光纤布拉格光栅(fbg)论文：基于匹配光栅的轨道交通计轴系统研究

光纤布拉格光栅(FBG)论文：基于匹配光栅的轨道交通计轴 系统研究 【中文摘要】基于匹配光栅的轨道交通计轴系统主要用作列车 定位。利用光纤光栅(FBG)的传感原理,依据匹配光栅检测应变的原 理和列车载荷作用下铁轨应变分析,对铁轨粘贴光栅的区域的应力进 行检测,对测量的数据进行处理和分析后就可以完成列车占用和区间 空闲的检测。将计轴设备应用于铁路信号系统,其也是为了提高行车 安全技术水平和提高铁路运输效率。本文从理论分析与实验验证两 方面对基于匹配光栅的轨道交通计轴系统进行研究。首先,介绍了匹 配光栅检测应变的理论知识,结合列车载荷作用下铁轨应变分析设计 出一种检测铁轨局部轴向应变的光纤光栅轨道传感器方案,同时,对 轨道交通计轴系统的原理进行了说明。其次,针对匹配光栅的解调是 一种强度解调,给出了系统的硬件电路设计的整体架构；为了方便系 统设备的维护和升级,在此将系统硬件设计成主机板卡、从机板卡和 母板卡三部分,每个板卡上都有一个 ARM 微处理器芯片 LPC1768,系 统电路的每个模块中都增加有电路保护的功能,主从机板卡之间通过 I2C 总线进行通信,主机卡将接收到的四路从机卡信息再传给上位机。 最后,使用 Keil uVision3 开发工具实现了下位机程序的编写。软件 的设计均采用模块化的方法,这样的设计有利于软件代码的调试、维 护和升级。所取得的研究结果如下：经过列车载荷模拟实验,解调系 统设备(下位机)可以接收到布设有光纤光栅传感器的铁轨应变信息, 下位机的主机卡处理后的数据结果通过工业以太网传给上位机,通过 上位机绘图界面(C#编写)就可得出铁轨载荷作用下的周期性的应变 曲线,此曲线与下位机探测器端接收到的光强是一一对应的关系,光 强 I 的强弱又直接反映出铁轨的应变信息,选取合适的阈值参数,通 过对曲线加以整形,就可以获得铁轨上有无列车驶过及列车轮数,从 而实现对列车的计轴功能。不同环境温度、不同加载频率下采集到 的实验数据表明匹配光栅的解调方法能有效地解决温度应变交叉敏 感带来的问题,四个通道采集数据均正常,并在构建交通动态测重系 统(WIM)方面有好的发展前景。 【英文摘要】Track traffic photoelectric axle-counting systems based on matched Fiber Bragg Gratings are mainly used for train positioning. From the principle of conventional fiber Bragg grating (FBG) sensors and according to the proposed strain sensing method using two matched FBGs and theoretical analysis of track strain distribution under load we detect the stress of Paste the grating area on the rails, after the measurement data processing and analysis the inspection and free range of the train are completed. The axle-counting equipment using in railway signaling system are objective to improve traffic safety technology and the efficiency of rail transport.Track traffic photoelectric axle-counting systems based on matched Fiber Bragg Gratings is investigated from the two aspects of theoretical analysis and experimental verification in this paper. Firstly, the principle of conventional fiber Bragg grating sensors are introduced, according to theoretical analysis of track strain distribution under load we design a track sensor that can detect the local axial strain. At the same time, the principle of Track traffic photoelectric axle-counting systems based on matched Fiber Bragg Gratings. Then, matched grating demodulation for an intensity demodulation we give the system the hardware design of the overall framework. In order to facilitate system maintenance and upgrading of equipment, this axle-counting system is designed for three parts:motherboard card module、module from the board and template module, on each board has a LPC1768 ARM microprocessor chip. Simultaneously, system circuits have increased circuit protection in each module features, the motherboard card and slave card communicate through I2C bus, the host receives information from the slave cards, then passes to the host computer. Finally, a lower computer programs are written with Keil uVision3 development tool. Modular software design methods are adopted and this design is conducive to software code debugging、maintenance and upgrades.The available results are as follows:After the train load simulation, track traffic photoelectric axle-counting systems based on matched Fiber Bragg Gratings receive rails strain information laying a Fiber Bragg Grating sensor. The data results of motherboard card processing on the Lower computer are passed to the host computer (PC) by Ethernet. After drawing, the periodic strain curves of track strain distribution under load are gained, this curve and the detector on the Lower computer receiving the light intensity is one to one relationship, the light intensity I is directly reflected in the strength of the tracks of the strain information, the appropriate threshold parameter is selected and the curves are be shaped so that we can obtain whether the train tracks and the number of passing train wheel, the function of train axle-counting is correspondingly achieved. Results under different environmental temperatures and load frequencies indicate that the matched-FBG approach can effectively solve the temperature and strain induced cross sensitivity problem, four-channel data acquisition were normal, therefore it can meet requirements for axle-counting in rail systems. Such design may be a good candidate for constructing WIM systems as well. 【关键词】光纤布拉格光栅(FBG) 解调 轨道传感器 计轴 ARM 【英文关键词】Fiber Bragg grating(FBG) Demodulation Track sensor Axle-counting ARM 【目录】基于匹配光栅的轨道交通计轴系统研究 摘要 6-7 Abstract 7-8 目录 9-11 第 1 章 绪论 11-14 1.1 本课题研究目的及意义 11 1.2 国内外发展概况 11-12 1.3 本文的 主要工作和结构安排 12-14 第 2 章 基于匹配光栅的 轨道交通计轴系统原理 14-23 2.1 匹配光纤光栅(FBG)检 测应变原理 14-17 2.2 列车载荷作用下铁轨应变分析 17-19 2.3 轨道交通计轴系统原理 19-22 本章小结 22-23 第 3 章 系统硬件电路设计 23-34 3.1 硬件电路设计开发环境及其开发流程 23-24 3.2 系统硬件电路设计整体架构 24-25 3.3 主机板卡电路 设计和所用器件的功能描述 25-30 3.3.1 主机板卡电 路设计 25-27 3.3.2 所用器件的功能描述 27-30 3.4 从机板卡电路设计和所用器件的功能描述 30-33 3.4.1 从机板卡电路设计 30-31 3.4.2 所用器件的功 能描述 31-33 本章小结 33-34 第 4 章 系统软件设计 34-49 4.1 软件开发工具及其开发流程 34-35 4.2 系统程序设计 35-46 4.2.1 软 件整体设计架构 35-36 4.2.2 模块划分及功能描述 36-46 4.2.2.1 从机板卡数据采集(A/D)及数据处理模块 3