【作者】 张毅；

【导师】 周肇飞；

【作者基本信息】 四川大学 ， 测试技术及仪器， 2002， 硕士

【摘要】 在环境试验中，针对武器层间结构的位移测试，许多传统的位移传感器由于体积较大安装困难，或因对试验件狭小层间的测试面需特殊处理等因素都不太适用，所以我们改用光纤传感器进行位移测试。为避免使用昂贵的光学系统，减小测试调试的复杂性，我们选用了结构简单可靠的强度调制式光纤位移传感器，其技术方案分反射式和光闸式两种。反射式可实现非接触测量，但对我们的使用条件来看有很多缺点，如对反射面的材料、曲率等因素要求高，受背景光干扰，探头制作复杂，实际测试需设计专用支架，量程只有100μm左右，为扩大其动态范围必须在光纤端增加光学透镜组，这样大大增加了传感器探头的体积。由于以上种种原因使得这种方法在我们的实际工程中应用可行性小。为此技术部门研究决定选用使用可靠、制作简单的第二种方案，并研制出光纤传感位移测试系统。它由光纤传感器、位移测试电路和计算机三部分组成，通过专用软件可对位移进行实时测试和显示。其传感器结构紧凑，系统调试简单，量程1mm、分辨力0． 5μm，可在项目要求的环境试验中代替传统的位移计。本文包括以下几部份。第一章绪论概述了位移检测的现状及发展，对几种典型检测方法的优缺点作了比较，指出在环境试验中用光闸式位移测试的必要性及优势。第二章在对光纤光场分布特性进行了理论分析的基础上，推导出光闸式位移测试的调制特性的数学模型。第三章概述了系统的工作原理，对比了几种不同的测试方案。本文所提出的方案可扩大量程且不以减小分辨力为代价，其独特的光路及传感器结构设计，在光闸式位移计的研究中，作者未见相关的文献报道，有一定的创新性。第四章主要介绍了主要部分的电路设计。目前，这种微弱输入信号的采集电路及抗干扰技术对很多新型传感器都适用，故该电路的设计具有一定代表性。第五章介绍了测试软件的界面及主要功能函数的程序。 摘要 第六章介绍了标定装置并通过测定验证了理论推导的调制特性方程。实验说明引进参考通道有助于减小干扰，使系统更适用于工程应用。采用我们提出的光纤束扩大量程的方案，不但扩大了量程，而且工作曲线的线性度也有显著提高。更多还原

【Abstract】 In environmefit test, lotS of conveniional disPlaeement tusducers aren’tsuitable, esPecially aimed tO measure the displacement in the itherlayer strUctUre ofweaPon, because the volume of sensor is too large tO install, or the test plane ofnarrow interlayer mwt be dealed with .So we chOose fiber optic sensors to measurethe disPlacement.In order tO avoid using exPensive optical systCm, reduce the complexity indebugging, we choose the intensity modulation tyPe of fiber optic sensors, whosestrUctUre is simple and reliable. There are two schemes, one is the mask type and theother is the reflective tyPe. The reflective tyPe can be used in uncontacted test, but ithas some shortcoming on our condition. For examPle, high quality is asked for theWrial and curvwt of reflective plane, the sensor sthers frOm the interference ofbackgrOund ligh, mmpfactUre of probe is comPlicated,we need tO design theaPProPriative hOlder in tes’ the span is only about l00mp, to extend the dynamicrange we must increase a set of oPtical lens on the end of oPtic fiber, but consurnedlyincrease the probe’s volume. Because of all above reason, the possibility of this kindof method aPplied tO actual work is little, so technical dePchent decides to chOosethe second methed tO develop the system using fiber optic sensors tO measure thediSPlacement, Which is more reliable and easier tO produce. It is comPosed of threepnd, Which are the fiber oPtic sensor, the circult of displacement measurement andcompUteL By the aPpropriative softwar, it can measure the disPlacement and displayit in real time. The stwthe of sensor is compact, the debugging of system is simple,meanwhile the sPan is lnnn and the resoluton is 0.5mp, so it can rePlaceconventional disPlaeemeni sensors in the environment tCSt required by taSk. msIIIpaper comPrises sevend partS as follows.In the first chaPer as preface, this paPer sunnnarizes the actUality anddevelopment of displacement measurements. It shOws tha the necessity andadvantae using the mask tyPe of displaeement measurend in environment test,comParing the excellence and defect of several tyPical measurements.On the basis of analyzing the distribution of light field of fiber thcoretically, thepaper deduces the math model of modulation function of the mask tyPe ofmeasurement in the second chaPterIn the third chaPtr, thes pape summarizes the operation ~iple of system, andcomPares several different measurement projeets. The Proect put forwar by thispaper may extend span not tO deerease the resolution. The particular light Way andsensor stfUCture are innovative on the research of displaeemellt measurements usingthe mask tyPe of fiber oPtic sensof, and we hav not seen releVan reportedliteratos.The paPer mainly illtrOduCes some designs of chief circuitS. At present, thiscireuit gathering faint input signal and the anti-interference tecboquCs can aPPly tOW new sensors, so it is a tyPical circuit design.’In the fiffe chaPtr, the pape intrOduces the ifor of softwar and listSrelevan Propos of clyef fhaotions.In the sixth chaPter, this pape recomrnnds the calibration device and verifiesthe aCademic modulation boon by measurement. The experimellt indicates thatreferenced chaImls can reduce the intefference in favOr of using it in engineering.MWle, the prOject advanced by us to extend SPan with fiber oPtic bind not onlydOes so, bu also grcaly imProves the liwi of the operaion curv.更多还原