JP2017187338A - Abnormality detection method for duct and abnormality monitoring for duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abnormality detection method for duct and an abnormality monitoring for duct that are free of a risk of wrong determination depending upon whether there are vibrations characteristic of a duct or whether there is a continuous vibration source such as a machine, according to a principal object of the present invention.SOLUTION: An abnormality detection method for duct is designed to specify an abnormal place by measuring vibrations at a plurality of places of a duct, and includes: a first measuring process of measuring a vibration level in a first time zone for a predetermined time; a second measuring process of measuring vibrations in a second time zone in which hydraulic pressure in the duct is higher than that in the first time zone; a vibration level difference calculating process of calculating a difference between a vibration level at which a minimum region is obtained in the first measuring process and a vibration level at which a minimum region is obtained in the second measuring process; and a determination process of determining abnormality when the difference of the vibration level calculating process is less than a predetermined threshold.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipeline abnormality detection method and a pipeline abnormality monitoring method.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 2015-75440) does not require the skill and experience of an operator to determine whether or not water leakage has occurred, and easily grasps progress information and the like. A water line monitoring device that can be used is disclosed.

  A water pipe monitoring device described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-75440) includes a plurality of data collection devices and a data analysis device capable of transmitting and receiving data wirelessly with these data collection devices. It is a water pipe monitoring device, and the data collection device measures and records the sound pressure value at predetermined intervals over a predetermined time per day, and extracts and stores the minimum sound pressure value at the measured time. Then, the minimum sound pressure value data is compared with an arbitrarily set sound pressure threshold value, and the presence or absence of an abnormality such as water leakage is determined based on the magnitude of the minimum sound pressure value data and the sound pressure threshold value.

  In Patent Document 2 (Japanese Patent Laid-Open No. 8-121700), it is possible to easily and reliably determine the presence or absence of leakage, eliminate the need for dangerous work at night in a noisy place, and perform dangerous and long hours on the road. A method for determining the occurrence of leakage in a buried pipeline that does not require work is disclosed.

  According to the leak occurrence determination method described in Patent Document 2 (Japanese Patent Application Laid-Open No. 8-121700), sound pressure data is collected over a predetermined measurement time at a predetermined sampling time at an appropriate location in the buried pipeline, and the collected sound is collected. A frequency distribution relating to the sound pressure level of the pressure data is formed, and the presence or absence of leakage in the buried pipeline is determined based on the degree of concentration of the sound pressure data in the frequency distribution.

  Patent Document 3 (Japanese Patent Application Laid-Open No. 2010-48058) discloses a water leakage node estimation device that makes it possible to make an initial plan for water leakage investigation and a cost effective pipeline renewal plan.

  The water leakage node estimation apparatus described in Patent Document 3 (Japanese Patent Application Laid-Open No. 2010-48058) is a flow and pressure of a water distribution pipe network collected and accumulated in a water distribution pipe network process for supplying purified water to a terminal consumer. A water leakage node estimation device that analyzes data, measures water usage at the hydrant as a water charge at a certain period, and stores water consumption at the hydrant and stores the water usage at each hydrant. Based on the amount of water used in the stopper, the node demand amount assigning means for setting the demand amount of the node, the pipe material constituting the target water distribution pipe network, extension, diameter, connection information, pipe friction coefficient and Pipe network analysis model storage means for storing the altitude of the node that is the connection point, and the amount of water leakage in the target distribution pipeline network is allocated as the amount of water leakage at each node, and the amount of water leakage allocation for each node is set Leakage amount distribution optimization means and water distribution network Process data storage means for storing inflow flow rate and pressure data in the pipeline network, pipe network analysis model from the pipe network model storage means, nighttime flow rate and pressure data from the process data storage means, and optimal leakage distribution From the network analysis means that performs pipe network analysis based on the amount of water leakage allocated to each node obtained by the networking means and the demand of each node obtained from the node demand quantity allocation means, Pressure error calculation means for calculating the error between the estimated pressure value at each obtained node and the actual pressure value at the pressure measurement point, and the water leakage distribution optimization means minimizes the pressure error obtained by the pressure error calculation means. In this way, optimization calculation is performed to distribute the amount of water leakage to each node.

