WO2014157539A1

WO2014157539A1 - Defect analysis device, defect analysis method, and program

Info

Publication number: WO2014157539A1
Application number: PCT/JP2014/058919
Authority: WO
Inventors: 慎冨永; 佐々木　康弘; 尚武高橋; 裕文井上
Original assignee: 日本電気株式会社
Priority date: 2013-03-29
Filing date: 2014-03-27
Publication date: 2014-10-02
Also published as: JPWO2014157539A1

Abstract

A defect analysis device that has the following: a vibration-application unit (6) that applies vibrations to a pipe (2) installed at a distance from ground level (4); a first vibration-application control unit (101) that controls the vibration-application unit (6) so as to apply, to the pipe (2), first vibrations that include vibrations of a plurality of frequencies; a first detection unit (7) that detects the first vibrations propagating down the pipe (2) after having been applied by the vibration-application unit (6); a second detection unit (9) that is installed at ground level (4) and detects the first vibrations; a second vibration-application control unit (103) that controls the vibration-application unit (6) so as to apply second vibrations to the pipe (2), said second vibrations having a frequency determined using a vibration waveform (first vibration waveform) obtained from the detection of the first vibrations by the first detection unit (7) and a vibration waveform (second vibration waveform) obtained from the detection of the first vibrations by the second detection unit (9); and a third detection unit (8) that is installed at ground level (4) and detects the second vibrations applied by the vibration-application unit (6).

Description

Defect analysis apparatus, defect analysis method and program

The present invention relates to a defect analysis apparatus, a defect analysis method, and a program.

With the advancement of IT and network technology supported by digitalization, the amount of information handled and stored by people and electronic devices is steadily increasing. It is safe and secure for human society, which is getting distracted by a large amount of information, to acquire accurate data of events from sensors that are input devices, and to accurately analyze, judge, and process them and recognize them as useful information It is in an important position in forming a healthy society.

In modern life, facilities such as water and sewage networks, high-pressure chemical pipelines such as gas and oil, high-speed railways, long-span bridges, high-rise buildings, large passenger planes, and automobiles have been built and have become the foundation of a prosperous society. If these are destroyed by natural disasters such as unexpected earthquakes and life deterioration, leading to serious accidents, the impact on society will be great, and the economic loss will be great. The members used in the equipment are subject to deterioration such as corrosion, wear, rattling and the like according to the usage time, and eventually malfunction such as destruction. In order to ensure the safety and security of facilities, great efforts are being made to develop technologies that transcend academic fields such as science, engineering, and sociology. In particular, the advancement of non-destructive inspection technology, which is a low-cost and easy-to-operate inspection technology, is becoming more and more important for preventing serious accidents caused by deterioration and destruction of equipment.

By the way, as a fluid leakage inspection due to deterioration or destruction of piping such as water and sewage networks and pipelines, an auditory sensory inspection in which a person hears the leakage sound is generally performed. However, since pipes are often buried in the ground or installed at high places in buildings, the inspection involves dangerous work and requires a great deal of labor. For this reason, high-precision and sufficient inspection has not been realized. Also, the sensory sensory test depends on the level of proficiency of the inspector, and its low detection accuracy makes it difficult to prevent leakage accidents.

Also, when the existence of water leakage becomes clear, it is necessary to specify the position with high accuracy because it is necessary to keep repair costs low. At present, the position is specified by an auditory sensory test of a specialized inspector. However, for example, when there is a disturbance such as traffic noise during the inspection and the sound generated by the water leak is similar in frequency component, it is difficult to determine the occurrence of the water leak. For this reason, contrivances have been made such as measurement in the midnight time zone with little disturbance, but this is a heavy burden on the inspector.

In order to solve such problems, various leak inspection methods using machines have been proposed.

Patent Document 1 includes a vibration source that generates a pressure wave in a fluid in a pipe, and a detection unit that detects a pressure wave reflected at a leaked location. A method for identifying a leaked part from the time difference from the time is disclosed.

In Patent Document 2, a vibrator that excites sound waves is installed in a water pipe buried in the ground, and a leak point is identified by detecting the vibration level that has passed through the water pipe and the ground and reached the ground. A technique is disclosed.

In Patent Document 3, a variable oscillator that oscillates an electric vibration that is not a sine wave while changing the frequency, and a concrete object to be measured are installed on the concrete surface, excited by the electric vibration from the variable oscillator, and directed toward the opposite surface of the concrete. Installed on the same surface of the transducer of the sonic transducer that makes the concrete resonant by repeatedly transmitting sonic pulses and the concrete on which the transducer is installed, depending on the thickness of the concrete or the position of the internal crack An apparatus for measuring the thickness and the internal crack position of concrete is disclosed which comprises a receiver for receiving a resonant wave having a frequency and a spectrum analyzer for searching for the resonant frequency of the resonant wave.

In Patent Document 4, an output of a vibration sensor provided in a resonant vibration body is input to a constant amplitude control circuit, and an excitation is performed to vibrate the resonant vibration body based on a result of comparison with a set input in the constant amplitude control circuit. In the control device for a resonant vibration body that outputs a predetermined drive signal to the detector, a resonance detection circuit is provided separately from the constant amplitude control circuit, and the output of the vibration sensor is input to the resonance detection circuit. A control device for a resonant vibration body is disclosed in which the drive signal automatically follows the resonance frequency of the resonant vibration body.

Japanese Patent Application Laid-Open No. 60-13237 JP 60-238734 A JP-A-64-65407 Japanese Utility Model Publication No. 5-95678

The accuracy of the conventional leakage inspection method using machines was not sufficient.

In the method described in Patent Document 1, since the spectrum and amplitude of the reflected pressure wave change depending on the shape of the hole at the leak location, when the reflected pressure wave and the disturbance vibration are superimposed, the pressure wave and the disturbance vibration are distinguished. Is difficult. In the method described in Patent Document 2, the vibration amplitude transmitted from the water leakage location to the ground differs depending on the shape of the hole at the leakage location, and thus there is a problem that the water leakage location cannot be specified depending on the shape of the hole at the water leakage location. As described above, in the case of the methods described in

Patent Documents

1 and 2, the accuracy is affected by disturbance vibration and the size of the hole at the leak location. Note that the methods described in Patent Documents 3 and 4 are not configured to solve the problem.

