CN104596558A - Self-adaptation gain equalization type distributed optical fiber sensing optical signal receiving method and device - Google Patents

Abstract

The invention discloses a self-adaptation gain equalization type distributed optical fiber sensing optical signal receiving method and device. The self-adaptation gain equalization type distributed optical fiber sensing optical signal receiving method and device can automatically adapt to various kinds of optical fibers and various kinds of lasers, and have the disturbance distinguishing function, the influence caused by sensing information on system parameter control is eliminated, the inherent offset output by a pre-amplifier can be eliminated, slow drifting of the pre-amplifier can be compensated for, the automatic gain equalization function of a distributed optical fiber sensing system is fulfilled, the spatial dynamic range of the system is enlarged, uniformity of flexibility within the spatial range is guaranteed, and the self-adaptation gain equalization type distributed optical fiber sensing optical signal receiving method and device have high adaptability and stability.

Description

Adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance and device

Technical field

The present invention is a kind of adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance and device, relates to technical field of optical fiber measurement and signal transacting field.

Background technology

Distributing optical fiber sensing is the technology utilizing the one-dimensional space continuation property of optical fiber to carry out sensing.Optical fiber both made sensing element, made transfer element again, can carry out continuous coverage, obtain measured space distribution state and time dependent information simultaneously on whole fiber lengths to the environmental parameter along fiber distribution.Because the phase place of the light propagated in a fiber, intensity and polarization state can be subject to the physical field around optical fiber, such as, the impact of temperature, pressure, vibration etc., by detecting the parameter of light, can restore these physical quantitys.This technology is all widely used and wide prospect in every field such as circumference security protection, Aero-Space, shipping industry, power industry, petrochemical industry and medical science.

Distributed Optical Fiber Sensing Techniques needs to receive faint backscattering light signal and process.Traditional disposal route or sensor measuring distance, can reach tens kilometers, but spatial resolution is lower; Spatial resolution is higher, can reach 5 ~ 10 meters, but sensor measuring scope only 1 ~ 2 kilometer.Cause the reason of this problem to be because laser transmits in light, its intensity is along with the decay of distance exponentially, and distance is longer, and light is also more weak.And the light that back-scattering light transmits than forward is much smaller, cause the luminous energy that receives at receiving end very little.In order to strengthen the energy of laser pulse, its pulsewidth can be increased, but just sacrifice resolution and sensitivity like this.

In order to address this problem, improve detection range and the sensitivity of distributing optical fiber sensing, the employing temporal gain had in the industry controls the method (as " CN200810024484.8 wide-field full-optical fiber perturbance locating signal time gain control device ") of (TGC), allow the gain of photoreceiver along with the increase of time index increase, thus realize the equilibrium of the back-scattering light of exponentially decaying is amplified; Signal intensity compares with predetermined threshold value by some employings, overflow then reduces enlargement factor, and signal gets too small then increases the auto gain control method (as " CN201110286454.6 wide-field full-optical fiber sensor system continuous wave self-adaptation great dynamic range signal processing method ") of enlargement factor.

But these methods are not eliminated the direct current biasing of electrooptical device output signal.DC-offset correction does not just carry out temporal gain control, and DC voltage can be made also to be amplified by index, cause rear class operational amplifier or analog to digital converter saturated, light heat transfer agent is submerged.DC-offset correction does not just carry out automatic growth control, and DC offset voltage can be caused also to be counted into signal intensity, gain is controlled incorrect, loss dynamic range.In addition, these methods do not consider system real work, the backscattering on optical fiber only modulate by ambient conditions, be not the signal of clean exponential damping, but the superposition of Damped exponential signals and disturbing signal.In order to gain balance, need to extract the mathematic parameter of Damped exponential signals.Only under the prerequisite not having disturbing signal, the extraction of mathematic parameter is only accurately.These methods do not consider the impact that disturbing signal controls gain balance.

Summary of the invention

Technical matters: the invention provides and a kind ofly can automatically adapt to dissimilar optical fiber and laser instrument, there is disturbance discrimination function, eliminate the impact that heat transfer agent controls systematic parameter, the intrinsic biased adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance that also can compensate its slow drift that prime amplifier exports can be eliminated.The present invention provides a kind of adaptive gain balanced type distributing optical fiber sensing light signal receiving realizing said method simultaneously.The present invention realizes the Gain Automatic equalization function of distributed optical fiber sensing system, has expanded the spatial dynamic range of system, ensure that the homogeneity of sensitivity in spatial dimension, has high-adaptability and stability simultaneously.

Technical scheme: adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance of the present invention, comprises the following steps:

1) prime amplifier export after amplifying primary light electric signal shape as shown in the formula electric signal F _i(t):

$F_i\left(t\right)=A_i{e}^{-B_{i}t}+D_i\left(t\right)e^{-B_{i}t}+C_i$

Wherein, exponential part for the deamplification of back-scattering light during undisturbed itself, C _ifor DC offset voltage, D _it () is disturbance superposed signal, i is the sequence number that laser pulse sends the cycle, and t is the timing in the laser pulse transmission cycle, A _ifor the initial strength of light signal received, B _ifor index optical fiber decay factor, A _iand B _isize and the model of optical fiber, the wavelength of laser relevant with power;

2) by described electric signal F _it () inputs to main amplifier, be amplified signal G _i(t) be:

$G_i\left(t\right)={\mathrm{kA}}_i{e}^{-B_{i}t}+{\mathrm{kD}}_i\left(t\right)e^{-B_{i}t}+{\mathrm{kC}}_i$

Wherein, k is main amplifier enlargement factor;

3) by described amplifying signal G _it () inputs the in-phase input end of the first analog to digital converter and subtracter simultaneously, and by bias correction signal C ' _ithe inverting input of input subtracter, obtains subtracter output signal I according to following formula _i(t):

