【作者】 贾艳丽；

【导师】 刘月明；

【作者基本信息】 西安理工大学 ， 测试计量技术及仪器， 2008， 硕士

【摘要】 针对检测机械振动故障需要分析设备的机械振动频率、加速度等参数,本论文设计出一种振动/温度双参数光纤光栅传感器。该传感器具有抗电磁干扰、灵敏度高、动态范围大、体积小等优点,并能够有效地解决在工程结构中各种因素的互相影响及交叉敏感问题。本论文采用等强度悬臂梁进行振动传感测试,设计出一种基于长周期光纤光栅的新型解调系统。该系统可以实现温度与振动信号的解调,并能有效消除光源波动及外界环境干扰。系统测量范围达到:动态信号频率20Hz～160Hz,加速度0～140g,温度0℃～100℃;温度分辨力为0.1℃,加速度分辨力为0.1g。论文主要内容包括:(1)介绍光纤光栅传感器及多参数传感器的应用及发展现状。概述光纤光栅基本传感原理及其基本特性、振动传感器基本原理,研究光纤光栅温度、振动传感特性,并介绍光纤光栅传感系统组成。(2)分析几种常用光纤光栅解调方案的解调原理及其优缺点,利用长周期光纤光栅的边缘滤波效应,设计出一种新型解调方案。详细介绍方案解调原理、光路设计,并理论计算出传感光强/FBG谐振波长灵敏度。(3)设计等强度梁式振动传感器结构,分析振动悬臂梁静态特性、动态特性及悬臂梁的固有频率等。根据系统测量要求,对悬臂梁尺寸进行优化设计。利用ANSYS软件对振动悬臂梁固有频率进行仿真分析,验证理论计算的正确性。(4)设计光电转换电路、滤波电路、差动电路、数据采集电路、动态显示电路等,并通过系统软件设计实现传感信号的检测与显示。(5)实验研究光纤光栅传感系统的温度传感特性、应变传感特性、振动传感特性,并对实验结果进行分析。更多还原

【Abstract】 Aiming at the purpose of analyzing equipment’s vibration parameters such as frequency and acceleration during mechanical vibration fault diagnosis, in this paper one kind of vibration/temperature two-parameter fiber grating sensor with the merits EMI (Electromagnetic interference) resistance, high sensitivity, wide dynamic range, small size, etc, was designed and the problems of multi factors’ interaction and cross-sensitivity in engineering structure were effectively solved.Vibration sensing text of constant strength cantilever was employed in this paper, and a novel demodulating system was designed based on long period fiber grating to demodulate the temperature and vibration, which could effectively minimize the effect of fluctuation of optical source and decrease the interference of external environment. System measurement range could be as follows: dynamic signal range, 20Hz～160Hz, acceleration measurement range, 0～140g with the sensitivity 0.1g, temperature measurement range, 0℃～100℃with the sensitivity 0.1℃. Following were the main contents in this paper:Firstly, the application and the present development of fiber grating sensor and multi parameter sensor were introduced, and then the basic sensing principle and characters of fiber grating, vibration sensor’s fundamental principle was briefly discussed, besides, temperature /vibration sensing and the composition of fiber grating sensing system was studied.Secondly, the principle, merits and faults of several general fiber grating demodulation scheme was analyzed, a novel demodulation scheme was presented based on edge filter effect of long period fiber grating. Then we discussed intensively its’ working principle, beam path design, and did the theoretical calculation of resonant wavelength sensitivity of sensing optical intensity and FBG.Thirdly, the structure of constant strength cantilever vibration sensor was designed, static and dynamic characteristic, natural frequency of cantilever analyzed. According to the requirement of system, the size of cantilever was optimized, and simulation about natural frequency of vibration cantilever via ANSY software was realized, which verified the results of theoretical calculation.Forth, system circuits including photoelectric conversion, filtration, differential, data acquisition, dynamic display, etc, were designed, and the test and display of sensing signal was fulfilled by system software.Finally, some experiments were finished to study the temperature sensing character, strain sensing character, vibration sensing character, and the result analysis of experiment was make.更多还原