An object of the present invention is to provide a technique for specifying a defect position of a pipe with high accuracy.

According to the present invention,
Vibration means for applying vibration to at least one of the pipe and the fluid flowing in the pipe;
First vibration control means for controlling the vibration means to apply a first vibration including vibrations at a plurality of frequencies to at least one of the fluid and the pipe;
First detection means for detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection means installed on a first surface spaced from the pipe and detecting the first vibration;
Using the first vibration waveform obtained by detecting the first vibration by the first detection means and the second vibration waveform obtained by detecting the first vibration by the second detection means. Second vibration control means for controlling the vibration means to apply a second vibration, which is a vibration of a determined frequency, to at least one of the fluid or the pipe;
A third detection means installed on the first surface for detecting the second vibration;
A defect analysis apparatus having the following is provided.

Moreover, according to the present invention,
Computer
A vibration means for applying vibration to at least one of a pipe or a fluid flowing in the pipe is controlled, and a first vibration including vibrations having a plurality of frequencies is applied to at least one of the fluid or the pipe. A first vibration control step to be performed;
A first detection step of detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection step that is installed on a first surface spaced from the pipe and detects the first vibration;
The first vibration waveform obtained by controlling the vibration means and detecting the first vibration by the first detection step, and the first vibration obtained by the second detection step. A second vibration control step of applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, to at least one of the fluid or the pipe;
A third detection step installed on the first surface and detecting the second vibration;
A defect analysis method for performing is provided.

Moreover, according to the present invention,
Computer
A vibration means for applying vibration to at least one of the pipe and the fluid flowing in the pipe is controlled, and a first vibration including vibrations having a plurality of frequencies is applied to at least one of the fluid and the pipe. First excitation control means for causing
First detection means for detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection means installed on a first surface spaced from the pipe and detecting the first vibration;
The first vibration waveform obtained by controlling the vibration means and detecting the first vibration by the first detection means, and the first vibration obtained by the second detection means. A second vibration control means for applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, to at least one of the fluid and the pipe;
Third detection means installed on the first surface for detecting the second vibration;
A program for functioning as a server is provided.

According to the present invention, it is possible to specify the defect position of the pipe with high accuracy.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is a figure which shows an example of the schematic of the defect analyzer of this embodiment. It is an example of the vibration spectrum of a leaky wave. It is an example of the vibration spectrum of a reflected wave. It is an example of the spectrum of a 1st vibration waveform. It is an example of the spectrum of a 2nd vibration waveform. It is an example of the spectrum of the vibration waveform which multiplied the 1st vibration waveform and the 2nd vibration waveform. It is a flowchart which shows an example of the flow of a process of the defect analysis method of this embodiment. It is a figure which shows an example of the schematic of the defect analyzer of this embodiment. It is a figure which shows an example of the schematic of the defect analyzer of this embodiment. It is a figure which shows an example of the schematic of the defect analyzer of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The apparatus according to the present embodiment includes an arbitrary computer CPU, memory, and a program loaded in the memory (a program stored in the memory in advance from the stage of shipping the apparatus, a storage medium such as a CD, and the like on the Internet). And a storage unit such as a hard disk for storing the program, and a network connection interface, and any combination of hardware and software. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus.

Further, the functional block diagram used in the description of the present embodiment shows functional unit blocks, not hardware unit configurations. In these drawings, each device is described as being realized by one device, but the means for realizing it is not limited to this. That is, it may be a physically separated configuration or a logically separated configuration.

First, an outline of the defect detection apparatus of this embodiment will be described. In the defect detection device of the present embodiment, the position of a defect formed in a pipe installed at a position (e.g., underground) away from the first surface (e.g., the ground) is installed on the first surface. It is specified using a vibration sensor.

When there is a defect in the pipe, part of the vibration propagating through the pipe or the fluid flowing in the pipe (vibration with a specific frequency) leaks to the outside of the pipe through the defect formed in the pipe. The defect apparatus according to the present embodiment detects the position of the defect by detecting vibration (vibration having a specific frequency) leaking from the defect to the outside of the pipe by a vibration sensor installed on the first surface.

By the way, when the magnitude of the vibration that leaks from the defect and reaches the first surface is not sufficient, the vibration that can be detected by the vibration sensor becomes minute, and sufficient detection accuracy cannot be obtained. Therefore, the defect detection apparatus of the present embodiment applies vibration to the pipe and / or the fluid flowing through the pipe using the vibrator, and detects the vibration in this state. According to the said means, the magnitude | size of the vibration which leaks from a defect and arrives at a 1st surface can be made into sufficient magnitude | size.

However, when vibration in a wide frequency band is applied using a vibrator, vibrations (disturbance vibrations) other than the detection target (vibration having the specific frequency) are also amplified, and the S / N ratio is lowered. As a result, sufficient detection accuracy cannot be obtained.

Therefore, the defect detection apparatus of the present embodiment does not apply vibrations in a wide frequency band using a vibrator, but applies only vibrations of a predetermined frequency to a pipe or a fluid flowing in the pipe. Specifically, a vibration frequency that is likely to leak from the defect to the outside of the pipe and has good transmission efficiency between the pipe and the first surface is applied to the pipe and / or the fluid flowing through the pipe. In the case of this embodiment in which vibration is detected in such a state, the S / N ratio is increased, and the detection accuracy is improved.

Next, the configuration of the defect detection apparatus of this embodiment will be described in detail with reference to the drawings. FIG. 1 shows an example of a schematic diagram of the defect detection apparatus of the present embodiment that specifies the position of a defect (eg, leakage hole) 3 formed in the pipe 2.

The pipe 2 shown in Fig. 1 is installed in the ground. That is, the pipe 2 is installed at a position away from the ground (first surface) 4. A fluid 5 flows in the pipe 2. The fluid corresponds to a liquid such as water or a gas such as air or gas. The pipe 2 may be installed in the attic or underground of the building, or may be embedded in a wall or a pillar. In such a case, the first surface is a ceiling surface, a wall surface, a side surface of a column, a floor surface, or the like.

