CN101799556A - Extremely low frequency transmitting and receiving system and device - Google Patents

Extremely low frequency transmitting and receiving system and device Download PDF

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Publication number
CN101799556A
CN101799556A CN 201010122723 CN201010122723A CN101799556A CN 101799556 A CN101799556 A CN 101799556A CN 201010122723 CN201010122723 CN 201010122723 CN 201010122723 A CN201010122723 A CN 201010122723A CN 101799556 A CN101799556 A CN 101799556A
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extremely low
low frequency
signal
frequency
transmitter
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CN101799556B (en
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郭静波
胡铁华
王淳
刘红旗
徐新智
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CHINA PRODUCTIVITY CENTER FOR MACHINERY
Tsinghua University
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CHINA PRODUCTIVITY CENTER FOR MACHINERY
Tsinghua University
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Abstract

The invention provides extremely low frequency transmitting and receiving system and device. An extremely low frequency transmitter comprises a battery pack, a transmitting coil, a control switch and a controller, wherein the transmitting coil is connected with the battery pack, the control switch is respectively connected with the transmitting coil and the battery pack, and the controller is connected with the control switch and controls the starting of the control switch according to a predetermined frequency so as to generate an extremely low frequency triangular wave magnetic signal with a main frequency as a certain fixed frequency. Through the improvement of the transmitter and a receiver in the embodiment, the transmitter can output the extremely low frequency triangular wave magnetic signal. In addition, because the receiver adopts a novel test statistic and a matched detection judgment method based on the ratio of an estimated signal power to an observation signal power, the receiver can carry out real-time and reliable detection on extremely low frequency weak magnetic field signals which have large dynamic range and short time of duration and are almost submerged by narrow band noises.

Description

Extremely low frequency emission and receiving system and device
Technical field
The present invention relates to electronic information technical field, particularly a kind of extremely low frequency emission and receiving system and device more specifically, relate to a kind of system and device that is used for pipeline mobile robot spike location.
Background technology
The extremely low frequency signal is meant the signal of frequency in 3Hz～30Hz scope, has obtained using widely owing to it has good penetrability to media such as metal, seawater, soil layers.For example, in recent years, just obtained using widely in fields such as defect of pipeline Non-Destructive Testings based on the pipeline mobile robot spike localization method of extremely low frequency field signal.At present, the pipeline mobile robot spike positioning system based on the extremely low frequency field signal comprises signal transmitter and signal receiver two parts.Robot in the pipeline constantly moves with the speed of 2 meter per seconds～8 meter per seconds, is contained in the extremely low frequency single-frequency field signal that signal transmitter in the robot is constantly launched 23Hz.Penetrable metallic conduit of this signal and soil horizon arrive the receiver on ground.Receiver carries out frequency-selecting to the feeble signal that receives earlier and amplifies and the filtering out-of-band noise, detects judgement according to the signal after the amplification filtering then, provides court verdict.If receiver detects the 23Hz extremely low frequency single-frequency field signal that transmitter sends, then writing down the current time is the time that pipe robot passes through its below, thereby realizes pipeline mobile robot's spike location.
The shortcoming of prior art is at present: the transmitter of existing extremely low frequency spike positioning system is mainly sine-wave oscillator, and its frequency stability is poor, wave-shape amplitude is fade-in the permanent width of cloth.And at present the receiver of system mainly detects based on the envelope of received signal, and it wrong report occurs and fail to report through regular meeting in actual applications, so poor reliability and can't requirement of real time.
Summary of the invention
Purpose of the present invention is intended to solve at least one of above-mentioned technological deficiency, and can realize accurately detecting in real time of extremely low frequency feeble signal.
For achieving the above object, one aspect of the present invention proposes a kind of extremely low frequency transmitter, comprising: electric battery; The transmitting coil that links to each other with described electric battery; The gauge tap that links to each other with described electric battery with described transmitting coil respectively; With the controller that is connected with described gauge tap, described controller is controlled the unlatching of described gauge tap according to fixed frequency, is the extremely low frequency triangular wave field signal of described fixed frequency to produce dominant frequency.
