WO2016152131A1 - Leak detection device, leak detection system, leak detection method, and computer-readable recording medium - Google Patents

Leak detection device, leak detection system, leak detection method, and computer-readable recording medium Download PDF

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Publication number
WO2016152131A1
WO2016152131A1 PCT/JP2016/001590 JP2016001590W WO2016152131A1 WO 2016152131 A1 WO2016152131 A1 WO 2016152131A1 JP 2016001590 W JP2016001590 W JP 2016001590W WO 2016152131 A1 WO2016152131 A1 WO 2016152131A1
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signal
spectrum
noise
sound source
leak detection
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PCT/JP2016/001590
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French (fr)
Japanese (ja)
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友督 荒井
裕三 仙田
宝珠山　治
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日本電気株式会社
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Priority to JP2017507494A priority Critical patent/JP6773026B2/en
Publication of WO2016152131A1 publication Critical patent/WO2016152131A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/24—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using infrasonic, sonic, or ultrasonic vibrations

Definitions

  • the present invention relates to a leak detection device, a leak detection system, a leak detection method, and a computer-readable recording medium that detect the presence or absence of a leak of a tube based on a signal from a sensor.
  • Patent Document 1 An example of a method for efficiently investigating and correctly investigating leakage even in a noisy environment is described in Patent Document 1 and Patent Document 2.
  • a ground installation vibration sensor installed on the ground is used to generate noise other than leakage sound measured by pipe installation vibration sensors installed at intervals on a plurality of points on the pipe.
  • the measured signal is used for suppression by an adaptive digital filter.
  • a leak position is specified by the cross correlation process between the signals of the obtained several leaked sound. That is, in the pipe leakage position detection method described in Patent Document 1, the coherence (function representing the degree of association) between the signal captured by the pipe installation vibration sensor and the signal detected by the ground installation vibration sensor is large in the noise component, This is a noise suppression method using the small sound component.
  • the pipe leakage position detection method described in Patent Document 1 can suppress noise mainly due to a fixed sound source that does not move.
  • a target original signal can be satisfactorily restored from a mixed signal obtained by mixing a plurality of original signals.
  • the main object of the present invention is to provide a leak detection device that solves the above-described problems and accurately detects leaks from piping even in an environment where noise is generated by a moving sound source.
  • the leak detection device is obtained from a first signal acquired from a sensor installed at a position where a leak sound from a pipe can be detected and a sensor installed at a position where ambient noise can be detected.
  • Subtracting means for subtracting noise from the non-moving sound source from the first signal, and subtracting noise from the moving sound source from the first signal, and noise from the non-moving sound source and moving sound source from the first signal.
  • Leakage determining means for determining the presence or absence of leakage based on the result.
  • a leak detection system includes a first sensor installed at a position where leakage sound from a pipe can be detected, a second sensor installed at a position where ambient noise can be detected, and the above-described sensor. And a leak detection device.
  • the leak detection method in one aspect of the present invention is obtained from a first signal acquired from a sensor installed at a position where a leak sound from a pipe can be detected and a sensor installed at a position where ambient noise can be detected. Based on the second signal, the noise from the non-moving sound source is subtracted from the first signal, the noise from the moving sound source is further subtracted, and the noise from the non-moving sound source and the moving sound source is subtracted from the first signal. Based on this, the presence or absence of leakage is determined.
  • a computer-readable recording medium includes a first signal acquired from a sensor installed at a position where leakage sound from a tube can be detected and a sensor installed at a position where ambient noise can be detected. Based on the acquired second signal, the noise from the non-moving sound source is subtracted from the first signal, and the noise from the moving sound source is further subtracted, and the noise from the non-moving sound source and the moving sound source is subtracted from the first signal.
  • a program for causing a computer to execute a process for determining the presence or absence of leakage based on the obtained result is stored temporarily.
  • the present invention can accurately detect leakage from piping even in an environment where noise is generated by a moving sound source.
  • FIG. 1 is a block diagram of a leak detection apparatus 10 according to the first embodiment.
  • the leak detection device 10 in this embodiment includes a subtraction unit 11 and a leak determination unit 12.
  • the subtracting unit 11 is based on a first signal acquired from a sensor installed so as to detect leakage sound from the pipe and a second signal acquired from a sensor installed so as to detect ambient noise.
  • the noise due to the non-moving sound source is subtracted from the signal, and further the noise due to the moving sound source is subtracted.
  • the first signal is a signal that mainly includes a pipe or a sound that propagates through a gas or liquid flowing through the pipe. If the tube is leaking, the first signal includes a leaking sound.
  • the sensor for acquiring the first signal is installed in, for example, a pipe or a facility attached to the pipe.
  • the second signal is a signal including noise mainly propagating in the surrounding area of the pipe or on the ground surface.
  • the second signal includes, for example, noise caused by a non-moving sound source and noise caused by a moving sound source.
  • a non-moving sound source is a sound source that emits sound at the same point, such as an object fixed on the ground or a building.
  • the moving sound source is a sound source that emits sound while moving, such as a vehicle.
  • the sensor that acquires the second signal is installed, for example, on the ground surface or in the ground.
  • the subtracting unit 11 obtains, for example, noise due to the non-moving sound source and noise due to the moving sound source using the second signal. Then, the subtracting unit 11 subtracts the noise caused by the non-moving sound source from the first signal using the noise caused by the non-moving sound source and the noise caused by the moving sound source obtained as described above, and further subtracts the noise caused by the moving sound source. .
  • the leakage determination unit 12 determines the presence or absence of leakage from the tube based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal.
  • the leakage determination unit 12 determines the presence or absence of leakage based on the level of a signal indicating the result. For example, the leakage determination unit 12 determines that there is leakage from the pipe when the level of the signal indicating the result is higher than a predetermined level.
  • FIG. 2 is a flowchart showing the operation of the leak detection apparatus 10.
  • the subtracting unit 11 subtracts the noise due to the non-moving sound source from the first signal based on the first signal and the second signal, and further subtracts the noise due to the moving sound source (step S101).
  • Leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal (step S102).
  • the leak detection apparatus 10 having the above configuration subtracts noise caused by a non-moving sound source from the first signal based on the first signal and the second signal, and further subtracts noise caused by the moving sound source.
  • the first signal generally includes leaked sound caused by leak and noise caused by a non-moving sound source and a moving sound source.
  • the second signal generally includes non-moving sound sources and noise caused by moving sound sources.
  • the leak detection device 10 determines whether there is a leak based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal. Therefore, the leak detection device 10 can detect leaks from the pipes accurately even in an environment where noise due to the moving sound source is generated by suppressing both noise due to the non-moving sound source and noise due to the moving sound source.
  • FIG. 3 is a block diagram of the leak detection device 20 according to the second embodiment.
  • the leakage detection device 20 in the present embodiment includes a subtraction unit 11 and a leakage determination unit 12.
  • the subtraction unit 11 includes a subtraction spectrum calculation unit 13 and a subtraction amplitude spectrum calculation unit 14.
  • the subtraction spectrum calculation unit 13 calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal.
  • the subtraction spectrum of the first signal indicates, for example, a spectrum obtained by subtracting noise from a non-moving sound source from the spectrum of the first signal.
  • the subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal.
  • the amplitude spectrum of the first signal indicates, for example, an amplitude spectrum obtained by subtracting noise from the non-moving sound source and the moving sound source from the spectrum of the first signal.
  • the leakage determination unit 12 determines whether there is leakage from the tube from the amplitude spectrum of the first signal obtained by subtracting noise from the non-moving sound source and the moving sound source. The leak determination unit 12 determines whether there is a leak from the tube based on the magnitude of the amplitude indicated by the amplitude spectrum of the first signal.
  • FIG. 4 is a flowchart showing the operation of the leak detection device 20.
  • the subtraction spectrum calculation unit 13 calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal (step S201).
  • the subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal (step S202).
  • Leakage determination unit 12 determines the presence or absence of leakage of the tube from the amplitude spectrum of the first signal (step S203).
  • the leak detection device 20 having the above configuration calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal.
  • the subtracted spectrum of the first signal indicates a spectrum obtained by subtracting noise from a non-moving sound source from the spectrum of the first signal, for example.
  • the leak detection device 20 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal.
  • the amplitude spectrum of the first signal indicates, for example, an amplitude spectrum obtained by subtracting noise from the non-moving sound source and the moving sound source from the spectrum of the first signal.
  • the leak detection device 20 determines whether there is a leak from the tube from the amplitude spectrum of the first signal.
  • the leak detection apparatus 20 determines the amplitude spectrum of the first signal in which both the noise caused by the non-moving sound source and the noise caused by the moving sound source are suppressed. It is possible to detect leaks from piping well.
  • FIG. 5 is a block diagram of the leak detection device 30 in the third embodiment.
  • the leak detection device 30 in the present embodiment includes the subtraction unit 11 and the leak determination unit 12.
  • the subtraction unit 11 includes a subtraction spectrum calculation unit 13 and a subtraction amplitude spectrum calculation unit 14.
  • the subtraction spectrum calculation unit 13 includes a spectrum calculation unit 15 and a spectrum subtraction unit 16.
  • the subtraction amplitude spectrum calculation unit 14 includes an amplitude spectrum calculation unit 17 and an amplitude spectrum subtraction unit 18.
  • the spectrum calculation unit 15 is a spectrum of the tube signal from the first signal (hereinafter sometimes referred to as “tube signal”) and the second signal (hereinafter sometimes referred to as “ground signal”).
  • a ground signal spectrum that is a tube signal spectrum and a ground signal spectrum is calculated.
  • the tube signal is acquired by a sensor installed in, for example, a tube or a facility attached to the tube.
  • the ground signal is acquired by a sensor installed on the ground surface or underground.
  • the spectrum calculation unit 15 calculates the tube signal spectrum X 1, i (f) , which is the frequency spectrum of the tube signal, from the tube signal x 1 (t) by Fourier transform, wavelet transform, or the like.
  • the spectrum calculating unit 15 for example, from the ground signal x 2 (t), similarly calculated is a frequency spectrum of the ground Ground signal spectrum X 2, i (f).
  • X 1, i (f) and X 2, i (f) are spectra of the frequency f at the i-th time.
  • X 1, i (f) and X 2, i (f) include both an amplitude component and a phase component. Therefore, X 1, i (f) and X 2, i (f) are represented by complex numbers.
  • the spectrum subtraction unit 16 subtracts the product of the subtraction spectrum coefficient and the ground signal spectrum from the tube signal spectrum. For example, the spectrum subtraction unit 16 calculates a subtraction spectrum obtained by subtracting the ground spectrum X 2, i (f) from the tube signal spectrum X 1, i (f). As described above, since X 1, i (f) and X 2, i (f) both include both an amplitude component and a phase component, there is a correlation between both the time variation of the amplitude and the time variation of the phase. The effect of subtracting noise increases. That is, the spectrum subtracting unit 16 can subtract noise caused by a non-moving sound source, which is noise with high coherence between X 1, i (f) and X 2, i (f). That is, the subtracted spectrum is a spectrum obtained by subtracting noise due to a non-moving sound source from the tube signal spectrum. The spectrum subtracting unit 16 calculates a subtracted spectrum using, for example, Equation 1 (hereinafter described as Equation 1).
  • the subtracted spectrum S a, i (f) is subtracted from the tube signal spectrum X 1, i (f) (hereinafter, may be referred to as “first coefficient”) k. It is calculated by subtracting the product of a (f) and the ground spectrum X 2, i (f). Subtraction spectral coefficients k a (f) is calculated using equation 2.
  • Equation 3 E [
  • R 12 (f) is a correlation coefficient between X 1, i (f) and X 2, i (f), and is expressed by Equation 3.
  • X 2, i * (f) is a complex conjugate of X 2, i (f).
  • Formula 2 is derived
  • X 1, i (f) can be expressed using Equation 4. The reason is that the ground signal spectrum X 2, i (f) mainly includes a noise component and the leaked sound component C i (f) is hardly included, and the tube signal spectrum X 1, i This is because (f) includes the leaked sound component C i (f) and the noise component k a (f) X 2, i (f) transmitted from the ground.
  • Equation 5 the time average of the product of X 1, i (f) and X 2, i (f) is expressed by Equation 5.
  • Equation 6 Equation 6
  • Equation 2 is derived by applying Equation 3 to Equation 6.
  • noise which is represented by the number 4, by using the subtraction method in the spectral subtraction unit 16 to use the number 1 to number 6 for subtraction spectral coefficients k a (f), is suppressed.
  • the more noise components are included in the tube signal that is, the greater the correlation between the tube signal spectrum and the ground signal spectrum, the greater the proportion of subtraction of the ground signal.
  • the amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal and the amplitude spectrum of the ground signal obtained by subtracting noise from the non-moving sound source from the subtraction spectrum and the ground signal spectrum.
  • the amplitude spectrum of the tube signal indicates the amplitude component of the subtracted spectrum, which is the tube signal spectrum calculated by the spectrum subtracting unit 16 and subtracted with noise due to the non-moving sound source.
  • the amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal from Equation 7.
  • the amplitude spectrum Y 1, i (f) of the tube signal is the absolute value of the subtraction spectrum S a, i (f).
  • the amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the ground signal, which is the amplitude component of the ground signal spectrum calculated by the spectrum calculation unit 15, from Equation 8.
  • the amplitude spectrum Y 2, i (f) of the ground signal is the absolute value of the ground signal spectrum X 2, i (f).