The defect inspection apparatus includes a vibration unit 6, a first detection unit 7, a second detection unit 9, a third detection unit 8, a first vibration control unit 101, a second vibration control unit 103, and signal processing. The first processing apparatus 100 including the unit 102 and the defect position estimation unit 104 are included. First, the positional relationship between these components will be described.

The vibration unit 6 is installed at a position where vibration can be applied to the pipe 2. For example, it may be installed directly on the outer surface or inner surface of the pipe 2 or may be installed on an accessory (flange, fire hydrant, etc.) of the pipe 2. The 1st detection part 7 is installed in the position which can detect the vibration which propagates the piping 2. As shown in FIG. For example, it may be installed directly on the outer surface or inner surface of the pipe 2 or may be installed on an accessory (flange, fire hydrant, etc.) of the pipe 2. In the case of the example shown in FIG. 1, both the excitation unit 6 and the first detection unit 7 are installed on the outer surface of the pipe 2. In the case of the example shown in FIG. 9, both the excitation unit 6 and the first detection unit 7 are installed inside the pipe 2. Although not shown, either one of the vibration unit 6 and the first detection unit 7 may be installed on the outer surface of the pipe 2 and the other may be installed inside the pipe 2.

The vibration unit 6 and the first detection unit 7 have the same or sufficiently close positions in the extending direction of the pipe 2 (left and right direction shown in FIG. 1) (hereinafter referred to as “pipe extending direction position”). For this reason, when the defect 3 is formed at an arbitrary position of the pipe 2, the position in the pipe extending direction of the vibration unit 6 and the first detection unit 7 is located on the same side as viewed from the defect 3 with high probability. It becomes.

The second detection unit 9 and the third detection unit 8 are installed on the ground 4. The second detection unit 9 may be installed, for example, immediately above or near the excitation unit 6.

The installation position of the first processing apparatus 100 is not particularly limited, and may be anywhere as long as it can communicate with the vibration unit 6, the first detection unit 7, and the second detection unit 9. It may be installed on the ground or installed in the ground. For example, the first processing apparatus 100 may be installed on the ground, and may communicate with the vibration unit 6, the first detection unit 7, and the second detection unit 9 by wired and / or wireless communication.

The installation position of the defect position estimation unit 104 is not particularly limited and may be anywhere as long as communication with the second detection unit 9 is possible. In addition, since the 2nd detection part 9 is installed on the ground, it is preferable that the defect position estimation part 104 is also installed on the ground.

Next, the configuration of each element will be described in detail.

The vibration unit 6 applies vibration to at least one of the fluid 5 flowing in the pipe 2 and the pipe 2. In the case of the example shown in FIG. 1, the excitation unit 6 applies vibration to the pipe 2. The vibration applied to the pipe 2 may be transmitted to the fluid 5. In the case of the example shown in FIG. 9, the excitation unit 6 applies vibration to the fluid 5. The vibration applied to the fluid 5 may be transmitted to the pipe 2. The vibration applied to the pipe 2 by the vibration unit 6 mainly proceeds along the extending direction of the pipe 2.

The vibration unit 6 applies a vibration having a frequency corresponding to the vibration signal input from the first vibration control unit 101 and the second vibration control unit 103. For example, the vibration unit 6 can apply vibrations having a plurality of frequencies (high-band frequencies) in accordance with the vibration signal input from the first vibration control unit 101. The means for applying vibrations having a plurality of frequencies is not particularly limited, and vibrations having a plurality of frequencies may be applied simultaneously, or vibrations having a plurality of frequencies may be sequentially applied while changing the frequency. The vibration unit 6 may apply, for example, impulse vibration or white noise. In addition, the vibration unit 6 can continuously apply vibration of a specific frequency in accordance with the vibration signal input from the second vibration control unit 103.

As the vibration unit 6, vibration can be applied to the fluid 5 and the pipe 2 such as an electromagnetic vibrator, a permanent magnet vibrator, an electromagnetic speaker, an ultrasonic vibrator, and the vibration frequency can be changed. Those capable of exciting vibrations having a plurality of frequency components can be used.

The first vibration control unit 101 controls the vibration unit 6 (inputs a vibration signal to the vibration unit 6), and has a plurality of frequencies for at least one of the fluid 5 flowing in the pipe 2 and the pipe 2. A first vibration including vibration is applied. As shown in the figure, the incident wave 20 of the first vibration applied by the vibration unit 6 in a state where the defect 3 exists in the pipe 2 is reflected by the transmitted wave 21 passing through the position of the defect 3 and the position of the defect 3. Then, it is separated into a reflected wave 22 that returns to the side where the excitation unit 6 and the first detection unit 7 are located, and a leakage wave 23 that leaks outside the pipe 2 through the defect 3.

The first detection unit 7 detects at least one of the first vibration that is applied by the vibration unit 6 and propagates through the pipe 2 and the first vibration that propagates through the fluid 5. In the case of the example shown in FIG. 1, the first detection unit 7 detects the first vibration that propagates through the pipe 2. In the case of the example shown in FIG. 9, the first detection unit 7 detects the first vibration that propagates through the fluid 5. As described above, the pipe extending direction positions of the excitation unit 6 and the first detection unit 7 are located on the same side as viewed from the defect 3 with high probability. For this reason, when the 1st vibration is applied in the state where defect 3 exists in piping 2, the 1st detection part 7 can detect reflected wave 22 of the 1st vibration.

The first detection unit 7 inputs an electric signal corresponding to the detected amplitude and frequency of the first vibration to the signal processing unit 102 as a detection signal. As the first detection unit 7, a piezoelectric vibration sensor, an electromagnetic vibration sensor, an ultrasonic sensor, a microphone, or the like can be used.

The second detection unit 9 is installed on the first surface (the ground 4) and detects the first vibration applied by the vibration unit 6. That is, the second detection unit 9 detects the first vibration that has passed through the underground 1 after being applied by the excitation unit 6. As the second detection unit 9, a piezoelectric vibration sensor, an electromagnetic vibration sensor, an ultrasonic sensor, a microphone, or the like can be used.

