CN102798487A - System and method for off-line automatic calibration for attenuation parameters of detection optical cable - Google Patents
System and method for off-line automatic calibration for attenuation parameters of detection optical cable Download PDFInfo
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- CN102798487A CN102798487A CN2011101408118A CN201110140811A CN102798487A CN 102798487 A CN102798487 A CN 102798487A CN 2011101408118 A CN2011101408118 A CN 2011101408118A CN 201110140811 A CN201110140811 A CN 201110140811A CN 102798487 A CN102798487 A CN 102798487A
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Abstract
The invention discloses a system and a method for off-line automatic calibration for attenuation parameters of a detection optical cable. The method comprises the following steps of: when calibration is needed, connecting a light reflection module at the tail end of the detection optical cable, controlling a distributed optical fiber temperature sensing system host, adjusting pulse light source repetition frequency to be half of a normal mode, and adjusting a signal acquisition module to double the acquisition length of the signal acquisition module for automatic calibration so as to accurately obtain attenuation parameters of the detection optical cable; and in normal work, adjusting the pulse light source repetition frequency to be in the normal mode, and taking down the light reflection module to enter a normal working mode so as to realize the on-site calibration and compensation for the detection optical cable. According to the invention, the effective use degree of a distributed optical fiber temperature sensing system and the system performance are improved.
Description
Technical field
The present invention relates to the distributed optical fiber temperature sensor technology field, relate in particular to the Automatic Calibration Technique field of distributed optical fiber temperature sensing system.
Background technology
Distributed optical fiber temperature sensing system is based on the backscattering principle; When laser pulse during in Optical Fiber Transmission; Can constantly produce scattered lights such as Raman scattering (Stokes, anti-Stokes), Rayleigh scattering and Brillouin scattering in the optical fiber; Wherein a part can be transferred to " source " in the other direction, and we claim that this part scattered light is " back-scattering light ".Distributed optical fiber temperature sensing system is exactly to adopt in the Raman scattering dorsad anti-Stokes as a kind of temperature-sensing system of responsive to temperature signal.
Distributed optical fiber temperature sensing system is made up of distributed fiber temperature sensing main frame and detecting optical cable usually.Distributed optical fiber temperature sensing system need carry out the demarcation of calculating parameter before dispatching from the factory, this demarcation is an object with the particular probe optical cable.When distributed optical fiber temperature sensing system delivered to customer to use, the detecting optical cable of use possibly be different, will cause the change of coefficient parameters such as Stokes and anti-Stokes attenuation parameter.In order to guarantee The measuring precision, need compensate and correct calculating parameter.And the working environment of the used detecting optical cable of distributed optical fiber temperature sensing system field environments such as tunnel, colliery, transformer station normally; The temperature of detecting optical cable is difficult to confirm with the distribution situation of length; The attenuation parameter demarcation that will as producer or laboratory, carry out optical cable is unpractical; Effective use that this has influenced distributed optical fiber temperature sensing system has to a certain extent reduced system performance.
Summary of the invention
In order to solve the problem that exists in the above-mentioned technology, the present invention provides a kind of and non-ly calibrates detecting optical cable attenuation parameter system automatically in line style.
In order to achieve the above object, the technical scheme that the present invention adopted is following:
A kind of non-system of calibrating the detecting optical cable attenuation parameter automatically in line style comprises distributed optical fiber temperature sensing system main frame and detecting optical cable, it is characterized in that: said detecting optical cable tail end connects a smooth reflecting module.
Said detecting optical cable tail end is provided with joints of optical fibre, connects said smooth reflecting module on the joints of optical fibre.
Described smooth reflecting module is the reflection unit with reflected light function, can be catoptron, plated film device, metal covering or Bragg grating.
Described reflecting module is the manifold type reflection unit, can be 1 * 2 coupling mechanism, 2 * 2 coupling mechanisms; One side ports of manifold type reflection unit directly is connected with detecting optical cable or is connected with detecting optical cable through the joints of optical fibre, and two ports of an other side link to each other through optical waveguide.