The present invention has also proposed a kind of extremely low frequency receiver on the other hand, comprising: the electric battery that is used to power; Be used to receive first receiving coil of space magnetic field signal; The first amplification filtering circuit that is connected with described first receiving coil is used for the signal that described receiving coil receives is carried out filtering and amplification, the extremely low frequency signal that obtains wanting; AD converter, the extremely low frequency conversion of signals that is used for the described first amplification filtering circuit is obtained is a digital signal; With the detection module that links to each other with described AD converter, be used for test statistics, and judge whether to detect the signal of transmitter with continuing to count according to described test statistics with the described digital signal of computation of Period that presets.
Further aspect of the present invention has also proposed a kind of extremely low frequency signal emitting-receiving system, comprises above-mentioned extremely low frequency transmitter and above-mentioned extremely low frequency receiver.Wherein, this system can be used for pipeline mobile robot's spike location.
By the improvement of the embodiment of the invention to transmitter and receiver, make transmitter can export the extremely low frequency triangular signal that dominant frequency is 23Hz, and because the main circuit of transmitter is a digital circuit, so frequency stability height of waveform, constant amplitude, because receiver adopts based on the novel test statistics of power estimator signal and observation signal power ratio and supporting detection decision method, so the receiver that the present invention proposes can be big to dynamic range in addition, duration is short, almost the extremely low frequency Weak magentic-field signal that is flooded by narrow band noise carries out the real-time reliable detection.
The performance of the extremely low frequency transmitting and receiving device of the embodiment of the invention is as follows:
(1) real-time: in sample rate f s=1000Hz, data length N=750, sampling period T s=0.75s will provide about 1 second and detect court verdict accurately.
(2) accuracy: at Y-PSNR is PSNR=3dB, transmitter translational speed 5m/s, data N=750, sample rate f s=1000Hz, decision threshold η=0.5, under the condition of the M=300 that continues to count, invariable false alerting is P CFAR=4%, detection probability reaches P D=98%.
Aspect that the present invention adds and advantage part in the following description provide, and part will become obviously from the following description, or recognize by practice of the present invention.
Description of drawings
Above-mentioned and/or additional aspect of the present invention and advantage are from obviously and easily understanding becoming the description of embodiment below in conjunction with accompanying drawing, wherein:
Fig. 1 is the schematic diagram of the extremely low frequency transmitter of the embodiment of the invention;
Fig. 2 is the schematic diagram of the extremely low frequency receiver of the embodiment of the invention;
Fig. 3 is the result of calculation of noise waveform and test statistics;
Fig. 4 is waveform and the test statistics result of calculation behind the signal superimposed noise;
Fig. 5 is the relational result of receiver invariable false alerting of the present invention and decision parameter (thresholding continues to count);
Fig. 6 is the relational result that receiver of the present invention detects detection probability and decision parameter (thresholding continues to count).
Embodiment
Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, and wherein identical from start to finish or similar label is represented identical or similar elements or the element with identical or similar functions.Below by the embodiment that is described with reference to the drawings is exemplary, only is used to explain the present invention, and can not be interpreted as limitation of the present invention.
In real time accurate detection for the extremely low frequency signal at present will run into following difficult point:
(1) the extremely low frequency signal power of mobile apparatus philtrum transmitter emission is limited, waveform quality is not high;
(2) because of transmitter is in mobile status, field signal along with the increase of receiving range decays rapidly, the dynamic range of signals of reception is big;
(3) but the speed that moves with transmitter of the duration of receiver signal acquisition increase and shorten;
(4) the shared bandwidth difference of the frequency spectrum of the frequency spectrum of signal and narrowband Gaussian noise is very little.
Therefore, the signal that receives of receiver normally big, duration of dynamic range short, by the feeble signal that narrow band noise is almost flooded, this will cause very big difficulty to accurately detecting in real time.