The second vibration control unit 103 controls the vibration unit 6 (inputs a vibration signal to the vibration unit 6), and will be described below with respect to at least one of the fluid 5 flowing in the pipe 2 and the pipe 2. The vibration of the frequency determined by the signal processing unit 102 to be applied (second vibration) is applied. The frequency of the second vibration includes a first vibration waveform that is a vibration waveform obtained by the first detection unit 7 detecting the first vibration in a state where the defect 3 exists in the pipe 2, and the first vibration. Is determined using a second vibration waveform which is a vibration waveform obtained by detecting by the second detection unit 9 installed on the first surface (ground 4). The second vibration will be described in detail in the description of the signal processing unit 102 below. The second vibration control unit 103 controls the vibration unit 6 to detect the second vibration determined by using the first vibration waveform detected by the first detection unit 7 in the state where the defect 3 exists. 3 is applied to the pipe 2 in which it exists.

The signal processing unit 102 determines the frequency of the second vibration using the first vibration waveform and the second vibration waveform. By determining the frequency of the second vibration using the first vibration waveform and the second vibration waveform, leakage from the defect 3 to the outside of the pipe 2 is facilitated, and the transmission efficiency between the pipe 2 and the ground 4 is improved. The frequency of vibration that is good can be determined. Hereinafter, the reason will be described.

First, the first vibration waveform will be described. The first vibration applied to the pipe 2 and / or the fluid 5 propagates as an incident wave (vibration wave) 20 in the pipe and / or the fluid 5 (see FIG. 1). When the defect 3 is formed in the pipe 2, the incident wave 20 is reflected at the transmitted wave 21 passing through the position of the defect 3 and the position of the defect 3, and the side where the excitation unit 6 and the first detection unit 7 are located. Is separated into a reflected wave 22 that returns to the outside and a leaky wave 23 that leaks to the outside of the pipe 2 through the defect 3.

Note that the spectrum of the leaky wave 23 has a characteristic that the vibration amplitude of a specific frequency is larger than the spectrum of the incident wave 20. The reflected wave 22 also has a feature that the vibration amplitude of a specific frequency is large, like the leaky wave 23. The spectrum of the leaky wave 23 and the reflected wave 22 has a larger vibration amplitude at a specific frequency than the incident wave 20 because resonance occurs between the incident wave 20 and the defect 3. The defect 3 has a resonance frequency corresponding to the diameter, length, etc. of the defect 3. When vibration having the same frequency as the resonance frequency is incident on the defect 3, resonance occurs in the defect 3, and the vibration amplitude of the resonance frequency increases.

FIG. 2 shows a vibration spectrum of the leaky wave 23 when the first vibration having a flat frequency characteristic is incident on the defect 3 as the incident wave 20. In FIG. 2, the horizontal axis represents the frequency f, and the vertical axis represents the vibration amplitude I. The vibration amplitude I of the leaky wave 23 has a plurality of peaks at the fundamental frequency f ₀ and its harmonic frequencies f ₁ , f ₂ , f ₃ ..., And has the largest amplitude I at the fundamental frequency f _0. A large peak is obtained. Here, the frequency f ₀ of this fundamental wave and the frequencies f ₁ , f ₂ , f ₃ ... Of its harmonics are defined as resonance frequencies. A frequency having a large vibration amplitude in the spectrum of the leaky wave 23 is a frequency of vibration that easily leaks to the outside of the pipe 2 through the defect 3.

Next, FIG. 3 shows a vibration spectrum of the reflected wave 22 when the first vibration having a flat frequency characteristic is incident on the defect 3 as the incident wave 20. In FIG. 3, the horizontal axis represents the frequency f, and the vertical axis represents the vibration amplitude I. The spectrum of the reflected wave 22 has a plurality of peaks at the fundamental frequency f ₀ and its harmonic frequencies f ₁ , f ₂ , f ₃ ..., As with the leaky wave 23, and the fundamental frequency f _0. The peak with the largest amplitude I is obtained at

It should be noted that the frequency at which the vibration amplitude in the reflected wave 22 increases and the frequency at which the vibration amplitude in the leaky wave 23 increases coincide. For this reason, in the spectrum of the reflected wave 22, it can be considered that a peak appears at the frequency of vibration that easily leaks to the outside of the pipe 2 through the defect 3. That is, in the first vibration waveform including the component of the reflected wave 22, a peak appears at the frequency of vibration that easily leaks to the outside of the pipe 2 through the defect 3.

Next, the second vibration waveform will be described. As described above, the second vibration waveform is a vibration waveform obtained by detecting the first vibration with the second detection unit 9 installed on the first surface (ground 4). For this reason, the peak frequency that appears in the second vibration waveform can be said to be a frequency that is easily transmitted between the pipe 2 and the first surface (the ground surface 4). That is, the second vibration waveform has a peak at the frequency of vibration that is easily transmitted between the pipe 2 and the first surface (the ground surface 4).

The signal processing unit 102 determines the frequency of the second vibration using the first vibration waveform and the second vibration waveform. Specifically, the signal processing unit 102 determines the transfer function G1 (f) = A1 (f) / P0 (f) using the first vibration waveform. Further, the transfer function G2 (f) = A2 (f) / P0 (f) is determined using the second vibration waveform. In addition, f shows a frequency, P0 (f) shows the magnitude | size of the 1st vibration applied from the vibration part 6, A1 (f) is the 1st vibration detected by the 1st detection part 7. A2 (f) indicates the magnitude of the first vibration detected by the second detector 9. The magnitude of the vibration is acceleration, speed, displacement or the like. Then, the signal processing unit 102 includes the second vibration so as to include the peak frequency appearing in the vibration waveform of the transfer function G3 (f) obtained by the product of the transfer function G1 (f) and the transfer function G2 (f). Determine the frequency. In the transfer function G3 (f), a peak appears at the frequency of vibration that easily leaks to the outside of the pipe 2 through the defect 3 and is easily transmitted between the pipe 2 and the first surface (the ground surface 4). The transfer function G3 (f) is expressed by the following equation.