The function of described reflecting module is and can the reflection of the light in the detecting optical cable be got into detecting optical cable; The rear orientation light that reflection gets into the light generation of detecting optical cable carries out data processing through reflecting module by detecting optical cable entering distributed optical fiber temperature sensing system main frame once more; Finally obtain two groups of data messages of same section detecting optical cable, in order to the attenuation parameter of calibration detecting optical cable.
Described detecting optical cable is laid on field environments such as tunnel, colliery, transformer station, is used to measure ambient temperature; Said detecting optical cable tail end is provided with joints of optical fibre.
When detecting optical cable need be calibrated automatically, can reflecting module be connected to the detecting optical cable tail end through the joints of optical fibre, and the distributed optical fiber temperature sensing system main frame is set to automatic calibration mode.
Comprise parts such as light-pulse generator, wavelength division multiplexer, signal receiving module, signal acquisition module, signal processing module, reference optical fiber in the described distributed optical fiber temperature sensing system main frame.
Light-pulse generator produces pulsed light, and the Raman diffused light dorsad that pulsed light produces in the transmission course of detecting optical cable carries the temperature information at respective place; Wavelength division multiplexer is used for Raman diffused light is dorsad filtered out from other back-scattering lights, and is transported to signal receiving module from corresponding optical interface;
Signal receiving module is in order to the opto-electronic conversion and the amplification of scattered light signal;
Signal acquisition module is used for the simulating signal that signal receiving module transmits is converted into digital signal for subsequent treatment; The synchronization pulse that in addition can also the received pulse light source sends is controlled some other parts in the main frame;
Signal processing module is used for the data that receive are handled and analyzed, and correlation module is controlled and operated;
Reference optical fiber places the distributed optical fiber temperature sensing system main frame inner, and an end connects wavelength division multiplexer, and an end connects detecting optical cable, is used for said non-temperature of calibrating the system of detecting optical cable attenuation parameter automatically in line style is calibrated.
The invention discloses a kind of non-method of calibrating the detecting optical cable attenuation parameter automatically, comprise the following steps: in line style
The first step; Switch the distributed optical fiber temperature sensing system main frame and get into automatic calibration mode, adjustment light-pulse generator repetition frequency is to down half of normal mode; Under the prerequisite of the system of assurance operate as normal; The repetition frequency of light-pulse generator reduces half the, and the recurrence interval is doubled, and makes the measurement length of detecting optical cable be doubled.Because the existence of light reflecting module, for same section detecting optical cable, measure length and double and mean same detecting optical cable is carried out twice data acquisition; Adjust acquisition module simultaneously, its acquisition length is doubled.Data to collecting are carried out the data pre-service, revise because the data distortion problem that receiving circuit causes;
Second step; Respectively to carry out the doubling processing of being divided by through the pretreated Stokes of data and anti-Stokes data; Because the data that under calibration mode, collect are actually twice and obtain through same optical cable, the doubling here requires the data points should be corresponding one by one for this reason, thereby obtains two groups of new data; These two groups of data are relevant with the anti-Stokes attenuation parameter with Stokes respectively, constitute attenuation parameter equation one for this reason; Because the direction of twice excitation light pulse signal entering optical cable is opposite; So the attenuation parameter of symmetric points position (attenuation parameter of certain position is defined as the average attenuation parameter from the optical cable initiating terminal to this position) in fact also is different; But decay (decay factor) sum that two attenuation parameters cause is a fixed value; Equal the total decay of optical cable (the overall attenuation factor), this constitutes attenuation parameter equation two.Above-mentioned two equations of simultaneous can solve the decay factor of each position of optical cable.
In the 3rd step,, just can obtain the Stokes and the anti-Stokes coefficient difference of on-the-spot detecting optical cable, i.e. the system attenuation parameter with the decay factor data of two groups of Stokes that obtain and the anti-Stokes mathematics manipulation of being divided by.This attenuation parameter is revised, eliminated because the differential loss that detecting optical cable brings.
