重复性测量精度的新方法,利用同一种型号的标准SMR与待校验SMR进行比对测量,分别进行了SMR的重复性测量精度实验和误差补偿半径校验实验,得到了待校验SMR的重复性精度和半径补偿精度.实验表明,待校验SMR仍然能够进行高精度地测量.这项研究工作为SMR的校验提供了一种检测方法,具有一定的实用价值.  相似文献   

11.
在逆向调制无线光通信系统中,大气湍流对系统的影响大于传统的无线光通信系统。本文研究了一种基于逆向端调制器分集的逆向调制无线光通信系统,以减小大气湍流对系统的影响。利用相位屏法,建立了弱湍流下的激光大气的传输模型,对比分析了逆向调制无线光通信系统逆向端逆向调制器分集和不分集分别所受到的大气湍流的影响。结果显示在相同情况下,逆向调制无线光通信系统在逆向端对逆向调制器进行分集能抑制大气湍流对系统的影响,使整个系统的闪烁指数下降。  相似文献   

12.
Holy JA 《Applied spectroscopy》2004,58(10):1219-1227
The grating equation is used to generate quadratic calibration equations for multichannel detectors with perpendicular and tilted focal planes. The quadratic coefficients are not independent and contain terms that are used to solve for spectrometer-detector parameters. The parameters can be calculated from a quadratic fit at one spectrometer position, but more accurate values can be obtained from quadratic fits at two spectrometer positions. The calculations show that the detector focal plane is tilted by about two degrees. Once values for the spectrometer-detector parameters are obtained from calibrations using at least three lines at one or two spectrometer positions, only one calibration line at any spectrometer position is required to obtain accuracies on the order of 0.1 cm(-1) over a several thousand wavenumber range. The main cause of spectrometer drift is a change in the diffraction angle and/or the spectrometer included angle. This drift is almost totally compensated by the one-line calibration, which adjusts the diffraction angle. A neon pen lamp is used to generate the calibration spectra. Using standard air wavelengths compared to true wavelengths can produce calibration errors of 0.1 to 0.6 cm(-1); the magnitude depends on local conditions and how the laser wavelength is treated.  相似文献   

13.
The position sensing resolution of a lateral-effect photodiode (LEP) and a four-quadrant (4Q) photodetector used as the position sensitive detector (PSD) in a sensor which measures the lateral displacement of a corner cube reflector (CCR) by illuminating it and detecting the position of the reflected light spot with the PSD is studied. An LEP is much noisier than a 4Q detector, but in an outdoor environment the sensitivity of the 4Q detector to atmospheric turbulence due to defocusing makes its resolution worse than that of an LEP. Submillimeter resolutions at the target distances of several hundreds of meters are electrically achievable with an LEP. Outdoors, however, its resolution is also bounded by the atmospheric turbulence. In turbulent measurement conditions, standard deviations of better than 1 cm were typically achievable up to the distance of 300 m and about 10 cm up to half a kilometer  相似文献   

14.
This paper presents the exact average bit error rate (BER) analysis of the free-space optical system employing subcarrier intensity modulation (SIM) with Gray-coded quadrature amplitude modulation (QAM). The intensity fluctuations of the received optical signal are caused by the path loss, atmospheric turbulence and pointing errors. The exact closed-form analytical expressions for the average BER are derived assuming the SIM-QAM with arbitrary constellation size in the presence of the Gamma–Gamma scintillation. The simple approximate average BER expressions are also provided, considering only the dominant term in the finite summations of obtained expressions. Derived expressions are reduced to the special case when optical signal transmission is affected only by the atmospheric turbulence. Numerical results are presented in order to illustrate usefulness of the derived expressions and also to give insights into the effects of different modulation, channel and receiver parameters on the average BER performance. The results show that the misalignment between the transmitter laser and receiver detector has the strong effect on the average BER value, especially in the range of the high values of the average electrical signal-to-noise ratio.  相似文献   

15.
We analyze the accuracy of a laser keratopographer in the evaluation of corneal topography for non-smooth corneal surfaces and when some noise is introduced into measured data. Through some numerical simulations, cosinesoidal deformations with different amplitudes and spatial periods are introduced on theoretical surfaces. Gaussian noise is introduced on the simulated x and y position coordinates for the measured position of the reflected beam in order to simulate detection errors that are due to vibrations or electric and other noise on the position-sensing detector. We found that the topography of the surface could be obtained with reliable accuracy if the height-to-width ratio of the deformations of the surface is smaller than 0.02 and the error in the detection of position at the position-sensing detector is under 0.5 mm.  相似文献   