  • the amplitude spectrum subtracting unit 18 calculates a subtracted amplitude spectrum Sb, i (f) by subtracting a correlated component of the ground amplitude spectrum Y 2, i (f) from the tube amplitude spectrum Y 1, i (f). To do.
  • the subtracted amplitude spectrum can be regarded as corresponding to the amplitude component of the spectrum obtained by subtracting noise from the moving sound source from the subtracted spectrum.
  • Equations (9) and (10) show that Y 1, i (f) and Y 2, i (f) are fixed signal components B 1 (f) and B 2 (f), which are fixed signal components, respectively. It is represented by fluctuation components Z 1, i (f) and Z 2, i (f) which are signal components.
  • the “fixed signal component” is a signal component with small temporal variation.
  • the “variable signal component” is a signal component having temporal variation.
  • Amplitude spectrum Y2 of the ground signal, i (f) is expressed by the sum of the variation component of the ground signal Z2, and i (f) fixing component of the ground signals B 2 and (f).
  • the amplitude spectrum Y 1, i (f) of the tube signal is represented by the sum of the fluctuation component Z 1, i (f) of the tube signal and the fixed component B 1 (f) of the tube signal.
  • the fluctuation component Z 1, i (f) of the tube signal mainly includes a noise component.
  • the fluctuation component Z 1, i (f) of the tube signal is a noise component Z 12, i (f) transmitted from the ground as shown in Equation 11 and other noise components Z 11, i (f). It can be expressed as a sum.
  • the amplitude spectrum subtraction unit 18 subtracts the noise component Z 12, i (f) transmitted from the ground. This is represented by Equation 12.
  • the noise component Z 12, i (f) transmitted from the ground or the like is a subtracted amplitude spectrum coefficient (hereinafter sometimes referred to as “second coefficient”) k b (f) and a ground fluctuation component Z 2.
  • i is the product of (f).
  • the amplitude spectrum subtraction unit 18 calculates the subtraction amplitude spectrum S b, i (f) using Equation 13.
  • the subtracted amplitude spectrum S b, i (f) is the product of the subtracted amplitude spectrum coefficient k b (f) and the ground fluctuation component Z 2, i (f) from the amplitude spectrum Y 1 , i (f) of the tube signal. Is calculated by subtracting.
  • the subtracted amplitude spectrum coefficient k b (f) is 1 when the amplitude components of the tube signal and the ground signal are approximately the same, for example, the distance to the noise source is sufficiently larger than the distance between the two sensors. Further, the subtraction amplitude spectrum coefficient k b (f) is calculated using Equation 14 in the same manner as in the case of the subtraction spectrum coefficient k a (f), for example.
  • Y ′ 1, i (f) and Y ′ 2, i (f) represent fluctuation components from the average of Y 1, i (f) and Y 2, i (f), respectively. It is represented by each of Equation 16.
  • Equation 15 which is the fluctuation component of the tube signal amplitude spectrum Y 1, i (f) Y '1, i (f) is the amplitude spectrum Y 1, i (f) a tube signal tube signal It is expressed as a difference from the time average E [Y 1, i (f)] of the amplitude spectrum Y 1, i (f).
  • Equation 16 Y ′ 2, i (f) , which is a fluctuation component of the amplitude spectrum Y 2, i (f) of the ground signal, represents the amplitude spectrum Y 2, i (f) of the ground signal and the amplitude of the ground signal. It is expressed as a difference from the time average E [Y 2, i (f)] of the spectrum Y 2, i (f).
  • R b 12 (f) described on the right side of Equation 14 is a correlation coefficient when calculated from Y ′ 1, i (f) and Y ′ 2, i (f).
  • B 2 (f) is calculated, for example , as the minimum value of the moving average value of Y 2, i (f), the 25th percentile value, the median value, the average value, or the like. Further, when the fixed component B 1 of the pipe signal (f) is assumed to be a component that is propagated from the fixed component B 1 of the ground signal (f), instead of the number 13, number 19 can be used.
  • K d (f) B 2 (f) which is the third term on the right-hand side of Equation 19, cannot be captured by coherence or amplitude coherence (coherence calculated only from the amplitude component) in noise propagating from the ground signal to the tube.
  • the noise component that cannot be captured by coherence or amplitude coherence is a noise component that cannot be subtracted in Equations 1 and 13 because both the coherence and the amplitude coherence are small.
  • the coefficient k d (f) is an arbitrary real number.
  • the coefficient k d (f) may be set to an optimum value from actual measurement, or the subtraction amplitude spectrum coefficient k b (f) may be used as the coefficient k d (f). If these values are not known, the coefficient k d (f) may be set to zero.
  • Expression 19 can be transformed to Expression 20.
  • the leakage determination unit 12 determines the presence or absence of leakage from the subtraction spectrum 2 calculated by the amplitude spectrum subtraction unit 18. For example, the leakage determination unit 12 determines the presence or absence of leakage based on the presence or absence of a spectrum peak or spectrum variation characteristic of leakage. The leak determination unit 12 may cause the subtracted spectrum 2 to be displayed as a spectrogram on a display device (not shown). In this case, the operator may determine whether or not there is a spectrum peak or spectrum fluctuation characteristic of leakage. In addition, the leak determination unit 12 has a leak if f exists such that the sound pressure level for each frequency f calculated based on the amplitude and power of the subtraction spectrum 2 exceeds a preset threshold value ⁇ (f). May be determined.
  • 2 for the time i is used.
  • the influence of sudden noise that cannot be subtracted by the amplitude spectrum subtracting unit 18 can be minimized.
  • the minimum value of the moving average value, the 25th percentile value, the median value, the average value, or the like may be used.
  • the range of time i is set to be sufficiently long with respect to the noise generation time.
  • the threshold value ⁇ (f) may be obtained from an empirical value, or a background noise spectrum is calculated from a signal measured at a past non-leakage or a signal measured at a place without other leakage, and the sound of the background noise spectrum is calculated. It may be determined as a pressure level.
  • the leak determination unit 12 automatically determines that there is a leak when a spectrum peak that is continuously generated over a certain time or a spectrum peak that is stably generated is detected. Also good.
  • the leakage determination unit 12 may perform comparison with the background noise spectrum and determine that there is leakage when there is a change, such as when a peak that does not appear in the background noise spectrum appears.
  • FIG. 6 is a flowchart showing the operation of the leak detection device 30.
  • the spectrum calculation unit 15 calculates the spectrum of the tube signal and the spectrum of the ground signal from the tube signal and the ground signal (step S301).
  • the spectrum subtracting unit 16 subtracts the product of the subtracted spectrum coefficient and the spectrum of the ground signal from the spectrum of the tube signal (step S302).
  • the subtraction spectral coefficient (first coefficient) is calculated based on, for example, the correlation coefficient between the spectrum of the tube signal and the spectrum of the ground signal.
  • the amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal and the amplitude spectrum of the ground signal from the spectrum of the tube signal and the spectrum of the ground signal obtained by subtracting the product of the subtracted spectrum coefficient and the spectrum of the ground signal (step S303). .
  • the subtraction amplitude spectrum calculation unit 18 subtracts the product of the subtraction amplitude spectrum coefficient (second coefficient) and the amplitude spectrum of the ground signal from the amplitude spectrum of the tube signal (step S304).
  • the leak determination unit 12 determines whether or not there is a leak from the tube from the subtracted amplitude spectrum of the tube signal (step S305).
  • the leak detection device 30 having the above configuration calculates the subtraction spectrum and the spectrum of the ground signal based on the tube signal and the ground signal.
  • the leak detection device 30 calculates a subtraction amplitude spectrum based on the subtraction spectrum and the spectrum of the ground signal.
  • the leak detection device 30 determines whether or not there is a leak in the pipe using the subtracted amplitude spectrum.
  • the leak detection device 30 performs leak detection using the feature that the correlation of the noise amplitude spectrum by the moving sound source is large between the tube signal and the ground signal.
  • the leak detection device 30 performs spectral subtraction in two stages.
  • the leak detection device 30 subtracts noise with high coherence in the first stage and subtracts noise with high amplitude coherence in the second stage.
  • the leak detection device 30 determines the subtraction amplitude spectrum in which both the noise caused by the non-moving sound source and the noise caused by the moving sound source are suppressed. Leakage can be detected.
  • the noise suppression effect is low particularly in a high frequency band of noise caused by a moving sound source.
  • the leak detection device 30 in this embodiment has a high noise suppression effect even in a high frequency band.
  • the leak detection apparatus 30 in the present embodiment uses a spectral subtraction method instead of noise suppression by the adaptive digital filter used in the method of Patent Document 1. Therefore, the leak detection device 30 also has an effect that the calculation time is shorter than that of the method described in Patent Document 1.
  • FIG. 7 is a block diagram of the leak detection device 40 according to the fourth embodiment.
  • the leak detection device 40 includes a subtraction unit 11, a subtraction amplitude spectrum calculation unit 14, and a leak determination unit 12.
  • the subtraction unit 11 includes an adaptive noise cancellation unit 19 and a spectrum calculation unit 15.
  • the adaptive noise cancellation unit 19 calculates a noise suppression signal, which is a tube signal subjected to noise suppression, using an adaptive digital filter calculated using the ground signal.
  • the noise suppression signal is a signal in which noise due to a non-moving sound source is suppressed using an adaptive digital filter among noises other than leakage sound included in the tube signal. That is, the noise suppression signal is a tube signal obtained by subtracting noise from a non-moving sound source.
  • the adaptive digital filter coefficient is a coefficient estimated using, for example, a least square method algorithm.
  • the spectrum calculation unit 15 calculates the spectrum of the noise suppression signal and the spectrum of the ground signal from the noise suppression signal and the ground signal.
  • the spectrum calculation unit 15 calculates each spectrum by, for example, Fourier transform.
  • the subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the tube signal from which the noise due to the non-moving sound source and the moving sound source is subtracted based on the spectrum of the noise suppression signal and the spectrum of the ground signal.
  • the leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal. That is, the leakage determination unit 12 determines whether there is leakage based on the subtracted amplitude spectrum of the tube signal.
  • FIG. 8 is a flowchart showing the operation of the leak detection device 40.
  • the adaptive noise cancellation unit 19 calculates a noise suppression signal based on the adaptive digital filter calculated using the tube signal and the ground signal (step S401).
  • the spectrum calculation unit 15 calculates the spectrum of the noise suppression signal and the spectrum of the ground signal from the noise suppression signal and the ground signal (step S402).
  • the subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the tube signal from which the noise due to the non-moving sound source and the moving sound source is subtracted based on the spectrum of the noise suppression signal and the spectrum of the ground signal (step S403).
  • the leakage determination unit 12 determines the presence or absence of leakage based on the result obtained by subtracting noise from the non-moving sound source and the moving sound source from the tube signal (step S404).
  • the leak detection apparatus 40 having the above configuration suppresses noise caused by a non-moving sound source by adaptive noise cancellation, and then suppresses noise caused by the moving sound source using a spectral subtraction method. Thereby, since both the noise by a non-moving sound source and the noise by a moving sound source as described in the first to third embodiments can be suppressed, leakage detection can be performed with high accuracy. Furthermore, the leak detection device 40 can also suppress noise caused by a non-moving sound source in which the leaky sound and the frequency band overlap.
  • FIG. 9 is a block diagram of a leak detection system 50 according to the fifth embodiment.
  • the leak detection system 50 in this embodiment includes a leak detection device 10, a first sensor 21, and a second sensor 22.
  • the leak detection apparatus 10 in the present embodiment has the same configuration and function as the leak detection apparatus 10 in the first embodiment. In the present embodiment, description of the leak detection device 10 is omitted. Further, instead of the leak detection device 10, the leak detection device in the second to fourth embodiments of the present invention may be used.
  • the first sensor 21 is installed in a pipe or a facility attached to the pipe.
  • the first sensor 21 detects sound or vibration propagating through a tube or a gas or liquid flowing through the tube.
  • the first sensor 21 outputs a tube signal indicating the detected sound or vibration to the leak detection device 10.
  • the second sensor 22 is installed in the ground or on the ground surface.
  • the second sensor 22 detects sound or vibration that propagates in the ground or on the ground.
  • the second sensor 22 outputs a ground signal indicating the detected sound or vibration to the leak detection device 10.
  • FIG. 10 is a diagram illustrating an example of installation locations of the first sensor 21 and the second sensor 22.
  • the 1st sensor 21 is installed in the position which leaks sound, such as the installation accompanying a piping and piping, for example. That is, the 1st sensor 21 is installed in the position which can detect the leak sound from a pipe.
  • the second sensor 22 is installed on the ground or underground. In the example shown in FIG. 10, the second sensor 22 is directly installed on the ground. That is, the second sensor 22 is installed at a position where ambient noise of the tube can be detected.
  • FIG. 11 is a flowchart showing the operation of the leak detection system 50.
  • the first sensor 21 and the second sensor 22 detect sounds and signals propagating through pipes and underground, respectively, and output the detected sounds to the leak detection device 10 as tube signals or ground signals (step S501). .
  • the subtracting unit 11 subtracts the noise due to the non-moving sound source from the tube signal based on the tube signal and the ground signal output from the first sensor 21 and the second sensor 22, and further subtracts the noise due to the moving sound source (step). S502).
  • the leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal (step S503).
  • the leak detection system 50 having the above configuration subtracts noise due to the non-moving sound source from the tube signal based on the tube signal and the ground signal, and further subtracts noise due to the moving sound source.