In the 4th step, adjustment light-pulse generator and acquisition module recover normal mode of operation, and the light reflecting module is taken off from detecting optical cable, accomplish the automatic calibration of detecting optical cable attenuation parameter.
Adopt the advantage of technical scheme of the present invention to be: to connect a reflecting module through end at detecting optical cable; And calibrate automatically through control distributed optical fiber temperature sensing system main frame; Thereby can accurately obtain the attenuation parameter of detecting optical cable; The scene of being implemented in is calibrated, is compensated detecting optical cable, has increased effective usage degree of distributed optical fiber temperature sensing system, has improved system performance.
Description of drawings
Fig. 1 embodiment of the invention 1 described system architecture synoptic diagram;
Fig. 2 embodiment of the invention 2 described system architecture synoptic diagram;
Fig. 3 is for being the reflecting module of reflection mode;
Fig. 4 is the reflecting module of coupling scheme;
Fig. 5 is the program flow diagram of calibrating automatically;
Embodiment
Below in conjunction with accompanying drawing automatic calibrating method and the device that is used for distributed optical fiber temperature sensing system of the present invention made detailed description.
Embodiment 1: as shown in Figure 1; A kind of non-system of calibrating the detecting optical cable attenuation parameter in line style automatically; Comprise distributed optical fiber temperature sensing system main frame and detecting optical cable 8, connect a reflecting module 10 at detecting optical cable 8 tail ends, the described reflecting module 10 of present embodiment is a reflective reflection unit; Can be catoptron, plated film device, metal covering or Bragg grating, present embodiment is selected plated film device 11 for use.
Plated film device 11 can get into detecting optical cable 8 with the light reflection of detecting optical cable 8 tail ends; The back scattering that reflection gets into the light generation of detecting optical cable 8 gets into the distributed optical fiber temperature sensing system main frames through reflection unit 10 by detecting optical cable 8 once more; Finally obtain two groups of data messages of same section detecting optical cable 8, in order to the attenuation parameter of calibration detecting optical cable.
Described distributed optical fiber temperature sensing system main frame comprises parts such as light-pulse generator 1, wavelength division multiplexer 2, signal receiving module 3 and signal receiving module 4, signal acquisition module 5, signal processing module 6, reference optical fiber 7.
Light-pulse generator 1 produces pulsed light, and the Raman diffused light dorsad that pulsed light produces in the transmission course of detecting optical cable 8 carries the temperature information at respective place; Wavelength division multiplexer 2 is used for Raman diffused light is dorsad filtered out from other back-scattering lights, and is transported to signal receiving module 3 and signal receiving module 4 from corresponding optical interface; Signal receiving module 3 and signal receiving module 4 are in order to carry out opto-electronic conversion and amplification to the Raman diffused light dorsad that receives; Signal acquisition module 5 is used for the simulating signal that signal receiving module 3 and signal receiving module 4 transmit is converted into digital signal for subsequent treatment; Signal processing module 6 is used for the data that receive are handled and analyzed, and correlation module is controlled and operated; Reference optical fiber 7 places main frame inner, connects detecting optical cable outward, is used for the temperature of system is calibrated.
