光纤FBG高压传感器的优化设计与实验研究

基于对FBG传感器薄壁圆筒材料和结构的优化设计,制作了FBG高压传感器,在0～50MPa压力范围,进行了加压和减压高压实验,实验结果表明:FBG的压力灵敏度为0.0374nm/MPa,其中心波长与压力变化有着良好的线性关系和重复性,且迟滞性好。模拟结果与实验结果很好吻合。     

单光纤光栅对温度与应变的同步测量

提出了一种采用单光纤布拉格光栅(FBG)进行温度与应变同步测量的新颖设计。一根FBG被分成等长的两部分,用环氧胶水涂敷在其中一部分的表面,再套上金属套管,此时可以看成具有不同的布拉格波长的2个FBG,利用它们之间不同的杨氏模量和热膨胀系数,应变和温度能够同步测量。实验结果表明,在2700με和75℃的测量范围内,可以达到约6.1με和1.0℃的应变和温度精确度,误差主要来源于光谱仪分辨率的限制和FBG其中一部分的胶水涂抹不够均匀,通过使用高分辨率的解调仪和提高胶水涂抹工艺可得到更高的测量精确度。     

光纤光栅冰力传感器的开发及应用

根据裸光纤光栅(FBG)对应变的灵敏度远高于对压力的灵敏度这一特点,设计了一种基于等强度梁结构的FBG冰力传感器,并可以通过调节封装构件的尺寸调节其测量压力的灵敏度系数。对传感器的标定结果显示,这种FBG冰力传感器的线性相关度良好,实测的灵敏度系数与理论值一致。该种传感器在冰激桥墩振动模型试验中得到了应用,成功监测了桥墩在不同冰速撞击下受到的冰力。实验表明,这种FBG传感器灵敏度高、可靠性好、对结构自身的影响很小,可直接测量冰的撞击力,适合于模型实验中的冰力监测。     

卡尔曼滤波在时栅传感器动态标定系统中的应用

在时栅传感器误差曲线的动态自动标定中,利用软件实现卡尔曼滤波方法,以达到消除随机误差的目的。该方法在大幅度减少了标定所需时间的同时,进一步提高了动态标定精度。介绍了系统工作原理及卡尔曼滤波的实现方法。使用结果表明,采用该方法后自动测试效率和标定精度达到了预定的指标。     

深部巷道围岩破裂模型试验变形量测研究

针对地质力学模型试验内部变形难以精确量测的难题,以深部巷道围岩破裂模型试验为基础,在模型中布置了布拉格光纤光栅应变传感器和光栅尺位移传感器,对巷道围岩内部的应变和位移进行监测,并布置了电阻应变砖进行对比分析.研究成果表明:1)电阻应变砖、布拉格光纤光栅应变传感器和光栅尺位移传感器测得的围岩内部变形规律基本一致,将光纤光栅应变传感器和光栅尺位移传感器应用于模型试验的内部变形量测是可行的;2)光栅尺位移传感器精度可达到0.001 mm,且具有制作简单、稳定性强、不易损坏等优点,在模型试验中具有广泛的应用前景;3)3种量测手段均揭示出深部巷道围岩内部变形呈现波峰与波谷交替变化,这与模型断面出现的破裂区与非破裂区交替破裂现象相吻合.     

基于悬臂梁啁啾调谐的光纤光栅滤波器

提出并发展了一种基于悬臂梁结构的啁啾光纤Bragg光栅(CFBG)啁啾调谐方案,获得了一系列性能优异的可调谐CFBG滤波器,包括调谐范围达到36 nm(1.8～37.8 nm)的带宽可变反射滤波器、色散在178～2 100ps/nm范围内可调的色散补偿器、基于取样CFBG或重叠写入CFBG的信道间隔可调谐滤波器等。这些FBG滤波器不但能维持较高的反射率,还能保持中心波长基本不变。     

Digital monitoring for heavy duty mechanical equipment based on fiber Bragg grating sensor

The digital monitoring principle and technologies for heavy duty mechanical equipment based on fiber Bragg grating (FBG) technology are introduced in this paper. The fundamentals of new-style FBG sensing technology, including the photorefractive effect of FBG, the physical formation, and the relation between optical properties and grating parameters, are investigated. The plaster, encapsulation and distribution planning of FBG sensor (FBGS), which is used to monitor heavy duty mechanical equipment under abominable environment and extreme conditions, are also studied. In addition, theoretical and experimental researches on the strain, temperature, displacement, and stress transmission characteristics between FBGS and detection interface are presented. The principle and method for temperature compensation in non-uniformity temperature field are described in detail as well. Comparing with the traditional sensing monitoring techniques, the application of FBGS technology on digital monitoring and diagnosis for heavy duty mechanical equipment has a number of significant technical advantages and will make a new breakthrough in this field.     

塑料齿轮传动误差试验机数据采集系统设计

塑料齿轮传动误差试验机是一种新型齿轮测量仪器,针对塑料齿轮传动误差试验机对数据采集系统高速度、多种类、并行采集的技术要求,设计了一款基于Zynq7000的数据采集系统。通过Zynq7000的PL部分实现多路光栅信号的同步采集,设计状态机驱动一个16位精度的ADC芯片ADS8584S采集模拟信号,把采集到的结果写入FIFO中,通过AXI和DMA控制器把数据存储到DDR3中,利用LWIP协议栈实现了数据采集系统和上位机之间以太网通信。经初步验证,该系统可以实现光栅信号和模拟信号采集、电机控制和频率测量等功能,光栅信号采集频率可以达到10 MHz,模信号采集精度可以达到0.06%。系统能够满足试验机数据采集要求,也可以用于其他仪器光栅信号高速采集,采用网络通信,为以后仪器智能测量、远程测量奠定了基础,具有很好的应用前景。     

Performance Comparison of Long-Wave Infrared Imaging Spectrometer Between Dyson Form and Offner Form

In view of the difficulties in traditional long-wave infrared imaging spectrometer which is hard to realize a high signal-to-noise ratio and miniaturization as well under the weak remote sensing signal,Offner convex grating spectrometer and Dyson concave grating spectrometer,both having concentric structure,are designed and analyzed in the band of 8-12 μm. The diffraction angle expressions of the two spectrometers are obtained and the diffraction characteristics are acquired. Both of the spectrometers are designed in Zemax environment under different F-numbers and different grating constants with the same slit,spatial resolution,spectral resolution and detector. The results show that Dyson grating spectrometer possesses the advantages of higher throughput and smaller volume, and Offner grating spectrometer possesses the advantage of more accessible material and the absence of chromatic aberration. The differences between Dyson form and Offner form show that the former is a better choice in the long-wave infrared imaging spectrometer.     

飞秒激光制备亚波长周期光栅及其光学特性

使用中心波长800 nm、重复频率1 kHz的飞秒激光,在金属钨表面斜入射下制备了亚波长周期光栅结构,在入射角为0o~80o时,光栅结构的周期为349~620 nm. 利用表面等离子体激元的理论分析了在钨表面制备光栅结构的过程,实验结果与理论符合较好. 利用严格耦合波分析方法计算了实验中得到的光栅结构的反射光谱,其吸收增强波长大小与光栅结构周期相近. 研究结果表明:利用飞秒激光可以在金属表面直接诱导周期可控的光栅结构,此光栅结构具有一定的应用前景.