光纤Bragg光栅流体压力传感技术的研究
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摘要
压力是最基本的工业参数之一。在工业生产过程中，尤其是在许多易燃、易爆的场合中，准确、安全、可靠地测量压力对保证生产工艺过程的安全性和经济性具有十分重要意义，因此，研制一种能够应用于易燃、易爆环境下的高精度压力传感测系统变得尤为迫切。
近年来，光纤Bragg光栅(FBG)传感检测技术的应用研究受到了科研工作者和工程技术人员的极大关注，已经成功地应用到压力传感领域中。本文提出了一种基于FBG的弹簧管式流体压力传感方案。首先，详细介绍了FBG的基本光学传感特性，并测量了FBG的温度、应变特性；其次，研究了C型弹簧管的位移—压力特性，并利用CCD成像和计算机图像处理技术对其进行了非接触测量；再次，研究了C型弹簧管的应变—压力特性，在此基础上提出直弹簧管的设计方案，并制作了直弹簧管，采用应变测量技术对C型弹簧管和直弹簧管的应变—压力特性分别进行了测量，对两者的应变特性做了比较；最后，建立了基于弹簧管的FBG压力传感系统理论模型，设计完成了基于直弹簧管横向应变—压力特性的FBG流体压力传感系统。实验结果表明：在0～80KPa的压力范围内，FBG的中心反射波长移动量约为0.78nm；在升压和降压过程中，该系统的压力测量灵敏度分别高达9.660×10~(-3)pm／Pa和9.665×10~(-3)pm／Pa，相应的压力敏感系数分别为6.219×10~(-3)MPa~(-1)和
西安理工大学硕士学位论文
6．223X10－3Mps”，大约是裸FBG压力敏感系数门．98X106Mps”l）的引41｛ff；
FBG的中心反射波长位移量与施加给直弹簧管的压力之间具有良好的线性关系。
Pressure is one of the most fundamental parameters. Pressure measurement in high accuracy, safe, and reliable manner is of great significance in the industry productions, especially in the potentially flammable and explosive situation. Accordingly, it is urgent to research and develop a high-accuracy pressure sensing system that can be applied in the flammable and explosive environment.
In recent years, more and more researchers and engineers show great interests in the applications of the fiber Bragg grating (FBG) sensing and measuring technologies, which have already been applied successfully in the pressure-sensing field. A novel fluid pressure sensing system based on both the FBG and the Bourdon tube is presented and demonstrated in this thesis. Firstly, the basically optical sensing characteristics of the FBG are introduced in detail, and its temperature and strain characteristics are measured experimentally. Secondly, the characteristic of the displacement v.s. the applied pressure of a C-shape Bourdon tube (CBT) is studied, and a non-contact measurement of this characteristic is realized using CCD imaging and computer-image-processing technologies. Thirdly, CBT's characteristic of the strain v.s. the applied pressure is studied, on the basis of this, a new scheme of the straight Bourdon tube (SBT) is presented, a SBT is designed and fabricated, and then the strain-pressure characteristics of both the CBT and SBT are measured experimentally using a strain measuring technique, a comparison between the CBT's and SBT's strain
characteristics is also made. Finally, theoretical models of a FBG fluid pressure sensing system scheme based on the Bourdon tube are developed, and a FBG-based fluid pressure sensing system using the transverse strain-pressure characteristic of the SBT is designed and set up. The experimental results have shown that the shift of the central reflecting wavelength of the FBG is 0.78nm when the applied pressure varies in the range of 0-80KPa, and the pressure measurement sensitivities are as high as 9.660 + 10-3pm/Pa and 9.665 + 10-3pm/Pa when the pressure is increased and decreased respectively, corresponding to pressure sensitive coefficients of 6.219 +10-3MPa-1 and 6.222 +10 -3MPa-1, which are approximately 3141 times greater than that of a bare FBG(1.98 +10-6MPa-1). In addition, the center-reflecting wavelength shift of the FBG varies in good linearity with the applied pressure.
近年来，光纤Bragg光栅(FBG)传感检测技术的应用研究受到了科研工作者和工程技术人员的极大关注，已经成功地应用到压力传感领域中。本文提出了一种基于FBG的弹簧管式流体压力传感方案。首先，详细介绍了FBG的基本光学传感特性，并测量了FBG的温度、应变特性；其次，研究了C型弹簧管的位移—压力特性，并利用CCD成像和计算机图像处理技术对其进行了非接触测量；再次，研究了C型弹簧管的应变—压力特性，在此基础上提出直弹簧管的设计方案，并制作了直弹簧管，采用应变测量技术对C型弹簧管和直弹簧管的应变—压力特性分别进行了测量，对两者的应变特性做了比较；最后，建立了基于弹簧管的FBG压力传感系统理论模型，设计完成了基于直弹簧管横向应变—压力特性的FBG流体压力传感系统。实验结果表明：在0～80KPa的压力范围内，FBG的中心反射波长移动量约为0.78nm；在升压和降压过程中，该系统的压力测量灵敏度分别高达9.660×10~(-3)pm／Pa和9.665×10~(-3)pm／Pa，相应的压力敏感系数分别为6.219×10~(-3)MPa~(-1)和
西安理工大学硕士学位论文
6．223X10－3Mps”，大约是裸FBG压力敏感系数门．98X106Mps”l）的引41｛ff；
FBG的中心反射波长位移量与施加给直弹簧管的压力之间具有良好的线性关系。
Pressure is one of the most fundamental parameters. Pressure measurement in high accuracy, safe, and reliable manner is of great significance in the industry productions, especially in the potentially flammable and explosive situation. Accordingly, it is urgent to research and develop a high-accuracy pressure sensing system that can be applied in the flammable and explosive environment.