  • the leak detection system 50 determines whether or not there is a leak based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal. Therefore, the leak detection system 50 can accurately detect leaks from the piping even in an environment where noise due to the moving sound source is generated by suppressing both noise due to the non-moving sound source and noise due to the moving sound source.
  • FIG. 12 is a schematic block diagram showing a configuration example of the computer 100 in each embodiment of the present invention.
  • the computer 100 includes a CPU 101, a main storage device 102, an auxiliary storage device 103, an interface 104, an input device 105, and a display device 106.
  • the leakage detection apparatus 10 and the like of each embodiment and each example are mounted on a computer 100.
  • the operation of the leak detection device 10 and the like is stored in the auxiliary storage device 103 in the form of a program.
  • the CPU 101 reads out the program from the auxiliary storage device 103 and develops it in the main storage device 102, and executes the above processing according to the program.
  • the auxiliary storage device 103 is an example of a tangible medium that is not temporary.
  • Other examples of the non-temporary tangible medium include a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, and a semiconductor memory connected via the interface 104.
  • the interface 104 is connected to the CPU 101 and connected to a network or an external storage medium. External data may be taken into the CPU 101 via the interface 104.
  • the input device 105 is, for example, a keyboard, a mouse, or a touch panel.
  • the display 106 displays a screen corresponding to drawing data processed by the CPU 101 or GPU (Graphics Processing Unit) (not shown) such as an LCD (Liquid Crystal Display) or CRT (Cathode Ray Tube) display. Device. Note that the hardware configuration illustrated in FIG. 12 is merely an example, and each unit illustrated in FIG. 1 may be configured with independent logic circuits.
  • the program may realize a part of the above processing.
  • the program may be a differential program that realizes the above-described processing in combination with another program already stored in the auxiliary storage device 103.

Abstract

A leak from a pipeline can be detected accurately, even in an environment where noise due to moving sources of noise occurs. This leak detection device of one aspect of the present invention is provided with: a subtraction unit for subtracting noise from non-moving sources of noise from a first signal, on the basis of the first signal which is acquired from a sensor installed at a location at which it is possible to detect leak noise from a pipe, and a second signal which is acquired from a sensor installed at a location at which it is possible to detect ambient noise, and further subtracting noise from moving sources of noise; and a leak assessment unit for assessing whether a leak exists, on the basis of the result of subtracting the noise from non-moving sources of noise and the moving sources of noise from the first signal.

Description

漏洩検知装置、漏洩検知システム、漏洩検知方法及びコンピュータ読み取り可能記録媒体Leakage detection apparatus, leak detection system, leak detection method, and computer-readable recording medium
　本発明は、センサからの信号に基づき、管の漏洩の有無を検知する漏洩検知装置、漏洩検知システム、漏洩検知方法及びコンピュータ読み取り可能記録媒体に関する。 The present invention relates to a leak detection device, a leak detection system, a leak detection method, and a computer-readable recording medium that detect the presence or absence of a leak of a tube based on a signal from a sensor.
　ガスや水などを運ぶ配管からの漏洩を調査する作業においては、いかに効率よく正確に調査するかが重要である。漏洩の調査のため古くから利用されている方法として、漏洩の際に発生する音や振動を聴音する方法が知られている。しかし、本方法は熟練者しか行えないため効率が悪く、また雑音の多い時間帯や場所では正しく調査できない。 In the work of investigating leakage from pipes that carry gas or water, it is important how to investigate efficiently and accurately. As a method that has been used for a long time for investigating leaks, a method of listening to sounds and vibrations generated at the time of leaks is known. However, since this method can only be performed by skilled personnel, it is inefficient and cannot be correctly investigated in a noisy time zone or place.
　調査を効率化し、雑音の多い環境でも正しく漏洩を調査する方法の一例が、特許文献１と特許文献２に記載されている。 An example of a method for efficiently investigating and correctly investigating leakage even in a noisy environment is described in Patent Document 1 and Patent Document 2.
　特許文献１に記載の配管漏洩位置検知方法では、配管上の複数地点に間隔を置いて設置された配管設置振動センサが測定した漏洩音以外の雑音を、地盤上に設置した地盤設置振動センサが測定した信号を用いて適応デジタルフィルタによって抑圧する。そして、得られた複数の漏洩音の信号間での相互相関処理により漏洩位置が特定される。すなわち、特許文献１に記載の配管漏洩位置検知方法は、配管設置振動センサが捉えた信号と地盤設置振動センサが捉えた信号とのコヒーレンス（関連度を表す関数）が、雑音成分では大きく、漏洩音成分では小さいことを利用した雑音抑圧方法である。特許文献１に記載の配管漏洩位置検知方法は、主に移動のない固定された音源による雑音を抑圧することができる。 In the pipe leakage position detection method described in Patent Document 1, a ground installation vibration sensor installed on the ground is used to generate noise other than leakage sound measured by pipe installation vibration sensors installed at intervals on a plurality of points on the pipe. The measured signal is used for suppression by an adaptive digital filter. And a leak position is specified by the cross correlation process between the signals of the obtained several leaked sound. That is, in the pipe leakage position detection method described in Patent Document 1, the coherence (function representing the degree of association) between the signal captured by the pipe installation vibration sensor and the signal detected by the ground installation vibration sensor is large in the noise component, This is a noise suppression method using the small sound component. The pipe leakage position detection method described in Patent Document 1 can suppress noise mainly due to a fixed sound source that does not move.
　特許文献２に記載の雑音除去装置では、複数の原信号が混合された混合信号から、対象となる原信号を良好に復元することができる。 In the noise removal apparatus described in Patent Document 2, a target original signal can be satisfactorily restored from a mixed signal obtained by mixing a plurality of original signals.
特許第４１７２２４１号公報Japanese Patent No. 4172241 国際公開第２００８／１２３３１５号International Publication No. 2008/123315 特開２００６－１３８６３８号公報JP 2006-138638 A
　しかしながら、特許文献１および２に記載の技術においては、配管で捉えた雑音と地盤で捉えた雑音とのコヒーレンスが低いような雑音については抑圧できないため、精度よく漏洩検知を行うことができないという問題がある。 However, in the techniques described in Patent Documents 1 and 2, noise that has low coherence between the noise captured by the pipe and the noise captured by the ground cannot be suppressed, so that leakage detection cannot be performed with high accuracy. There is.
　本発明の主たる目的は、上記の問題を解決し、移動音源による雑音が発生する環境においても、精度よく配管からの漏洩を検知する漏洩検知装置を提供することである。 The main object of the present invention is to provide a leak detection device that solves the above-described problems and accurately detects leaks from piping even in an environment where noise is generated by a moving sound source.
　本発明の一態様における漏洩検知装置は、管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する減算手段と、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する漏洩判定手段と、を備える。 The leak detection device according to one aspect of the present invention is obtained from a first signal acquired from a sensor installed at a position where a leak sound from a pipe can be detected and a sensor installed at a position where ambient noise can be detected. Subtracting means for subtracting noise from the non-moving sound source from the first signal, and subtracting noise from the moving sound source from the first signal, and noise from the non-moving sound source and moving sound source from the first signal. Leakage determining means for determining the presence or absence of leakage based on the result.
　本発明の一態様における漏洩検知システムは、管からの漏洩音を検知可能な位置に設置された第１のセンサと、周囲雑音を検知可能な位置に設置された第２のセンサと、上述した漏洩検知装置と、を有する。 A leak detection system according to an aspect of the present invention includes a first sensor installed at a position where leakage sound from a pipe can be detected, a second sensor installed at a position where ambient noise can be detected, and the above-described sensor. And a leak detection device.
　本発明の一態様における漏洩検知方法は、管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算し、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する。 The leak detection method in one aspect of the present invention is obtained from a first signal acquired from a sensor installed at a position where a leak sound from a pipe can be detected and a sensor installed at a position where ambient noise can be detected. Based on the second signal, the noise from the non-moving sound source is subtracted from the first signal, the noise from the moving sound source is further subtracted, and the noise from the non-moving sound source and the moving sound source is subtracted from the first signal. Based on this, the presence or absence of leakage is determined.
　本発明の一態様におけるコンピュータ読み取り可能記録媒体は、管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する処理と、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する処理と、をコンピュータに実行させるプログラムを非一時的に格納する。 A computer-readable recording medium according to one embodiment of the present invention includes a first signal acquired from a sensor installed at a position where leakage sound from a tube can be detected and a sensor installed at a position where ambient noise can be detected. Based on the acquired second signal, the noise from the non-moving sound source is subtracted from the first signal, and the noise from the moving sound source is further subtracted, and the noise from the non-moving sound source and the moving sound source is subtracted from the first signal. A program for causing a computer to execute a process for determining the presence or absence of leakage based on the obtained result is stored temporarily.
　本発明は、移動音源による雑音が発生する環境においても、精度よく配管からの漏洩を検知することができる。 The present invention can accurately detect leakage from piping even in an environment where noise is generated by a moving sound source.
本発明の第１の実施形態における漏洩検知装置１０の構成を示すブロック図である。It is a block diagram which shows the structure of the leak detection apparatus 10 in the 1st Embodiment of this invention. 本発明の第１の実施形態における漏洩検知装置１０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection apparatus 10 in the 1st Embodiment of this invention. 本発明の第２の実施形態における漏洩検知装置２０の構成を示すブロック図である。It is a block diagram which shows the structure of the leak detection apparatus 20 in the 2nd Embodiment of this invention. 本発明の第２の実施形態における漏洩検知装置２０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection apparatus 20 in the 2nd Embodiment of this invention. 本発明の第３の実施形態における漏洩検知装置３０の構成を示すブロック図である。It is a block diagram which shows the structure of the leak detection apparatus 30 in the 3rd Embodiment of this invention. 本発明の第３の実施形態における漏洩検知装置３０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection apparatus 30 in the 3rd Embodiment of this invention. 本発明の第４の実施形態における漏洩検知装置４０の構成を示すブロック図である。It is a block diagram which shows the structure of the leak detection apparatus 40 in the 4th Embodiment of this invention. 本発明の第４の実施形態における漏洩検知装置４０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection apparatus 40 in the 4th Embodiment of this invention. 本発明の第５の実施形態における漏洩検知システム５０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection system 50 in the 5th Embodiment of this invention. 本発明の第５の実施形態における第１のセンサ２１および第２のセンサ２２の設置場所の一例を示す図である。It is a figure which shows an example of the installation place of the 1st sensor 21 and the 2nd sensor 22 in the 5th Embodiment of this invention. 本発明の第５の実施形態における漏洩検知システム５０の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the leak detection system 50 in the 5th Embodiment of this invention. 本発明の各実施形態におけるコンピュータ１００の構成例を示すブロック図である。It is a block diagram which shows the structural example of the computer 100 in each embodiment of this invention.
　以下、漏洩検知装置等および漏洩検知システムの各実施形態について、図面を参照して説明する。なお、各実施形態において同じ符号を付した構成要素は同様の動作を行うので、再度の説明を省略する場合がある。また、以下の各実施形態の構成を示す図面において、矢印はデータの流れの一例を示すが、データの流れは図中の矢印が示す向きに限られない。以下の各実施形態においては、管路には、気体、紛体、液体等が流れることを想定するが、これらに限定されない。 Hereinafter, embodiments of the leakage detection device and the like and the leakage detection system will be described with reference to the drawings. In addition, since the component which attached | subjected the same code | symbol in each embodiment performs the same operation | movement, re-explanation may be abbreviate | omitted. In the drawings showing the configuration of each embodiment below, an arrow indicates an example of a data flow, but the data flow is not limited to the direction indicated by the arrow in the drawing. In each of the following embodiments, it is assumed that a gas, powder, liquid, or the like flows in the pipeline, but the present invention is not limited to these.
＜第１の実施形態＞
　以下、第１の実施形態について、図面を参照して詳細に説明する。 <First Embodiment>
Hereinafter, a first embodiment will be described in detail with reference to the drawings.
　図１は、第１の実施形態における漏洩検知装置１０のブロック図である。図１を参照すると、本実施形態における漏洩検知装置１０は、減算部１１および漏洩判定部１２を備える。 FIG. 1 is a block diagram of a leak detection apparatus 10 according to the first embodiment. Referring to FIG. 1, the leak detection device 10 in this embodiment includes a subtraction unit 11 and a leak determination unit 12.
　減算部１１は、管からの漏洩音を検知可能に設置されたセンサから取得される第１の信号と周囲雑音を検知可能に設置されたセンサから取得される第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する。 The subtracting unit 11 is based on a first signal acquired from a sensor installed so as to detect leakage sound from the pipe and a second signal acquired from a sensor installed so as to detect ambient noise. The noise due to the non-moving sound source is subtracted from the signal, and further the noise due to the moving sound source is subtracted.
　第1の信号は、主に管や管を流れる気体や液体等を伝搬する音を含む信号である。管に漏洩が生じている場合には、第1の信号には漏洩音が含まれる。第1の信号を取得するセンサは、例えば管や管に付随する設備等に設置される。 The first signal is a signal that mainly includes a pipe or a sound that propagates through a gas or liquid flowing through the pipe. If the tube is leaking, the first signal includes a leaking sound. The sensor for acquiring the first signal is installed in, for example, a pipe or a facility attached to the pipe.