For example, the signal processing unit 102 may set the frequency band of a predetermined range (a predetermined range centered on the peak) including the frequency of the peak appearing in the vibration waveform of the transfer function G3 (f) as the frequency of the second vibration. . As another example, the signal processing unit 102 may determine the peak frequency appearing in the vibration waveform of the transfer function G3 (f) as the second vibration frequency. When a plurality of peaks appear in the vibration waveform of the transfer function G3 (f), the signal processing unit 102 may set a frequency band in a predetermined range including the frequencies of the plurality of peaks as the second vibration frequency. Alternatively, a frequency band in a predetermined range (a predetermined range centered on the peak) including the frequency of the strongest peak may be used as the frequency of the second vibration. In addition, when a plurality of peaks appear in the vibration waveform of the transfer function G3 (f), the signal processing unit 102 may set the frequency of the plurality of peaks therein as the frequency of the second vibration, or the highest among them. The strong peak frequency may be set as the frequency of the second vibration. The frequency determined in this way is a frequency of vibration that is likely to leak from the defect 3 to the outside of the pipe 2 and that the transmission efficiency between the pipe 2 and the ground surface 4 (first surface) is good. I can say that. In addition, when determining the frequency band of the predetermined range as the second vibration, since the problem of the S / N ratio occurs if the predetermined range is too wide, the range is preferably set to about 100 Hz or less.

For example, when the first vibration waveform is shown in FIG. 4 and the second vibration waveform is shown in FIG. 5, the vibration waveform of the transfer function G3 (f) is as shown in FIG. As shown in FIG. 6, the peak frequency appearing in the vibration waveform of the transfer function G3 (f) may deviate from the peak frequency appearing in the first vibration waveform, or may coincide with the peak frequency appearing in the first vibration waveform. There is also a case.

1, the third detection unit 8 detects the second vibration applied to the pipe 2 in which the defect 3 exists and / or the fluid 5 flowing through the pipe 2 by the vibration unit 6. Specifically, the third detection unit 8 leaks to the outside of the pipe 2 through the defect 3 in the second vibration applied by the vibration unit 6 according to the control of the second vibration control unit 103. The second vibration propagating through the underground 1 is detected. As described above, the second vibration is a vibration having a frequency that easily leaks from the defect 3 to the outside of the pipe 2 and has good transmission efficiency between the pipe 2 and the ground surface 4 (first surface). For this reason, the third detection unit 8 can detect the second vibration with sufficient strength that has propagated to the ground 4 after propagating to the outside of the pipe 2 through the defect 3.

The third detection unit 8 may be configured to change the installation position and detect the second vibration at a plurality of positions. Alternatively, a plurality of third detection units 8 may exist, the plurality of second detection units 9 may be installed at different positions with predetermined intervals, and each may detect the second vibration (FIG. 8). reference). The third detection unit 8 inputs an electrical signal corresponding to the detected amplitude and frequency of the second vibration to the defect position estimation unit 104 as a detection signal. As the third detection unit 8, a piezoelectric vibration sensor, an electromagnetic vibration sensor, an ultrasonic sensor, a microphone, or the like can be used. The second detection unit 9 and the third detection unit 8 may be the same device or different devices. The sensors constituting the second detection unit 9 and the third detection unit 8 may be provided separately, or may be configured by the same sensor or the like. Since the second detector 9 and the third detector 8 are used at different timings, there is no problem even if the latter is configured.

The defect position estimation unit 104 estimates the position of the defect 3 using the vibration waveforms of the plurality of second vibrations detected at the plurality of positions by the third detection unit 8. Alternatively, the defect position estimation unit 104 estimates the position of the defect 3 using the vibration waveforms of the plurality of second vibrations detected by the plurality of second detection units 9. For example, the defect position estimation unit 104 compares the vibration waveforms of the plurality of second vibrations measured at each of the plurality of installation positions, and determines the installation position where the peak output is maximum as the position immediately above the defect 3. Can be estimated. In addition, when the position of the rough defect 3 can be grasped, it is preferable that the installation position of the third detection unit 8 is in the vicinity immediately above the defect 3.

Next, a defect detection method realized using the defect detection apparatus of this embodiment will be described. FIG. 7 is an example of a flowchart showing a processing flow of the defect detection method of the present embodiment. As shown in the figure, the defect detection method of the present embodiment includes an external propagation frequency specifying step S10 and an external propagation vibration detection step S20.

In the external propagation frequency specifying step S10, the frequency of vibration at which the defect 3 existing in the pipe 2 easily leaks to the outside of the pipe 2 and the transmission efficiency between the pipe 2 and the ground surface 4 (first surface) is good. Is determined as the frequency of the second vibration.

First, the presence of the defect 3 in the pipe 2 is detected by some means. For example, the spectrum of the reflected wave 22 is constantly or intermittently (eg, once a day, once an hour, once every 12 hours, etc.) using the first detector 7 by the same means as described above. Measurement of the defect 3 can be detected from the change in the spectrum of the reflected wave 22 when the defect 3 occurs. When the defect 3 is detected, the following steps for specifying the position of the defect 3 are executed.

First, the vibration unit 6 applies vibrations in a plurality of frequency bands (first vibrations) to the fluid 5 according to the vibration signal output from the first vibration control unit 101. The first vibration applied to the fluid 5 propagates in the fluid 5 as an incident wave (vibration wave) 20 (see FIG. 1). When the defect 3 is formed in the pipe 2, the incident wave 20 is reflected at the transmitted wave 21 passing through the position of the defect 3 and the position of the defect 3, and the side where the excitation unit 6 and the first detection unit 7 are located. Is separated into a reflected wave 22 that returns to the outside and a leaky wave 23 that leaks to the outside of the pipe 2 through the defect 3.

The first detection unit 7 is reflected by the defect 3 in the first vibration applied by the vibration unit 6 according to the control of the first vibration control unit 101, and the reflected wave 22 propagates through the pipe 2 and / or the fluid 5. Detect vibrations. Then, the first detection unit 7 inputs a detection signal to the signal processing unit 102.

Then, the signal processing unit 102 includes the data of the vibration waveform (first vibration waveform) detected by the first detection unit 7 and the vibration waveform (second vibration waveform) detected by the second detection unit 9 of the first vibration. The frequency of the second vibration is determined using the data. Details are as described above.