In recent years, more and more researchers and engineers show great interests in the applications of the fiber Bragg grating (FBG) sensing and measuring technologies, which have already been applied successfully in the pressure-sensing field. A novel fluid pressure sensing system based on both the FBG and the Bourdon tube is presented and demonstrated in this thesis. Firstly, the basically optical sensing characteristics of the FBG are introduced in detail, and its temperature and strain characteristics are measured experimentally. Secondly, the characteristic of the displacement v.s. the applied pressure of a C-shape Bourdon tube (CBT) is studied, and a non-contact measurement of this characteristic is realized using CCD imaging and computer-image-processing technologies. Thirdly, CBT's characteristic of the strain v.s. the applied pressure is studied, on the basis of this, a new scheme of the straight Bourdon tube (SBT) is presented, a SBT is designed and fabricated, and then the strain-pressure characteristics of both the CBT and SBT are measured experimentally using a strain measuring technique, a comparison between the CBT's and SBT's strain
characteristics is also made. Finally, theoretical models of a FBG fluid pressure sensing system scheme based on the Bourdon tube are developed, and a FBG-based fluid pressure sensing system using the transverse strain-pressure characteristic of the SBT is designed and set up. The experimental results have shown that the shift of the central reflecting wavelength of the FBG is 0.78nm when the applied pressure varies in the range of 0-80KPa, and the pressure measurement sensitivities are as high as 9.660 + 10-3pm/Pa and 9.665 + 10-3pm/Pa when the pressure is increased and decreased respectively, corresponding to pressure sensitive coefficients of 6.219 +10-3MPa-1 and 6.222 +10 -3MPa-1, which are approximately 3141 times greater than that of a bare FBG(1.98 +10-6MPa-1). In addition, the center-reflecting wavelength shift of the FBG varies in good linearity with the applied pressure.
引文
[1]王惠文，江先进，赵长明，等．光纤传感技术与应用．北京：国防工业出版社，2001：24—296
[2]郁有文，常健．传感器原理及工程应用．西安：西安电子科技大学出版社，2000：161—166
[3]林钧岫，彭伟．光纤布拉格光栅及其应用．光学技术，1999：50—53
[4]尚丽平，张淑清，史锦珊．光纤光栅传感器的现状与发展．燕山大学学报，25(2)，2001：139—143
[5]M.G. XU, L. Reekie,Y. T. Chow, et al.,Optical in-fiber grating high pressure sensor.Electronics Letters,Vol:19,1993:398-399
[6]M.G. XU, H. Geiger, G. P.Dakin, et al.,Fiber grating pressure sensor with enhanced sensitivity using a glass-bubble housing, Electronics Letters,Vol:32,1996:398-399
[7]刘云启，刘志国，郭转运等．光纤光栅弹簧管压力传感器的压力和温度特性．光子学报，27(12)，1998：1111—1115
[8]Y.Q. Liu,Z. Y. Guo, Y. Zhang, et al.,Simultaneous pressure and temperature measurement with poly-coated fiber Bragg grating. Electronics Letters,Vol36, 2000:564-566
[9]Y. Zhang, D. J. Feng, Z. G. Liu, et al.,High-sensitivity pressure sensor using a shielded polymer-coated fiber Bragg grating.IEEE Photonics Technology Letters,Vol:13,Iss:6, 2001:618-619
[10]A.D. Kersey, M. A. Davis, H.J. Patrick et al.,Fiber grating sensors. J. Lightwave Technology,Vol:15,Iss:8, 1997:1442～463
[11]Y. J. Rao, Recent progress in applications of in-fiber Bragg grating
sensors.Opticals and Lasers in Engineering,vol:31,1999:297～324
[12]K.O. Hill, et al.,Photosensitivity in optic fiber waveguides.Application to reflector filter fabrication.Applied Physics Letter,Vol:32,Iss:10,1978:647-649
