Non-destructive detection method and non-destructive detection system for leakage phenomena

Abstract

To provide a nondestructive detection method and a nondestructive detection system capable of identifying a leakage phenomenon of a fluid in an existing pipeline without performing processing or the like on the pipeline.SOLUTION: A nondestructive detection method for a leakage phenomenon of a fluid in a pipeline includes: an analysis surface installation step of installing an image analysis surface on a surface of a pipe material of the pipeline; an analysis surface imaging step of imaging the image analysis surface by imaging means; a displacement amount measuring step of measuring a circumferential direction displacement amount of the pipe material on the basis of the image captured by the imaging means; and a leakage phenomenon determination step capable of making an analysis on the basis of the measured circumferential direction displacement amount to at least determine the presence or absence of the leakage phenomenon of the fluid. The leakage phenomenon determination step can determine an attenuation behavior in a time-frequency domain based on the circumferential direction displacement amount to at least estimate the presence or absence of a water leakage and a water leakage position.SELECTED DRAWING: Figure 25

Description

Technical Field

[0001] The present invention relates to a non-destructive detection method and a non-destructive detection system for a leakage phenomenon that can identify a fluid leakage phenomenon in a pipeline.

Background Art

[0002] Conventionally, there is a water conservancy system that enables water supply and distribution to agricultural land by utilizing the water pressure in an agricultural pipeline. Leakage in the agricultural pipeline may lead to disruption of the farming plan associated with loss of agricultural water and a decrease in the yield and quality of crops.

[0003] Since most of the existing pipelines are buried in the ground, it is difficult to efficiently detect leakage, and establishing inspection technology from the perspective of maintenance and management becomes an issue. Generally, for detecting pipeline leakage, the main aim is to detect a decrease in water pressure. However, in existing facilities, pressure gauges can only be installed at limited locations such as air valves.

[0004] Under such circumstances, in the technologies disclosed in Non-Patent Document 1, Non-Patent Document 2, and Patent Document 1, for leakage in an irrigation pipeline, by adding leakage information to the water hammer pressure associated with valve operation and applying numerical simulation, establishing a detailed detection method has been studied.

[0005] Also, in the technology disclosed in Non-Patent Document 3, as a direct measurement method, a capsule-type exploration device is inserted into the pipeline, and identifying the leakage location of the pipeline from the leakage sound acquired by the exploration device has been studied.

Prior Art Documents

Non-Patent Documents

[0006]

Non-Patent Document 1

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-115707 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, the methods disclosed in Non-Patent Documents 1 and 2, and Patent Document 1, require the installation of a pressure gauge in the pipeline to measure the water pressure. In particular, it is anticipated that installing a pressure gauge will be difficult in aging existing pipelines.

[0009] Furthermore, the method disclosed in Non-Patent Document 3 requires the insertion of a φ55mm × 165mm capsule containing an underwater microphone into the pipeline, making it particularly difficult to use with pipelines of small diameters. In addition, since capsule recovery is essential, there are challenges such as the need to modify existing pipelines for insertion and recovery, and the risks involved if the capsule cannot be recovered.

[0010] Therefore, the present invention aims to provide a non-destructive detection method and a non-destructive detection system for fluid leakage phenomena that can identify fluid leakage phenomena in an existing pipeline without performing any processing on the pipeline. [Means for solving the problem]

[0011] The present invention relates to a non-destructive detection method for fluid leakage phenomena in a pipeline, comprising: an analysis surface installation step of installing an image analysis surface on the surface of the pipe material of the pipeline; an analysis surface imaging step of imaging the image analysis surface with an imaging means; a displacement measurement step of measuring the circumferential displacement of the pipe material based on the image captured by the imaging means; and a leakage phenomenon determination step of performing an analysis based on the measured circumferential displacement to determine at least whether or not the fluid leakage phenomenon is occurring, wherein the leakage phenomenon determination step can determine the attenuation behavior in the time-frequency domain based on the circumferential displacement to estimate at least the presence or absence of leakage and the location of leakage.