　また、第２の信号は、主に管の周囲地中や地表等を伝搬する雑音を含む信号である。第２の信号には、例えば非移動音源による雑音及び移動音源による雑音が含まれる。非移動音源は、例えば地面や建物等に固定された物体等、同じ地点において音を発する音源である。移動音源は、例えば車両等、移動しつつ音を発する音源である。第２の信号を取得するセンサは、例えば地表や地中などに設置される。 Further, the second signal is a signal including noise mainly propagating in the surrounding area of the pipe or on the ground surface. The second signal includes, for example, noise caused by a non-moving sound source and noise caused by a moving sound source. A non-moving sound source is a sound source that emits sound at the same point, such as an object fixed on the ground or a building. The moving sound source is a sound source that emits sound while moving, such as a vehicle. The sensor that acquires the second signal is installed, for example, on the ground surface or in the ground.
　減算部１１は、例えば、第２の信号を用いて非移動音源による雑音及び移動音源による雑音を求める。そして、減算部１１は、上述のように求めた非移動音源による雑音及び移動音源による雑音を用いて、第１の信号から、非移動音源による雑音を減算し、更に移動音源による雑音を減算する。 The subtracting unit 11 obtains, for example, noise due to the non-moving sound source and noise due to the moving sound source using the second signal. Then, the subtracting unit 11 subtracts the noise caused by the non-moving sound source from the first signal using the noise caused by the non-moving sound source and the noise caused by the moving sound source obtained as described above, and further subtracts the noise caused by the moving sound source. .
　漏洩判定部１２は、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、管からの漏洩の有無を判定する。漏洩判定部１２は、当該結果を示す信号のレベル等に基づいて、漏洩の有無を判定する。例えば、漏洩判定部１２は、当該結果を示す信号のレベルが所定の大きさと比較して大きい場合に、管からの漏洩があると判定する。 The leakage determination unit 12 determines the presence or absence of leakage from the tube based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal. The leakage determination unit 12 determines the presence or absence of leakage based on the level of a signal indicating the result. For example, the leakage determination unit 12 determines that there is leakage from the pipe when the level of the signal indicating the result is higher than a predetermined level.
　次に、第１の実施形態における漏洩検知装置１０の動作について、図２のフローチャートを用いて説明する。図２は、漏洩検知装置１０の動作を示すフローチャートである。 Next, the operation of the leak detection device 10 in the first embodiment will be described using the flowchart of FIG. FIG. 2 is a flowchart showing the operation of the leak detection apparatus 10.
　減算部１１は、第１の信号と第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する（ステップＳ１０１）。漏洩判定部１２は、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する（ステップＳ１０２）。 The subtracting unit 11 subtracts the noise due to the non-moving sound source from the first signal based on the first signal and the second signal, and further subtracts the noise due to the moving sound source (step S101). Leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal (step S102).
　以上で、第１の実施形態における漏洩検知装置１０の動作が終了する。 This completes the operation of the leak detection device 10 in the first embodiment.
　上記構成を有する漏洩検知装置１０は、第１の信号と第２の信号に基づき、第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する。第1の信号には、一般に、漏洩に起因して生じる漏洩音と、非移動音源および移動音源による雑音とが含まれる。第２の信号には、一般に、非移動音源および移動音源による雑音とが含まれる。漏洩検知装置１０は、第１の信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する。したがって、漏洩検知装置１０は、非移動音源による雑音と、移動音源による雑音の両方を抑圧することで、移動音源による雑音が発生する環境においても精度よく配管からの漏洩を検知することができる。 The leak detection apparatus 10 having the above configuration subtracts noise caused by a non-moving sound source from the first signal based on the first signal and the second signal, and further subtracts noise caused by the moving sound source. The first signal generally includes leaked sound caused by leak and noise caused by a non-moving sound source and a moving sound source. The second signal generally includes non-moving sound sources and noise caused by moving sound sources. The leak detection device 10 determines whether there is a leak based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal. Therefore, the leak detection device 10 can detect leaks from the pipes accurately even in an environment where noise due to the moving sound source is generated by suppressing both noise due to the non-moving sound source and noise due to the moving sound source.
＜第２の実施形態＞
　以下、第２の実施形態について、図面を参照して詳細に説明する。 <Second Embodiment>
Hereinafter, the second embodiment will be described in detail with reference to the drawings.
　図３は、第２の実施形態における漏洩検知装置２０のブロック図である。図３を参照すると、本実施形態における漏洩検知装置２０は、減算部１１および漏洩判定部１２を備える。減算部１１は減算スペクトル算出部１３と、減算振幅スペクトル算出部１４を備える。 FIG. 3 is a block diagram of the leak detection device 20 according to the second embodiment. Referring to FIG. 3, the leakage detection device 20 in the present embodiment includes a subtraction unit 11 and a leakage determination unit 12. The subtraction unit 11 includes a subtraction spectrum calculation unit 13 and a subtraction amplitude spectrum calculation unit 14.
　減算スペクトル算出部１３は、第１の信号および第２の信号に基づき、第１の信号の減算スペクトル、および第２の信号のスペクトルを算出する。第１の信号の減算スペクトルは、例えば第１の信号のスペクトルから非移動音源による雑音が減算されたスペクトルを示す。減算振幅スペクトル算出部１４は、第１の信号の減算スペクトルと第２の信号のスペクトルに基づき、第１の信号の振幅スペクトルを算出する。第１の信号の振幅スペクトルは、例えば第１の信号のスペクトルから非移動音源および移動音源による雑音が減算された振幅スペクトルを示す。 The subtraction spectrum calculation unit 13 calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal. The subtraction spectrum of the first signal indicates, for example, a spectrum obtained by subtracting noise from a non-moving sound source from the spectrum of the first signal. The subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal. The amplitude spectrum of the first signal indicates, for example, an amplitude spectrum obtained by subtracting noise from the non-moving sound source and the moving sound source from the spectrum of the first signal.
　漏洩判定部１２は、非移動音源および移動音源による雑音が減算された第１の信号の振幅スペクトルから、管からの漏洩の有無を判定する。漏洩判定部１２は、第１の信号の振幅スペクトルが示す振幅の大きさなどに基づいて管からの漏洩の有無を判定する。 The leakage determination unit 12 determines whether there is leakage from the tube from the amplitude spectrum of the first signal obtained by subtracting noise from the non-moving sound source and the moving sound source. The leak determination unit 12 determines whether there is a leak from the tube based on the magnitude of the amplitude indicated by the amplitude spectrum of the first signal.
　次に、第２の実施形態における漏洩検知装置２０の動作について、図４のフローチャートを用いて説明する。図４は、漏洩検知装置２０の動作を示すフローチャートである。 Next, the operation of the leak detection apparatus 20 in the second embodiment will be described using the flowchart of FIG. FIG. 4 is a flowchart showing the operation of the leak detection device 20.
　減算スペクトル算出部１３は、第１の信号と第２の信号に基づき、第１の信号の減算スペクトル、および第２の信号のスペクトルを算出する（ステップＳ２０１）。減算振幅スペクトル算出部１４は、第１の信号の減算スペクトルと第２の信号のスペクトルに基づき、第１の信号の振幅スペクトルを算出する（ステップＳ２０２）。漏洩判定部１２は、第１の信号の振幅スペクトルから、管の漏洩の有無を判定する（ステップＳ２０３）。 The subtraction spectrum calculation unit 13 calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal (step S201). The subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal (step S202). Leakage determination unit 12 determines the presence or absence of leakage of the tube from the amplitude spectrum of the first signal (step S203).
　以上で、第２の実施形態における漏洩検知装置２０の動作が終了する。 This completes the operation of the leak detection device 20 in the second embodiment.
　上記構成を有する漏洩検知装置２０は、第１の信号と第２の信号に基づき、第１の信号の減算スペクトル、および第２の信号のスペクトルを算出する。第１の信号の減算スペクトルは、上述のように、例えば第１の信号のスペクトルから非移動音源による雑音が減算されたスペクトルを示す。漏洩検知装置２０は、第１の信号の減算スペクトルと第２の信号のスペクトルに基づき、第１の信号の振幅スペクトルを算出する。第１の信号の振幅スペクトルは、上述のように、例えば第１の信号のスペクトルから非移動音源および移動音源による雑音が減算された振幅スペクトルを示す。漏洩検知装置２０は、第１の信号の振幅スペクトルから、管からの漏洩の有無を判定する。 The leak detection device 20 having the above configuration calculates the subtraction spectrum of the first signal and the spectrum of the second signal based on the first signal and the second signal. As described above, the subtracted spectrum of the first signal indicates a spectrum obtained by subtracting noise from a non-moving sound source from the spectrum of the first signal, for example. The leak detection device 20 calculates the amplitude spectrum of the first signal based on the subtraction spectrum of the first signal and the spectrum of the second signal. As described above, the amplitude spectrum of the first signal indicates, for example, an amplitude spectrum obtained by subtracting noise from the non-moving sound source and the moving sound source from the spectrum of the first signal. The leak detection device 20 determines whether there is a leak from the tube from the amplitude spectrum of the first signal.
　したがって、漏洩検知装置２０は、非移動音源による雑音と、移動音源による雑音の両方が抑圧された第１の信号の振幅スペクトルを判定することで、移動音源による雑音が発生する環境においても、精度よく配管からの漏洩を検知することができる。 Therefore, the leak detection apparatus 20 determines the amplitude spectrum of the first signal in which both the noise caused by the non-moving sound source and the noise caused by the moving sound source are suppressed. It is possible to detect leaks from piping well.
＜第３の実施形態＞
　以下、第３の実施形態について、図面を参照して詳細に説明する。 <Third Embodiment>
Hereinafter, the third embodiment will be described in detail with reference to the drawings.
　図５は、第３の実施形態における漏洩検知装置３０のブロック図である。図５を参照すると、本実施形態における漏洩検知装置３０は、漏洩検知装置３０は、減算部１１および漏洩判定部１２を備える。減算部１１は減算スペクトル算出部１３と、減算振幅スペクトル算出部１４を備える。減算スペクトル算出部１３は、スペクトル算出部１５と、スペクトル減算部１６を備える。減算振幅スペクトル算出部１４は、振幅スペクトル算出部１７と、振幅スペクトル減算部１８を備える。 FIG. 5 is a block diagram of the leak detection device 30 in the third embodiment. Referring to FIG. 5, the leak detection device 30 in the present embodiment includes the subtraction unit 11 and the leak determination unit 12. The subtraction unit 11 includes a subtraction spectrum calculation unit 13 and a subtraction amplitude spectrum calculation unit 14. The subtraction spectrum calculation unit 13 includes a spectrum calculation unit 15 and a spectrum subtraction unit 16. The subtraction amplitude spectrum calculation unit 14 includes an amplitude spectrum calculation unit 17 and an amplitude spectrum subtraction unit 18.
　スペクトル算出部１５は、第１の信号（以下、「管信号」とする場合がある）と第２の信号（以下、「地盤信号」とする場合がある）とから、管信号のスペクトルである管信号スペクトルおよび地盤信号のスペクトルである地盤信号スペクトルを算出する。管信号は、例えば管や管に付随する設備等に設置されたセンサによって取得される。また、地盤信号は、地表や地中などに設置されたセンサによって取得される。スペクトル算出部１５は、例えば、管信号ｘ1（ｔ）から、フーリエ変換やウェーブレット変換等により管信号の周波数スペクトルである管信号スペクトルＸ1,i（ｆ）を算出する。 The spectrum calculation unit 15 is a spectrum of the tube signal from the first signal (hereinafter sometimes referred to as “tube signal”) and the second signal (hereinafter sometimes referred to as “ground signal”). A ground signal spectrum that is a tube signal spectrum and a ground signal spectrum is calculated. The tube signal is acquired by a sensor installed in, for example, a tube or a facility attached to the tube. The ground signal is acquired by a sensor installed on the ground surface or underground. For example, the spectrum calculation unit 15 calculates the tube signal spectrum X 1, i (f) , which is the frequency spectrum of the tube signal, from the tube signal x 1 (t) by Fourier transform, wavelet transform, or the like.
　また、スペクトル算出部１５は、例えば、地盤信号ｘ2（ｔ）から、同様に地盤の周波数スペクトルである地盤信号スペクトルＸ2,i（ｆ）を算出する。ここで、Ｘ1,i（ｆ）およびＸ2,i（ｆ）は、ｉ番目の時間における周波数ｆのスペクトルである。Ｘ1,i（ｆ）およびＸ2,i（ｆ）は、振幅成分と位相成分の両方を含む。したがって、Ｘ1,i（ｆ）およびＸ2,i（ｆ）は、複素数で表される。 Further, the spectrum calculating unit 15, for example, from the ground signal x 2 (t), similarly calculated is a frequency spectrum of the ground Ground signal spectrum X 2, i (f). Here, X 1, i (f) and X 2, i (f) are spectra of the frequency f at the i-th time. X 1, i (f) and X 2, i (f) include both an amplitude component and a phase component. Therefore, X 1, i (f) and X 2, i (f) are represented by complex numbers.
