CN111289142B - Signal adaptive interference cancellation method for distributed optical fiber Raman temperature measurement system - Google Patents
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Abstract
The invention relates to a signal self-adaptive trunk of a distributed optical fiber Raman temperature measurement systemA method of interference cancellation comprising the steps of: determining the number N of Raman Stokes and Raman anti-Stokes signal sequence pointsSAnd NasAnd signal strength Vs(n) and Vas(n); calculating the input Raman Stokes Signal Vs(n) comparing the output response of the adaptive filter Y (n) with the Raman anti-Stokes signal Vas(n) generating a noise filtered Raman anti-Stokes signal Uas(n); the self-adaptive filter filters the Raman anti-Stokes signal U according to the filtered noiseasAnd (n) automatically adjusting the weight w (n) of the filter, and continuously performing iterative computation until the filtered Raman anti-Stokes signal is obtained. The method adopts the self-adaptive interference cancellation technology to process the Raman anti-Stokes signals, and can simultaneously improve the temperature measurement precision and the spatial resolution of the system without upgrading the hardware of the conventional temperature measurement system.
Description
Technical Field
The invention relates to the field of distributed optical fiber temperature sensing, in particular to a signal adaptive interference cancellation method for a distributed optical fiber Raman temperature measurement system.
Background
A Distributed Optical Fiber Raman Temperature sensing System (dofsrts) is a novel sensing technology that can be used for Distributed and real-time measurement of spatial Temperature field distribution. The technology uses common optical fibers as sensitive media and transmission media, utilizes the spontaneous Raman scattering effect and the optical time domain reflection technology in the optical fibers, can realize distributed measurement and positioning of long-distance transmission, and is widely applied to the field of long-distance temperature measurement of lakes, rivers, dams, glaciers and the like.
At present, the sensing system is limited by factors such as laser pulse width, photoelectric module bandwidth and data acquisition rate, and the spatial resolution is generally not high on the premise of ensuring the measurement accuracy of the system. However, in many practical applications, such as measuring the temperature distribution of the air-snow interface on glaciers or the temperature distribution of the lake water and air interface in lakes, the requirement for the spatial resolution of temperature measurement is high, so that it is of great significance to improve the spatial resolution of the distributed optical fiber temperature measurement system on the basis of the existing system.
The traditional solution is to improve the hardware performance of the system: liu et al (Design and implementation of distributed ultra-high temperature sensing system with a single crystal fiber, Journal of Lightwave Technology,2018,36(23): 5511-; wang et al (FPGA IP Cores of Current Filter for OTDR-distributed Fiber optical Sensors, Cybernetics Robotics and Control (CRC) 20172 nd International Conference on, pp.121-125,2017) reported a method for achieving higher sampling rates using a four-channel data acquisition system. However, the above method is complex in system, high in cost and difficult to popularize and apply.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a signal adaptive interference cancellation method for a distributed optical fiber raman temperature measurement system, aiming at the above defects in the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows: a signal self-adaptive interference cancellation method of a distributed optical fiber Raman temperature measurement system is constructed, and comprises the following steps:
the first step is as follows: synchronously acquiring Raman Stokes signals and Raman anti-Stokes signals of the same optical fiber length in the distributed optical fiber Raman temperature measurement system, and respectively determining the number N of sequence points of the Raman Stokes signals and the Raman anti-Stokes signalsSAnd NasAnd signal strength Vs(n) and Vas(n)；
The second step is that: filtering the raman anti-stokes signal; selecting pullRaman Stokes light signal as noise source, Raman anti-Stokes light signal as signal source, Raman Stokes signal Vs(n) calculating the output response y (n) when inputting an adaptive filter; and comparing the output response Y (n) with the Raman Stokes signal Vas(n) generating a noise filtered Raman Stokes signal Uas(n)；
The third step: a self-adaptive process; according to Raman anti-Stokes signal U after noise filteringas(n) adjusting the weight w (n) of the filter, and continuously performing iterative computation until a Raman anti-Stokes signal after adaptive filtering optimization is obtained;
the calculation formula for updating the weight value by the adaptive filter is as follows:
w(n+1)＝w(n)+k(n)×Uas(n)×Vs(n)
wherein k (n) ═ α k0e1-n,n＝1,2,3...,NasAlpha is an adjusting factor, the value range is more than or equal to 0.9 and less than or equal to 1, and the fixed step length k0Representing the maximum allowed step size.