Non-method of calibrating the detecting optical cable attenuation parameter automatically in line style, as shown in Figure 5, comprise the following steps:
The first step is switched the distributed optical fiber temperature sensing system main frame and is got into automatic calibration mode, and adjustment light-pulse generator 1 repetition frequency to down half of normal mode, is adjusted acquisition module 5 simultaneously, and its acquisition length is doubled.Data to collecting are carried out the data pre-service, revise because the data distortion problem that receiving circuit causes;
Second step; Respectively to carry out the doubling processing of being divided by through the pretreated Stokes of data and anti-Stokes data; Thereby obtain two groups of new data, these two groups of data are relevant with the anti-Stokes attenuation parameter with Stokes respectively, constitute attenuation parameter equation one for this reason; Because the direction of twice excitation light pulse signal entering optical cable is opposite; So the attenuation parameter of symmetric points position in fact also is different; But the decay sum that two attenuation parameters cause is a fixed value, equals the total decay of detecting optical cable, and this constitutes attenuation parameter equation two; Above-mentioned two equations of simultaneous can solve the decay factor of each position of detecting optical cable;
In the 3rd step,, just can obtain the Stokes and the anti-Stokes coefficient difference of on-the-spot detecting optical cable, i.e. the system attenuation parameter with the decay factor data of two groups of Stokes that obtain and the anti-Stokes mathematics manipulation of being divided by.This attenuation parameter is revised, eliminated because the differential loss that detecting optical cable brings;
In the 4th step, adjustment light-pulse generator 1 is recovered normal mode of operation with acquisition module 5, and the light reflecting module is taken off from detecting optical cable, accomplishes the automatic calibration of detecting optical cable attenuation parameter.
Embodiment 2: as shown in Figure 2; A kind of non-system of calibrating the detecting optical cable attenuation parameter automatically in line style comprises distributed optical fiber temperature sensing system main frame and detecting optical cable 8, at the tail end of detecting optical cable 8 joints of optical fibre 9 is set; Reflecting module 10 is connected on the joints of optical fibre 9; The described reflecting module 10 of present embodiment is a reflective reflection unit, can be catoptron, plated film device, metal covering or Bragg grating, and present embodiment is selected catoptron 11 for use.
Catoptron 11 can get into detecting optical cable 8 with the light reflection of detecting optical cable 8 tail ends; The back scattering that reflection gets into the light generation of detecting optical cable 8 gets into the distributed optical fiber temperature sensing system main frames through catoptron 11 by detecting optical cable 8 once more; Finally obtain two groups of data messages of same section detecting optical cable 8, in order to the attenuation parameter of calibration detecting optical cable.
Detecting optical cable 8 is laid on field environments such as tunnel, colliery, transformer station, is used to measure ambient temperature; Detecting optical cable 8 tail ends are provided with joints of optical fibre 9.When detecting optical cable 8 need be calibrated automatically, can reflecting module 10 be connected to detecting optical cable 8 tail ends through the joints of optical fibre 9, and the distributed optical fiber temperature sensing system main frame is set to automatic calibration mode.
The concrete calibrating principle of system and step are with embodiment 1.
1 * 2 coupling mechanism 12 can get into detecting optical cable 8 with the light reflection of detecting optical cable 8 tail ends; The back scattering that reflection gets into the light generation of detecting optical cable 8 gets into the distributed optical fiber temperature sensing system main frames through 1 * 2 coupling mechanism 12 by detecting optical cable 8 once more; Finally obtain two groups of data messages of same section detecting optical cable 8, in order to the attenuation parameter of calibration detecting optical cable.
The concrete calibrating principle of system and step are with embodiment 1.
More than show and describe ultimate principle of the present invention and principal character advantage of the present invention.The technician of the industry should understand the restriction that the present invention does not receive above-mentioned method of application; That describes in above-mentioned method of application and the instructions just says principle of the present invention; The present invention also has various changes and modifications under the prerequisite that does not break away from spirit and scope of the invention, and these variations and improvement all fall into and require the interior requirement protection domain of the present invention of the protection scope of the invention to be defined by appending claims and equivalent thereof.
Claims (8)
1. a non-system of calibrating the detecting optical cable attenuation parameter automatically in line style comprises distributed optical fiber temperature sensing system main frame and detecting optical cable, it is characterized in that: said detecting optical cable tail end connects a smooth reflecting module.
2. non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 1 is characterized in that: said detecting optical cable tail end is provided with joints of optical fibre, connects said smooth reflecting module on the joints of optical fibre.
3. non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 1 and 2 is characterized in that: described smooth reflecting module is the reflection unit with reflected light function.