[0012] According to the configuration of the present invention, for example, it is possible to identify the presence or absence of fluid leakage and the location of leakage in an existing pipeline without modifying the pipeline, even within the limited space inside a manhole. [Brief explanation of the drawing]

[0013] [Figure 1] This diagram illustrates the model pipeline analysis flow in the present invention. [Figure 2]It is a schematic diagram explaining the overall configuration of the model pipeline. [Figure 3] (a) is a table showing the specifications of the pipe material of the model pipeline. (b) is a table showing the breakdown details of the examination cases in the experiment. [Figure 4] It is a schematic diagram explaining the measurement mode and system configuration for the pipeline. [Figure 5] It is a schematic diagram explaining the model in the cylindrical coordinate system in the pipeline. [Figure 6] (a) is a visible image of the image measurement and analysis plane A, and (b) is a three-dimensional analysis image of the image measurement and analysis plane A. [Figure 7] It is a transition diagram explaining the water hammer action. [Figure 8] It is a graph (Case1) showing the relationship between water pressure and circumferential strain. [Figure 9] It is a graph (Case2) showing the relationship between water pressure and circumferential strain. [Figure 10] It is a graph (Case3) showing the relationship between water pressure and circumferential strain. [Figure 11] It is a graph (Case4) showing the relationship between water pressure and circumferential strain. [Figure 12] It is a graph (Case5) showing the relationship between water pressure and circumferential strain. [Figure 13] It is a graph (Case6) showing the relationship between water pressure and circumferential strain. [Figure 14] It is a graph comparing the water pressure and circumferential strain according to the presence or absence of leakage (Case1 and Case2). )]] [Figure 15] It is a graph comparing the water pressure and circumferential strain according to the presence or absence of leakage (Case3 and Case4). [Figure 16] It is a graph comparing the water pressure and circumferential strain according to the presence or absence of leakage (Case5 and Case6). [Figure 17] It is a graph (Case1) showing the relationship between water pressure and circumferential displacement and the relationship between circumferential strain and circumferential displacement. [Figure 18]This graph (Case 2) shows the relationship between water pressure and circumferential displacement, and between circumferential strain and circumferential displacement. [Figure 19] This graph (Case 3) shows the relationship between water pressure and circumferential displacement, and between circumferential strain and circumferential displacement. [Figure 20] This graph (Case 4) shows the relationship between water pressure and circumferential displacement, and between circumferential strain and circumferential displacement. [Figure 21] This graph (Case 5) shows the relationship between water pressure and circumferential displacement, and between circumferential strain and circumferential displacement. [Figure 22] This graph (Case 6) shows the relationship between water pressure and circumferential displacement, and between circumferential strain and circumferential displacement. [Figure 23] This graph compares the amount of circumferential displacement with and without water leakage. [Figure 24] This graph shows the difference in frequency distribution depending on whether or not there is a water leak (Case 1 and Case 2). [Figure 25] This graph shows the difference in frequency distribution depending on whether or not there is a water leak (Case 3 and Case 4). [Figure 26] This graph shows the difference in frequency distribution depending on whether or not there is a water leak (Case 5 and Case 6). [Figure 27] This figure (Case 1) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 28] This figure (Case 1) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 29] This figure (Case 2) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 30] This figure (Case 2) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 31] This figure (Case 3) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 32] This figure (Case 3) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 33] This figure (Case 4) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 34] This figure (Case 4) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 35] This figure (Case 5) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 36] This figure (Case 5) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 37] This figure (Case 6) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Figure 38] This figure (Case 6) shows the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method). [Modes for carrying out the invention]

[0014] The following describes embodiments of the non-destructive detection method and non-destructive detection system for leakage phenomena of the present invention, with reference to the drawings, using a method for identifying leakage phenomena in water supply and distribution pipelines as an example.