　スペクトル減算部１６は、管信号スペクトルから、減算スペクトル係数と地盤信号スペクトルの積を減算する。スペクトル減算部１６は、例えば、管信号スペクトルＸ1,i（ｆ）から地盤スペクトルＸ2,i（ｆ）を減算した、減算スペクトルを算出する。前述のようにＸ1,i（ｆ）とＸ2,i（ｆ）はいずれも振幅成分と位相成分の両方を含むため、振幅の時間変化と位相の時間変化の両方に相関がある場合に、雑音を減算する効果が高くなる。つまりスペクトル減算部１６では、Ｘ1,i（ｆ）とＸ2,i（ｆ）のコヒーレンスの高い雑音である、非移動音源による雑音を減算することができる。すなわち、減算スペクトルは、管信号スペクトルから非移動音源による雑音が減算されたスペクトルである。スペクトル減算部１６は、例えば数式１（以降、数１と記載する）を用いて減算スペクトルを算出する。 The spectrum subtraction unit 16 subtracts the product of the subtraction spectrum coefficient and the ground signal spectrum from the tube signal spectrum. For example, the spectrum subtraction unit 16 calculates a subtraction spectrum obtained by subtracting the ground spectrum X 2, i (f) from the tube signal spectrum X 1, i (f). As described above, since X 1, i (f) and X 2, i (f) both include both an amplitude component and a phase component, there is a correlation between both the time variation of the amplitude and the time variation of the phase. The effect of subtracting noise increases. That is, the spectrum subtracting unit 16 can subtract noise caused by a non-moving sound source, which is noise with high coherence between X 1, i (f) and X 2, i (f). That is, the subtracted spectrum is a spectrum obtained by subtracting noise due to a non-moving sound source from the tube signal spectrum. The spectrum subtracting unit 16 calculates a subtracted spectrum using, for example, Equation 1 (hereinafter described as Equation 1).
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　数１で示すように、減算スペクトルであるＳa,i（ｆ）は、管信号スペクトルＸ1,i（ｆ）から減算スペクトル係数（以下、「第１の係数」とする場合がある）ｋa（ｆ）と地盤スペクトルＸ2,i（ｆ）との積を減算して算出される。減算スペクトル係数ｋa（ｆ）は、数２を用いて算出される。 As shown in Equation 1, the subtracted spectrum S a, i (f) is subtracted from the tube signal spectrum X 1, i (f) (hereinafter, may be referred to as “first coefficient”) k. It is calculated by subtracting the product of a (f) and the ground spectrum X 2, i (f). Subtraction spectral coefficients k a (f) is calculated using equation 2.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　Ｅ［｜Ｘ1,i（ｆ）｜2］およびＥ［｜Ｘ2,i（ｆ）｜2］は、ｉについての時間平均を表す。Ｒ12（ｆ）は、Ｘ1,i（ｆ）とＸ2,i（ｆ）の相関係数であり、数３で表される。 E [| X 1, i (f) | 2 ] and E [| X 2, i (f) | 2 ] represent the time average for i. R 12 (f) is a correlation coefficient between X 1, i (f) and X 2, i (f), and is expressed by Equation 3.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　Ｘ2,i *（ｆ）はＸ2,i（ｆ）の複素共役である。また、以下に記載する数４から数６を用いることで、数２が導かれる。さらに、Ｘ1,i（ｆ）は数４を用いて書き表せる。その理由としては、地盤信号スペクトルＸ2,i（ｆ）には主に雑音成分が含まれ漏洩音成分Ｃi（ｆ）はほぼ含まれないと想定され、また、管信号スペクトルＸ1,i（ｆ）には漏洩音成分Ｃi（ｆ）および地盤から伝わってきた雑音成分ｋa（ｆ）Ｘ2,i（ｆ）が含まれるためである。 X 2, i * (f) is a complex conjugate of X 2, i (f). Moreover, Formula 2 is derived | led-out by using Formula 4 to Formula 6 described below. Furthermore, X 1, i (f) can be expressed using Equation 4. The reason is that the ground signal spectrum X 2, i (f) mainly includes a noise component and the leaked sound component C i (f) is hardly included, and the tube signal spectrum X 1, i This is because (f) includes the leaked sound component C i (f) and the noise component k a (f) X 2, i (f) transmitted from the ground.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　Ｃi（ｆ）とＸ2,i（ｆ）が無相関であるため、Ｘ1,i（ｆ）とＸ2,i（ｆ）との積の時間平均は、数５によって表される。 Since C i (f) and X 2, i (f) are uncorrelated, the time average of the product of X 1, i (f) and X 2, i (f) is expressed by Equation 5.
Figure JPOXMLDOC01-appb-M000005
Figure JPOXMLDOC01-appb-M000005
　また、数５から、減算スペクトル係数ｋa（ｆ）は数６によって表される。 Further, from equation (5) subtracts the spectral coefficient k a (f) is represented by Equation 6.
Figure JPOXMLDOC01-appb-M000006
Figure JPOXMLDOC01-appb-M000006
　数２は、数６に数３を当てはめることで導出される。このように、数４で表される雑音は、数１に数６の減算スペクトル係数ｋa（ｆ）を利用するスペクトル減算部１６での減算方法を用いることで、抑圧される。雑音成分が管信号に多く含まれているほど、つまり管信号スペクトルと地盤信号スペクトルの相関が大きいほど、地盤信号を減算する割合が大きくなる。 Equation 2 is derived by applying Equation 3 to Equation 6. Thus, noise which is represented by the number 4, by using the subtraction method in the spectral subtraction unit 16 to use the number 1 to number 6 for subtraction spectral coefficients k a (f), is suppressed. The more noise components are included in the tube signal, that is, the greater the correlation between the tube signal spectrum and the ground signal spectrum, the greater the proportion of subtraction of the ground signal.
　振幅スペクトル算出部１７は、減算スペクトルおよび地盤信号スペクトルから、非移動音源による雑音が減算された管信号の振幅スペクトル、および地盤信号の振幅スペクトルを算出する。管信号の振幅スペクトルは、スペクトル減算部１６にて算出された、非移動音源による雑音が減算された管信号スペクトルである減算スペクトルの振幅成分を示す。振幅スペクトル算出部１７は、例えば、管信号の振幅スペクトルを、数７より算出する。 The amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal and the amplitude spectrum of the ground signal obtained by subtracting noise from the non-moving sound source from the subtraction spectrum and the ground signal spectrum. The amplitude spectrum of the tube signal indicates the amplitude component of the subtracted spectrum, which is the tube signal spectrum calculated by the spectrum subtracting unit 16 and subtracted with noise due to the non-moving sound source. For example, the amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal from Equation 7.
Figure JPOXMLDOC01-appb-M000007
Figure JPOXMLDOC01-appb-M000007
　管信号の振幅スペクトルＹ1,i（ｆ）は減算スペクトルＳa,i（ｆ）の絶対値である。振幅スペクトル算出部１７は、スペクトル算出部１５で算出した地盤信号スペクトルの振幅成分である地盤信号の振幅スペクトルを、数８より算出する。 The amplitude spectrum Y 1, i (f) of the tube signal is the absolute value of the subtraction spectrum S a, i (f). The amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the ground signal, which is the amplitude component of the ground signal spectrum calculated by the spectrum calculation unit 15, from Equation 8.
Figure JPOXMLDOC01-appb-M000008
Figure JPOXMLDOC01-appb-M000008
　地盤信号の振幅スペクトルＹ2,i（ｆ）は地盤信号スペクトルＸ2,i（ｆ）の絶対値である。 The amplitude spectrum Y 2, i (f) of the ground signal is the absolute value of the ground signal spectrum X 2, i (f).
　振幅スペクトル減算部１８は、管の振幅スペクトルＹ1,i（ｆ）から地盤の振幅スペクトルＹ2,i（ｆ）の相関のある成分を減算した、減算振幅スペクトルＳb,i（ｆ）を算出する。減算振幅スペクトルは、減算スペクトルから移動音源による雑音が減算されたスペクトルの振幅成分に相当するとみなすことができる。 The amplitude spectrum subtracting unit 18 calculates a subtracted amplitude spectrum Sb, i (f) by subtracting a correlated component of the ground amplitude spectrum Y 2, i (f) from the tube amplitude spectrum Y 1, i (f). To do. The subtracted amplitude spectrum can be regarded as corresponding to the amplitude component of the spectrum obtained by subtracting noise from the moving sound source from the subtracted spectrum.
　以下に記載の数９から数２０を用いて、減算振幅スペクトルＳb,i（ｆ）の算出方法を説明する。数９および数１０は、Ｙ1,i（ｆ）とＹ2,i（ｆ）をそれぞれ、固定的な信号成分である固定成分Ｂ1（ｆ）およびＢ2（ｆ）と、変動的な信号成分である変動成分Ｚ1,i（ｆ）およびＺ2,i（ｆ）で表す。ここでいう「固定的な信号成分」とは時間的な変動が小さい信号成分である。また、「変動的な信号成分」とは時間的な変動のある信号成分である。 The calculation method of the subtraction amplitude spectrum S b, i (f) will be described using Equations 9 to 20 described below. Equations (9) and (10) show that Y 1, i (f) and Y 2, i (f) are fixed signal components B 1 (f) and B 2 (f), which are fixed signal components, respectively. It is represented by fluctuation components Z 1, i (f) and Z 2, i (f) which are signal components. Here, the “fixed signal component” is a signal component with small temporal variation. Further, the “variable signal component” is a signal component having temporal variation.
Figure JPOXMLDOC01-appb-M000009
Figure JPOXMLDOC01-appb-M000009
　地盤信号の振幅スペクトルＹ2,i（ｆ）は、地盤信号の変動成分Ｚ2,i（ｆ）と地盤信号の固定成分Ｂ2（ｆ）との和で表される。 Amplitude spectrum Y2 of the ground signal, i (f) is expressed by the sum of the variation component of the ground signal Z2, and i (f) fixing component of the ground signals B 2 and (f).
Figure JPOXMLDOC01-appb-M000010
Figure JPOXMLDOC01-appb-M000010
　管信号の振幅スペクトルＹ1,i（ｆ）は、管信号の変動成分Ｚ1,i（ｆ）と管信号の固定成分Ｂ1（ｆ）との和で表される。管信号の変動成分Ｚ1,i（ｆ）は、主に雑音成分を含む。管信号の変動成分Ｚ1,i（ｆ）は、数１１に示すように地盤から伝わってきた雑音成分Ｚ12,i（ｆ）と、それ以外の雑音成分Ｚ11,i（ｆ）との和で表せる。 The amplitude spectrum Y 1, i (f) of the tube signal is represented by the sum of the fluctuation component Z 1, i (f) of the tube signal and the fixed component B 1 (f) of the tube signal. The fluctuation component Z 1, i (f) of the tube signal mainly includes a noise component. The fluctuation component Z 1, i (f) of the tube signal is a noise component Z 12, i (f) transmitted from the ground as shown in Equation 11 and other noise components Z 11, i (f). It can be expressed as a sum.
Figure JPOXMLDOC01-appb-M000011
Figure JPOXMLDOC01-appb-M000011
　振幅スペクトル減算部１８は、地中などから伝わってきた雑音成分Ｚ12,i（ｆ）を減算する。これは、数１２によって表される。 The amplitude spectrum subtraction unit 18 subtracts the noise component Z 12, i (f) transmitted from the ground. This is represented by Equation 12.
Figure JPOXMLDOC01-appb-M000012
Figure JPOXMLDOC01-appb-M000012
　地中などから伝わってきた雑音成分Ｚ12,i（ｆ）は、減算振幅スペクトル係数（以下、「第２の係数」とする場合がある）ｋb（ｆ）と地盤の変動成分Ｚ2,i（ｆ）との積である。振幅スペクトル減算部１８は、数１３を用いて減算振幅スペクトルＳb,i（ｆ）を算出する。 The noise component Z 12, i (f) transmitted from the ground or the like is a subtracted amplitude spectrum coefficient (hereinafter sometimes referred to as “second coefficient”) k b (f) and a ground fluctuation component Z 2. i is the product of (f). The amplitude spectrum subtraction unit 18 calculates the subtraction amplitude spectrum S b, i (f) using Equation 13.
Figure JPOXMLDOC01-appb-M000013
Figure JPOXMLDOC01-appb-M000013
　減算振幅スペクトルＳb,i（ｆ）は、管信号の振幅スペクトルＹ1,i（ｆ）から、減算振幅スペクトル係数ｋb（ｆ）と地盤の変動成分Ｚ2,i（ｆ）との積を減算して算出される。 The subtracted amplitude spectrum S b, i (f) is the product of the subtracted amplitude spectrum coefficient k b (f) and the ground fluctuation component Z 2, i (f) from the amplitude spectrum Y 1 , i (f) of the tube signal. Is calculated by subtracting.
　減算振幅スペクトル係数ｋb（ｆ）は、例えば雑音源までの距離が２センサ間の距離に対して十分大きいなど、管信号と地盤信号の振幅成分が同程度の場合、１となる。また、減算振幅スペクトル係数ｋb（ｆ）は、例えば、減算スペクトル係数ｋa（ｆ）の場合と同様に、数１４を用いて算出される。 The subtracted amplitude spectrum coefficient k b (f) is 1 when the amplitude components of the tube signal and the ground signal are approximately the same, for example, the distance to the noise source is sufficiently larger than the distance between the two sensors. Further, the subtraction amplitude spectrum coefficient k b (f) is calculated using Equation 14 in the same manner as in the case of the subtraction spectrum coefficient k a (f), for example.
Figure JPOXMLDOC01-appb-M000014
Figure JPOXMLDOC01-appb-M000014
　ここで、Ｙ’1,i（ｆ）とＹ’2,i（ｆ）は、それぞれＹ1,i（ｆ）とＹ2,i（ｆ）の平均からの変動成分を表し、数１５，数１６のそれぞれで表される。 Here, Y ′ 1, i (f) and Y ′ 2, i (f) represent fluctuation components from the average of Y 1, i (f) and Y 2, i (f), respectively. It is represented by each of Equation 16.