Note that the second vibration waveform data is acquired (measured) at the same timing (eg, the same day and the same time) as the first vibration waveform data is acquired (measured), and input to the signal processing unit 102. Or, it is acquired (measured) before the data of the first vibration waveform is acquired (measured) (for example, when the excitation unit 6 or the first detection unit 7 is installed in the pipe 2). Alternatively, it may be stored in the signal processing unit 102 in advance. In the latter case, instead of the data of the second vibration waveform, the transfer function G2 (f) determined using the data may be stored in the signal processing unit 102.

Next, external propagation vibration detection step S20 is executed. In this step, the frequency determined in the external propagation frequency specifying step S10 is likely to leak from the defect 3 to the outside of the pipe 2 and the transmission efficiency between the pipe 2 and the ground 4 (first surface) is good. Vibration (second vibration) is applied to the pipe 2 and / or the fluid 5, and this vibration is detected by the third detection unit 8 installed on the ground 4.

First, according to the control of the second vibration control unit 103, the vibration unit 6 applies vibration (second vibration) having the frequency determined in the external propagation frequency specifying step S10 to the pipe 2 and / or the fluid 5. During this time, the vibration unit 6 does not apply vibration according to the control of the first vibration control unit 101. The incident wave 20 of the second vibration is separated into a transmitted wave 21, a reflected wave 22, and a leakage wave 23 in the defect 3. Here, when the vibration of the resonance frequency (second vibration) is applied, the amplitude of the leakage wave 23 that leaks from the defect 3 to the outside of the pipe 2 and propagates to the ground 1 is amplified by resonance. The amplified leaky wave 23 propagates in the ground 1 and is detected by the second detection unit 9 installed on the ground 4, and a detection signal corresponding to the amplitude of the detection signal is input to the defect position estimation unit 104.

In addition, in order to specify the position of the defect 3, the third detection unit 8 changes the installation position and detects the second vibration at a plurality of positions. For example, the ground is scanned along the pipe 2. Alternatively, a plurality of third detection units 8 exist, the plurality of third detection units 8 are installed at different positions with a predetermined interval, and each detects a second vibration. For example, they are installed on the ground side by side at a predetermined interval along the pipe 2.

When the third detection unit 8 is near the defect 3, the vibration amplitude of the leaky wave 23 is large, so that the detection signal level also increases, and the vibration amplitude of the leaky wave 23 increases as the third detection unit 8 moves away from the defect 3. It becomes smaller and the detection signal level becomes smaller. From this, it is estimated that the place of the 3rd detection part 8 in which a detection signal level becomes the maximum right above the place where the defect 3 exists. That is, by specifying the installation location where the detection signal level is maximized, it is possible to estimate the location immediately above the location where the defect 3 exists.

The defect position estimation unit 104 compares a plurality of detection signals detected at a plurality of positions, and estimates the position where the detection signal level is the maximum directly above the place where the defect 3 is present.

In addition, instead of the defect position estimation unit 104 specifying the position of the defect 3, an operator can specify it. For example, when the third detection unit 8 is scanned on the ground (automatic scanning or manually scanned by an operator), the third detection unit 8 measures the second vibration at each position and processes the measured detection signal. The data is displayed on the display in real time. The worker may specify the position where the detection signal level is maximized by checking the data displayed on the display while scanning the third detection unit 8 on the ground.

As described above, in the defect detection device of the present embodiment, a frequency at which the defect 3 easily leaks to the outside of the pipe 2 and the transmission efficiency between the pipe 2 and the ground 4 (first surface) is good. The amplitude of the leakage wave 23 can be increased by calculating by the signal processing unit 102 and applying the vibration of the frequency to the fluid 5. In such a case, the third detector 8 can detect a sufficiently strong vibration without causing the inconvenience of a low S / N ratio. As a result, the leak position can be estimated with high accuracy.

In the present embodiment, the third detector 8 detects the second vibration in a state in which the second vibration including the frequencies of a plurality of peaks appearing in the vibration waveform of the transfer function G3 (f) is applied to the fluid 5. You can also Thereby, even when the frequency of the disturbance vibration overlaps with any one of the resonance frequencies, the influence of the disturbance vibration can be reduced by detecting the leakage wave 23 having another resonance frequency.

It should be noted that the reflected wave 22 may include a reflected wave other than the defect 3. For example, a reflected wave is also generated in a bent pipe of the pipe 2 or a branch portion of the pipe 2. However, these reflected waves can be distinguished from the reflected wave 22 caused by the defect 3 because it is possible to predict the reflected wave spectrum by measuring the reflected wave without leakage or by simulation. That is, such noise can be removed from the first vibration waveform. The frequency of the second vibration can be determined using the first vibration waveform from which such noise is removed.

In addition, the vibration detected by the first detection unit 7 in a state where the vibration unit 6 is not applying the first vibration to the fluid 5, and the state where the vibration unit 6 is applying the first vibration to the fluid 5 Thus, the disturbance vibration (traffic noise, etc.) and the reflected wave 22 from the defect 3 can be distinguished from the difference in frequency characteristics from the vibration detected by the first detection unit 7. That is, the frequency of the second vibration can be determined using the first vibration waveform from which such noise has been removed.

Moreover, the leak position can be estimated with higher accuracy by performing the leak position detection by the second detector 9 at night when there is little disturbance vibration.

In addition, the defect device of the present embodiment can also be configured as shown in FIG. That is, the defect device of the present embodiment does not have to include the signal processing unit 102 and the defect position estimation unit 104. In such a case, the signal processing unit 102 and the defect position estimation unit 104 are provided in an external device different from the defect device. The defective device and the external device exchange data by wired and / or wireless communication, or data exchange by a user operation using a portable storage device or the like, thereby realizing the above-described processing.

In addition, the defect position estimation unit 104 synchronizes the detection signals detected by the plurality of second detection units 9, calculates a time difference in timing when the feature due to the defect 3 is detected, and based on the time difference, A rough position may be estimated (correlation method).

In the present embodiment, if a plurality of third detection units 8 are installed in advance, it is not necessary to scan the third detection unit 8 along the pipe 2 in order to estimate the defect position, thereby reducing labor and time. .

