CN202033128U - Railway tunnel safety monitoring system based on three fiber bragg grating coding - Google Patents
Railway tunnel safety monitoring system based on three fiber bragg grating coding Download PDFInfo
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- CN202033128U CN202033128U CN2011200085637U CN201120008563U CN202033128U CN 202033128 U CN202033128 U CN 202033128U CN 2011200085637 U CN2011200085637 U CN 2011200085637U CN 201120008563 U CN201120008563 U CN 201120008563U CN 202033128 U CN202033128 U CN 202033128U
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Abstract
The utility model relates to a railway tunnel safety monitoring system based on three fiber bragg grating coding. An output end of a broadband light source (1) is connected with a first port of a three-port coupler, a second port of the three-port coupler is connected with a sensing fiber bragg grating array (3), a third port of the three-port coupler is connected with an input end of an array waveguide grating (4), an output end of the array waveguide grating is respectively connected with an input end of a first photoelectric detector, an input end of a second photoelectric detector and an input end of a third photoelectric detector, output ends of the first, the second and the third photoelectric detectors are respectively connected with an input end of a signal processing module (6), and the signal processing module is connected with a computer (7). The sensing fiber grating array comprises one or more serially connected sensing heads, and each sensing head comprises three fiber bragg gratings having different central wavelengths. In all the sensing heads, central wavelengths of corresponding fiber bragg gratings are the same, reflectivities of the three fiber gratings are not exactly the same in any two sensing heads, and if in each sensing head, the three fiber bragg gratings have m reflectivities, quantity of the sensing heads equals to m3.
Description
Technical field
The utility model relates to based on reflectivity encoding optic fiber grating fireproof monitoring system, is applicable to fields such as optical fiber sensing technology, civil engineering, track traffic.
Background technology
In recent years, sensor is developing towards sensitive, accurate, strong, the small and exquisite and intelligentized direction of adaptability.In this course, the newcomer of this sensor family of Fibre Optical Sensor gains great popularity.Optical fiber has the performance of a lot of excellences, for example: the performance of anti-electromagnetic interference (EMI) and atomic radiation, the footpath is thin, soft, the lightweight mechanical property of matter; Insulation, inductionless electric property; Water-fast, high temperature resistant, corrosion resistant chemical property etc., thereby Fibre Optical Sensor has widely than other sensors and uses.At present, most widely used is distributed optical fiber sensing system, and the sensing technology that these distributed optical fiber sensing systems adopt mainly is based on the distributed sensing of Raman scattering and based on the distributed sensing of Brillouin scattering.But the acceptance of these sensing technology signals is difficulty relatively, and Measuring Time is long, and Signal Processing is very complicated, and the overall cost of system is also relatively more expensive.
Fiber-optic grating sensor also has some obviously to be better than the place of other Fibre Optical Sensors except the many advantages with Fibre Optical Sensor.The influence of factors such as it is the device as a kind of spectral separation and optical wavelength selection, and not loss by bending of signal, junction loss, light source rise and fall and detector wears out; Problems such as the interferometric optical fiber sensor phase measurement is smudgy have been avoided; The information of several measurement target can be obtained simultaneously, and quasi-distributed measurement can be realized.Since in the practical application on a large scale, the needs of big monitoring distance, often need jumbo monitoring system.Traditional fiber grating sensing and monitoring system is to utilize single fiber grating as sensing head, because the restriction of light source bandwidth, the sensing head that makes whole sensor-based system to connect like this is limited, can not satisfy the needs of practical application.High capacity encoding optic fiber grating sensing and monitoring system, CN200310111529.2 has proposed a kind of large-capacity fiber grating sensing and monitoring system, but the wavelength of monochromatic light grid is all inequality in its sensor fibre grating array, makes trouble relatively; Measurement range is big more, and needed sensing head quantity is many more, and its coded system is also complicated relatively more; Adopted two light sources, two Y type shunts, two detuners, the overall cost of system is relatively more expensive.
The utility model content
Technical problem to be solved in the utility model provides a kind of simple, convenient and practical, cheap railway tunnel safety monitoring system based on three fiber gratings coding.
The technical solution of the utility model:
A kind of railway tunnel safety monitoring system based on three fiber gratings coding, the output of the wideband light source of this system connects first port of three port coupler, second port of three port coupler connects the sensor fibre grating array, and the 3rd port of three port coupler connects the input end of array waveguide grating.
The output terminal of array waveguide grating connects the input end of first photodetector, the input end of second photodetector, the input end of the 3rd photodetector respectively.
The output terminal of the output terminal of first photodetector, second photodetector, the 3rd photodetector output terminal connect the input end of signal processing module respectively, and signal processing module connects computing machine.
The sensor fibre grating array by first sensing head, second sensing head ..., the n sensing head composition that is connected in series, n 〉=1; Each sensing head is made up of 3 different fiber gratings of centre wavelength.
