补偿型强度调制光纤传感器测量处理的新方法

对补偿型强度财制光纤感器信号处理的共性的研究提出一种基于自扫描二极管阵列器件作为探测器的信号探测及处理新方法,较好地解决由于信号识别处理对传感性能的影响,尤其适合于多路探测传感器。     

新型簧片式光纤加速度传感器研究

研制了一种新型光纤加速度传感器。基于迈克尔逊干涉仪原理,采用了质量块和可 弯曲簧片结构,通过使用竖直 绕制传感光纤和横向绕制参考光纤的方式提高了加速度传感器的加速度灵敏度。实验测试了 其加速度灵敏度以及横向串扰。在簧片厚为1mm、质量块质量为208 g时,其加速度灵敏度 可达556rad/g(g为重力加速度);在噪声本底为10－4 rad/Hz 、加速度传感器工作频率为100Hz时,其可探测的最小加速度信号为 200ng/Hz(g为重力加速度)。采用该全金属结 构,传感器可更好地用于微弱信号检测。     

强度调制型光纤传感器信号补偿技术的现状与应用

简要地介绍了强度调制光纤传感器的特点,着重分析和比较目前国内外五种有代表性的强度调制型光纤传感器信号补偿方法及其应用状况.     

提高强度调制光纤位移传感器测量范围的综合方法探讨

分析提高强度调制光纤位移传感器测量范围的基本方法,研究将各种提高测量范围的基本方法集成的综合方法,构造出该系统的框架结构模型,研究宽测量范围的综合评判规则,达到宽测量范围的效果.充分利用各种方法的优点,实现优化组合,将能较好地满足不同场合.     

三分量全保偏光纤加速度传感器的研究

报道了三分量全保偏光纤加速度传感器的实验研究结果。传感器由6个弹性柱体共同支撑1个质量块构成三分量结构,由3个迈克尔逊全保偏光纤干涉仪共用一个光源组成。光学部分采用全保偏光纤干涉仪结构,消除了干涉光束偏振态随机变化引起的信号衰落,采用光频调制相位载波解调信号处理技术,消除了相位随机漂移引起的信号衰落,从而实现了对加速度信号的稳定检测。传感器的工作频带为5~500 Hz,加速度灵敏度达到660 rad/g,系统最小可测相位差为10-5rad,最小可测加速度达1.5×10-7m/s2,工作频带内加速度灵敏度变化小于2 dB。三轴加速度灵敏度和频率响应曲线与理论分析的结果基本一致。     

一种布拉格光纤光栅加速度传感器

本文介绍了一种基于布拉格光纤光栅 (FBG)的加速度传感器设计。为了克服等截面悬臂梁的局限性 ,该设计采用等强度悬臂梁的形式。结果表明 :该种光纤加速度传感器具有良好的稳定性和较高的分辨率 (0 .0 0 5g) ,适合海洋平台等大型工程结构的加速度测量。     

强度型光纤传感器补偿技术的研究综述

介绍了强度型光纤传感器中常见的十几种补偿技术的原理及应用现状,比较了它们的优缺点,并展望了补偿技术的发展趋势。     

强度调制光纤多传感补偿网络所能补偿传感器的极限数目

本论文从对传感补偿网络的基础理论的探索性研究出发，首次提出强度调制光纤多传感补偿网络所能补偿传感器数目的理论极限公式，对多传感补偿网络的设计和应用有着重要的指导意义。     

一种新型光纤加速度传感器的研究

基于光强调制原理以及耦合效率与纵向偏移距离 的关系,设计出了一种新型的光纤加速度传感器,突破传统 加速度传感器检测技术要求,实现高精度、高灵敏度以及具有快速响应能力。在发射光纤发 射光功率不变的情况下, 接收光纤的位置随系统振动而上下微动,从而导致接收的光功率发生变化。实验得到了在接 收光纤位移量由0～40μm变 化范围内接收光功率的变化规律和光功率随位移变化的拟合曲线。当接收光纤位移量为0时 ,两根接收光纤接收到的光功率大小相等;当位移量达到40μm 时,两根接收光纤的光功率差达到最大,模场分布差别最明显。实验研究了光 纤加速度传感系统的频率响应特性,得到了光纤加速度传感器频率响应特性曲线。在同一 实验平台上,通过与标准加速度计的测量数据对比,验证了本文光纤加速度传感器测量性能 的有效性和可靠性。     

全保偏光纤加速度矢量传感器的设计与实验

阐述了全保偏光纤加速度矢量传感器的基本工作原理,进行了三维探头结构设计,对系统的谐振频率和加速度灵敏度进行了理论分析,并进行了一维光纤加速度传感器实验,验证了这种全保偏光纤加速度矢量传感器的谐振频率和加速度灵敏度理论分析和结构设计的合理性.     

Side-projected fiber-optic velocity sensors

Side-projected dual-fiber velocity sensors with various fiber core separations for in vivo measurements were developed and tested. Good linearity between the flow velocity and the Doppler shift frequency is obtained with this sensor in both the forward (toward the sensor tip) and reverse (away from the sensor tip) flow directions. Experimental and numerical analysis of the data showed that the boundary layer along the side wall of the fiber sensor varies with the flow velocity     

平行光束反射式光纤位移传感器双值问题研究

文章针对平行光束反射式光纤位移传感器存在接收光强与被测位移量间双值对应问题,提出在试件表面设置光敏元件指示试件移动范围的方法来解决双值问题;并提出了双光路结构传感器设计方案,以消除光源波动、反射面反射率差异等因素对测量结果的影响;设计了基于C8051F410/2单片机的信号检测硬件电路.     