$I_i\left(t\right)=k{A}_i{e}^{-B_{i}t}+k{D}_i\left(t\right)e^{-B_{i}t}+k{C}_i-C_i^{\′};$

Wherein, described bias correction signal C ' _iexported by the first digital to analog converter by proportional integral (PI) controller;

4) by the signal input part of the controlled operational amplifier of described subtracter output signal input gain, the initial strength A ' of the light signal simultaneously parameter extraction module extracted _iwith index optical fiber decay factor B ' _ithe gain-controlled voltage input end of the controlled operational amplifier of input gain, then outputs signal J by the output of gain controllable operational amplifier after analog to digital conversion after treatment _i(t):

$J_i\left(t\right)=\mathrm{gk}(1+\frac{D_i\left(t\right)}{A_i^{\′}})+{\mathrm{\Δ}}_i\left(t\right)$

Wherein a ' _ithe initial strength of the light signal that parameter extraction module is extracted, B ' _ibe the index optical fiber decay factor that parameter extraction module is extracted, g is the gain of gain controllable operational amplifier when control voltage is 0.

In the preferred version of the inventive method, step 3) in bias correction signal C ' _idetermine according to following methods:

31) the output signal J of the gain controllable operational amplifier in a upper cycle that will collect of the second analog to digital converter _i-1t () delivers to biased extraction module and disturbance discrimination module; Disturbance discrimination module is according to following rule judgment signal J _i-1whether disturbance information is there is in (t):

If there is t ∈ (0, T), make then signal J _i-1there is disturbance information in (t), otherwise there is not disturbance information;

Wherein T is that laser pulse sends the cycle;

Regulation is as signal J simultaneously _i-1t when there is disturbance information in (), disturbance discrimination module exports 0, when there is not disturbance information, disturbance discrimination module exports 1, and namely disturbance discrimination module output signal is determined by following formula:

$K_{i-1}=\left\{\begin{array}{c}0,\&Exists;t\&Element;(0,T),\left|\frac{{\mathrm{dJ}}_{i-1}\left(t\right)}{\mathrm{dt}}\right|\&GreaterEqual;\mathrm{\&epsiv;}\\ 1,\&Exists;t\&Element;(0,T),\left|\frac{{\mathrm{dJ}}_{i-1}\left(t\right)}{\mathrm{dt}}\right|<\mathrm{\&epsiv;}\end{array}\right.$

Wherein ε is disturbance discrimination threshold;

32) by the gain controllable opamp-output signal J in a upper cycle _i-1the disturbance discrimination module output signal K in (t) and this cycle _i-1input to biased extraction module, at K _i-1when=1, the output C of biased extraction module " _idetermined by following formula:

$C_i^{\&prime;\&prime;}=A_{i-1}^{\&prime;}\frac{J_{i-1}\left(T\right)-J_{i-1}\left(0\right)}{g(e^{B_{i-1}^{\&prime;}T}-1)}$

Wherein T is the cycle of laser pulse;

At K _i-1when=0, then direct the output of extraction module biased in the upper laser pulse cycle was biased the output of extraction module, i.e. C as this cycle " _i=C " _i-1;

33) by the output C of described biased extraction module " _itransport to PI controller, PI controller is by the first digital to analog converter output signal C ' _i, namely have:

C′ _i＝K _PC″ _i+I _i

Wherein K _pfor scale-up factor, I _i=K _itC " _i+ I _i-1, K _ifor integral coefficient, during i=1, I ₀=0.

In the preferred version of the inventive method, step 4) in the initial strength A ' of light signal _iwith index optical fiber decay factor B ' _iextract according to following method:

The digital signal that data averaging module exports according to the first analog to digital converter, under the regulation and control of disturbance discrimination module, the output signal of the main amplifier that the first analog to digital converter in the common N number of laser pulse cycle before the present laser recurrence interval collects is averaged, output signal L _i(t) be:

$L_i\left(t\right)=\frac{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j{G}_j\left(t\right)}{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j}$

Wherein, j is the summation ordinal number from i-N to i-1;

By signal L _it () inputs to parameter extraction module, parameter extraction module is extracted by following formula and obtained parameter:

A′ _i＝L _i(0)/k-C′ _i

$B_i^{\&prime;}=\frac{1}{T}\ln \left(\frac{k{A}_i^{\&prime;}}{L_i\left(T\right)-k{C}_i^{\&prime;}}\right);$

Described step 4) in initial strength A ' to light signal _iwith index optical fiber decay factor B ' _ibe handled as follows after the gain-controlled voltage input end of the controlled operational amplifier of input gain again:

Gain controlling curve generator is according to the initial strength A ' of the described light signal of input _iwith index optical fiber decay factor B ' _i, according to following formula determination gain-controlled voltage U _i(t):

$U_i\left(t\right)=\frac{1}{l}(B_i^{\&prime;}t+\ln \frac{1}{A_i^{\&prime;}})$

Wherein l is the gain scale coefficient of gain controllable operational amplifier;

Finally by described gain-controlled voltage U _it () carries out digital-to-analog conversion.

In the preferred version of the inventive method, in data averaging module: if the output of disturbance discrimination module is 1, then data averaging module calculates output signal L _itime (t), by this cycle of main amplifier amplifying signal G _it () also includes the scope be averaged in, if the output of disturbance discrimination module is 0, then give up this cycle amplifying signal G of main amplifier _it (), the output of data averaging module remains unchanged.

Adaptive gain balanced type distributing optical fiber sensing light signal receiving of the present invention, comprises prime amplifier, main amplifier, the first analog to digital converter, data averaging module, parameter extraction module, gain controlling curve generator, subtracter, gain controllable operational amplifier, the second analog to digital converter, disturbance discrimination module, biased extraction module, proportional integral (PI) controller, the first digital to analog converter, the second digital to analog converter.