Described first the centre wavelength unanimity of fiber grating to the n sensing head, the reflectivity of three fiber gratings on each sensing head is similar and different; First to the n sensing head, and three each and every one reflectivity of fiber grating in any two sensing heads are incomplete same.
When the reflectivity value number of three fiber gratings was m in described each sensing head, the quantity of sensing head was n=m
3
The beneficial effects of the utility model: the railway tunnel safety monitoring system that the utility model proposes based on three fiber gratings coding, simple in structure, be easy to realize; Only need photodetector danger to take place near can judging which measurement point, do not need high demodulated equipment, low price, cost performance height; Adopt three fiber gratings to make sensing head, the fiber grating centre wavelength unanimity of each sensing head correspondence, reflectivity difference have increased the capacity of sensor-based system, can realize long distance, the large-scale monitoring.
Description of drawings
Fig. 1 is based on the railway tunnel safety monitoring system synoptic diagram of three fiber gratings coding.
Embodiment
Below in conjunction with accompanying drawing the utility model is further described.
Embodiment one, and present embodiment 1 is elaborated in conjunction with the accompanying drawings.
A kind of railway tunnel safety monitoring system based on three fiber gratings coding, the output of the wideband light source 1 of this system connects first port 21 of three port coupler, the 3rd port 23 that second port 22 of three port coupler connects sensor fibre grating array 3, three port coupler connects the input end of array waveguide grating 4.
The output terminal of array waveguide grating 4 connects the input end of first photodetector 51, the input end of second photodetector 52, the input end of the 3rd photodetector 53 respectively.
The output terminal of the output terminal of first photodetector 51, second photodetector 52, the 3rd photodetector 53 output terminals connect the input end of signal processing module 6 respectively, and signal processing module 6 connects computing machine 7.
Sensor fibre grating array 3 by first sensing head 31, second sensing head 32 ..., the 8th sensing head 38 composition that is connected in series; Each sensing head is made up of three different fiber gratings of centre wavelength.
The centre wavelength unanimity of the fiber grating on first to the 8th sensing head, the reflectivity of three fiber gratings is similar and different on each sensing head; In first to the 8th sensing head, the reflectivity of three fiber gratings in any two sensing heads is not exclusively together individual.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in first sensing head, and 1%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 1%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 1%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in second sensing head, and 1%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 1%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 99%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 3rd sensing head, and 1%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 99%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 1%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 4th sensing head, and 1%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 99%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 99%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 5th sensing head, and 99%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 1%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 1%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 6th sensing head, and 99%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 99%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 1%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 7th sensing head, and 99%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 1%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 99%.
The centre wavelength of first fiber grating and reflectivity are respectively 1550.1nm in the 8th sensing head, and 99%; The centre wavelength and the reflectivity of second fiber grating are respectively 1550.3nm, 99%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1550.5nm, 99%.
The centre wavelength of first, second in the present embodiment and the 3rd fiber grating is respectively 1550.1nm, 1550.3nm and 1550.5nm; First, second and the 3rd fiber grating reflectivity have two different values 1%, 99%.
The sensing head number of present embodiment is n=m
k=2
3=8, wherein m is a reflectivity value number.
Embodiment two, a kind of railway tunnel safety monitoring system based on three fiber gratings coding, the output of the wideband light source 1 of this system connects first port 21 of three port coupler, the 3rd port 23 that second port 22 of three port coupler connects sensor fibre grating array 3, three port coupler connects the input end of array waveguide grating 4.
The output terminal of array waveguide grating 4 connects the input end of first photodetector 51, the input end of second photodetector 52, the input end of the 3rd photodetector 53 respectively.
The output terminal of the output terminal of first photodetector 51, second photodetector 52, the 3rd photodetector 53 output terminals connect the input end of signal processing module 6 respectively, and signal processing module 6 connects computing machine 7.
Sensor fibre grating array 3 by first sensing head 31, second sensing head 32 ..., the 27 sensing head 327 composition that is connected in series; Each sensing head is made up of three different fiber gratings of centre wavelength.
The centre wavelength unanimity of the fiber grating on the first to the 27 sensing head, the reflectivity of three fiber gratings is similar and different on each sensing head; In the first to the 27 sensing head, the reflectivity of three fiber gratings in any two sensing heads is not exclusively together individual.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in first sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in second sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 3rd sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 4th sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 5th sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 6th sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 7th sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 8th sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 9th sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the tenth sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 11 sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 12 sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 13 sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 14 sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 15 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 16 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 17 sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 18 sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 19 sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 20 sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 21 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 22 sensing head, and 45%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 23 sensing head, and 80%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 5%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 24 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 45%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 25 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 5%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 26 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 45%.