[0015] (Model pipeline experiment) Prior to the present invention, a model pipeline as shown in Figure 2 was fabricated based on the study flow shown in Figure 1, and experiments were conducted to detect the presence or absence of simulated water leakage in the model pipeline, fluctuations in water pressure caused by valve operation, and the behavior of the pipe body using strain gauges and digital image correlation (DIC method), which is one of the image analysis techniques.

[0016] The appearance of the model pipeline is shown in Figure 2. The specifications of the pipe materials of the model pipeline are shown in Figure 3(a). To explain in more detail, a water tank is installed at the uppermost part, water is released from a pipe connected to the tank, and the water is discharged by operating a valve at the lowermost part.

[0017] The tank measures 0.47m x 0.47m x 0.47m x 1.2m and is fixed to a frame at a height of 2.9m above ground level. In this experiment, the flow rate is controlled by fully opening the upstream gate valve and operating the ball valve at the end. In addition, a model pipeline is installed to ensure a pressure head at the downstream end, creating a height difference between the upstream and downstream ends. By filling the upstream tank with water to a height of 1.1m and considering the height difference of the model pipeline installation, a pressure head of approximately 7.8m is secured at the downstream end.

[0018] Furthermore, as shown in Figure 3(b), six different study cases, Cases 1 to 6, have been established, taking into account the presence or absence of simulated water leakage and the measurement location. In other words, the study verifies that the presence or absence of water leakage can be detected even when the measurement is taken at a location far from the actual leak location. In all of the study cases, water is allowed to flow with the valve opening at 16.9°, and when the water level in the tank drops by 1m, the valve is abruptly closed to generate water hammer pressure.

[0019] For water pressure measurement, small pressure sensors (HTV-100KP, manufactured by Sensis Co., Ltd.) are installed in two locations: near the upstream water tank and near the downstream valve. Water pressure data is recorded using a voltage data logger (MCR-4V, manufactured by T&D Co., Ltd.) (sampling: 500Hz) and through synchronous connection during image measurement (sampling: 50Hz).

[0020] Furthermore, in this experiment, water pressure data obtained by synchronous connection was used for comparison with the image analysis results obtained from the image measurement described above. In the data analysis, data from 0.5s before the valve was closed to 8.192s (2 12 It uses data.

[0021] In addition, during the image measurement described above, circumferential strain and axial strain are measured using a strain gauge 13 (KFP-5-120-C1-65L1M2, manufactured by Kyowa Dengyo Co., Ltd.). As shown in Figure 4, the strain gauge 13 is attached to the opposite side (lower part of the pipe) of the image measurement surface created on the upper part of the pipe using waterproof tape. The measurement interval of the strain gauge 13 is 500 Hz and is synchronized with the water pressure measurement described above. In the data analysis, data from 0.5 s before closing the valve to 8.192 s (2 12 It uses data.

[0022] To non-contactly detect the deformation behavior of the pipe as described above, the deformation behavior of the pipe is measured by image measurement in the manner shown in Figure 4. The aforementioned DIC method is used to identify the deformation behavior of the pipe in three dimensions. In this method, a random pattern is applied to the image analysis surface A placed on the surface of the pipe material to be measured, and the amount of displacement is calculated from the dynamics of the pixel group in the digital image by capturing the amount of movement of the dots in the random pattern with CCD cameras 11 and 12.

[0023] As shown in Figure 4, an image analysis surface A with a random pattern is installed at the top of the pipe, and two CCD cameras 11 and 12 are positioned to look down on the image analysis surface A from directly above. The random pattern in this embodiment is a rectangle measuring 55 mm (width) x 80 mm (height). The measurement conditions are a shutter speed of 20 ms, an aperture of 6, and a frame rate of 50 Hz, with synchronous connection to also capture water pressure data. In addition, as shown in the figure, a clip light 20 is installed to adjust the brightness. The light 20 is not always necessary, and is not required during bright daytime hours.

[0024] The simulated water leakage in the model pipeline is reproduced by creating a single 5mm diameter leak hole H on the downstream side, as shown in Figure 2. In addition, to measure the water pressure inside the pipe and analyze the deformation behavior of the pipe body, a water pressure gauge is installed at the positions shown in the figure, and image analysis surfaces A are installed at three locations: measurement position 1 (2m upstream from the valve), measurement position 2 (23m upstream from the valve), and measurement position 3 (47.3m upstream from the valve).