The output interface of described prime amplifier is connected with the input interface of main amplifier, the output interface of main amplifier is connected with the input interface of the first analog to digital converter and the in-phase input end mouth of subtracter simultaneously, and the output interface of subtracter is connected with the signal input interface of gain controllable operational amplifier.

The output interface of described first analog to digital converter is connected with the Data Input Interface of data averaging module, the described output interface of data averaging module is connected with the input interface of parameter extraction module, the output interface of described parameter extraction module is connected with the input interface of gain controlling curve generator, the output interface of described gain controlling curve generator is connected with the input interface of the second digital to analog converter, the output interface of described second digital to analog converter is connected with the gain control interface of gain controllable operational amplifier, the output interface of described gain controllable operational amplifier is connected with the input interface of the second analog to digital converter.

The output interface of described second analog to digital converter is connected with the input interface of disturbance discrimination module and the Data Input Interface of biased extraction module simultaneously, the output interface of described disturbance discrimination module is connected with the control interface of data averaging module and the control interface of biased extraction module simultaneously, the output interface of described biased extraction module is connected with the input interface of PI controller, the output interface of described PI controller is connected with the input interface of the first digital to analog converter, and the described output interface of the first digital to analog converter is connected with the inverting input of subtracter.

Beneficial effect: the present invention compared with prior art, has the following advantages:

The present invention is by taking intelligent parameter identification module, analyze the parameter of backscattering light signal, the initial power of light signal and the decay factor in sensor fibre in system can be identified, and pass through the output of ride gain controlling curve generator, the enlargement factor of automatic real-time matching gain controllable operational amplifier, realize signal gain equilibrium to amplify, when elimination light is propagated in a fiber, exponential damping is on the impact of input, the backscatter signals of gain exponentially form decay is in time modified to the backscatter signals that gain evenly remains unchanged in time, extend the dynamic range of system, ensure that the sensitivity that sensor fibre is homogeneous along the line, simultaneously, simplify follow-up signal processing procedure.

In order to eliminate the impact of vibration signal on parameter identification, the present invention proposes disturbance discrimination module, being only averaged and parameter extraction to the optical fiber backscatter signals not being loaded with vibration signal, Obtaining Accurate correlation parameter, the precise equalization realizing gain amplifies.

The output signal of commercially available Optical Receivers is all with DC offset voltage, and the direct current biasing of different Optical Receivers is different, and slowly drift occurs in the impact that its DC offset voltage exported can be subject to working environment.If directly amplified the light signal being superimposed with direct current biasing or balanced amplification, DC offset voltage can be caused also to be exaggerated, to limit the dynamic range of system, cannot remote recording be realized.In addition, for exponential type gain equalizing method, because enlargement factor is exponential increase in time, the signal after amplification increases rapidly, reaches capacity, and cannot detect the transducing signal of sensor fibre second half section.The present invention, by biased extraction module, PI controller, subtracter, can detect the bias voltage of different Optical Receivers exactly, and can eliminate the bias voltage of Optical Receivers in real time, controls to lay a good foundation for realizing reliable and stable gain balance.Meanwhile, the structure due to biased extraction and elimination is a closed loop, adopts PI control algolithm, can the slow drift of output offset voltage of auto-compensation Optical Receivers, improves the stability of system.

Accompanying drawing explanation

Fig. 1 is circuit frame figure of the present invention;

Fig. 2 is the circuit diagram of prime amplifier;

Fig. 3 is the circuit diagram of main amplifier;

Fig. 4 is the circuit diagram of subtracter;

Fig. 5 is the circuit diagram of gain controllable operational amplifier;

Fig. 6 is the circuit diagram of the first digital to analog converter;

Fig. 7 is the circuit diagram of the second digital to analog converter;

Fig. 8 is the circuit diagram of the first analog to digital converter;

Fig. 9 is the circuit diagram of the second analog to digital converter;

Figure 10 is the hardware circuit diagram of the I/O BANK0 of field programmable gate array (FPGA);

Figure 11 is the hardware circuit diagram of the I/O BANK1 of field programmable gate array (FPGA);

Figure 12 is the hardware circuit diagram of the I/O BANK2 of field programmable gate array (FPGA);

Figure 13 is the hardware circuit diagram of the I/O BANK3 of field programmable gate array (FPGA);

Figure 14 is the hardware circuit diagram of the I/O BANK4 of field programmable gate array (FPGA);

Figure 15 is the hardware circuit diagram of the I/O BANK5 of field programmable gate array (FPGA);

Figure 16 is the power interface hardware circuit diagram of field programmable gate array (FPGA);

Figure 17 is the ground interface hardware circuit diagram of field programmable gate array (FPGA);

Figure 18 is the SFP circuit diagram of field programmable gate array (FPGA);

Figure 19 is the NC interface hardware circuitry figure of field programmable gate array (FPGA);

Figure 20 is the input-output wave shape figure of adaptive gain balanced type distributing optical fiber sensing signal receiving method of the present invention or device;

Figure 21 is adaptive gain balanced type distributing optical fiber sensing signal receiving method of the present invention or the optical fiber of device, the design sketch of laser instrument adaptation function;

Figure 22 is the compensation effect figure of the biased slowly drift of adaptive gain balanced type distributing optical fiber sensing signal receiving method of the present invention or device.

Embodiment

Below in conjunction with embodiment and Figure of description, the present invention is further illustrated.