16.
A Small Low-Cost Hybrid Orientation System and Its Error Analysis   总被引:1,自引:0,他引:1  
《IEEE sensors journal》2009,9(3):223-230
Inertial orientation systems have many potential uses beyond air- and spacecraft applications. Compared to the conventional large-scale system, the novel aspects of an orientation system based on micro electromechanical systems (MEMS) are small size, lightweight, low-power consumption, and low cost by the inclusion of microsensors with on-chip functionality, such as micromachined rate gyroscopes, accelerometers, and etc. However, the performance associated with these low-cost MEMS sensors is generally not satisfied. A conventional strapdown method based on integral of angular rate to figure out attitudes will inevitably induce long-term drift. For eliminating this accumulative error and thus using the low-cost navigation system for a long-duration mission, a hybrid configuration by combining a MEMS-based azimuth-level detector with the conventional strapdown system is proposed in this paper. The azimuth-level detector is composed of three-axis MEMS accelerometers and three-axis MEMS magnetometers. With an absolute solution based on the gravity and the earth magnetic field rather than the integral algorithm, attitude and heading estimation without drift errors can be obtained so as to facilitate adjusting the attitude and heading for the conventional strapdown system. The hierarchical computation process for estimating the attitude and heading using the hybrid system is depicted first. Then, comprehensive system errors including transformation errors of the computation, such as skew, scale, and drift errors, are analyzed. Finally, it is verified by both of formula analysis and experimental test that the accumulative errors can be effectively eliminated via this hybrid scheme.   相似文献   

17.
This study was conducted to verify that the probe-position error correction can be successfully applied to real data obtained on a planar near-field range where probe position errors are known. Since probe position-error correction is most important at high frequencies, measurements were made at 60 GHz. Six planar scans at z positions separated by 0.03 A were obtained. The correction technique was applied to an error-contaminated near field constructed out of the six scans according to a discretized periodic error function. The results indicate that probe position errors can be removed from real near-field data as successfully as from simulated data; some residual errors, which are thought to be due to multiple reflections, residual drift in the measurement system, and residual probe position errors in all three coordinates, are observed.  相似文献   

18.
A Doppler global velocimetry (DGV) measurement technique with a sinusoidal laser frequency modulation is presented for measuring velocity fields in fluid flows. A cesium absorption cell is used for the conversion of the Doppler shift frequency into a change in light intensity, which can be measured by a fiber coupled avalanche photo diode array. Because of a harmonic analysis of the detector element signals, no errors due to detector offset drifts occur and no reference detector array is necessary for measuring the scattered light power. Hence, large errors such as image misalignment errors and beam split errors are eliminated. Furthermore, the measurement system is also capable of achieving high measurement rates up to the modulation frequency (100 kHz) and thus opens new perspectives to multiple point investigations of instationary flows, e.g., for turbulence analysis. A fundamental measurement uncertainty analysis based on the theory of Cramér and Rao is given and validated by experimental results. The current relation between time resolution and measurement uncertainty, as well as further optimization strategies, are discussed.  相似文献   

19.
Sica L 《Applied optics》1996,35(2):264-272
Sheared-beam imaging (SBI) should compensate the effects of an idealized layer of turbulence located either in a transmitter/detector plane or in an object plane. This motivated the study of optical compensation of SBI in the presence of uniformly distributed turbulence over long horizontal paths in the cases of ideally smooth and ideally rough extended objects. The phase error along a one-dimensional wave front resulting from SBI observation is computed numerically in the long-path regime and is compared with that of an equivalent conventional system for the case of a large smooth object. It is found that for the conditions considered the phase errors of the SBI system are greater than those of a conventional system. In the case of an ideally rough object the extra information furnished by the SBI observations does not lead to data that can be inverted to compute an image by the conventional shearing-interferometric algorithm. The phase errors in imaging a point reflector, however, are perfectly compensated.  相似文献   

20.
为了精确测量大尺寸位姿,建立了一种由7台激光跟踪干涉仪组成的大尺寸位姿测量装置。根据测量各反射镜的激光跟踪干涉仪数量的不同,采用322和331两种跟踪方式对位姿测量精度的影响进行仿真实验,从而发现被测点位置与基站构成平面的距离相关,由坐标解算公式推导被测点坐标值与测量基站之间的相对位置与测量误差间的误差模型,通过分析x、y、z 方向上误差对距离变化的敏感程度,发现z方向距离变化引起的误差最为敏感。当被测点与测量基站的距离由1300.8mm减小到0mm时,测量误差由2.2μm增大到2626.1μm。实际姿态测量结果表明:当采用一种跟踪方式时可以避免被测点与测站点平面过近,有利于提高系统测量精度,所提出的误差模型可为多边法位姿测量系统的优化布局提供一种量化的理论分析方法。  相似文献   

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