[13]G. Meltz, W.W. Merey, W. H. Glenn, Formation of Bragg gratings in optical fiber by a transverse holographic method.Optics Letter,Vol:14,Iss:15,1989:823-825
[14]K.O. Hill, B. Malo, et al.,Bragg gratings fabrication in monomode fiber by UV exposure through a phase mask.Applied Physics Letter,Vol:62,Iss:10,1993:1035-1037
[15]L. Dong, J. L. Archambault, L. Reeke, et al.,Single pulse Bragg gratings written during fiber drawing.Electronics Letters, Vol:19, Iss:17,1993:1577-1578
[16]I. Bennion,J. A. R. Williams,et al., UV-written in-fiber Bragg gratings.Optical Quantum Electronics,Vol:28,1996:93-135
[17]贾宏志，李育林，忽满利，等．光纤Bragg光栅温度和应变的灵敏度分析及应用探讨．激光杂志，20(5)，1999：12—14
[18]靳伟，廖延彪，张志鹏，等．导波光学传感器原理与技术，北京：科学出版社，1998：45—102
[19]M. B. Reid, M. Ozcan. Temperature dependence of fiber optic Bragg gratings at low temperatures.Optical Engineering,Vol:37, Iss:1,1998:237-140
[20]施立亭．仪表机构零件．冶金工业出版社，1984：229—233
[21]钱俊霞．弹簧管的应力分析及其工程应用．仪器仪表学报，17(4)，1996：437—440
[22]翁善臣，林友德，徐振廷，等．仪表弹性元件设计基础．机械
工业出版社，1982：338—342
[23]何斌，马天予，王运坚等．Visual C++数字图像处理．人民邮电出版社，2001：335—448
[24]涂国平．传感器线性度的统计分析[J]．传感器技术，19(3)，2000：36—37
[2]郁有文，常健．传感器原理及工程应用．西安：西安电子科技大学出版社，2000：161—166
[3]林钧岫，彭伟．光纤布拉格光栅及其应用．光学技术，1999：50—53
[4]尚丽平，张淑清，史锦珊．光纤光栅传感器的现状与发展．燕山大学学报，25(2)，2001：139—143
[5]M.G. XU, L. Reekie,Y. T. Chow, et al.,Optical in-fiber grating high pressure sensor.Electronics Letters,Vol:19,1993:398-399
[6]M.G. XU, H. Geiger, G. P.Dakin, et al.,Fiber grating pressure sensor with enhanced sensitivity using a glass-bubble housing, Electronics Letters,Vol:32,1996:398-399
[7]刘云启，刘志国，郭转运等．光纤光栅弹簧管压力传感器的压力和温度特性．光子学报，27(12)，1998：1111—1115
[8]Y.Q. Liu,Z. Y. Guo, Y. Zhang, et al.,Simultaneous pressure and temperature measurement with poly-coated fiber Bragg grating. Electronics Letters,Vol36, 2000:564-566
[9]Y. Zhang, D. J. Feng, Z. G. Liu, et al.,High-sensitivity pressure sensor using a shielded polymer-coated fiber Bragg grating.IEEE Photonics Technology Letters,Vol:13,Iss:6, 2001:618-619
[10]A.D. Kersey, M. A. Davis, H.J. Patrick et al.,Fiber grating sensors. J. Lightwave Technology,Vol:15,Iss:8, 1997:1442～463
[11]Y. J. Rao, Recent progress in applications of in-fiber Bragg grating
sensors.Opticals and Lasers in Engineering,vol:31,1999:297～324
[12]K.O. Hill, et al.,Photosensitivity in optic fiber waveguides.Application to reflector filter fabrication.Applied Physics Letter,Vol:32,Iss:10,1978:647-649
[13]G. Meltz, W.W. Merey, W. H. Glenn, Formation of Bragg gratings in optical fiber by a transverse holographic method.Optics Letter,Vol:14,Iss:15,1989:823-825
[14]K.O. Hill, B. Malo, et al.,Bragg gratings fabrication in monomode fiber by UV exposure through a phase mask.Applied Physics Letter,Vol:62,Iss:10,1993:1035-1037
[15]L. Dong, J. L. Archambault, L. Reeke, et al.,Single pulse Bragg gratings written during fiber drawing.Electronics Letters, Vol:19, Iss:17,1993:1577-1578
[16]I. Bennion,J. A. R. Williams,et al., UV-written in-fiber Bragg gratings.Optical Quantum Electronics,Vol:28,1996:93-135
[17]贾宏志，李育林，忽满利，等．光纤Bragg光栅温度和应变的灵敏度分析及应用探讨．激光杂志，20(5)，1999：12—14
[18]靳伟，廖延彪，张志鹏，等．导波光学传感器原理与技术，北京：科学出版社，1998：45—102
[19]M. B. Reid, M. Ozcan. Temperature dependence of fiber optic Bragg gratings at low temperatures.Optical Engineering,Vol:37, Iss:1,1998:237-140
[20]施立亭．仪表机构零件．冶金工业出版社，1984：229—233
[21]钱俊霞．弹簧管的应力分析及其工程应用．仪器仪表学报，17(4)，1996：437—440
[22]翁善臣，林友德，徐振廷，等．仪表弹性元件设计基础．机械
工业出版社，1982：338—342
[23]何斌，马天予，王运坚等．Visual C++数字图像处理．人民邮电出版社，2001：335—448
[24]涂国平．传感器线性度的统计分析[J]．传感器技术，19(3)，2000：36—37