In order to overcome these difficulties, the present invention all makes improvement to present transmitter and receiver simultaneously, makes transmitter of the present invention can produce high-quality waveform, and receiver of the present invention can be realized accurately detecting in real time of extremely low frequency feeble signal.
In addition, also need to prove, extremely low frequency emission that the embodiment of the invention proposed and the system that receives and device not only can be applied to aspect, pipeline mobile robot spike location, also can be applicable in the other field, for example the detection of seabed tunnel, the extremely low frequency magnetic field communications in the ocean etc.
Below just the present invention is introduced in the mode of specific embodiment; but need to prove that following examples only are optimal ways of the present invention; be not only can realize the present invention, so modification that is equal to or conversion that those skilled in the art make following examples all should be included within protection scope of the present invention by following examples.
As shown in Figure 1, be the schematic diagram of the extremely low frequency transmitter of the embodiment of the invention.This extremely low frequency transmitter comprises electric battery 100, the transmitting coil 200 that links to each other with electric battery 100, the gauge tap 300 that links to each other with electric battery 100 with transmitting coil 200 respectively, in one embodiment of the invention, gauge tap 300 can be the MOSFET pipe, and those skilled in the art also can adopt other switching devices certainly.In another embodiment of the present invention, electric battery 100 can be the lithium battery group.In the present invention, this extremely low frequency transmitter also comprises the controller 400 of controlling gauge tap 300, and controller 400 is the extremely low frequency triangular wave field signal of fixed frequency according to the unlatching of fixed frequency control gauge tap 300 to produce dominant frequency.In one embodiment of the invention, the said fixing frequency is 23Hz, and those skilled in the art also can select other frequencies certainly, equally also should be included within protection scope of the present invention.If gauge tap 300 is the MOSFET pipe, then controller 400 is connected with the grid of MOSFET pipe.In another embodiment, controller 400 can be selected single-chip microcomputer, can certainly select other control devices.
MOSFET pipe among the present invention works on off operating mode, and for the sine wave output waveform, waveform is extremely short transit time.The main circuit of above-mentioned transmitter is a digital circuit in addition, so frequency stability height, the constant amplitude of waveform, and the standardization of waveform is good.
As shown in Figure 2, be the schematic diagram of the extremely low frequency receiver of the embodiment of the invention.This extremely low frequency receiver comprises the electric battery 510 (as the lithium battery group) that is used to power, first receiving coil 520 that is used to receive the space magnetic field signal, the first amplification filtering circuit 530 that is connected with first receiving coil 520, the first amplification filtering circuit 530 can be used for the signal that first receiving coil 520 receives is carried out filtering and amplification, the extremely low frequency signal that obtains wanting, if for example select 23Hz, then 520 pairs of centre frequencies of first amplification filtering circuit signal that is 23Hz carries out frequency-selecting and amplifies.
In one embodiment of the invention, this extremely low frequency receiver also comprises AD converter, being used for the extremely low frequency conversion of signals that the first amplification filtering circuit 530 obtains is digital signal, this AD converter can be independent device, also can be integrated in the detection module 540, AD converter is integrated in the detection module 540 in Fig. 2.
This extremely low frequency receiver also comprises detection module 540, is used for the test statistics with the digital signal of the computation of Period AD converter that presets conversion, and according to test statistics with continue to count and judge whether to detect the signal of transmitter.In a preferred embodiment of the invention, this detection module 540 is for having the DSP of AD unit, certainly those skilled in the art also can select other computing units, in this embodiment, the software program of DSP calculates a test statistics λ according to the real-time detection method of extremely low frequency single-frequency feeble signal every 1ms, detect judgement according to the predefined judging threshold η and the M that continues to count then, provide court verdict.
In a preferred embodiment of the invention, an extremely low frequency receiver can obtain signal simultaneously from two receiving coils, to improve the reliability of input, as shown in Figure 2, also can comprise second receiving coil 550 and the second amplification filtering circuit 560.