Wherein, distributed optical fiber Raman temperature measurement system includes: the device comprises a pulse light source, a wavelength division multiplexer, a photoelectric detector, a sensing optical fiber, a data processing module, a temperature measuring circuit, a sampling module, a digital signal processing module and an upper computer; the pulse light source outputs pulse light signals to the wavelength division multiplexer; the wavelength division multiplexer outputs optical signals to access the sensing optical fiber, and the reflected light of the sensing optical fiber is accessed to the wavelength division multiplexer; the reflected light output by the wavelength division multiplexer is connected into a photoelectric detector; the output of the photoelectric detector is connected to a data processing module, the sampling module samples the reflected light signals, and the reflected light signals are subjected to multiple accumulation average preprocessing during sampling and then are sent to a digital signal processing module for filtering processing; meanwhile, the temperature measuring circuit measures environmental temperature information and sends the environmental temperature information to the upper computer, and the temperature information distributed along the optical fiber is demodulated and displayed in the upper computer.
Wherein the step gain α e1-nComprising: at the beginning of the case α e1-nApproaching to 1; as the adaptive filter slowly approaches the useful signal, α e1-nApproaching 0.
Is distinguished from the presentIn the prior art, the signal adaptive interference cancellation method for the distributed optical fiber Raman temperature measurement system provided by the invention comprises the following steps: determining the number N of Raman Stokes and Raman anti-Stokes signal sequence pointsSAnd NasAnd signal strength Vs(n) and Vas(n); calculating the input Raman Stokes Signal Vs(n) comparing the output response of the adaptive filter Y (n) with the Raman anti-Stokes signal Vas(n) generating a noise filtered Raman anti-Stokes signal Uas(n); the self-adaptive filter filters the Raman anti-Stokes signal U according to the filtered noiseasAnd (n) automatically adjusting the weight w (n) of the filter, and continuously performing iterative computation until the filtered Raman anti-Stokes signal is obtained. The method adopts the self-adaptive interference cancellation technology to process the Raman anti-Stokes signals, and can simultaneously improve the temperature measurement precision and the spatial resolution of the system without upgrading the hardware of the conventional temperature measurement system.
Drawings
The invention will be further described with reference to the accompanying drawings and examples, in which:
fig. 1 is a schematic structural diagram of a distributed fiber raman temperature measurement system in a signal adaptive interference cancellation method for the distributed fiber raman temperature measurement system according to the present invention.
Fig. 2 is a schematic diagram illustrating a principle of a signal adaptive interference cancellation method of a distributed optical fiber raman temperature measurement system according to the present invention.
Fig. 3 is a schematic flow chart of a signal adaptive interference cancellation method for a distributed fiber raman temperature measurement system according to the present invention.
Detailed Description
For a more clear understanding of the technical features, objects and effects of the present invention, embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
The invention provides a signal self-adaptive interference cancellation method for a distributed optical fiber Raman temperature measurement system, which comprises the following steps:
the first step is as follows: in the synchronous acquisition distributed optical fiber Raman temperature measurement systemRespectively determining the number N of the sequence points of the Raman Stokes signal and the Raman anti-Stokes signal of the same optical fiber lengthSAnd NasAnd signal strength Vs(n) and Vas(n)；
The second step is that: filtering the raman anti-stokes signal; selecting a Raman Stokes light signal as a noise source, a Raman anti-Stokes light signal as a signal source, and a Raman Stokes signal Vs(n) calculating the output response y (n) when inputting an adaptive filter; and comparing the output response Y (n) with the Raman Stokes signal Vas(n) generating a noise filtered Raman Stokes signal Uas(n)；
The third step: a self-adaptive process; according to Raman anti-Stokes signal U after noise filteringas(n) adjusting the weight w (n) of the filter, and continuously performing iterative computation until a Raman anti-Stokes signal after adaptive filtering optimization is obtained;
the calculation formula for updating the weight value by the adaptive filter is as follows:
w(n+1)＝w(n)+k(n)×Uas(n)×Vs(n)
wherein k (n) ═ α k0e1-n,n＝1,2,3...,NasAlpha is an adjusting factor, the value range is more than or equal to 0.9 and less than or equal to 1, and the fixed step length k0Representing the maximum allowed step size.