<Appendix>
Hereinafter, examples of the reference form will be added.
1. Vibration means for applying vibration to at least one of the fluid flowing in the pipe installed at a position away from the first surface and the pipe;
First vibration control means for controlling the vibration means and applying a first vibration including vibrations of a plurality of frequencies to at least one of the fluid flowing in the pipe and the pipe;
First detection means for detecting at least one of the first vibration that is applied by the vibration means and propagates through the pipe and the first vibration that propagates the fluid;
A second detection means installed on the first surface for detecting the first vibration;
A first vibration waveform, which is a vibration waveform obtained by controlling the excitation means and detecting the first vibration by the first detection means, and the second detection means detecting the first vibration. And applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, which is a vibration waveform obtained by applying, to at least one of the fluid flowing in the pipe and the pipe. Second excitation control means for causing
Third detection means installed on the first surface and detecting the second vibration applied by the vibration means;
A defect analysis apparatus.
2. In the defect analysis apparatus according to 1,
Signal processing means for determining the frequency of the second vibration;
The signal processing means determines the transfer function G1 (f) = A1 (f) / P0 (f) using the first vibration waveform, and uses the second vibration waveform to transfer function G2 (f ) = A2 (f) / P0 (f) (where f is the frequency, P0 (f) is the magnitude of the first vibration applied from the excitation means, and A1 (f ) Indicates the magnitude of the first vibration detected by the first detection means, and A2 (f) indicates the magnitude of the first vibration detected by the second detection means). Determining the frequency of the second vibration so as to include the peak frequency appearing in the vibration waveform of the transfer function G3 (f) obtained by the product of the transfer function G1 (f) and the transfer function G2 (f);
The second vibration control unit is a defect analysis apparatus that controls the vibration of the frequency determined by the signal processing unit to be applied from the vibration unit as the second vibration.
3. In the defect analysis apparatus according to 2,
The defect analysis apparatus, wherein the signal processing means determines a peak frequency appearing in a vibration waveform of the transfer function G3 (f) as the frequency of the second vibration.
4). In the defect analysis apparatus according to 3,
The signal processing means, when a plurality of peaks appear in the vibration waveform of the transfer function G3 (f), determines the frequency of the strongest peak among them as the frequency of the second vibration.
5. In the defect analysis apparatus according to any one of 1 to 4,
The third detection means is configured to detect the second vibration at a plurality of positions on the first surface,
A defect analysis apparatus further comprising defect position estimation means for estimating the position of a defect using a plurality of vibration waveforms detected at a plurality of positions by the third detection means.
6). In the defect analysis apparatus according to any one of 1 to 4,
There are a plurality of the third detection means, and the plurality of third detection means are installed at different positions with a predetermined interval on the first surface, and each detects the second vibration. ,
A defect analysis apparatus further comprising defect position estimation means for estimating a defect position using a plurality of vibration waveforms detected by the plurality of third detection means.
7). Computer
Controlling at least one of a fluid flowing in a pipe installed at a position away from the first surface and at least one of the pipe, and controlling at least one of the fluid flowing in the pipe and the pipe A first excitation control step of applying a first vibration including vibrations of a plurality of frequencies to one side;
A first detection step of detecting at least one of the first vibration that is applied by the vibration means and propagates through the pipe and the first vibration that propagates through the fluid;
A second detection step of detecting the first vibration on the first surface;
A first vibration waveform that is a vibration waveform obtained by controlling the excitation means and detecting the first vibration in the first detection step, and detecting the first vibration in the second detection step. And applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, which is a vibration waveform obtained by applying, to at least one of the fluid flowing in the pipe and the pipe. A second excitation control step,
A third detection step installed on the first surface and detecting the second vibration applied by the vibration means;
Perform defect analysis method.
7-2. In the defect analysis method according to 7,
The computer further performs a signal processing step of determining a frequency of the second vibration;
In the signal processing step, the transfer function G1 (f) = A1 (f) / P0 (f) is determined using the first vibration waveform, and the transfer function G2 (f ) = A2 (f) / P0 (f) (where f is the frequency, P0 (f) is the magnitude of the first vibration applied from the excitation means, and A1 (f ) Indicates the magnitude of the first vibration detected in the first detection step, and A2 (f) indicates the magnitude of the first vibration detected in the second detection step). Determining the frequency of the second vibration so as to include the peak frequency appearing in the vibration waveform of the transfer function G3 (f) obtained by the product of the transfer function G1 (f) and the transfer function G2 (f);
In the second vibration control step, a defect analysis method for controlling the vibration of the frequency determined in the signal processing step to be applied as the second vibration from the vibration means.
7-3. In the defect analysis method described in 7-2,
In the signal processing step, a defect analysis method for determining a peak frequency appearing in a vibration waveform of the transfer function G3 (f) as the frequency of the second vibration.
7-4. In the defect analysis method described in 7-3,
In the signal processing step, when a plurality of peaks appear in the vibration waveform of the transfer function G3 (f), the defect analysis method of determining the frequency of the strongest peak among them as the frequency of the second vibration.
7-5. In the defect analysis method according to any one of 7 to 7-4,
In the third detection step, the second vibration can be detected at a plurality of positions on the first surface.
The defect analysis method, wherein the computer further executes a defect position estimation step of estimating the position of the defect using a plurality of vibration waveforms detected at a plurality of positions in the third detection step.
8). Computer
Controlling at least one of a fluid flowing in a pipe installed at a position away from the first surface and at least one of the pipe, and controlling at least one of the fluid flowing in the pipe and the pipe A first vibration control means for applying a first vibration including a plurality of vibrations to one side;
First detection means for detecting at least one of the first vibration that is applied by the vibration means and propagates through the pipe and the first vibration that propagates the fluid;
Second detection means for detecting the first vibration on the first surface;
A first vibration waveform, which is a vibration waveform obtained by controlling the excitation means and detecting the first vibration by the first detection means, and the second detection means detecting the first vibration. And applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, which is a vibration waveform obtained by applying, to at least one of the fluid flowing in the pipe and the pipe. Second excitation control means for causing
Third detection means installed on the first surface and detecting the second vibration applied by the vibration means;
Program to function as.
8-2. In the program described in 8,
Further causing the computer to function as signal processing means for determining a frequency of the second vibration,
The signal processing means determines the transfer function G1 (f) = A1 (f) / P0 (f) using the first vibration waveform, and uses the second vibration waveform to transfer function G2 (f ) = A2 (f) / P0 (f) (where f is the frequency, P0 (f) is the magnitude of the first vibration applied from the excitation means, and A1 (f ) Indicates the magnitude of the first vibration detected by the first detection means, and A2 (f) indicates the magnitude of the first vibration detected by the second detection means). The frequency of the second vibration is determined so as to include the peak frequency appearing in the vibration waveform of the transfer function G3 (f) obtained by the product of the transfer function G1 (f) and the transfer function G2 (f);
A program for causing the second vibration control means to control the vibration of the frequency determined by the signal processing means to be applied from the vibration means as the second vibration.
8-3. In the program described in 8-2,
A program for causing the signal processing means to determine a peak frequency appearing in a vibration waveform of the transfer function G3 (f) as the frequency of the second vibration.
8-4. In the program described in 8-3,
A program for causing the signal processing means to determine the frequency of the strongest peak among them as the frequency of the second vibration when a plurality of peaks appear in the vibration waveform of the transfer function G3 (f).
8-5. In the program according to any one of 8 to 8-4,
Causing the third detection means to detect the second vibration at a plurality of positions on the first surface;
A program for causing the computer to further function as defect position estimation means for estimating the position of the defect using a plurality of vibration waveforms detected at a plurality of positions by the third detection means.