Extremely low frequency field signal receiver is as follows to the real time detection algorithm of sampled signal:
The observation data that is mixed with the extremely low frequency single frequency sinusoidal signal of noise is:
X (k)=Asin (ω 0K+ φ)+and n (k), k=0,1, L, N-1, wherein, ω 0=2 π f 0/ f s, frequency f 0Be 23Hz, f sBe the signal sampling frequency, A is amplitude (the unknown), and φ is phase place (the unknown), and n (k) is the narrowband Gaussian noise.
For realizing detection to extremely low frequency single frequency sinusoidal signal, construct test statistics λ, concrete steps are:
Step 1, calculating N point observation signal x (k) (k=0,1 ..., power P N-1) x
Step 2, the amplitude of estimation extremely low frequency single frequency sinusoidal signal
Figure GSA00000048978500061
Wherein,
A ^ = α ^ 1 2 + α ^ 2 2 ,
α ^ 1 α ^ 2 = ( H T H ) - 1 H T x ,
H = 1 0 cos ω 0 sin ω 0 M M cos ω 0 ( N - 1 ) sin ω 0 ( N - 1 ) .
Step 3, the power of estimated signal
Figure GSA00000048978500065
Wherein, P s ^ = A ^ 2 2 .
Step 4 is calculated the test statistics λ that detects judgement, wherein, λ = P s ^ P x .
Step 5, with the judging threshold η comparison of test statistics λ and setting, and inspection continues the M that counts.If test statistics λ counts more than or equal to M greater than decision threshold η's, then judging has signal to exist; Otherwise, if test statistics λ, judges then that no signal exists greater than the counting continuously less than M of decision threshold η.
Step 6 is with graphic presentation test statistics and court verdict.
The extremely low frequency receiver of the embodiment of the invention adopts based on the novel test statistics of power estimator signal and observation signal power ratio and supporting detection decision method, can be big to dynamic range, the duration short, the extremely low frequency Weak magentic-field signal that almost flooded by narrow band noise is realized real-time reliable detection.
In addition, the invention allows for a kind of extremely low frequency signal emitting-receiving system, comprise above-mentioned extremely low frequency transmitter and above-mentioned extremely low frequency receiver, this system can be used for pipeline mobile robot's spike location.
Below just beneficial effect of the present invention is verified in the mode of concrete experimental simulation.As shown in Figure 3, be the result of calculation of noise waveform and test statistics.Fig. 3 (a) is the signal waveform of noise, and Fig. 3 (b) is for adopting the result of calculation of extremely low frequency feeble signal real time detection algorithm of the present invention to the test statistics λ of this noise waveform.Fig. 4 is waveform and the test statistics result of calculation behind the signal superimposed noise.The extremely low frequency signal waveform that Fig. 4 (a) produces for transmitter, Fig. 4 (b) is the waveform behind the noise of the waveform stacking diagram 3 (a) among Fig. 4 (a), and Fig. 4 (c) is for adopting the result of calculation of extremely low frequency feeble signal real time detection algorithm of the present invention to the test statistics λ of signal plus noise situation.
As seen, the result of calculation of the test statistics λ of noise is obviously less than normal among Fig. 3, and the result of calculation of the test statistics λ of signal is bigger than normal and the duration is very long among Fig. 4.Even Fig. 3 and Fig. 4 explanation is under the situation that the envelope of signal is flooded by noise fully, the signal real-time detecting system that the present invention proposes still can be distinguished signal and noise very reliably.Fig. 5 is the relational result of receiver invariable false alerting of the present invention and decision parameter (thresholding continues to count), and Fig. 6 is the relational result that receiver of the present invention detects detection probability and decision parameter (thresholding continues to count).