Figure JPOXMLDOC01-appb-M000015
Figure JPOXMLDOC01-appb-M000015
　数１５に示すように、管信号の振幅スペクトルＹ1,i（ｆ）の変動成分であるＹ’1,i（ｆ）は、管信号の振幅スペクトルＹ1,i（ｆ）と管信号の振幅スペクトルＹ1,i（ｆ）の時間平均Ｅ［Ｙ1,i（ｆ）］との差として表される。 As shown in Equation 15, which is the fluctuation component of the tube signal amplitude spectrum Y 1, i (f) Y '1, i (f) is the amplitude spectrum Y 1, i (f) a tube signal tube signal It is expressed as a difference from the time average E [Y 1, i (f)] of the amplitude spectrum Y 1, i (f).
Figure JPOXMLDOC01-appb-M000016
Figure JPOXMLDOC01-appb-M000016
　数１６に示すように、地盤信号の振幅スペクトルＹ2,i（ｆ）の変動成分であるＹ’2,i（ｆ）は、地盤信号の振幅スペクトルＹ2,i（ｆ）と地盤信号の振幅スペクトルＹ2,i（ｆ）の時間平均Ｅ［Ｙ2,i（ｆ）］との差として表される。数１４の右辺に記載のＲb 12（ｆ）は、Ｙ’1,i（ｆ）とＹ’2,i（ｆ）とから算出された場合の相関係数であり、数１７で表される。 As shown in Equation 16, Y ′ 2, i (f) , which is a fluctuation component of the amplitude spectrum Y 2, i (f) of the ground signal, represents the amplitude spectrum Y 2, i (f) of the ground signal and the amplitude of the ground signal. It is expressed as a difference from the time average E [Y 2, i (f)] of the spectrum Y 2, i (f). R b 12 (f) described on the right side of Equation 14 is a correlation coefficient when calculated from Y ′ 1, i (f) and Y ′ 2, i (f). The
Figure JPOXMLDOC01-appb-M000017
Figure JPOXMLDOC01-appb-M000017
　減算振幅スペクトル算出部１４における処理と同様に、数１２で表される雑音は、数１３に対して、数１４の減算振幅スペクトル係数ｋb（ｆ）を用いることで抑圧される。数１３におけるＺ2,i（ｆ）は、数９を変形した数１８から求められる。 Similar to the processing in the subtraction amplitude spectrum calculation unit 14, the noise represented by Expression 12 is suppressed by using the subtraction amplitude spectrum coefficient k b (f) of Expression 14 with respect to Expression 13. Z 2, i (f) in Expression 13 is obtained from Expression 18 obtained by transforming Expression 9.
Figure JPOXMLDOC01-appb-M000018
Figure JPOXMLDOC01-appb-M000018
　Ｂ2（ｆ）は、例えばＹ2,i（ｆ）の移動平均値の最小値や、２５パーセンタイル値、中央値、平均値等として算出される。また、管信号の固定成分Ｂ1（ｆ）が地盤信号の固定成分Ｂ1（ｆ）から伝搬した成分であると仮定すると、数１３の代わりに、数１９が利用できる。 B 2 (f) is calculated, for example , as the minimum value of the moving average value of Y 2, i (f), the 25th percentile value, the median value, the average value, or the like. Further, when the fixed component B 1 of the pipe signal (f) is assumed to be a component that is propagated from the fixed component B 1 of the ground signal (f), instead of the number 13, number 19 can be used.
Figure JPOXMLDOC01-appb-M000019
Figure JPOXMLDOC01-appb-M000019
　数１９の右辺第三項であるｋd（ｆ）Ｂ2（ｆ）は、地盤信号から管に伝搬する雑音の中で、コヒーレンスや振幅コヒーレンス（振幅成分のみで算出したコヒーレンス）では捉えられない雑音成分を表す。ここで、コヒーレンスや振幅コヒーレンスでは捉えられない雑音成分とは、コヒーレンスも振幅コヒーレンスも小さいために、数１および数１３では減算できなかった雑音成分である。 K d (f) B 2 (f), which is the third term on the right-hand side of Equation 19, cannot be captured by coherence or amplitude coherence (coherence calculated only from the amplitude component) in noise propagating from the ground signal to the tube. Represents a noise component. Here, the noise component that cannot be captured by coherence or amplitude coherence is a noise component that cannot be subtracted in Equations 1 and 13 because both the coherence and the amplitude coherence are small.
　また、係数ｋd（ｆ）は任意の実数である。係数ｋd（ｆ）は、実測から最適値が設定されてもよいし、減算振幅スペクトル係数ｋb（ｆ）が係数ｋd（ｆ）に流用されてもよい。これらの値が分からない場合には、係数ｋｄ（ｆ）は０とされてもよい。係数ｋd（ｆ）が減算振幅スペクトル係数ｋb（ｆ）と等しい場合は、数１９は数２０と変形できる。 The coefficient k d (f) is an arbitrary real number. The coefficient k d (f) may be set to an optimum value from actual measurement, or the subtraction amplitude spectrum coefficient k b (f) may be used as the coefficient k d (f). If these values are not known, the coefficient k d (f) may be set to zero. When the coefficient kd (f) is equal to the subtracted amplitude spectrum coefficient k b (f), Expression 19 can be transformed to Expression 20.
Figure JPOXMLDOC01-appb-M000020
Figure JPOXMLDOC01-appb-M000020
　数１３、数１９、数２０において、減算振幅スペクトルＳb,i（ｆ）が負になるような周波数ｆ＝ｆ1が存在した場合は、例えばＳb,i（ｆ1）に０または正の実数を代入するか、ｆ1の近傍の周波数ｆ2の場合のＳb,i（ｆ2）をＳb,i（ｆ1）に代入してもよい。 In the equations (13), (19) , and (20), if there is a frequency f = f 1 that makes the subtraction amplitude spectrum S b, i (f) negative, for example, S b, i (f 1 ) is 0 or positive. or substituting the real, S b when the frequency f2 in the vicinity of f 1, i and (f 2) may be substituted into S b, i (f 1) .
　漏洩判定部１２は、振幅スペクトル減算部１８が算出した減算スペクトル２から、漏洩の有無を判定する。漏洩判定部１２は、例えば、漏洩に特徴的なスペクトルピークやスペクトル変動等の有無に基づいて漏洩の有無を判定する。漏洩判定部１２は、図示しない表示装置等に減算スペクトル２をスペクトログラム表示させてもよい。この場合には、漏洩に特徴的なスペクトルピークやスペクトル変動等の有無を作業員が判断してもよい。
また、漏洩判定部１２は、減算スペクトル２の振幅やパワーに基づいて算出した周波数ｆごとの音圧レベルが、事前に設定した閾値θ（ｆ）を超えるようなｆが存在する場合に漏洩有と判定してもよい。 The leakage determination unit 12 determines the presence or absence of leakage from the subtraction spectrum 2 calculated by the amplitude spectrum subtraction unit 18. For example, the leakage determination unit 12 determines the presence or absence of leakage based on the presence or absence of a spectrum peak or spectrum variation characteristic of leakage. The leak determination unit 12 may cause the subtracted spectrum 2 to be displayed as a spectrogram on a display device (not shown). In this case, the operator may determine whether or not there is a spectrum peak or spectrum fluctuation characteristic of leakage.
In addition, the leak determination unit 12 has a leak if f exists such that the sound pressure level for each frequency f calculated based on the amplitude and power of the subtraction spectrum 2 exceeds a preset threshold value θ (f). May be determined.
　上記の音圧レベルとしては、例えば、減算振幅スペクトルＳb,i（ｆ）またはパワー｜Ｓb,i（ｆ）｜2の時間ｉについての最小値が用いられることで、スペクトル減算部１６または振幅スペクトル減算部１８で減算しきれなかった突発的な雑音の影響を最小限にすることができる。上述した最小値の代わりに、移動平均値の最小値や、２５パーセンタイル値、中央値、平均値等が用いられてもよい。時間ｉの範囲は、雑音の発生時間に対して十分長くなるように設定する。閾値θ（ｆ）は、経験値から求められてもよいし、過去の非漏洩時に測定した信号または他箇所の漏洩の無い場所で測定した信号から暗騒音スペクトルを算出し、暗騒音スペクトルの音圧レベルとして決定されてもよい。あるいは、漏洩判定部１２は、一定時間以上に渡って継続して発生しているスペクトルピークや、安定して発生しているスペクトルピークが検出された場合に、自動的に漏洩有と判定してもよい。あるいは、漏洩判定部１２は、暗騒音スペクトルとの比較を行い、暗騒音スペクトルには現れなかったピークが現れた場合など、変化があった場合に、漏洩有と判定してもよい。 As the sound pressure level, for example, the minimum value of the subtraction amplitude spectrum S b, i (f) or the power | S b, i (f) | 2 for the time i is used. The influence of sudden noise that cannot be subtracted by the amplitude spectrum subtracting unit 18 can be minimized. Instead of the minimum value described above, the minimum value of the moving average value, the 25th percentile value, the median value, the average value, or the like may be used. The range of time i is set to be sufficiently long with respect to the noise generation time. The threshold value θ (f) may be obtained from an empirical value, or a background noise spectrum is calculated from a signal measured at a past non-leakage or a signal measured at a place without other leakage, and the sound of the background noise spectrum is calculated. It may be determined as a pressure level. Alternatively, the leak determination unit 12 automatically determines that there is a leak when a spectrum peak that is continuously generated over a certain time or a spectrum peak that is stably generated is detected. Also good. Alternatively, the leakage determination unit 12 may perform comparison with the background noise spectrum and determine that there is leakage when there is a change, such as when a peak that does not appear in the background noise spectrum appears.
　次に、第３の実施形態における漏洩検知装置３０の動作について、図６のフローチャートを用いて説明する。図６は、漏洩検知装置３０の動作を示すフローチャートである。 Next, the operation of the leak detection device 30 in the third embodiment will be described using the flowchart of FIG. FIG. 6 is a flowchart showing the operation of the leak detection device 30.
　スペクトル算出部１５は、管信号および地盤信号から管信号のスペクトルおよび地盤信号のスペクトルを算出する（ステップＳ３０１）。スペクトル減算部１６は、管信号のスペクトルから、減算スペクトル係数と地盤信号のスペクトルとの積を減算する（ステップＳ３０２）。ここで、減算スペクトル係数（第１の係数）は、例えば、管信号のスペクトルと地盤信号のスペクトルの相関係数に基づいて算出される。 The spectrum calculation unit 15 calculates the spectrum of the tube signal and the spectrum of the ground signal from the tube signal and the ground signal (step S301). The spectrum subtracting unit 16 subtracts the product of the subtracted spectrum coefficient and the spectrum of the ground signal from the spectrum of the tube signal (step S302). Here, the subtraction spectral coefficient (first coefficient) is calculated based on, for example, the correlation coefficient between the spectrum of the tube signal and the spectrum of the ground signal.
　振幅スペクトル算出部１７は、減算スペクトル係数と地盤信号のスペクトルとの積が減算された管信号のスペクトルおよび地盤信号のスペクトルから管信号の振幅スペクトルおよび地盤信号の振幅スペクトルを算出する（ステップＳ３０３）。 The amplitude spectrum calculation unit 17 calculates the amplitude spectrum of the tube signal and the amplitude spectrum of the ground signal from the spectrum of the tube signal and the spectrum of the ground signal obtained by subtracting the product of the subtracted spectrum coefficient and the spectrum of the ground signal (step S303). .
　減算振幅スペクトル算出部１８は、管信号の振幅スペクトルから、減算振幅スペクトル係数（第２の係数）と地盤信号の振幅スペクトルとの積を減算する（ステップＳ３０４）。 The subtraction amplitude spectrum calculation unit 18 subtracts the product of the subtraction amplitude spectrum coefficient (second coefficient) and the amplitude spectrum of the ground signal from the amplitude spectrum of the tube signal (step S304).
　漏洩判定部１２は、減算された管信号の振幅スペクトルから管の漏洩の有無を判定する（ステップＳ３０５）。 The leak determination unit 12 determines whether or not there is a leak from the tube from the subtracted amplitude spectrum of the tube signal (step S305).
　以上で、第３の実施形態における漏洩検知装置３０の動作が終了する。 This completes the operation of the leak detection device 30 in the third embodiment.
　上記構成を有する漏洩検知装置３０は、管信号と地盤信号に基づき、減算スペクトルと地盤信号のスペクトルを算出する。漏洩検知装置３０は、減算スペクトルと地盤信号のスペクトルに基づき、減算振幅スペクトルを算出する。漏洩検知装置３０は、減算振幅スペクトルを用いて、管の漏洩の有無を判定する。 The leak detection device 30 having the above configuration calculates the subtraction spectrum and the spectrum of the ground signal based on the tube signal and the ground signal. The leak detection device 30 calculates a subtraction amplitude spectrum based on the subtraction spectrum and the spectrum of the ground signal. The leak detection device 30 determines whether or not there is a leak in the pipe using the subtracted amplitude spectrum.
　したがって、第３の実施形態における漏洩検知装置３０は、管信号と地盤信号との間で、移動音源による雑音振幅スペクトルの相関が大きいという特徴を利用して漏洩の検知を行う。
漏洩検知装置３０は、スペクトル減算を２段階にて行う。漏洩検知装置３０は、１段階目ではコヒーレンスの高い雑音を減算し、２段階目では振幅コヒーレンスの高い雑音を減算する。 Therefore, the leak detection device 30 according to the third embodiment performs leak detection using the feature that the correlation of the noise amplitude spectrum by the moving sound source is large between the tube signal and the ground signal.