[0025] For implementing the DIC method, we use Vic Snap (Correlated Solutions) for measurement and Vic 3D (Correlated Solutions) for analysis. Furthermore, as an evaluation index for the deformation behavior of the pipe using the DIC method, we use the circumferential displacement (rad) in the cylindrical coordinate system (represented as dTheta in the study results described later).

[0026] Figure 5 illustrates a cylindrical coordinate system model, where this index represents the displacement amount relative to the circumferential direction θ from the random pattern of the initial image analysis surface A. Counterclockwise rotation is considered positive, and clockwise rotation is considered negative, relative to the positive direction of the pipe axis Z.

[0027] Figure 6 shows an example of the analysis results of the experiment described above. Time-series data of the circumferential displacement at the center coordinate of the random pattern in the rectangular image analysis surface A is extracted and analyzed. Note that in the data analysis, data from 0.5s before the valve was closed to 10.24s (2 9 It uses data.

[0028] (Analysis method) • Internal pressure and circumferential strain acting on a thin-walled cylinder As a problem in mechanics of materials, in a thin-walled cylinder subjected to internal pressure, the circumferential strain εθ with respect to the change in radius can be obtained by the following equation 1 (Shibuya et al.: Modern Mechanics of Materials 1986).

[0029]

number

[0030] Here, R is the inner radius, p is the internal pressure, E is the Young's modulus, t is the wall thickness, and ν is Poisson's ratio. Equation 1 above shows the relationship between the water pressure, which is the internal pressure in a pipeline, and the circumferential strain of the pipe.

[0031] • Periodic cycle associated with water hammer The water hammer pressure, which is a rapid pressure increase caused by valve blockage, repeatedly reflects at the upstream and downstream ends of the pipeline. That is, as shown in the schematic diagram in Figure 7, this water hammer action progresses through propagation to the free water surface, reflection from the free water surface, reflection at the valve location, and re-reflection at the free water surface. Furthermore, the period T associated with the water hammer action can be expressed by the following equation 2.

[0032]

number

[0033] Here, L is the pipe length and a is the pressure wave propagation speed. By taking the reciprocal of the period T, the frequency associated with water hammer can be obtained.

[0034] (Results of the review) This section describes the time series of water pressure inside the pipe (measured by a pressure gauge) and circumferential strain of the pipe (measured by a strain gauge).

[0035] Figures 8 to 13 show the relationship between water pressure and circumferential strain inside the pipe in a time series for each of the cases described above. As shown in the figures, it can be observed that the circumferential strain tends to resemble the water pressure waveform on the downstream side at measurement locations closer to the downstream side (Cases 1 to 4), and the water pressure waveform on the upstream side at measurement locations closer to the upstream side (Cases 5 and 6). This is because the deformation of the pipeline is caused by the internal pressure, as shown in Equation 1 above.

[0036] Furthermore, Figures 14-16 show a comparison of the waveforms of water pressure and circumferential strain at each measurement location (Case 1-6) depending on whether or not water leakage is present. In cases where water leakage is present, a tendency for the period of the water hammer pressure waveform to shorten can be observed from around the third period.

[0037] Next, we will explain the time series of circumferential strain (measured by strain gauges) and circumferential displacement (measured by the DIC method) of the pipe body.

[0038] Figures 17-22 show the relationship between water pressure and circumferential displacement (by the DIC method) in time series for each of the aforementioned cases. As shown in the figures, the best correspondence between the water hammer pressure waveform and circumferential displacement (dTheta) can be observed in Cases 3 and 4 (see Figures 19 and 20). In addition, a good correspondence between the water hammer pressure waveform and circumferential displacement can be observed in Cases 5 and 6 (see Figures 21 and 22).