By the improvement of the embodiment of the invention to transmitter and receiver, make transmitter can export the extremely low frequency triangular signal that dominant frequency is 23Hz, and because the main circuit of transmitter is a digital circuit, so frequency stability height of waveform, constant amplitude, because receiver adopts based on the novel test statistics of power estimator signal and observation signal power ratio and supporting detection decision method, so the receiver that the present invention proposes can be big to dynamic range in addition, duration is short, almost the extremely low frequency Weak magentic-field signal that is flooded by narrow band noise carries out the real-time reliable detection.
The performance of the extremely low frequency transmitting and receiving device of the embodiment of the invention is as follows:
(1) real-time: in sample rate f s=1000Hz, data length N=750, sampling period T s=0.75s will provide about 1 second and detect court verdict accurately.
(2) accuracy: at Y-PSNR is PSNR=3dB, transmitter translational speed 5m/s, data N=750, sample rate f s=1000Hz, decision threshold η=0.5, under the condition of the M=300 that continues to count, invariable false alerting is P CFAR=4%, detection probability reaches P D=98%.
Although illustrated and described embodiments of the invention, for the ordinary skill in the art, be appreciated that without departing from the principles and spirit of the present invention and can carry out multiple variation, modification, replacement and modification that scope of the present invention is by claims and be equal to and limit to these embodiment.

Claims (14)

1. an extremely low frequency transmitter is characterized in that, comprising:
Electric battery;
The transmitting coil that links to each other with described electric battery;
The gauge tap that links to each other with described electric battery with described transmitting coil respectively; With
With the controller that described gauge tap is connected, described controller is controlled the unlatching of described gauge tap according to presetting fixed frequency, is the extremely low frequency triangular wave field signal of described fixed frequency to produce dominant frequency.
2. extremely low frequency transmitter as claimed in claim 1 is characterized in that, described fixed frequency is 23Hz.
3. extremely low frequency transmitter as claimed in claim 1 is characterized in that, described controller is a single-chip microcomputer.
4. as claim 1 or 3 described extremely low frequency transmitters, it is characterized in that described gauge tap is the MOSFET pipe, the grid of described MOSFET pipe is connected with described controller.
5. an extremely low frequency receiver is characterized in that, comprising:
The electric battery that is used to power;
Be used to receive first receiving coil of space magnetic field signal;
The first amplification filtering circuit that is connected with described first receiving coil is used for the signal that described receiving coil receives is carried out filtering and amplification, the extremely low frequency signal that obtains wanting;
AD converter, the extremely low frequency conversion of signals that is used for the described first amplification filtering circuit is obtained is a digital signal; With
With the detection module that described AD converter links to each other, be used for test statistics, and judge whether to detect the signal of transmitter with continuing to count according to described test statistics with the described digital signal of computation of Period that presets.
6. extremely low frequency receiver as claimed in claim 5 is characterized in that, also comprises second receiving coil and the second amplification filtering circuit, and described detection module obtains signal from the described first amplification filtering circuit and the second amplification filtering circuit simultaneously, and detects.
7. as claim 5 or 6 described extremely low frequency receivers, it is characterized in that the described first amplification filtering circuit and the second amplification filtering circuit are that the signal of 23Hz carries out frequency-selecting and amplifies to centre frequency.
8. as claim 5 or 6 described extremely low frequency receivers, it is characterized in that described detection module is DSP.
9. extremely low frequency receiver as claimed in claim 8 is characterized in that, the test statistics λ that described detection module calculates described digital signal comprises:
Calculating N point observation signal x (k) (k=0,1 ..., power P N-1) x, wherein, x (k)=A sin (ω 0K+ φ)+and n (k), k=0,1, L, N-1, ω 0=2 π f 0/ f s, frequency f 0Be 23Hz, f sBe the signal sampling frequency, A is an amplitude, and φ is a phase place, and n (k) is the narrowband Gaussian noise;
Estimate the amplitude of extremely low frequency single frequency sinusoidal signal
Figure FSA00000048978400021
The power of estimated signal
Figure FSA00000048978400022
Calculate the test statistics λ that detects judgement, wherein, λ = P s ^ P x .