The leak detection device 30 performs spectral subtraction in two stages. The leak detection device 30 subtracts noise with high coherence in the first stage and subtracts noise with high amplitude coherence in the second stage.
　すなわち、漏洩検知装置３０は、非移動音源による雑音と、移動音源による雑音の両方が抑圧された減算振幅スペクトルを判定することで、移動音源による雑音が発生する環境においても、精度よく配管からの漏洩を検知することができる。 In other words, the leak detection device 30 determines the subtraction amplitude spectrum in which both the noise caused by the non-moving sound source and the noise caused by the moving sound source are suppressed. Leakage can be detected.
　ここで、上述した特許文献１の方法では、移動音源による雑音の特に高周波数帯について雑音抑圧効果が低い。しかしながら、本実施形態における漏洩検知装置３０では、高周波数帯でも雑音抑圧効果が高い。また、本実施形態における漏洩検知装置３０は、特許文献１の方法で利用された適応デジタルフィルタによる雑音抑圧ではなく、スペクトル減算法を利用してする。したがって、漏洩検知装置３０は、特許文献１に記載の方法と比較して演算時間が短いという効果も有する。 Here, in the method of Patent Document 1 described above, the noise suppression effect is low particularly in a high frequency band of noise caused by a moving sound source. However, the leak detection device 30 in this embodiment has a high noise suppression effect even in a high frequency band. Moreover, the leak detection apparatus 30 in the present embodiment uses a spectral subtraction method instead of noise suppression by the adaptive digital filter used in the method of Patent Document 1. Therefore, the leak detection device 30 also has an effect that the calculation time is shorter than that of the method described in Patent Document 1.
＜第４の実施形態＞
　以下、第４の実施形態について、図面を参照して詳細に説明する。 <Fourth Embodiment>
Hereinafter, the fourth embodiment will be described in detail with reference to the drawings.
　図７は、第４の実施形態における漏洩検知装置４０のブロック図である。図７を参照すると、本実施形態における漏洩検知装置４０は、漏洩検知装置４０は、減算部１１と、減算振幅スペクトル算出部１４と、漏洩判定部１２とを備える。減算部１１は、適応ノイズキャンセル部１９とスペクトル算出部１５とを備える。 FIG. 7 is a block diagram of the leak detection device 40 according to the fourth embodiment. Referring to FIG. 7, the leak detection device 40 according to this embodiment includes a subtraction unit 11, a subtraction amplitude spectrum calculation unit 14, and a leak determination unit 12. The subtraction unit 11 includes an adaptive noise cancellation unit 19 and a spectrum calculation unit 15.
　適応ノイズキャンセル部１９は、地盤信号を用いて算出される適応デジタルフィルタを用いて、雑音抑圧された管信号である雑音抑圧信号を算出する。雑音抑圧信号は、管信号に含まれる漏洩音以外の雑音のうち、非移動音源による雑音が適応デジタルフィルタを用いて抑圧された信号である。つまり、雑音抑圧信号は、非移動音源による雑音が減算された管信号である。ここで、適応デジタルフィルタ係数は、例えば最小二乗法アルゴリズムを用いて推定される係数である。 The adaptive noise cancellation unit 19 calculates a noise suppression signal, which is a tube signal subjected to noise suppression, using an adaptive digital filter calculated using the ground signal. The noise suppression signal is a signal in which noise due to a non-moving sound source is suppressed using an adaptive digital filter among noises other than leakage sound included in the tube signal. That is, the noise suppression signal is a tube signal obtained by subtracting noise from a non-moving sound source. Here, the adaptive digital filter coefficient is a coefficient estimated using, for example, a least square method algorithm.
　スペクトル算出部１５は、雑音抑圧信号及び地盤信号から、雑音抑圧信号のスペクトル及び地盤信号のスペクトルを算出する。スペクトル算出部１５は、例えば、フーリエ変換等により、それぞれのスペクトルを算出する。 The spectrum calculation unit 15 calculates the spectrum of the noise suppression signal and the spectrum of the ground signal from the noise suppression signal and the ground signal. The spectrum calculation unit 15 calculates each spectrum by, for example, Fourier transform.
　減算振幅スペクトル算出部１４は、雑音抑圧信号のスペクトルと地盤信号のスペクトルちに基づき、非移動音源および移動音源による雑音が減算された管信号の振幅スペクトルを算出する。 The subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the tube signal from which the noise due to the non-moving sound source and the moving sound source is subtracted based on the spectrum of the noise suppression signal and the spectrum of the ground signal.
　漏洩判定部１２は、管信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する。すなわち、漏洩判定部１２は、減算された管信号の振幅スペクトルに基づき、漏洩の有無を判定する。 The leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal. That is, the leakage determination unit 12 determines whether there is leakage based on the subtracted amplitude spectrum of the tube signal.
　次に、第４の実施形態における漏洩検知装置４０の動作について、図８のフローチャートを用いて説明する。図８は、漏洩検知装置４０の動作を示すフローチャートである。 Next, the operation of the leak detection apparatus 40 in the fourth embodiment will be described using the flowchart of FIG. FIG. 8 is a flowchart showing the operation of the leak detection device 40.
　適応ノイズキャンセル部１９は、管信号および地盤信号を用いて算出される適応デジタルフィルタに基づき、雑音抑圧信号を算出する（ステップＳ４０１）。 The adaptive noise cancellation unit 19 calculates a noise suppression signal based on the adaptive digital filter calculated using the tube signal and the ground signal (step S401).
　スペクトル算出部１５は、雑音抑圧信号及び地盤信号から雑音抑圧信号のスペクトル及び地盤信号のスペクトルを算出する（ステップＳ４０２）。 The spectrum calculation unit 15 calculates the spectrum of the noise suppression signal and the spectrum of the ground signal from the noise suppression signal and the ground signal (step S402).
　減算振幅スペクトル算出部１４は、雑音抑圧信号のスペクトルと地盤信号のスペクトルに基づき、非移動音源および移動音源による雑音が減算された管信号の振幅スペクトルを算出する（ステップＳ４０３）。 The subtraction amplitude spectrum calculation unit 14 calculates the amplitude spectrum of the tube signal from which the noise due to the non-moving sound source and the moving sound source is subtracted based on the spectrum of the noise suppression signal and the spectrum of the ground signal (step S403).
　漏洩判定部１２は、管信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する（ステップＳ４０４）。 The leakage determination unit 12 determines the presence or absence of leakage based on the result obtained by subtracting noise from the non-moving sound source and the moving sound source from the tube signal (step S404).
　以上で、第４の実施形態における漏洩検知装置４０の動作が終了する。 With the above, the operation of the leak detection device 40 in the fourth embodiment is completed.
　上記構成を有する漏洩検知装置４０は、非移動音源による雑音を、適応ノイズキャンセルにより抑圧した後、移動音源による雑音をスペクトル減算法により抑圧する。これにより、第１の実施形態乃至第３の実施形態に記載の、非移動音源による雑音と移動音源による雑音の両方を抑圧することができるため、精度よく漏洩検知を行える。さらに、漏洩検知装置４０は、漏洩音と周波数帯の重なった非移動音源による雑音も抑圧することができる。 The leak detection apparatus 40 having the above configuration suppresses noise caused by a non-moving sound source by adaptive noise cancellation, and then suppresses noise caused by the moving sound source using a spectral subtraction method. Thereby, since both the noise by a non-moving sound source and the noise by a moving sound source as described in the first to third embodiments can be suppressed, leakage detection can be performed with high accuracy. Furthermore, the leak detection device 40 can also suppress noise caused by a non-moving sound source in which the leaky sound and the frequency band overlap.
＜第５の実施形態＞
　以下、第５の実施形態について、図面を参照して詳細に説明する。 <Fifth Embodiment>
Hereinafter, the fifth embodiment will be described in detail with reference to the drawings.
　図９は、第５の実施形態における漏洩検知システム５０のブロック図である。図９を参照すると、本実施形態における漏洩検知システム５０は、漏洩検知装置１０と、第１のセンサ２１と、第２のセンサ２２とを備える。ここで、本実施形態における漏洩検知装置１０は、第１の実施形態における漏洩検知装置１０と同様の構成及び機能を備える。本実施形態では、漏洩検知装置１０の説明を省略する。また、漏洩検知装置１０に代えて、本発明の第２から第４の実施形態における漏洩検知装置が用いられてもよい。 FIG. 9 is a block diagram of a leak detection system 50 according to the fifth embodiment. Referring to FIG. 9, the leak detection system 50 in this embodiment includes a leak detection device 10, a first sensor 21, and a second sensor 22. Here, the leak detection apparatus 10 in the present embodiment has the same configuration and function as the leak detection apparatus 10 in the first embodiment. In the present embodiment, description of the leak detection device 10 is omitted. Further, instead of the leak detection device 10, the leak detection device in the second to fourth embodiments of the present invention may be used.
　第１のセンサ２１は、管や管に付随する設備等に設置される。第１のセンサ２１は、管や管を流れる気体や液体等を伝搬する音又は振動を検知する。第１のセンサ２１は、検知した音又は振動を示す管信号を漏洩検知装置１０に出力する。 The first sensor 21 is installed in a pipe or a facility attached to the pipe. The first sensor 21 detects sound or vibration propagating through a tube or a gas or liquid flowing through the tube. The first sensor 21 outputs a tube signal indicating the detected sound or vibration to the leak detection device 10.
　第２のセンサ２２は、地中や地表等に設置される。第２のセンサ２２は、地中や地表等を伝搬する音又は振動を検知する。第２のセンサ２２は、検知した音又は振動を示す地盤信号を漏洩検知装置１０に出力する。 The second sensor 22 is installed in the ground or on the ground surface. The second sensor 22 detects sound or vibration that propagates in the ground or on the ground. The second sensor 22 outputs a ground signal indicating the detected sound or vibration to the leak detection device 10.
　図１０を用いて、第１のセンサ２１と第２のセンサ２２を説明する。図１０は、第１のセンサ２１および第２のセンサ２２の設置場所の一例を示す図である。図１０が示すように、第１のセンサ２１は、例えば、配管や配管に付随する設備など、漏洩音が伝搬する位置に設置されている。すなわち、第１のセンサ２１は、管からの漏洩音を検知可能な位置に設置される。第２のセンサ２２は、地面や地中などに設置される。図１０に示す例では、第２のセンサ２２は地面に直接設置される。すなわち、第２のセンサ２２は、管の周囲雑音を検知可能な位置に設置される。 The first sensor 21 and the second sensor 22 will be described with reference to FIG. FIG. 10 is a diagram illustrating an example of installation locations of the first sensor 21 and the second sensor 22. As FIG. 10 shows, the 1st sensor 21 is installed in the position which leaks sound, such as the installation accompanying a piping and piping, for example. That is, the 1st sensor 21 is installed in the position which can detect the leak sound from a pipe. The second sensor 22 is installed on the ground or underground. In the example shown in FIG. 10, the second sensor 22 is directly installed on the ground. That is, the second sensor 22 is installed at a position where ambient noise of the tube can be detected.
　次に、第５の実施形態における漏洩検知システム５０の動作について、図１１のフローチャートを用いて説明する。図１１は、漏洩検知システム５０の動作を示すフローチャートである。 Next, the operation of the leak detection system 50 in the fifth embodiment will be described using the flowchart of FIG. FIG. 11 is a flowchart showing the operation of the leak detection system 50.
　第１のセンサ２１および第２のセンサ２２は、配管や地中などを伝搬する音や信号をそれぞれ検知し、検知した音を管信号又は地盤信号として漏洩検知装置１０に出力する（ステップＳ５０１）。 The first sensor 21 and the second sensor 22 detect sounds and signals propagating through pipes and underground, respectively, and output the detected sounds to the leak detection device 10 as tube signals or ground signals (step S501). .
　減算部１１は、第１のセンサ２１および第２のセンサ２２から出力された管信号と地盤信号に基づき、管信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する（ステップＳ５０２）。 The subtracting unit 11 subtracts the noise due to the non-moving sound source from the tube signal based on the tube signal and the ground signal output from the first sensor 21 and the second sensor 22, and further subtracts the noise due to the moving sound source (step). S502).
　漏洩判定部１２は、管信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する（ステップＳ５０３）。 The leakage determination unit 12 determines the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal (step S503).
　以上で、第５の実施形態における漏洩検知システム５０の動作が終了する。 With the above, the operation of the leak detection system 50 in the fifth embodiment is completed.
　上記構成を有する漏洩検知システム５０は、管信号および地盤信号に基づき、管信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する。漏洩検知システム５０は、管信号から非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する。したがって、漏洩検知システム５０は、非移動音源による雑音と、移動音源による雑音の両方を抑圧することで、移動音源による雑音が発生する環境においても精度よく配管からの漏洩を検知することができる。 The leak detection system 50 having the above configuration subtracts noise due to the non-moving sound source from the tube signal based on the tube signal and the ground signal, and further subtracts noise due to the moving sound source. The leak detection system 50 determines whether or not there is a leak based on the result of subtracting noise from the non-moving sound source and the moving sound source from the tube signal. Therefore, the leak detection system 50 can accurately detect leaks from the piping even in an environment where noise due to the moving sound source is generated by suppressing both noise due to the non-moving sound source and noise due to the moving sound source.