双包层光纤微弯传感器及其暗场检测技术研究

提出一种基于双包层光纤和耦合器的双包层光纤微弯传感器结构及暗场检测方法.通过理论和仿真分析,建立了双包层光纤弯曲损耗的理论模型;通过对光纤结构参数与传感器灵敏度关系的仿真,获得了实验用光纤最佳结构参数;理论和仿真分析了变形器的最佳周期、齿间距和齿数问题;对双包层光纤微弯传感器及其暗场检测方法进行了实验研究,结果显示,传感器输出光场与光纤形变之间有着较好的线性关系.     

Planar flexible fiber-optic acoustic sensors

The acoustic sensitivity of optical fibers is considered analytically. High sensitivity is obtained with low bulk modulus, very thick polymeric coatings. The fiber coatings play an important role in determining the fiber acoustic sensitivity. The very thick coating limit is realized by embedding optical fibers in an appropriate elastomer (polyurethane). A planar flexible fiber-optic interferometric acoustic sensor is developed by wrapping optimized single-mode fibers in a planar spiral form, and then embedding the fiber in a thin polyurethane layer. The acoustic sensitivity of the sensor is found to be high, and frequency (0.2-2.5 kHz) and static pressure independent. The sensor is found to be compatible with water, and is compared favorably to that of a planar polyvinylidene fluoride sensor of similar geometry     

Smart bridges with fiber-optic sensors

This article describes an approach to bridge improvements that uses smart structures, introduces key technologies for health monitoring systems based on fiber optics and gives an overview of two instrumented bridges. A sensing system in one application monitors general performance and health of the structure, while the system in a second application interrogates the behavior of a major structural repair.     

光纤电流传感器在智能电网中检测原理的研究

在智能电网中,电流测量是电力系统中继电保护、电能计量、系统监测和系统分析的关键,其测量的精度与可靠性直接关系到电力系统能否安全、可靠和经济地运行。文章比较了电磁式电流传感器和光纤电流传感器的性能,介绍了目前3种最主要的光纤电流传感器的测量原理,并指出其各自的优点及存在的问题。同时,综述了国内外关于光纤电流传感器的最新研究现状及进展,最后对光纤电流传感器的应用和研究前景进行了展望。     

Effect of external perturbations on fiber-optic magnetic sensors

The effects of external nonmagnetic perturbations on a fiber-optic magnetic sensor are analyzed theoretically. It is shown that the deleterious effects of these perturbations can be controlled by maintaining the DC magnetic field at prescribed levels. Experiments have been performed with externally applied stresses and accelerations (vibrations) that validate the theory and yield values for the stress and acceleration responsivities of the sensors studied in this investigation. The analysis and techniques given apply equally well to any interferometric sensor using nonlinear transduction mechanisms     

光纤传感器中散射噪声的研究

基于光电探测器信号波散射波理论,研究了光纤气体传感器中的散射噪声。计算了透射型传感器中由于散射噪声造成甲烷气体浓度信号波与散射波之间干涉对输出信号产生的影响。并用Matlab对散射噪声进行了模拟,模拟结果与实验结果相符。     

Microwave ferrite acceleration sensors

This paper presents a new and potentially simple method of producing a frequency shift proportional to sensed acceleration in a passive microwave device. Magnetostriction effects in microwave ferrite rods are employed to convert an applied stress (acceleration) to a shift in resonant frequency. Equations for the ferrite effective permeability are derived in terms of the internal field component. Experimental verification was obtained by placing the resonant cavity on a rotatable test stand and using the earth's gravitational field as the accelerating field 0 to 1 g being applied to the device. A SHF signal generator excites the cavity, while a spectrum analyzer and digital frequency counter monitor the resonant frequency. Correction was made for spurious frequency shifts due to lead component movements. A net, non-linear frequency shift characterized by the value +1.064 kHz per gravity was obtained. Agreement as to sign and general magnitude of theory and experiment was encouraging. Magnesium-manganese ferrites have small magnetostriction coefficients, yet even the frequency shifts with these ferrites were easily detectable. This effect or application is certainly worthy of additional interest and exploration.     

Multiplexing of nonlinear fiber-optic interferometric sensors

The scheme is demonstrated with a three-sensor array consisting of magnetic-field, pressure, and displacement sensors exhibiting resolutions at 1 Hz of 20 μOe/√Hz (limited by ambient noise), 0.1 kPa/√Hz, and 30 nm/√Hz, respectively. Multiplexing is accomplished by dithering each transducer at a different frequency and using parallel phase-sensitive detectors (PSD) at the interferometer output to demultiplex the information. A single Mach-Zehnder interferometer driven by a single unmodulated laser was used. Factors affecting the performance of the multiplexing scheme, including interferometric demodulation technique, PSD performance, and nonlinear transduction mechanism, are discussed