Embodiment 1

Adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance of the present invention, comprises the following steps:

1) prime amplifier 1 export after amplifying primary light electric signal shape as shown in the formula electric signal F _i(t):

$F_i\left(t\right)=A_i{e}^{-B_{i}t}+D_i\left(t\right)e^{-B_{i}t}+C_i$

Wherein, exponential part for the deamplification of back-scattering light during undisturbed itself, C _ifor DC offset voltage, D _it () is disturbance superposed signal, i is the sequence number that laser pulse sends the cycle, and t is the timing in the laser pulse transmission cycle, A _ifor the initial strength of light signal received, B _ifor index optical fiber decay factor, A _iand B _isize and the model of optical fiber, the wavelength of laser relevant with power;

2) by described electric signal F _it () inputs to main amplifier 2, be amplified signal G _i(t) be:

$G_i\left(t\right)={\mathrm{kA}}_i{e}^{-B_{i}t}+{\mathrm{kD}}_i\left(t\right)e^{-B_{i}t}+{\mathrm{kC}}_i$

Wherein, k is main amplifier enlargement factor;

3) by described amplifying signal G _it the in-phase input end 701 of () input subtracter 7, simultaneously by bias correction signal C ' _ithe inverting input 702 of input subtracter 7, obtains subtracter 7 according to following formula and outputs signal I _i(t):

$I_i\left(t\right)=k{A}_i{e}^{-B_{i}t}+k{D}_i\left(t\right)e^{-B_{i}t}+k{C}_i-C_i^{\&prime;};$

Wherein, described bias correction signal C ' _iexported by the first digital to analog converter 13 by proportional integral (PI) controller 11;

Just described amplifying signal G simultaneously _it () inputs the first analog to digital converter 3;

4) described subtracter 7 is outputed signal the signal input part of the controlled operational amplifier 8 of input gain, the initial strength A ' of the light signal simultaneously parameter extraction module 5 extracted _iwith index optical fiber decay factor B ' _ithe gain-controlled voltage input end of the controlled operational amplifier 8 of input gain, then outputs signal J by the output of gain controllable operational amplifier 8 after 9 analog to digital conversion after treatment _i(t):

$J_i\left(t\right)=\mathrm{gk}(1+\frac{D_i\left(t\right)}{A_i^{\&prime;}})+{\mathrm{\&Delta;}}_i\left(t\right)$

Wherein a ' _ithe initial strength of the light signal that parameter extraction module 5 is extracted, B ' _ibe the index optical fiber decay factor that parameter extraction module 5 is extracted, g is the gain of gain controllable operational amplifier when control voltage is 0.

Described step 3) in bias correction signal C ' _idetermine according to following methods:

31) the output signal J of the gain controllable operational amplifier 8 in a upper cycle that will collect of the second analog to digital converter 9 _i-1t () delivers to biased extraction module 10 and disturbance discrimination module 12; Disturbance discrimination module 12 is according to following rule judgment signal J _i-1whether disturbance information is there is in (t):

If there is t ∈ (0, T), make then signal J _i-1there is disturbance information in (t), otherwise there is not disturbance information;

Wherein T is that laser pulse sends the cycle;

Regulation is as signal J simultaneously _i-1t when there is disturbance information in (), disturbance discrimination module 12 exports 0, when there is not disturbance information, disturbance discrimination module 12 exports 1, and namely disturbance discrimination module output signal is determined by following formula:

$K_{i-1}=\left\{\begin{array}{c}0,\&Exists;t\&Element;(0,T),\left|\frac{{\mathrm{dJ}}_{i-1}\left(t\right)}{\mathrm{dt}}\right|\&GreaterEqual;\mathrm{\&epsiv;}\\ 1,\&Exists;t\&Element;(0,T),\left|\frac{{\mathrm{dJ}}_{i-1}\left(t\right)}{\mathrm{dt}}\right|<\mathrm{\&epsiv;}\end{array}\right.$

Wherein ε is disturbance discrimination threshold;

32) by the gain controllable opamp-output signal J in a upper cycle _i-1the disturbance discrimination module output signal K in (t) and this cycle _i-1input to biased extraction module 10, at K _i-1when=1, the output C of biased extraction module " _idetermined by following formula:

$C_i^{\&prime;\&prime;}=A_{i-1}^{\&prime;}\frac{J_{i-1}\left(T\right)-J_{i-1}\left(0\right)}{g(e^{B_{i-1}^{\&prime;}T}-1)}$

Wherein T is the cycle of laser pulse;

At K _i-1when=0, then direct the output of extraction module biased in the upper laser pulse cycle was biased the output of extraction module, i.e. C as this cycle " _i=C " _i-1;

33) by the output C of described biased extraction module " _itransport to PI controller 11, PI controller 11 and output signal C ' by the first digital to analog converter 13 _i, namely have:

C′ _i＝K _PC″ _i+I _i

Wherein K _pfor scale-up factor, I _i=K _itC " _i+ I _i-1, K _ifor integral coefficient, during i=1, I ₀=0.

Described step 4) in the initial strength A ' of light signal _iwith index optical fiber decay factor B ' _iextract according to following method:

The digital signal that data averaging module 4 exports according to the first analog to digital converter 3, under the regulation and control of disturbance discrimination module 12, the output signal of the main amplifier 2 that the first analog to digital converter 3 in the common N number of laser pulse cycle before the present laser recurrence interval collects is averaged, output signal L _i(t) be:

$L_i\left(t\right)=\frac{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j{G}_j\left(t\right)}{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j}$

Wherein, j is the summation ordinal number between i-N to i-1; N desirable 16,32,64,128,256 etc.;

By signal L _it () inputs to parameter extraction module 5, parameter extraction module 5 is extracted by following formula and obtained parameter:

A′ _i＝L _i(0)/k-C′ _i

$B_i^{\&prime;}=\frac{1}{T}\ln \left(\frac{k{A}_i^{\&prime;}}{L_i\left(T\right)-k{C}_i^{\&prime;}}\right);$

Described step 4) in initial strength A ' to light signal _iwith index optical fiber decay factor B ' _ibe handled as follows after the gain-controlled voltage input end of the controlled operational amplifier 8 of input gain again:

Gain controlling curve generator 6 is according to the initial strength A ' of the described light signal of input _iwith index optical fiber decay factor B ' _i, according to following formula determination gain-controlled voltage U _i(t):

$U_i\left(t\right)=\frac{1}{l}(B_i^{\&prime;}t+\ln \frac{1}{A_i^{\&prime;}})$

Wherein l is the gain scale coefficient of gain controllable operational amplifier;

Finally by described gain-controlled voltage U _it () carries out digital-to-analog conversion.