　図１２は、本発明の各実施形態におけるコンピュータ１００の構成例を示す概略ブロック図である。コンピュータ１００は、ＣＰＵ１０１と、主記憶装置１０２と、補助記憶装置１０３と、インターフェース１０４と、入力デバイス１０５と、ディスプレイ装置１０６とを備える。 FIG. 12 is a schematic block diagram showing a configuration example of the computer 100 in each embodiment of the present invention. The computer 100 includes a CPU 101, a main storage device 102, an auxiliary storage device 103, an interface 104, an input device 105, and a display device 106.
　各実施形態および各実施例の漏洩検知装置１０等は、コンピュータ１００に実装される。漏洩検知装置１０等の動作は、プログラムの形式で補助記憶装置１０３に記憶されている。ＣＰＵ１０１は、プログラムを補助記憶装置１０３から読み出して主記憶装置１０２に展開し、そのプログラムに従って上記の処理を実行する。 The leakage detection apparatus 10 and the like of each embodiment and each example are mounted on a computer 100. The operation of the leak detection device 10 and the like is stored in the auxiliary storage device 103 in the form of a program. The CPU 101 reads out the program from the auxiliary storage device 103 and develops it in the main storage device 102, and executes the above processing according to the program.
　補助記憶装置１０３は、一時的でない有形の媒体の一例である。一時的でない有形の媒体の他の例として、インターフェース１０４を介して接続される磁気ディスク、光磁気ディスク、ＣＤ－ＲＯＭ、ＤＶＤ－ＲＯＭ、半導体メモリ等が挙げられる。また、このプログラムが通信回線によってコンピュータ１００に配信される場合、配信を受けたコンピュータ１００がそのプログラムを主記憶装置１０２に展開し、上記の処理を実行しても良い。 The auxiliary storage device 103 is an example of a tangible medium that is not temporary. Other examples of the non-temporary tangible medium include a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, and a semiconductor memory connected via the interface 104. When this program is distributed to the computer 100 via a communication line, the computer 100 that has received the distribution may develop the program in the main storage device 102 and execute the above processing.
　インターフェース１０４は、ＣＰＵ１０１に接続され、ネットワークあるいは外部記憶媒体に接続される。外部データがインターフェース１０４を介してＣＰＵ１０１に取り込まれても良い。入力デバイス１０５は、例えばキーボードやマウス、タッチパネルである。ディスプレイ１０６は、例えばＬＣＤ（Ｌｉｑｕｉｄ　Ｃｒｙｓｔａｌ　Ｄｉｓｐｌａｙ）やＣＲＴ（Ｃａｔｈｏｄｅ　Ｒａｙ　Ｔｕｂｅ）ディスプレイのような、ＣＰＵ１０１やＧＰＵ（Ｇｒａｐｈｉｃｓ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）（図示せず）等により処理された描画データに対応する画面を表示する装置である。なお、図１２が示すハードウェア構成は、一例にすぎず、図１が示す各部それぞれが独立した論理回路で構成されていても良い。 The interface 104 is connected to the CPU 101 and connected to a network or an external storage medium. External data may be taken into the CPU 101 via the interface 104. The input device 105 is, for example, a keyboard, a mouse, or a touch panel. The display 106 displays a screen corresponding to drawing data processed by the CPU 101 or GPU (Graphics Processing Unit) (not shown) such as an LCD (Liquid Crystal Display) or CRT (Cathode Ray Tube) display. Device. Note that the hardware configuration illustrated in FIG. 12 is merely an example, and each unit illustrated in FIG. 1 may be configured with independent logic circuits.
　また、プログラムは、前述の処理の一部を実現するものであっても良い。さらに、プログラムは、補助記憶装置１０３に既に記憶されている他のプログラムとの組み合わせで前述の処理を実現する差分プログラムであっても良い。 Further, the program may realize a part of the above processing. Furthermore, the program may be a differential program that realizes the above-described processing in combination with another program already stored in the auxiliary storage device 103.
　以上、実施形態を用いて本発明を説明したが、本発明は必ずしも上記実施形態に限定されるものではない。本発明の構成や詳細には、本発明のスコープ内で当業者が理解しうる（その技術的思想の範囲内において）様々な変更をし、実施することができる。 As mentioned above, although this invention was demonstrated using embodiment, this invention is not necessarily limited to the said embodiment. Various changes and modifications that can be understood by those skilled in the art within the scope of the present invention (within the scope of the technical idea) can be made to the configuration and details of the present invention.
　この出願は、２０１５年３月２５日に出願された日本出願特願２０１５－６１８５３を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2015-61853 filed on Mar. 25, 2015, the entire disclosure of which is incorporated herein.
　１０　　漏洩検知装置
　１１　　減算部
　１２　　漏洩判定部
　１３　　減算スペクトル算出部
　１４　　減算振幅スペクトル算出部
　１５　　スペクトル算出部
　１６　　スペクトル減算部
　１７　　振幅スペクトル算出部
　１８　　振幅スペクトル減算部
　１９　　適応ノイズキャンセル部
　２０　　漏洩検知装置
　２１　　第１のセンサ
　２２　　第２のセンサ
　３０　　漏洩検知装置
　４０　　漏洩検知装置
　５０　　漏洩検知システム
　１００　　コンピュータ
　１０１　　ＣＰＵ
　１０２　　主記憶装置
　１０３　　補助記憶装置
　１０４　　インターフェース
　１０５　　入力デバイス
　１０６　　ディスプレイ装置 DESCRIPTION OF SYMBOLS 10 Leakage detection apparatus 11 Subtraction part 12 Leakage determination part 13 Subtraction spectrum calculation part 14 Subtraction amplitude spectrum calculation part 15 Spectrum calculation part 16 Spectrum subtraction part 17 Amplitude spectrum calculation part 18 Amplitude spectrum subtraction part 19 Adaptive noise cancellation part 20 Leakage detection apparatus 21 First sensor 22 Second sensor 30 Leakage detection device 40 Leakage detection device 50 Leakage detection system 100 Computer 101 CPU
102 Main storage device 103 Auxiliary storage device 104 Interface 105 Input device 106 Display device

Claims (9)

  1. 　管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と、周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号とに基づき、前記第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する減算手段と、
    　前記第１の信号から前記非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する漏洩判定手段と、
    　を備える漏洩検知装置。     Based on a first signal acquired from a sensor installed at a position where leakage sound from the tube can be detected and a second signal acquired from a sensor installed at a position where ambient noise can be detected, Subtracting means for subtracting noise from the non-moving sound source from the first signal, and further subtracting noise from the moving sound source;
    Leakage determination means for determining the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and moving sound source from the first signal;
    A leak detection device comprising:
  2. 　前記減算手段は、
    　　前記第１の信号および前記第２の信号に基づき、非移動音源による雑音が減算された第１の信号のスペクトル、および第２の信号のスペクトルを算出する減算スペクトル算出手段と、
    　　前記減算された第１の信号のスペクトルと前記第２の信号のスペクトルに基づき、非移動音源および移動音源による雑音が減算された第１の信号の振幅スペクトルを算出する減算振幅スペクトル算出手段と、
    　を備え、
    　前記漏洩判定手段は、前記第１の信号の振幅スペクトルに基づいて前記管の漏洩の有無を判定する、
    　請求項１に記載の漏洩検知装置。     The subtracting means is
    Subtracted spectrum calculating means for calculating a spectrum of the first signal from which noise due to a non-moving sound source is subtracted based on the first signal and the second signal, and a spectrum of the second signal;
    Subtracted amplitude spectrum calculating means for calculating an amplitude spectrum of the first signal from which noise caused by the non-moving sound source and the moving sound source is subtracted based on the subtracted first signal spectrum and the second signal spectrum;
    With
    The leakage determination means determines the presence or absence of leakage of the tube based on an amplitude spectrum of the first signal;
    The leak detection device according to claim 1.
  3. 　前記減算スペクトル算出手段は、
    　　前記第１の信号および前記第２の信号から前記第１の信号のスペクトルおよび前記第２の信号のスペクトルを算出するスペクトル算出手段と、
    　　前記第１の信号のスペクトルから、第１の係数と前記第２の信号のスペクトルの積を減算するスペクトル減算手段と、
    　を備え、
    　前記減算振幅スペクトル算出手段は、
    　　前記減算された第１の信号のスペクトルおよび前記第２の信号のスペクトルから前記第１の信号の振幅スペクトル、および前記第２の信号の振幅スペクトルを算出する振幅スペクトル算出手段と、
    　　前記第１の信号の振幅スペクトルから、第２の係数と前記第２の信号の振幅スペクトルとの積を減算する振幅スペクトル減算手段と、
    　を備える請求項２に記載の漏洩検知装置。     The subtracted spectrum calculating means includes
    Spectrum calculating means for calculating a spectrum of the first signal and a spectrum of the second signal from the first signal and the second signal;
    Spectral subtraction means for subtracting the product of the first coefficient and the spectrum of the second signal from the spectrum of the first signal;
    With
    The subtraction amplitude spectrum calculation means includes
    Amplitude spectrum calculating means for calculating an amplitude spectrum of the first signal and an amplitude spectrum of the second signal from the subtracted spectrum of the first signal and the spectrum of the second signal;
    Amplitude spectrum subtracting means for subtracting the product of the second coefficient and the amplitude spectrum of the second signal from the amplitude spectrum of the first signal;
    The leak detection device according to claim 2, comprising:
  4. 　前記第１の係数は、前記第１のスペクトルと前記第２のスペクトルの相関係数に基づいて算出され、
    　前記第２の係数は、前記第１の信号の振幅スペクトルと前記第２の信号の振幅スペクトルの相関係数に基づいて算出される
    　請求項３に記載の漏洩検知装置。     The first coefficient is calculated based on a correlation coefficient between the first spectrum and the second spectrum,
    The leak detection device according to claim 3, wherein the second coefficient is calculated based on a correlation coefficient between an amplitude spectrum of the first signal and an amplitude spectrum of the second signal.
  5. 　前記減算スペクトル算出手段は、
    　　前記第１の信号および前記第２の信号を用いて算出される適応デジタルフィルタに基づき、前記非移動音源による雑音が減算された第１の信号を算出する適応ノイズキャンセル手段と、
    　　前記非移動音源による雑音が減算された第１の信号と前記第２の信号とから、前記非移動音源による雑音が減算された第１の信号のスペクトルと前記第２のスペクトルとを算出する前記スペクトル算出手段と、
    　を備える請求項２に記載の漏洩検知装置。     The subtracted spectrum calculating means includes
    Adaptive noise cancellation means for calculating a first signal obtained by subtracting noise due to the non-moving sound source based on an adaptive digital filter calculated using the first signal and the second signal;
    The spectrum of the first signal from which the noise from the non-moving sound source is subtracted and the second spectrum are calculated from the first signal from which the noise from the non-moving sound source is subtracted and the second signal. Spectrum calculation means;
    The leak detection device according to claim 2, comprising:
  6. 　前記漏洩判定手段は、前記第１の信号の振幅スペクトルまたは前記第１の信号の振幅スペクトルの絶対値の時間方向の最小値が所定の閾値を超える場合に、漏洩有と判定することを特徴とする請求項１乃至５のいずれか１項に記載の漏洩検知装置。 The leakage determination means determines that there is leakage when the amplitude value of the first signal or the absolute value of the amplitude spectrum of the first signal in the time direction exceeds a predetermined threshold value. The leak detection device according to any one of claims 1 to 5.
  7. 　管からの漏洩音を検知可能な位置に設置された第１のセンサと、
    　周囲雑音を検知可能な位置に設置された第２のセンサと、
    　請求項１から６のいずれか１項に記載の漏洩検知装置と、
    　を有する漏洩検知システム。     A first sensor installed at a position where leakage sound from the pipe can be detected;
    A second sensor installed at a position where ambient noise can be detected;
    The leak detection device according to any one of claims 1 to 6,
    Leak detection system.
  8. 　管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と、周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号とに基づき、前記第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算し、
    　前記第１の信号から前記非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する
    　漏洩検知方法。     Based on a first signal acquired from a sensor installed at a position where leakage sound from the tube can be detected and a second signal acquired from a sensor installed at a position where ambient noise can be detected, Subtract noise from the non-moving sound source from the first signal, subtract noise from the moving sound source,
    A leakage detection method for determining presence or absence of leakage based on a result of subtracting noise from the non-moving sound source and moving sound source from the first signal.
  9. 　管からの漏洩音を検知可能な位置に設置されたセンサから取得される第１の信号と周囲雑音を検知可能な位置に設置されたセンサから取得される第２の信号とに基づき、前記第１の信号から非移動音源による雑音を減算し、さらに移動音源による雑音を減算する処理と、
    　前記第１の信号から前記非移動音源および移動音源による雑音が減算された結果に基づき、漏洩の有無を判定する処理と、
    　をコンピュータに実行させるプログラムを格納した、コンピュータ読み取り可能記録媒体。     Based on a first signal acquired from a sensor installed at a position where leakage sound from the tube can be detected and a second signal acquired from a sensor installed at a position where ambient noise can be detected, the first signal A process of subtracting noise from a non-moving sound source from the signal 1 and further subtracting noise from a moving sound source;
    A process for determining the presence or absence of leakage based on the result of subtracting noise from the non-moving sound source and the moving sound source from the first signal;
    A computer-readable recording medium storing a program for causing a computer to execute the program.
PCT/JP2016/001590 2015-03-25 2016-03-18 Leak detection device, leak detection system, leak detection method, and computer-readable recording medium WO2016152131A1 (en)

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