[0039] In Cases 1 and 2, it is possible that vibrations caused by noise had a significant impact. Figure 23 shows a comparison of the waveforms of water pressure and circumferential displacement with and without water leakage at each measurement location. As shown in the figure, in Cases 3 to 6, similar to circumferential strain, a tendency for the period of the water hammer pressure waveform to shorten can be observed in cases with water leakage.

[0040] Next, we will explain the frequency distribution of the water pressure inside the pipe (measured by a pressure gauge), the circumferential strain of the pipe (measured by a strain gauge), and the circumferential displacement of the pipe (measured by the DIC method).

[0041] Figures 24-26 show the frequency distributions of water pressure, circumferential strain, and circumferential displacement at each measurement location (Case 1-6) depending on the presence or absence of water leakage. In Cases 3 and 4, where relatively good results were obtained in the time-series waveforms, as shown in Figure 25, the frequency distributions also show a tendency for frequency (1) (1.7 Hz) and frequency (2) (peak value) to coincide for water pressure, circumferential strain, and circumferential displacement, respectively.

[0042] In addition, in the time-series waveform of the water leakage waveform, where the period is shorter, it can be confirmed that frequency (3) is higher than frequency (2). Frequency (1) is approximately 1.7 Hz, which can be calculated in advance from the pipe length and pressure propagation velocity. This can be calculated from the drawing information based on the pipe specifications. From this, if waveforms like those in Cases 3 and 4 can be input, then if there is a water leakage, a frequency higher than the frequency due to the water hammer action (1.7 Hz in Figure (1)) obtained from the pipeline drawing information (the frequency in Figure (3)) can be obtained from the information of the water hammer pressure waveform due to the sudden closure of the valve, making it possible to detect the presence or absence of water leakage even without actual measurement comparison data of no water leakage. Furthermore, as can be seen from the fact that the amplitude spectrum is lower in the case of water leakage (Figure (3)) than in the case of no water leakage (Figure (2)), it is possible to grasp the energy loss due to water leakage and detect the presence or absence and scale of water leakage.

[0043] Furthermore, the waveforms in Figures 24-26 above, which represent the case when there is no water leakage, do not necessarily have to be obtained through actual measurement. They can be calculated using known transient flow analysis based on the specifications and drawing information of the pipeline, and various information regarding the leakage phenomenon can be determined by comparing them.

[0044] Next, we will explain the time-frequency analysis of the water pressure inside the pipe (measured by a pressure gauge), the circumferential strain of the pipe (measured by strain gauges), and the circumferential displacement of the pipe (measured by the DIC method).

[0045] Figures 27-38 show the results of time-frequency analysis of water pressure, circumferential strain, and circumferential displacement (by DIC method) for each of the aforementioned cases. Note that the horizontal axis for circumferential displacement by DIC method is different due to the difference in the number of data points used in the data analysis. In each case, it can be confirmed that the waveform attenuation is faster when there is water leakage in the case of water pressure, circumferential strain, or circumferential displacement.

[0046] This revealed that even at measurement locations 47.3m upstream from the valve (Cases 5 and 6), the effects of water leakage near the valve can be detected by measuring the circumferential strain and displacement of the pipe. This makes it possible to reliably detect the presence or absence of water leakage even when the measurement location is far from the leak hole by checking the damping pattern of the circumferential strain or displacement.

[0047] From the results of the aforementioned studies, it is possible to detect water leaks in the pipeline by measuring only with strain gauges 13 or by image measurement using CCD cameras 11 and 12, focusing on the behavior of the pipeline body. Furthermore, by combining these strain gauges 13 and CCD cameras 11 and 12, it becomes possible to detect leaks through image measurement that takes into account the internal pressure information contained in the circumferential strain, thereby improving detection accuracy and increasing the certainty of whether or not there is a water leak.

[0048] (System Configuration) The configuration of the leakage phenomenon identification system 100 in an embodiment of the present invention will be described below.