10. extremely low frequency receiver as claimed in claim 9 is characterized in that, A ^ = α ^ 1 2 + α ^ 2 2 ,
Wherein, α ^ 1 α ^ 2 = ( H T H ) - 1 H T x ;
H = 1 0 cos ω 0 sin ω 0 M M cos ω 0 ( N - 1 ) sin ω 0 ( N - 1 ) .
11. extremely low frequency receiver as claimed in claim 9 is characterized in that, wherein, P s ^ = A ^ 2 2 .
12. extremely low frequency receiver as claimed in claim 9 is characterized in that, described detection module judges whether that with continuing to count the signal that detects transmitter comprises according to described test statistics:
The judging threshold η of test statistics λ and setting is compared, and inspection continues the M that counts;
If test statistics λ counts more than or equal to M greater than decision threshold η's, then judging has signal to exist;
If test statistics λ counts less than M continuously greater than decision threshold η's, judge that then no signal exists.
13. an extremely low frequency signal emitting-receiving system is characterized in that, comprises each described extremely low frequency transmitter of claim 1-4 and each described extremely low frequency receiver of claim 5-12.
14. extremely low frequency signal emitting-receiving system as claimed in claim 13 is characterized in that, described system is used for pipeline mobile robot's spike location.
CN2010101227230A 2010-03-11 2010-03-11 Extremely low frequency transmitting and receiving system and device Expired - Fee Related CN101799556B (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106324365A (en) * 2016-09-21 2017-01-11 广东骏丰频谱股份有限公司 Schumann resonance receiving device
CN109655788A (en) * 2019-02-11 2019-04-19 清华大学 A kind of magnetic echo signal universal test method and receiving detection device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187661A (en) * 1989-07-21 1993-02-16 Halliburton Logging Services, Inc. Method of determining invaded formation properties including resistivity dielectric constant and zone diameter
JP2000088571A (en) * 1998-07-15 2000-03-31 Osaka Gas Co Ltd Detecting method for position of moving body at inside of pipe
DE20320909U1 (en) * 2003-10-06 2005-07-14 Rst Raumfahrt Systemtechnik Gmbh Method of determining irregularities in ground formation, involves emitting electromagnetic waves of low frequency and high frequency to ground formations, and receiving reflection from irregularities
CN101147084A (en) * 2005-01-10 2008-03-19 诺尔斯海德公司 Shallow marine electromagnetic hydrocarbon prospecting
CN201788291U (en) * 2010-03-11 2011-04-06 清华大学 Extremely-low-frequency transmitting and receiving system, extremely-low-frequency transmitter and extremely-low-frequency receiver

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187661A (en) * 1989-07-21 1993-02-16 Halliburton Logging Services, Inc. Method of determining invaded formation properties including resistivity dielectric constant and zone diameter
JP2000088571A (en) * 1998-07-15 2000-03-31 Osaka Gas Co Ltd Detecting method for position of moving body at inside of pipe
DE20320909U1 (en) * 2003-10-06 2005-07-14 Rst Raumfahrt Systemtechnik Gmbh Method of determining irregularities in ground formation, involves emitting electromagnetic waves of low frequency and high frequency to ground formations, and receiving reflection from irregularities
CN101147084A (en) * 2005-01-10 2008-03-19 诺尔斯海德公司 Shallow marine electromagnetic hydrocarbon prospecting
CN201788291U (en) * 2010-03-11 2011-04-06 清华大学 Extremely-low-frequency transmitting and receiving system, extremely-low-frequency transmitter and extremely-low-frequency receiver

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106324365A (en) * 2016-09-21 2017-01-11 广东骏丰频谱股份有限公司 Schumann resonance receiving device
CN109655788A (en) * 2019-02-11 2019-04-19 清华大学 A kind of magnetic echo signal universal test method and receiving detection device
CN109655788B (en) * 2019-02-11 2021-02-09 清华大学 Universal detection method and receiving detection device for magnetic target signal

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