Described data averaging module has following feature: if the output of disturbance discrimination module 12 is 1, then data averaging module 4 calculates output signal L _itime (t), by this cycle amplifying signal G of main amplifier 2 _it () also includes the scope be averaged in, if the output of disturbance discrimination module 12 is 0, then give up this cycle amplifying signal G of main amplifier 2 _it (), the output of data averaging module 4 remains unchanged.

Embodiment 2

Adaptive gain balanced type distributing optical fiber sensing light signal receiving of the present invention, comprises prime amplifier 1, main amplifier 2, first analog to digital converter 3, data averaging module 4, parameter extraction module 5, gain controlling curve generator 6, subtracter 7, gain controllable operational amplifier 8, second analog to digital converter 9, disturbance discrimination module 12, biased extraction module 10, proportional integral (PI) controller 11, first digital to analog converter 13, second digital to analog converter 14;

The output interface of described prime amplifier 1 is connected with the input interface of main amplifier 2, the output interface of main amplifier 2 is connected with the input interface of the first analog to digital converter 3 and the in-phase input end mouth of subtracter 7 simultaneously, the output interface of subtracter 7 is connected with the signal input interface of gain controllable operational amplifier 8

The described output interface of the first analog to digital converter 3 is connected with the Data Input Interface 401 of data averaging module 4, the output interface of described data averaging module 4 is connected with the input interface of parameter extraction module 5, the output interface of described parameter extraction module 5 is connected with the input interface of gain controlling curve generator 6, the output interface of described gain controlling curve generator 6 is connected with the input interface of the second digital to analog converter 14, the output interface of described second digital to analog converter 14 is connected with the gain control interface of gain controllable operational amplifier 8, the output interface of described gain controllable operational amplifier 8 is connected with the input interface of the second analog to digital converter 9,

The output interface of described second analog to digital converter 9 is connected with the input interface of disturbance discrimination module 12 and the Data Input Interface of biased extraction module 10 simultaneously, the output interface of described disturbance discrimination module 12 is connected with the control interface of data averaging module 4 and the control interface of biased extraction module 10 simultaneously, the output interface of described biased extraction module 10 is connected with the input interface of PI controller 11, the output interface of described PI controller 11 is connected with the input interface of the first digital to analog converter 13, the output interface of described first digital to analog converter 13 is connected with the inverting input of subtracter 7.

In the specific embodiment of adaptive gain balanced type distributing optical fiber sensing light signal receiving of the present invention, prime amplifier comprises photodiode, amplifier A, resistance Rf, the anode of photodiode is connected with the input end of amplifier A, one end of resistance Rf is connected with the input end of amplifier A, and the other end of resistance Rf is connected with the output terminal of amplifier A;

Described main amplifier comprises chip U2, resistance R1, R5, R9, R11, R12.The model of chip U2 is AD8336, R1 resistance is 1k Europe, is potentiometer.R5 resistance is 510 Europe.R9 resistance is 510 Europe.R11 resistance is 100 Europe.R12 resistance is 910 Europe.1 pin of chip U2 is the output terminal of described main amplifier 1, 2 pin of chip U2, 3 pin ground connection, 4 pin of chip U2 are connected with one end of R5, 5 pin of chip U2 and one end of R11 and R12, 8 pin of chip U2 are connected with 9 pin of chip U2, 9 pin of chip U2 are connected with the other end of R12, 10 pin of chip U2 meet negative supply VEE=-5V, 11 pin of chip U2 are connected with the sliding contact of R1, the 12 pin ground connection of chip U2, 13 pin of chip U2 meet positive supply VCC=5V, the other end of R5 is input, be connected with the output terminal of described prime amplifier, one end of R9 is connected with 4 pin of chip, the other end ground connection of R9, the other end ground connection of R11,

Described subtracter comprises chip U4, resistance R2, R3, R6, R8.The model of chip U4 is MAX4104, R2, the resistance of R3, R6, R8 is 4k Europe.2 pin of U4 are connected with one end of R3 with R2,3 pin of U4 are connected with one end of R8 with one end of R6,4 pin of U4 meet negative supply VEE=-5V, 6 pin of U4 are the output terminals of described subtracter, and 6 pin of U4 are connected with the other end of R2, and 7 pin of U4 meet positive supply VCC=5V, the other end ground connection of R8, the other end of R3 is the inverting input of described subtracter, and the other end of R6 is the in-phase input end of subtracter, is connected with the output terminal of described main amplifier;

Described gain controllable operational amplifier comprises chip U3, resistance R4, R7, R10, R13.The model of chip U3 is AD8336, R4, the resistance of R5 is 510 Europe, and the resistance of R10 is 100 Europe, and the resistance of R13 is 910 Europe.1 pin of U3 is the output terminal of described gain controllable operational amplifier, 2 pin of U3,3 pin ground connection, 4 pin of U3 are connected with one end of R4 with R7,5 pin of U3 are connected with one end of R10 with R13,8 pin of U3 are connected with 9 pin of U3, and be connected with the other end of R13,10 pin of U3 meet negative supply VEE=-5V, 11 pin of U3 are the gain control end of described gain controllable operational amplifier, the 12 pin ground connection of U3,13 pin of U3 meet positive supply VCC=5V, and the other end of R4 is the input end of described gain controllable operational amplifier, the other end ground connection of R7, the other end ground connection of R10;