[0049] As shown in Figure 4, the leakage phenomenon identification system 100 in an embodiment of the present invention includes at least an image analysis surface A installed on the surface of a pipeline pipe, imaging means (CCD cameras 11, 12) for photographing the image analysis surface A, displacement measurement means 101a for measuring the circumferential displacement of the pipe based on the image captured by the imaging means, strain measurement means 101b for measuring the circumferential strain of the pipe using a strain gauge 13 installed on the pipe, and leakage phenomenon determination means 103 that performs analysis based on the measured circumferential displacement and circumferential strain and can determine whether or not there is a fluid leakage phenomenon.

[0050] In this embodiment, as shown in Figure 4, at least two CCD cameras 11 and 12 are provided as the imaging means to capture the image analysis surface A from different directions. However, the number of imaging cameras, including CCD cameras, may be one or more, as long as the imaging means can capture a three-dimensional image of the image analysis surface A. The imaging means (CCD cameras 11 and 12) are connected to a PC that incorporates a leakage phenomenon determination means 103, etc.

[0051] Furthermore, the leakage phenomenon discrimination means 103 within the PC includes an analysis means 104 and a learning means 105 that machine-learns at least the circumferential displacement of the pipe material (learning step), and the analysis is performed based on a predetermined algorithm of the learning means 105. Based on the analysis results, the identification information of the water leakage phenomenon is output to the water leakage information output unit 102.

[0052] Furthermore, the leakage phenomenon discrimination means 103 is connected to the measurement facility information input means 106, which allows input of information such as the diameter and material of the pipeline, the diameter of the leak hole H actually discovered, and the distance from the image capture position to the leak hole H. By using this various information and the circumferential displacement of the pipe material as learning data, it becomes possible to identify not only the presence or absence of a leak hole H, but also the location and scale of the leak from the acquired 3D image, thereby further improving the accuracy of identifying the leakage phenomenon.

[0053] (Method for identifying water leakage phenomena) In existing pipelines, since most are buried underground, an image analysis surface A is installed on the surface of the exposed pipeline pipe material inside a manhole containing a shut-off valve, etc. (analysis surface installation step). Then, a shooting device (CCD cameras 11, 12) is installed and the image analysis surface A is photographed with the shooting device (analysis surface shooting step).

[0054] Images captured by the imaging device are sent to a PC, and the circumferential displacement of the pipe is measured based on these images (displacement measurement step). Based on the measured circumferential displacement of the pipe, analysis is performed to determine whether or not fluid leakage is occurring (leakage phenomenon determination step). In other words, by evaluating the deformation behavior of the pipe using the DIC method described above, determining the circumferential displacement in the cylindrical coordinate system (Figure 5 "θ"), and determining the damping behavior in both time and frequency (time-frequency domain), leakage phenomena in the pipeline can be identified.

[0055] In other words, by determining the attenuation behavior in the time-frequency domain described above, it becomes possible to detect not only the presence or absence of water leakage and its location, but also the water leakage pattern (for example, the presence or absence of a jet flow at the leak hole) from its time waveform information.

[0056] Furthermore, the experimental results described above revealed that it is possible to identify the presence or absence of water leakage even at measurement points far from the leak hole. Therefore, for example, by placing image analysis surface A and imaging means at two manholes, and performing analysis based on the circumferential displacement of the pipe material measured at the two manholes, and comparing these damping behaviors, it becomes possible to estimate not only the presence or absence of water leakage but also the location of the leakage. Then, by using the damping behavior described above and the actual location of the leak hole as training data, it becomes possible to improve the accuracy of identifying water leakage phenomena.

[0057] (Other embodiments) The embodiments of the non-destructive detection method and non-destructive detection system for leakage phenomena of the present invention have been described above, using a method for identifying leakage phenomena in water supply and distribution pipelines as an example. However, the present invention is not necessarily limited to the configuration described above, and various modifications are possible as follows.

[0058] For example, the non-destructive detection method and non-destructive detection system for leakage phenomena of the present invention are not necessarily limited to water supply and distribution pipelines, but can be applied to pressurized pipelines that transport various fluids, such as fuel pipes, gas pipes, and steam pipes. By considering the characteristics of the fluid and the pipe, it is possible to identify fluid leakage phenomena with high accuracy.