4. non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 3 is characterized in that: described reflection unit can be catoptron, plated film device, metal covering or Bragg grating.
5. non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 1 and 2 is characterized in that: described smooth reflecting module is the manifold type reflection unit, can be 1 * 2 coupling mechanism, 2 * 2 coupling mechanisms.
6. a kind of non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 1, it is characterized in that: described distributed optical fiber temperature sensing system main frame comprises light-pulse generator, wavelength division multiplexer, signal receiving module, signal acquisition module, signal processing module, reference optical fiber.
7. a kind of non-system of calibrating the detecting optical cable attenuation parameter automatically in line style according to claim 6 is characterized in that: described reference optical fiber one end connects wavelength division multiplexer, and an end connects detecting optical cable.
8. a non-method of calibrating the detecting optical cable attenuation parameter automatically in line style is characterized in that: comprise the steps:
The first step is switched the distributed optical fiber temperature sensing system main frame and is got into automatic calibration mode, and adjustment light-pulse generator repetition frequency to down half of normal mode, is adjusted acquisition module simultaneously, and its acquisition length is doubled.Data to collecting are carried out the data pre-service, revise because the data distortion problem that receiving circuit causes;
Second step; Respectively to carry out the doubling processing of being divided by through the pretreated Stokes of data and anti-Stokes data; Thereby obtain two groups of new data, these two groups of data are relevant with the anti-Stokes attenuation parameter with Stokes respectively, constitute attenuation parameter equation one for this reason; Because the direction of twice excitation light pulse signal entering optical cable is opposite; So the attenuation parameter of symmetric points position in fact also is different; But the decay sum that two attenuation parameters cause is a fixed value, equals the total decay of detecting optical cable, and this constitutes attenuation parameter equation two; Above-mentioned two equations of simultaneous can solve the decay factor of each position of detecting optical cable;
In the 3rd step,, just can obtain the Stokes and the anti-Stokes coefficient difference of on-the-spot detecting optical cable, i.e. the system attenuation parameter with the decay factor data of two groups of Stokes that obtain and the anti-Stokes mathematics manipulation of being divided by.This attenuation parameter is revised, eliminated because the differential loss that detecting optical cable brings; In the 4th step, adjustment light-pulse generator and acquisition module recover normal mode of operation, and the light reflecting module is taken off from detecting optical cable, accomplish the automatic calibration of detecting optical cable attenuation parameter.
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| CN201110140811.8A CN102798487B (en) | 2011-05-27 | Non-line type calibrates the System and method for of detecting optical cable attenuation parameter automatically |
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| CN201110140811.8A CN102798487B (en) | 2011-05-27 | Non-line type calibrates the System and method for of detecting optical cable attenuation parameter automatically |
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| CN103217232A (en) * | 2013-03-27 | 2013-07-24 | 深圳供电局有限公司 | Automatic calibration method and device for attenuation parameters of detection optical cable |
| CN103364107A (en) * | 2013-07-31 | 2013-10-23 | 北京航空航天大学 | Optical fiber Raman cable temperature monitoring and alarm system with attenuation self-compensation |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102980683A (en) * | 2012-11-22 | 2013-03-20 | 威海北洋电气集团股份有限公司 | Pulse coding self-correction distributed optical fiber temperature sensor, temperature measurement device and temperature method |
| CN103217232A (en) * | 2013-03-27 | 2013-07-24 | 深圳供电局有限公司 | Automatic calibration method and device for attenuation parameters of detection optical cable |
| CN103364107A (en) * | 2013-07-31 | 2013-10-23 | 北京航空航天大学 | Optical fiber Raman cable temperature monitoring and alarm system with attenuation self-compensation |
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Inventor after: Wang Zhanfeng Inventor after: Zhang Lili Inventor after: Long Yi Inventor after: Mao Lijuan Inventor after: Guo Zhaokun Inventor before: Guo Zhaokun |
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