The centre wavelength of first fiber grating and reflectivity are respectively 1551.8nm in the 27 sensing head, and 5%; The centre wavelength and the reflectivity of second fiber grating are respectively 1552.0nm, 80%; The centre wavelength and the reflectivity of the 3rd fiber grating are respectively 1552.2nm, 80%.
The centre wavelength of first, second in the present embodiment and the 3rd fiber grating is respectively 1551.8nm, 1552.0nm and 1552.2nm; The first and second fiber grating reflectivity have three different values 5%, 45%, 80%.
The sensing head number of present embodiment is n=m
3=3
3=27, wherein m is a reflectivity value number.
Select the value number of optical fiber optical grating reflection rate according to the size of the scope of required measurement.
The light that sends based on the wideband light source 1 of the railway tunnel safety monitoring system of three fiber gratings codings advances overcoupling device 2 and enters sensor fibre grating array 3; The signal that sensor fibre grating array 3 reflects enters array waveguide grating 4, three fiber gratings are to the temperature of institute's measuring point on each sensing head, stress is encoded, when the environment temperature of measurement point or stress change, the centre wavelength of three fiber gratings changes simultaneously, because the reflectivity difference of corresponding three fiber gratings of each sensing head, light by array waveguide grating 4 back three wavelength is separated to enter first photodetector 51, second photodetector 52, the 3rd photodetector 53, the optical power change difference that these three photodetectors receive, behind signal processing module 6, just can judge is that danger has taken place which measurement point.
The employed device of the utility model is commercially available device.
Claims (3)
1. railway tunnel safety monitoring system based on three fiber gratings codings, the output of the wideband light source of this system (1) connects first port (21) of three port coupler, second port (22) of three port coupler connects sensor fibre grating array (3), and the 3rd port (23) of three port coupler connects the input end of array waveguide grating (4);
The output terminal of array waveguide grating (4) connects the input end of first photodetector (51), the input end of second photodetector (52), the input end of the 3rd photodetector (53) respectively;
The output terminal of the output terminal of first photodetector (51), second photodetector (52), the 3rd photodetector (53) output terminal connect the input end of signal processing module (6) respectively, and signal processing module (6) connects computing machine (7); It is characterized in that:
Sensor fibre grating array (3) by first sensing head (31), second sensing head (32) ..., n sensing head (3n) composition that is connected in series, n 〉=1; Each sensing head is made up of 3 different fiber gratings of centre wavelength.
2. the railway tunnel safety monitoring system based on three fiber gratings coding according to claim 1 is characterized in that:
First the centre wavelength unanimity of fiber grating to the n sensing head, the reflectivity of three fiber gratings on each sensing head is similar and different; First to the n sensing head, and three each and every one reflectivity of fiber grating in any two sensing heads are incomplete same.
3. the railway tunnel safety monitoring system based on three fiber gratings coding according to claim 1 is characterized in that:
When the reflectivity value number of three fiber gratings was m in each sensing head, the quantity of sensing head was n=m
3
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| Application Number | Priority Date | Filing Date | Title |
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| CN2011200085637U CN202033128U (en) | 2011-01-13 | 2011-01-13 | Railway tunnel safety monitoring system based on three fiber bragg grating coding |
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| CN2011200085637U CN202033128U (en) | 2011-01-13 | 2011-01-13 | Railway tunnel safety monitoring system based on three fiber bragg grating coding |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103235363A (en) * | 2013-04-22 | 2013-08-07 | 天津工业大学 | Array waveguide grating demodulation integration micro system |
| CN107123477A (en) * | 2017-05-17 | 2017-09-01 | 北京恒润生工程科技有限公司 | The existing railway Through ground wire burglary-resisting system designed based on optical fiber micro-bending |
| CN114323251A (en) * | 2022-03-10 | 2022-04-12 | 武汉理工大学 | Signal equalization device and method for distributed optical fiber phase-sensitive optical time domain reflectometer |
-
2011
- 2011-01-13 CN CN2011200085637U patent/CN202033128U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103235363A (en) * | 2013-04-22 | 2013-08-07 | 天津工业大学 | Array waveguide grating demodulation integration micro system |
| CN107123477A (en) * | 2017-05-17 | 2017-09-01 | 北京恒润生工程科技有限公司 | The existing railway Through ground wire burglary-resisting system designed based on optical fiber micro-bending |
| CN107123477B (en) * | 2017-05-17 | 2020-11-03 | 北京恒润生工程科技有限公司 | Existing railway through ground wire anti-theft system based on optical fiber microbend design |
| CN114323251A (en) * | 2022-03-10 | 2022-04-12 | 武汉理工大学 | Signal equalization device and method for distributed optical fiber phase-sensitive optical time domain reflectometer |
| CN114323251B (en) * | 2022-03-10 | 2022-06-17 | 武汉理工大学 | Signal equalization device and method for distributed optical fiber phase-sensitive optical time domain reflectometer |
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