Wherein the step gain α e1-nComprising: at the beginning of the case α e1-nApproaching to 1; as the adaptive filter slowly approaches the useful signal, α e1-nApproaching 0.
Fig. 1 is a schematic structural diagram of a distributed optical fiber raman temperature measurement system according to an embodiment of the present invention, and the distributed optical fiber raman temperature measurement system according to the embodiment of the present invention includes a pulse light source 1, a wavelength division multiplexer 2, a photodetector 4, a sensing optical fiber 3, a data processing module 6, a temperature measurement circuit 5, and an upper computer 9. The connection of each part is as follows:
the pulse light source 1 outputs pulse light signals to access the wavelength division multiplexer 2; the wavelength division multiplexer 2 outputs optical signals to access the sensing optical fiber 3, and the reflected light of the sensing optical fiber 3 is accessed to the wavelength division multiplexer 2; the reflected light output by the wavelength division multiplexer 2 is connected to the photoelectric detector 4; the output of the photoelectric detector 4 is connected to the data processing module 6, the sampling module 7 samples the reflected light signal, and the reflected light signal is subjected to multiple accumulation average preprocessing during sampling and then is sent to the digital signal processing module 8 for filtering processing. Meanwhile, the temperature measuring circuit 5 measures environmental temperature information and sends the environmental temperature information to the upper computer 9, and the temperature information distributed along the optical fiber is demodulated and displayed in the upper computer 9.
The performance parameters of each key device in the distributed optical fiber Raman temperature measurement system are shown in the following table.
Fig. 2 is a schematic diagram illustrating an adaptive interference cancellation technique according to an embodiment of the present invention. Raman anti-stokes signal Vas(n) is the sum of the temperature signal and noise, i.e. Vas(n)＝Vas'(N) + N (N), and the input to the adaptive processor is another noise N' (N) associated with N (N). The adaptive processor adjusts the parameters so that N' (N) becomes the best estimate of N (N)
Thus, Uas(n) will approximate a Raman anti-Stokes signal Vas' (n) and its mean square value E [ U ]as 2(n)]To a minimum, the noise n (n) is suppressed.
Fig. 3 shows a signal adaptive interference cancellation method for a distributed fiber raman temperature measurement system according to an embodiment of the present invention: synchronously acquiring a Raman Stokes signal and a Raman anti-Stokes signal at a temperature T to be measured, wherein the Raman Stokes signal and the Raman anti-Stokes signal are respectively: the number of Raman Stokes signals is NSSignal intensity of VS(T,n),n＝1,2,3...,NSAnd the number of Raman anti-Stokes signals is NasSignal intensity of Vas(T,n),n＝1,2,3...,NasAnd normal temperature T0Raman Stokes signal and Raman anti-Stokes signal at: the number of Raman Stokes signals is NS0Signal intensity of VS(T0,n),n＝1,2,3...,NS0And the number of Raman anti-Stokes signals is Nas0Signal intensity of Vas0(T0,n),n＝1,2,3...,Nas0(ii) a Demodulating corresponding temperatures T (n) at different distances by using a single-path demodulation method based on Raman anti-Stokes, wherein the self-adaptive interference cancellation method comprises the following steps:
the first step is as follows: calculating input Raman Stokes signal V at temperature T to be measuredsOutput response Y (T, n) of adaptive filter at (T, n) and normal temperature T0Lower input raman stokes signal Vs(T0N) output response of the adaptive filter Y (T)0,n)：
Y(T,n)＝wH(T,n)×Vs(T,n)
Y(T0,n)＝wH(T0,n)×Vs(T0,n)
The second step is that: by comparing the output responses Y (T, n), Y (T)0N) and Raman anti-Stokes signal Vas(T,n)、Vas(T0N) generating a Raman anti-Stokes signal U after noise filteringas(T, n) and Uas(T0,n)：
Uas(T,n)＝Vas(T,n)-Y(T,n)
Uas(T0,n)＝Vas(T0,n)-Y(T0,n)
The third step: according to Raman anti-Stokes signal U after noise filteringas(T,n)、Uas(T0N) self-adjusting self-weight w (T, n) and w (T) of self-adaptive filter0,n)：
w(T,n+1)＝w(T,n)+k(n)×Uas(T,n)×Vs(T,n)
k(n)＝αk0e1-n,n＝1,2,3,...,Nas
w(T0,n+1)＝w(T0,n)+k0(n)×Uas(T0,n)×Vs(T0,n)
k0(n)＝α0k0e1-n,n＝1,2,3,...,Nas0
Wherein, alpha0The value range of alpha is more than or equal to 0.9 and less than or equal to 1 and more than or equal to 0.9 and less than or equal to alpha for adjusting the factor0Less than or equal to 1; fixed step k0Representing the maximum allowed step size.
