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为了实现光学元件精密检测平台定位误差的自适应补偿,以保证在不同的检测环境中平台能够自行保持高精度,提出了基于检测环境监测和支持向量回归机的定位误差自适应补偿方法。首先,以多组检测环境中温度、湿度和气压的具体测量值作为训练数据,利用支持向量回归机建立定位误差最大值的预测模型,进行最大值预测。然后,将最大值同温度、湿度、气压等环境因素和位置信息一起作为训练数据,迭代使用支持向量回归机,建立任意位置定位误差预测模型。最后,将预测到的定位误差值传入检测平台控制器中进行补偿。应用雷尼绍激光干涉仪,温度、湿度和气压传感器等仪器设备,在光学元件精密检测平台上进行了具体实验。实验结果表明该技术切实可行,预测数据与实测数据差值绝对值的平均值为0.88μm,Pearson相关系数的平方为0.99,自适应补偿后平均定位误差由43μm降为1.4μm。 相似文献
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针对光纤光栅应变传感器测量桥梁结构动态应变值的准确性问题,提出了一种动态激励下的光纤光栅应变传感器的校准方法。采用等强度悬臂梁模拟桥梁结构,在等强度悬臂梁末端瞬间悬挂不同重量的砝码来模拟桥梁上汽车产生的动态激励。以电阻应变片作为参考传感器,光纤光栅应变传感器作为待校准传感器,将这两个传感器的测量数据序列进行比对。针对传感器的测量数据序列出现的时间错位问题,采用互相关算法对参考传感器和待校准传感器的测量数据进行数据匹配。在光纤光栅应变传感器有初始值的情况下进行测量值校准的研究。实验结果表明,该方法有效解决了测量数据序列的时间错位问题,实现了光纤光栅应变传感器的动态校准,采用不同重量的砝码作为激励源对校准结果没有影响,1529 nm和1547 nm波长的光纤光栅应变传感器灵敏度校准系数与静态标定结果基本一致。 相似文献
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为了解决传感器MEMS进行姿态估计易受外界干扰的问题,首先设计了基于四元数的扩展卡尔曼滤波器,通过自适应地建立协方差矩阵和引入传感器偏差补偿的方法实现三自由度的姿态测量;其次,提出了基于粒子滤波和卡尔曼滤波的数据融合算法,实现了能有效解决接收信号强度时域浮动的WiFi/MARG 组合定位系统;最后设计了自适应加权算法,对WiFi/MARG和GPS/MARG两子系统进行融合,构建了能实现室内外的无缝定位的GPS/WiFi/MARGE定位系统,结果表明,该算法比WiFi/MARG和GPS/MARG系统的最大误差分别减少了51%和82%,平均定位误差减少53%和62%,有效地提高了定位精度。 相似文献
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利用甲烷气体分子在3.3μm处的主吸收峰,研制了一种基于非色散红外光谱技术的红外甲烷传感器.传感器的光学部分由峰值波长为3.4μm的测量发光二极管、峰值波长为2.7μm的参考发光二极管、截止波长为3.6μm的光电二极管及球面反射面组成;电路部分包括发光二极管驱动电路、光敏信号处理电路、温度测量电路、微处理器.采用短脉冲供电控制逻辑的工作模式,降低红外光源的上电时间,将光学测量器件的功耗降至16mW.实验研究了温度变化对传感器甲烷浓度测量结果的影响,通过数据分析及线性拟合,得出了温度补偿算法公式.补偿后的传感器及检测系统平台实验结果表明:传感器平均功耗为23.56mW,在-20~50℃的温度范围内温度变化对测量值的影响不超过真值的3%,湿度影响不超过真值的4%,响应时间小于25s,工作稳定性时间大于60天,性能指标均满足或优于AQ6211-2008煤矿用非色散红外甲烷传感器行业标准相关要求.与热辐射红外光源或激光检测原理的甲烷传感器相比,基于双窄带发光二极管的红外甲烷传感器功耗降低70%以上,能够满足便携式、无线化应用场合低功耗的技术要求. 相似文献
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针对测角系统在线校准问题,提出了一种基于多读数头布局的自校准方法。通过多组传感器的测量数据,利用圆封闭原则和傅里叶级数的性质,建立测量值与误差之间的函数关系,并基于多读数头布局原理,对自校准读数头布局进行优化,以提高校准方法对误差的抑制能力,实现单读数头测角传感器的自校准。设计了单轴转台,搭建了自校准测角系统,并进行了实验验证。实验结果表明:测角系统采用自校准方法后,单读数头测角传感器的测角误差为6.10″,在相同的测量环境下,其校准精度接近借助外部参考标准的传统谐波标定方法。自校准方法可有效抑制测角误差,显著提高测量精度。 相似文献
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本文研制了一种光纤耦合湿敏监测装置,此装置采用MEMS微位移传感器来进行湿敏微腔耦合位置的辅助校准,再用光强传感器对耦合输出的光波进行湿度感测和量化。这种基于MEMS位移传感器的耦合位置校准方法与现有的校准平台相比,无需外加太多繁琐、庞大的仪器装置,就可获得精准又便捷的校准效果。另外在传感系统后端可进行可编程控制程序开发,用加载的数据采集卡来实现湿度敏感单元敏感量的采集与显示。 相似文献
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Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide 总被引:1,自引:0,他引:1
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs. 相似文献
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A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users. 相似文献
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S. G. Nedel’ko M. A. Krysyuk A. L. Apanasenko L. N. Lymarenko Z. T. Moroz 《Journal of Applied Spectroscopy》1997,64(1):55-61
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped
with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly
described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation
(5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum
cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics
of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure
crystals is analyzed (preliminarily).
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997. 相似文献
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A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output. 相似文献
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The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper. 相似文献
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We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed. 相似文献
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Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell. 相似文献
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A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques. 相似文献
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Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing. 相似文献