Japanese Patent Laying-Open No. 2015-75440 JP-A-8-121700 JP 2010-48058 A

In the method of Patent Document 1, it is necessary to set a threshold value every time depending on vibration inherent to a pipe line caused by water flow or presence / absence of a continuous vibration source such as a machine (vending machine, transformer, pump). Further, there is a risk of erroneous determination if this threshold value is not set appropriately.
In the method of Patent Document 2, when there are few vibration sources in the suburbs, etc., the sound pressure level is concentrated on a small value, and when there is a large vibration source such as a pump, the sound pressure level is concentrated on a large value. There is a risk of accidents.
The method of Patent Document 3 has a problem that water leakage is often minute with respect to the flow rate due to the use of water, and it is difficult to detect minute water leakage.

  SUMMARY OF THE INVENTION The main object of the present invention is to provide a method for detecting an abnormality of a pipeline and a method for monitoring an abnormality of the pipeline that are less likely to cause erroneous discrimination due to the presence of vibration inherent to the pipeline due to water flow or the presence of a continuous vibration source such as a machine. It is.

(1)
An abnormality detection method for a pipeline according to one aspect is a method for detecting an abnormality in a pipeline by measuring vibration at a plurality of locations in the pipeline and specifying the abnormality location, and the vibration level is set over a predetermined time in a first time zone. In the first measurement step, the second measurement step of measuring vibration over a predetermined time in the second time zone in which the water pressure in the pipe line is higher than the first time zone, and the first measurement step When the difference between the vibration level difference calculation step that calculates the difference between the vibration level that became the minimum region and the vibration level that became the minimum region in the second measurement step and the difference in the vibration level difference calculation step is below a predetermined threshold And a determination step for determining an abnormality.

In this case, the vibration level is measured in the first measurement process and the second measurement process in a time zone in which the water pressure in the pipe is different. Furthermore, an abnormality in the pipeline can be detected using the difference in vibration level in the minimum region where the influence of disturbance is small. Further, by using the difference, it is possible to cancel the inherent vibration in the pipe line or disturbance noise such as a machine.
As a result, it is possible to detect an abnormality in the pipeline that is less likely to cause an erroneous discrimination depending on the presence of a continuous vibration source such as a machine or a vibration that is unique to the pipeline due to the water flow only by the vibration level.

Here, the minimum area means an area showing the minimum amplitude in a predetermined time. Further, by taking the difference in the vibration level of the minimum region, it is possible to exclude disturbance and detect water leakage.
The predetermined time is preferably in the range of 1 sec to 100 sec. If the predetermined time becomes long, the power consumption for operating the measuring instrument becomes large, and if it is too short, sudden noise due to traffic or the like may be mixed into the minimum area.

(2)
An abnormality detection method for a pipeline according to a second invention is the abnormality detection method for a pipeline according to one aspect, in which a first division step for dividing the vibration level measured in the first measurement step and a second measurement step are performed. A second dividing step of dividing the measured vibration level, wherein the vibration level difference calculating step sets the vibration level that has become the minimum region from the plurality of vibration levels divided in the first dividing step to 1 or a predetermined value. A first extraction step for extracting the number of vibration levels, and a second extraction step for extracting one or a predetermined number of vibration levels that have become the minimum region from among the plurality of vibration levels divided in the second division step, In the difference calculation step, the difference may be calculated from the vibration level between the first extraction step and the second extraction step.

In this case, the first division step and the second division step can be divided according to time, and one or a predetermined number of vibration levels in the minimum region can be selected, so that an abnormality in the pipeline can be detected reliably.
Here, the minimum area means an area showing the minimum amplitude when divided by a predetermined time.

(3)
An abnormality detection method for a pipeline according to a third invention is the method for detecting an abnormality of a pipeline according to one aspect or the second invention, wherein the first measurement step, the second measurement step, the vibration level difference calculation step, and the determination step are performed. You may repeat over multiple times.

  In this case, it is possible to reliably detect an abnormality in the pipe line by repeating the process a plurality of times.

(4)
According to a pipeline abnormality detection method according to a fourth aspect of the present invention, in the pipeline abnormality detection method according to the second or third aspect of the invention, the predetermined threshold may be zero.

  In this case, since the detection result in the high water pressure state is subtracted from the detection result in the low water pressure state, if the result is negative, it can be determined that the pipeline is abnormal. Therefore, the predetermined threshold is preferably 0.