The fourth step: and returning to the second step for iteration until all the filter weights are calculated.
The fifth step: obtaining the output sequence Y (T, n) and Y (T) of the optimal time filter0,n)：
Y(T,n)＝wH(T,n)×Vs(T,n)
Y(T0,n)＝wH(T0,n)×Vs(T0,n)
And a sixth step: calculating a filtered Raman anti-Stokes signal Uas(T,n)、Uas(T0,n)：
Uas(T,n)＝Vas(T,n)-Y(T,n)
Uas(T0,n)＝Vas(T0,n)-Y(T0,n)
Uas(T,n)、Uas(T0And n) is the Raman anti-Stokes signal after the self-adaptive filtering.
The seventh step: raman anti-stokes single-pass temperature demodulation. The temperature demodulation formula is as follows:
wherein h is Planck constant, h is 6.63 × 10-34J.s, respectively; Δ v is raman shift, and in a silica fiber, Δ v is 1.32 × 1013Hz; k is Boltzmann constant, k is 1.38 × 10-23J/K；T0Is normal temperature and has a unit of Kelvin; u shapeas(T, n) and Uas(T0N) is the temperature T to be demodulated and the temperature T at normal temperature0The voltage strength of the raman anti-stokes signal.
By obtaining Raman anti-Stokes signalsVoltage strength Uas(T,n)、Uas(T0N) and ambient temperature T0(n), the temperature T (n) of each segment of the optical fiber can be obtained from the above formula.
Eighth step: and (6) positioning. When an incident laser pulse is transmitted through the fiber, backscattered light generated at points along the fiber is transmitted back to the incident end of the fiber. The total time from the emission of the pulse to the return can be expressed as
Wherein, F is the sampling frequency of the sampling module; the distance between the position of the scattering in the fiber and the laser incidence end can be expressed as:
wherein c represents the speed of light in vacuum and is 3X 108m/s，neffRepresenting the effective refractive index in the fiber.
The distance from each scattering point to the head end of the optical fiber can be calculated by measuring the flight time of the optical pulse in the optical fiber, and the temperature information measurement and positioning of each point along the whole optical fiber are realized by combining the temperature-sensitive characteristic of Raman anti-Stokes scattering light.
Different from the prior art, the signal adaptive interference cancellation method for the distributed optical fiber Raman temperature measurement system provided by the invention comprises the following steps: determining the number N of Raman Stokes and Raman anti-Stokes signal sequence pointsSAnd NasAnd signal strength Vs(n) and Vas(n); calculating the input Raman Stokes Signal Vs(n) comparing the output response of the adaptive filter Y (n) with the Raman anti-Stokes signal Vas(n) generating a noise filtered Raman anti-Stokes signal Uas(n); the self-adaptive filter filters the Raman anti-Stokes signal U according to the filtered noiseasAnd (n) automatically adjusting the weight w (n) of the filter, and continuously performing iterative computation until the filtered Raman anti-Stokes signal is obtained. The method adopts self-adaptive interference cancellation technology to perform Raman reflectionThe Stokes signal is processed, so that the temperature measurement precision and the spatial resolution of the system can be improved simultaneously without hardware upgrading of the conventional temperature measurement system.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (3)
1. A signal adaptive interference cancellation method for a distributed optical fiber Raman temperature measurement system is characterized by comprising the following steps:
the first step is as follows: synchronously acquiring Raman Stokes signals and Raman anti-Stokes signals of the same optical fiber length in the distributed optical fiber Raman temperature measurement system, and respectively determining the number of sequence points of the Raman Stokes signals and the Raman anti-Stokes signals
And signal strength
；
The second step is that: filtering the raman anti-stokes signal; selecting Raman Stokes light signals as a noise source, Raman anti-Stokes light signals as a signal source and Raman Stokes signals
Computing output response when inputting an adaptive filter
(ii) a And comparing the output responses
And RamanInverse directionStokes signal
Generating noise filtered RamanInverse directionStokes signal
；
The third step: a self-adaptive process; according to Raman anti-Stokes signals after noise filtering
Adjusting the weight of the filter
Continuously carrying out iterative computation until a Raman anti-Stokes signal after adaptive filtering optimization is obtained;
the calculation formula for updating the weight value by the adaptive filter is as follows:
wherein,
，
for adjusting the factor, the value range is
Fixed step length
Representing the maximum allowed step size.