[0059] Furthermore, the magnitude of pipe deformation depends on the elastic modulus and the second moment of area of ​​the pipe. Therefore, the non-destructive detection method and non-destructive detection system for leakage phenomena of the present invention can be more suitably applied to polyvinyl chloride pipes than to cast iron pipes or other steel pipes.

[0060] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments. The scope of the present invention is indicated by the claims rather than the above-described embodiments, and furthermore, all modifications within the meaning and scope of equivalence to the claims are included. In addition, the specific materials, dimensions, shapes, etc., described in the above embodiments can be modified to the extent that they solve the problems of the present invention. [Explanation of symbols]

[0061] A Image Analysis Surface 11 CCD camera 12 CCD cameras 20 Lighting 100 Leakage Phenomenon Identification System 101a Displacement measurement means 101b Strain measurement means 102 Leakage Information Output Means 103 Leakage Phenomenon Discrimination Means 104 Analysis means 105 Learning Methods 106 Measurement facility information input means

Claims

1. A non-destructive detection method for fluid leakage phenomena in pipelines, The analysis surface installation step involves installing an image analysis surface on the surface of the pipe material of the pipeline, The analysis surface imaging step involves imaging the aforementioned image analysis surface with an imaging means, A displacement measurement step in which the circumferential displacement of the pipe material is measured based on the image captured by the aforementioned photographic means, The system includes a leakage phenomenon determination step that performs an analysis based on the measured circumferential displacement and can determine whether or not there is a leakage phenomenon of the fluid, The leakage phenomenon determination step can determine the attenuation behavior in the time-frequency domain based on the circumferential displacement amount, and estimate at least the presence or absence of water leakage and the location of the water leakage. A non-destructive detection method for leakage phenomena characterized by the following.

2. The procedure includes a strain measuring means installation step, in which strain measuring means capable of measuring the circumferential strain of the pipe material is installed on the surface of the pipe material of the pipeline, The leakage phenomenon determination step can determine at least whether or not water is leaking by determining the damping behavior in the time-frequency domain based on the circumferential displacement and the damping behavior in the time-frequency domain based on the circumferential strain. A non-destructive method for detecting a leakage phenomenon as described in claim 1.

3. The aforementioned imaging means is at least two or more imaging cameras that photograph the image analysis surface from different directions. A non-destructive method for detecting a leakage phenomenon according to claim 1 or 2.

4. The learning step includes at least one machine learning step for the circumferential displacement, In the leakage phenomenon determination step, it is possible to estimate the presence or absence of water leakage and the location of water leakage based on a predetermined algorithm using machine learning. A non-destructive method for detecting a leakage phenomenon according to claim 1 or 2.

5. The learning step includes at least one machine learning step for the circumferential displacement, In the leakage phenomenon determination step, it is possible to estimate the presence or absence of water leakage and the location of water leakage based on a predetermined algorithm using machine learning. A non-destructive method for detecting a leakage phenomenon as described in claim 3.

6. A non-destructive detection system for fluid leakage phenomena in pipelines, An image analysis surface is installed on the surface of the pipe material of the aforementioned pipeline, A means for capturing images of the aforementioned image analysis surface, Displacement measurement means for measuring the circumferential displacement of the pipe material based on the image captured by the aforementioned imaging means, A leakage phenomenon determination means capable of determining at least the presence or absence of fluid leakage by performing an analysis based on the measured circumferential displacement and determining the damping behavior in the time-frequency domain based on the circumferential displacement, The system comprises at least a strain measuring means positioned on the surface of the pipe material of the pipeline and capable of measuring the circumferential strain of the pipe material. A non-destructive detection system for leakage phenomena characterized by the following.

7. The aforementioned imaging means is at least two or more imaging cameras that photograph the image analysis surface from different directions. A non-destructive detection system for leakage phenomena according to claim 6.

Images