This application claims priority based on Japanese Patent Application No. 2013-073381 filed on Mar. 29, 2013, the entire disclosure of which is incorporated herein.

Claims

Vibration means for applying vibration to at least one of the pipe and the fluid flowing in the pipe;
First vibration control means for controlling the vibration means to apply a first vibration including vibrations at a plurality of frequencies to at least one of the fluid and the pipe;
First detection means for detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection means installed on a first surface spaced from the pipe and detecting the first vibration;
Using the first vibration waveform obtained by detecting the first vibration by the first detection means and the second vibration waveform obtained by detecting the first vibration by the second detection means. Second vibration control means for controlling the vibration means to apply a second vibration, which is a vibration of a determined frequency, to at least one of the fluid or the pipe;
A third detection means installed on the first surface for detecting the second vibration;
A defect analysis apparatus.
The defect analysis apparatus according to claim 1,
Signal processing means for determining the frequency of the second vibration;
The signal processing means obtains a transfer function G1 of the fluid or the pipe from the first vibration waveform and obtains a transfer function G2 between the vibration means and the third detection means from the second vibration waveform. , Determining the frequency of the second vibration based on the peak frequency appearing in the transfer function G3 obtained from the transfer function G1 and the transfer function G2.
The second vibration control unit is a defect analysis apparatus that controls the vibration of the frequency determined by the signal processing unit to be applied from the vibration unit as the second vibration.
The defect analysis apparatus according to claim 2,
Signal processing means for determining the frequency of the second vibration;
The signal processing means determines the transfer function G1 (f) = A1 (f) / P0 (f) using the first vibration waveform, and uses the second vibration waveform to transfer function G2 (f ) = A2 (f) / P0 (f) (where f is the frequency, P0 (f) is the magnitude of the first vibration applied from the excitation means, and A1 (f ) Indicates the magnitude of the first vibration detected by the first detection means, and A2 (f) indicates the magnitude of the first vibration detected by the second detection means). Defect that determines the frequency of the second vibration so as to include the peak frequency appearing in the vibration waveform of the transfer function G3 (f) obtained by the product of the transfer function G1 (f) and the transfer function G2 (f) Analysis equipment.
In the defect analysis apparatus according to claim 2 or 3,
The defect analysis apparatus, wherein the signal processing means determines a peak frequency appearing in a vibration waveform of the transfer function G3 (f) as the frequency of the second vibration.
The defect analysis apparatus according to claim 4,
The signal processing means, when a plurality of peaks appear in the vibration waveform of the transfer function G3 (f), determines the frequency of the strongest peak among them as the frequency of the second vibration.
In the defect analysis apparatus according to any one of claims 1 to 5,
The third detection means is configured to detect the second vibration at a plurality of positions on the first surface,
A defect analysis apparatus further comprising defect position estimation means for estimating the position of a defect using a plurality of vibration waveforms detected at a plurality of positions by the third detection means.
In the defect analysis apparatus according to any one of claims 1 to 5,
There are a plurality of the third detection means, and the plurality of third detection means are installed at different positions with a predetermined interval on the first surface, and each detects the second vibration. ,
A defect analysis apparatus further comprising defect position estimation means for estimating a defect position using a plurality of vibration waveforms detected by the plurality of third detection means.
Computer
A vibration means for applying vibration to at least one of a pipe or a fluid flowing in the pipe is controlled, and a first vibration including vibrations having a plurality of frequencies is applied to at least one of the fluid or the pipe. A first vibration control step to be performed;
A first detection step of detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection step that is installed on a first surface spaced from the pipe and detects the first vibration;
The first vibration waveform obtained by controlling the vibration means and detecting the first vibration by the first detection step, and the first vibration obtained by the second detection step. A second vibration control step of applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, to at least one of the fluid or the pipe;
A third detection step installed on the first surface and detecting the second vibration;
Perform defect analysis method.
Computer
A vibration means for applying vibration to at least one of a pipe or a fluid flowing in the pipe is controlled, and a first vibration including vibrations having a plurality of frequencies is applied to at least one of the fluid or the pipe. First excitation control means for causing
First detection means for detecting the first vibration propagating through at least one of the pipe or the fluid;
A second detection means installed on a first surface spaced from the pipe and detecting the first vibration;
The first vibration waveform obtained by controlling the vibration means and detecting the first vibration by the first detection means, and the first vibration obtained by the second detection means. A second vibration control means for applying a second vibration, which is a vibration having a frequency determined using the second vibration waveform, to at least one of the fluid or the pipe;
A third detection means installed on the first surface for detecting the second vibration;
Program to function as.