2. The signal adaptive interference cancellation method for the distributed optical fiber Raman temperature measurement system according to claim 1, wherein the distributed optical fiber Raman temperature measurement system comprises: the device comprises a pulse light source (1), a wavelength division multiplexer (2), a photoelectric detector (4), a sensing optical fiber (3), a data processing module (6), a temperature measuring circuit (5), a sampling module (7), a digital signal processing module (8) and an upper computer (9); wherein, the pulse light source (1) outputs pulse light signals to be connected to the wavelength division multiplexer (2); the wavelength division multiplexer (2) outputs optical signals to be accessed into the sensing optical fiber (3), and reflected light of the sensing optical fiber (3) is accessed into the wavelength division multiplexer (2); the reflected light output by the wavelength division multiplexer (2) is connected into a photoelectric detector (4); the output of the photoelectric detector (4) is connected to a data processing module (6), a sampling module (7) samples the reflected light signal, and the reflected light signal is subjected to multiple accumulation average preprocessing during sampling and then is sent to a digital signal processing module (8) for filtering processing; meanwhile, the ambient temperature information measured by the temperature measuring circuit (5) is also sent to the upper computer (9), and the temperature information distributed along the optical fiber is demodulated and displayed in the upper computer (9).
3. The signal adaptive interference cancellation method for the distributed optical fiber Raman temperature measurement system according to claim 1, wherein the step gain is
Comprising: at the beginning
Approaching to 1; as the adaptive filter slowly approaches the useful signal,
approaching 0.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101943615A (en) * | 2010-09-29 | 2011-01-12 | 山东大学 | Temperature measuring device and method based on Raman light reflection |
| CN104596670A (en) * | 2015-02-05 | 2015-05-06 | 吉林大学 | Method for solving temperature drift of distributed optical fiber Raman temperature sensing system |
| CN104864979A (en) * | 2015-06-16 | 2015-08-26 | 北京航天易联科技发展有限公司 | Correction method of errors measured by distributed raman optical fiber temperature measuring system |
| CN106404016A (en) * | 2016-08-29 | 2017-02-15 | 深圳艾瑞斯通技术有限公司 | Fiber sampling signal filtering method and device and fiber sensing system |
| CN106505974A (en) * | 2016-09-20 | 2017-03-15 | 深圳艾瑞斯通技术有限公司 | The filtering method and device of Optical fibre sampling signal, optical fiber temperature-measurement method and device |
| CN209605977U (en) * | 2019-01-02 | 2019-11-08 | 山西天然气有限公司 | A kind of temperature-measuring system of distributed fibers containing auto-adaptive filter circuit |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013092388A (en) * | 2011-10-24 | 2013-05-16 | Yokogawa Electric Corp | Fiber temperature distribution measurement device |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101943615A (en) * | 2010-09-29 | 2011-01-12 | 山东大学 | Temperature measuring device and method based on Raman light reflection |
| CN104596670A (en) * | 2015-02-05 | 2015-05-06 | 吉林大学 | Method for solving temperature drift of distributed optical fiber Raman temperature sensing system |
| CN104864979A (en) * | 2015-06-16 | 2015-08-26 | 北京航天易联科技发展有限公司 | Correction method of errors measured by distributed raman optical fiber temperature measuring system |
| CN106404016A (en) * | 2016-08-29 | 2017-02-15 | 深圳艾瑞斯通技术有限公司 | Fiber sampling signal filtering method and device and fiber sensing system |
| CN106505974A (en) * | 2016-09-20 | 2017-03-15 | 深圳艾瑞斯通技术有限公司 | The filtering method and device of Optical fibre sampling signal, optical fiber temperature-measurement method and device |
| CN209605977U (en) * | 2019-01-02 | 2019-11-08 | 山西天然气有限公司 | A kind of temperature-measuring system of distributed fibers containing auto-adaptive filter circuit |
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