The first described analog to digital converter comprises chip U10, chip U9, resistance R14, R15, R16, R19, the model of R20, described chip U10 is AD8138, and the model of described chip U9 is AD9236, described resistance R14, R15, R16, the resistance of R19 is 499 Europe, the resistance of described resistance R20 is 5k Europe, one end of described resistance R14 is the input end of described first analog to digital converter, the other end of described resistance R14 is connected with 8 pin of described chip U10, one end of described resistance R15 is connected with 8 pin of U10, the other end of R15 is connected with 5 pin of U10, and one end of R19 is connected with 1 pin of U10, the other end of R19 is connected with 4 pin of U10, one end of R16 is connected with 1 pin of U10, the other end ground connection of R16, and 2 pin of U10 connect 1.5V voltage, 3 pin connect 5V voltage, 6 pin connect-5V voltage, and 5 pin are connected with 9 pin of U9, and 4 pin are connected with 10 pin of U9, one end of R20 is connected with 14 pin of U9, the other end ground connection of R20,2 pin of U9 connect 1.5V voltage, 3 of U9, 8, 11, No. 23 pin ground connection, 7 of U9, No. 12 pins connect 3V voltage, and 24 pin of U9 connect 3.3V voltage, 1 of chip U9, 15, 16, 17, 18, 19, 20, 21, 22, 25, 26, 27 and No. 28 pins are as the output interface of the first described analog to digital converter, and 13 pin of chip U9 are the input end of clock mouth of described first analog to digital converter,

The second described analog to digital converter comprises chip U12, chip U11, resistance R21, R22, R23, R26, the model of R27, described chip U12 is AD8138, and the model of described chip U11 is AD9236, described resistance R21, R22, R23, the resistance of R26 is 499 Europe, the resistance of described resistance R27 is 5k Europe, one end of described resistance R21 is the input end of described second analog to digital converter, the other end of described resistance R21 is connected with 8 pin of described chip U12, one end of described resistance R22 is connected with 8 pin of U12, the other end of R22 is connected with 5 pin of U12, and one end of R26 is connected with 1 pin of U12, the other end of R26 is connected with 4 pin of U12, one end of R23 is connected with 1 pin of U12, the other end ground connection of R23, and 2 pin of U12 connect 1.5V voltage, 3 pin connect 5V voltage, 6 pin connect-5V voltage, and 5 pin are connected with 9 pin of U11, and 4 pin are connected with 10 pin of U11, one end of R27 is connected with 14 pin of U11, the other end ground connection of R27,2 pin of U11 connect 1.5V voltage, 3 of U11, 8, 11, No. 23 pin ground connection, 7 of U11, No. 12 pins connect 3V voltage, and 24 pin of U11 connect 3.3V voltage, 1 of chip U11, 15, 16, 17, 18, 19, 20, 21, 22, 25, 26, 27 and No. 28 pins are as the output interface of the second described analog to digital converter, and 13 pin of chip U11 are the input end of clock mouth of described second analog to digital converter,

Described first digital to analog converter comprises chip U6, chip U5, electric capacity DA1, electric capacity C_LF1, resistance R_LF1, resistance DA2, DA3, the model of DA4, U6 is the model of AD5445, U5 is ADA4896-2, and the size of electric capacity DA1 is 2pF, and the size of electric capacity C_LF1 is 2pF, and the size of resistance R_LF1 is 50 Europe, resistance DA2, the size of DA4 is 20k Europe, and the size of resistance DA3 is 10k Europe, and 1 pin of chip U6 is connected with one end of electric capacity DA1, 20 pin of chip U6 are connected with the other end of electric capacity DA1, 1 pin of chip U6 is connected with 2 pin of chip U5, and 20 pin of chip U6 are connected with 1 pin of chip U5,2 of chip U6, 3, No. 16 pin ground connection, 19 pin of chip U6 connect 2.048V voltage, and 18 pin of chip connect 3.3V voltage, 4 of chip U6, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, No. 17 pins are the input port of described first digital to analog converter, 3 of chip U5, No. 5 pin ground connection, 4 pin of chip U5 connect-5V voltage, 8 pin of chip connect+5V voltage, 7 pin of chip are connected with one end of resistance R_LF1 with resistance DA2,6 pin of chip U5 and one end of resistance DA3 and DA4, and the other end of resistance DA2 is connected, another termination 2.048V voltage of resistance DA4, the other end of resistance DA3 is connected with 20 pin of chip U6, the other end of resistance R_LF1 is connected with one end of electric capacity C_LF1, the other end ground connection of electric capacity C_LF1, one end of electric capacity C_LF1 is the output port of described first digital to analog converter,

Described second digital to analog converter comprises chip U8, chip U7, electric capacity DA5, electric capacity C_LF2, resistance R_LF2, resistance DA6, DA7, the model of DA8, U8 is the model of AD5445, U7 is ADA4896-2, and the size of electric capacity DA5 is 2pF, and the size of electric capacity C_LF2 is 2pF, and the size of resistance R_LF2 is 50 Europe, resistance DA6, the size of DA8 is 20k Europe, and the size of resistance DA7 is 10k Europe, and 1 pin of chip U8 is connected with one end of electric capacity DA5, 20 pin of chip U8 are connected with the other end of electric capacity DA5, 1 pin of chip U8 is connected with 2 pin of chip U7, and 20 pin of chip U8 are connected with 1 pin of chip U7,2 of chip U8, 3, No. 16 pin ground connection, 19 pin of chip U8 connect 2.048V voltage, and 18 pin of chip connect 3.3V voltage, 4 of chip U8, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, No. 17 pins are the input port of described second digital to analog converter, 3 of chip U7, No. 5 pin ground connection, 4 pin of chip U7 connect-5V voltage, 8 pin of chip connect+5V voltage, 7 pin of chip are connected with one end of resistance R_LF2 with resistance DA6,6 pin of chip U7 and one end of resistance DA7 and DA8, and the other end of resistance DA6 is connected, another termination 2.048V voltage of resistance DA8, the other end of resistance DA7 is connected with 20 pin of chip U8, the other end of resistance R_LF2 is connected with one end of electric capacity C_LF2, the other end ground connection of electric capacity C_LF2, one end of electric capacity C_LF2 is the output port of described second digital to analog converter,

Described data averaging module, parameter extraction module, gain controlling curve generator, disturbance discrimination module, biased extraction module, proportional integral (PI) controller realizes in programmable gate array (FPGA) chip U17 all at the scene, the model of chip U17 is XC6SLX100T-2FGG900, the pin W29 of chip U17 connects outside 100M clock signal clk, the A7 of chip U17, B7, D7, B6, C6, D6, A5, B5, A4, C4, A3, B3, A2, B1 pin respectively with 1 of the chip U9 in described first analog to digital converter, 28, 27, 26, 25, 22, 21, 20, 19, 18, 17, 16, 15, No. 13 pins are connected, the H1 of chip U17, H2, J1, K1, K2, L1, L3, M1, M2, N1, P1, P2, R1, T1 pin respectively with 1 of the chip U11 in described second analog to digital converter, 28, 27, 26, 25, 22, 21, 20, 19, 18, 17, 16, 15, No. 13 pins are connected, the G1 of chip U17, G3, G4, F1, F2, F4, E1, B2, C4, D3, D2, D1, E3 pin respectively with 4 of the chip U6 in described first digital to analog converter, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, No. 17 pins are connected, the AB1 of chip U17, AB2, AC1, AD1, AD2, AE1, AF1, Y3, Y2, Y1, W1, V2, U1 pin respectively with 4 of the chip U8 in described second digital to analog converter, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, No. 17 pins are connected.

Above-described embodiment is only the preferred embodiment of the present invention; be noted that for those skilled in the art; under the premise without departing from the principles of the invention; some improvement and equivalent replacement can also be made; these improve the claims in the present invention and are equal to the technical scheme after replacing, and all fall into protection scope of the present invention.

Claims (5)

1. an adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance, it is characterized in that, the method comprises the following steps:

1) prime amplifier (1) export after amplifying primary light electric signal shape as shown in the formula electric signal F _i(t):

$F_i\left(t\right)=A_i{e}^{-B_{i}t}+D_i\left(t\right)e^{-B_{i}t}+C_i$

Wherein, exponential part for the deamplification of back-scattering light during undisturbed itself, C _ifor DC offset voltage, D _it () is disturbance superposed signal, i is the sequence number that laser pulse sends the cycle, and t is the timing in the laser pulse transmission cycle, A _ifor the initial strength of light signal received, B _ifor index optical fiber decay factor, A _iand B _isize and the model of optical fiber, the wavelength of laser relevant with power;

2) by described electric signal F _it () inputs to main amplifier (2), be amplified signal G _i(t) be:

$G_i\left(t\right)={\mathrm{kA}}_i{e}^{-B_{i}t}+{\mathrm{kD}}_i\left(t\right)e^{-B_{i}t}+{\mathrm{kC}}_i$

Wherein, k is main amplifier enlargement factor;

3) by described amplifying signal G _it () inputs the in-phase input end (701) of the first analog to digital converter (3) and subtracter (7) simultaneously, and by bias correction signal C ' _ithe inverting input (702) of input subtracter (7), obtains subtracter (7) output signal I according to following formula _i(t):

$I_i\left(t\right)={\mathrm{kA}}_i{e}^{-B_{i}t}+{\mathrm{kD}}_i\left(t\right)e^{-B_{i}t}+{\mathrm{kC}}_i-C_i^{\&prime;};$

Wherein, described bias correction signal C ' _iexported by the first digital to analog converter (13) by proportional integral (PI) controller (11);

4) by the signal input part of described subtracter (7) the output signal controlled operational amplifier of input gain (8), the initial strength A ' of the light signal simultaneously parameter extraction module (5) extracted _iwith index optical fiber decay factor B ' _ithe gain-controlled voltage input end of the controlled operational amplifier of input gain (8) after treatment, then outputs signal J by the output of gain controllable operational amplifier (8) after (9) analog to digital conversion _i(t):

$J_i\left(t\right)=\mathrm{gk}(1+\frac{D_i\left(t\right)}{A_i^{\&prime;}})+{\mathrm{\&Delta;}}_i\left(t\right)$

Wherein a ' _ithe initial strength of the light signal that parameter extraction module (5) is extracted, B ' _ibe the index optical fiber decay factor that parameter extraction module (5) is extracted, g is the gain of gain controllable operational amplifier when control voltage is 0.

2. adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance according to claim 1, is characterized in that, described step 3) in bias correction signal C ' _idetermine according to following methods:

31) the output signal J of the gain controllable operational amplifier (8) in a upper cycle that will collect of the second analog to digital converter (9) _i-1t () delivers to biased extraction module (10) and disturbance discrimination module (12); Disturbance discrimination module (12) is according to following rule judgment signal J _i-1whether disturbance information is there is in (t):

If there is t ∈ (0, T), make then signal J _i-1there is disturbance information in (t), otherwise there is not disturbance information;

Wherein T is that laser pulse sends the cycle;

Regulation is as signal J simultaneously _i-1t when there is disturbance information in (), disturbance discrimination module (12) exports 0, when there is not disturbance information, disturbance discrimination module (12) exports 1, and namely disturbance discrimination module output signal is determined by following formula:

$K_{i-1}=\left\{\begin{array}{c}0,\&Exists;t\&Element;(0,T),\left|\frac{d{J}_{i-1}\left(t\right)}{\mathrm{dt}}\right|\&GreaterEqual;\mathrm{\&epsiv;}\\ 1,\&Exists;t\&Element;(0,T),\left|\frac{d{J}_{i-1}\left(t\right)}{\mathrm{dt}}\right|<\mathrm{\&epsiv;}\end{array}\right.$

Wherein ε is disturbance discrimination threshold;

32) by the gain controllable opamp-output signal J in a upper cycle _i-1the disturbance discrimination module output signal K in (t) and this cycle _i-1input to biased extraction module (10), at K _i-1when=1, the output C of biased extraction module " _idetermined by following formula:

$C_i^{\&prime;\&prime;}=A_{i-1}^{\&prime;}\frac{J_{i-1}\left(T\right)-J_{i-1}\left(0\right)}{g(e^{B_{i-1}^{\&prime;}T}-1)}$

Wherein T is the cycle of laser pulse;

At K _i-1when=0, then direct the output of extraction module biased in the upper laser pulse cycle was biased the output of extraction module, i.e. C as this cycle " _i=C " _i-1;

33) by the output C of described biased extraction module " _itransport to PI controller (11), PI controller (11) is by the first digital to analog converter (13) output signal C ' _i, namely have:

C′ _i＝K _PC″ _i+I _i

Wherein K _pfor scale-up factor, I _i=K _itC " _i+ I _i-1, K _ifor integral coefficient, during i=1, I ₀=0.

3. adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance according to claim 1 and 2, is characterized in that, described step 4) in the initial strength A ' of light signal _iwith index optical fiber decay factor B ' _iextract according to following method:

The digital signal that data averaging module (4) exports according to the first analog to digital converter (3), under the regulation and control of disturbance discrimination module (12), the output signal of the main amplifier (2) that the first analog to digital converter (3) in the common N number of laser pulse cycle before the present laser recurrence interval collects is averaged, output signal L _i(t) be:

$L_i\left(t\right)=\frac{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j{G}_j\left(t\right)}{\underset{j=i-N}{\overset{i-1}{\mathrm{\&Sigma;}}}{K}_j}$

Wherein, j is the summation ordinal number from i-N to i-1;

By signal L _it () inputs to parameter extraction module (5), parameter extraction module (5) is extracted by following formula and obtained parameter:

A′ _i＝L _i(0)/k-C′ _i

$B_i^{\&prime;}=\frac{1}{T}\ln \left(\frac{k{A}_i^{\&prime;}}{L_i\left(T\right)-k{C}_i^{\&prime;}}\right);$

Described step 4) in initial strength A ' to light signal _iwith index optical fiber decay factor B ' _ibe handled as follows after the gain-controlled voltage input end of the controlled operational amplifier of input gain (8) again:

Gain controlling curve generator (6) is according to the initial strength A ' of the described light signal of input _iwith index optical fiber decay factor B ' _i, according to following formula determination gain-controlled voltage U _i(t):

$U_i\left(t\right)=\frac{1}{l}(B_i^{\&prime;}t+\ln \frac{1}{A_i^{\&prime;}})$

Wherein l is the gain scale coefficient of gain controllable operational amplifier;

Finally by described gain-controlled voltage U _it () carries out digital-to-analog conversion.

4. adaptive gain balanced type distributing optical fiber sensing light signal method of reseptance according to claim 3, is characterized in that, if the output of disturbance discrimination module (12) is 1, then data averaging module (4) calculates output signal L _itime (t), by this cycle amplifying signal G of main amplifier (2) _it () also includes the scope be averaged in, if the output of disturbance discrimination module (12) is 0, then give up this cycle amplifying signal G of main amplifier (2) _it (), the output of data averaging module (4) remains unchanged.

5. an adaptive gain balanced type distributing optical fiber sensing light signal receiving, it is characterized in that, this device comprises prime amplifier (1), main amplifier (2), first analog to digital converter (3), data averaging module (4), parameter extraction module (5), gain controlling curve generator (6), subtracter (7), gain controllable operational amplifier (8), second analog to digital converter (9), disturbance discrimination module (12), biased extraction module (10), pi controller (11), first digital to analog converter (13), second digital to analog converter (14),

The output interface of described prime amplifier (1) is connected with the input interface of main amplifier (2), the output interface of main amplifier (2) is connected with the input interface of the first analog to digital converter (3) and the in-phase input end mouth of subtracter (7) simultaneously, the output interface of subtracter (7) is connected with the signal input interface of gain controllable operational amplifier (8)

The output interface of described first analog to digital converter (3) is connected with the Data Input Interface (401) of data averaging module (4), the output interface of described data averaging module (4) is connected with the input interface of parameter extraction module (5), the output interface of described parameter extraction module (5) is connected with the input interface of gain controlling curve generator (6), the output interface of described gain controlling curve generator (6) is connected with the input interface of the second digital to analog converter (14), the output interface of described second digital to analog converter (14) is connected with the gain control interface of gain controllable operational amplifier (8), the output interface of described gain controllable operational amplifier (8) is connected with the input interface of the second analog to digital converter (9),

The output interface of described second analog to digital converter (9) is connected with the input interface of disturbance discrimination module (12) and the Data Input Interface of biased extraction module (10) simultaneously, the output interface of described disturbance discrimination module (12) is connected with the control interface of data averaging module (4) and the control interface of biased extraction module (10) simultaneously, the output interface of described biased extraction module (10) is connected with the input interface of PI controller (11), the output interface of described PI controller (11) is connected with the input interface of the first digital to analog converter (13), the output interface of described first digital to analog converter (13) is connected with the inverting input of subtracter (7).