(5)
An abnormality monitoring method for a pipeline according to another aspect is an abnormality monitoring method for a pipeline that measures vibration at a plurality of locations in a pipeline and identifies the abnormal location, and the vibration level is set to a predetermined time in a first time zone. A first measurement step that measures over a predetermined time, a second measurement step that measures vibration over a predetermined time in a second time zone in which the water pressure in the pipeline is higher than the first time zone, and a first measurement step The difference in the vibration level difference calculation step for calculating the difference between the vibration level that has become the minimum region in step 2 and the vibration level that has become the minimum region in the second measurement step, and the difference in the vibration level difference calculation step has fallen below a predetermined threshold value. A determination step that determines that there is an abnormality, and the first measurement step, the second measurement step, and the vibration level difference calculation step are repeated a plurality of times over a plurality of days. The given It is intended to determine an abnormality when it falls below the one or more times the value.

In this case, the vibration level is measured in the first measurement process and the second measurement process in a time zone in which the water pressure in the pipe is different. Furthermore, an abnormality in the pipeline can be detected using the difference in vibration level in the minimum region where the influence of disturbance is small. Further, by using the difference, it is possible to cancel the inherent vibration in the pipe line or disturbance noise such as a machine.
As a result, it is possible to monitor the abnormality of the pipe line that is less likely to be erroneously discriminated by the presence or absence of a continuous vibration source such as a machine or the like due to the water flow, or the vibration level alone.

(6)
A pipeline abnormality monitoring method according to a sixth aspect of the invention is the pipeline abnormality monitoring method according to the fifth aspect of the invention, in which a first division step for dividing the vibration level measured in the first measurement step and a second measurement are performed. And a second division step for dividing the vibration level measured in the step, wherein the vibration level difference calculation step sets the vibration level that has become the minimum region from among the plurality of vibration levels divided in the first division step. Or a first extraction step for extracting a predetermined number, and a second extraction step for extracting one or a predetermined number of vibration levels that have become a minimum region from among a plurality of vibration levels divided in the second division step, In the vibration level difference calculation step, the difference may be calculated from the vibration level between the first extraction step and the second extraction step.

  In this case, the first division step and the second division step can be divided according to time, and one or a predetermined number of vibration levels in the minimum region can be selected, so that an abnormality in the pipeline can be detected reliably.

(7)
The abnormality monitoring method for a pipeline according to a seventh aspect is the abnormality monitoring method for a pipeline according to another aspect or the sixth invention, wherein the predetermined threshold value may be zero.

  In this case, since the detection result in the high water pressure state is subtracted from the detection result in the low water pressure state, if the result is negative, it can be determined that the pipeline is abnormal. Therefore, the predetermined threshold is preferably 0.

It is a schematic diagram for demonstrating the condition of the water leak location specifying method. It is a schematic diagram which shows an example of the water leak position detection apparatus containing a vibration sensor. It is a schematic diagram for demonstrating the water leak when a time slot | zone differs. It is a flowchart which shows an example of operation | movement of a calculating device. It is a flowchart which shows the other example of operation | movement of an arithmetic unit. It is a flowchart which shows the other example of operation | movement of an arithmetic unit. It is a flowchart which shows the other example of operation | movement of an arithmetic unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<Situation explanation of water leak location method>
FIG. 1 is a schematic diagram for explaining the situation of the water leakage position specifying method.

  As shown in FIG. 1, a pipe network 110 is provided in the ground. The pipe network 110 is provided with vertical holes (manholes) 120 at regular intervals. In the present embodiment, vertical holes 120 are provided at intervals between point A and point B. In this case, vibration sensors 200 are provided in the vertical holes 120 at point A and point B in FIG.

<Description of vibration sensor>
FIG. 2 is a schematic diagram illustrating an example of a water leakage position detection device including a vibration sensor.

As shown in FIG. 2, the abnormal sound generation specifying device 100 according to the present embodiment includes an arithmetic device 300 and at least a pair of vibration sensors 200. The pair of vibration sensors 200 is a resonance type vibration sensor 200.
The vibration sensor 200 in FIG. 2 includes a pedestal 210, support columns 220, thin film electrodes 230 and 240, lead wires 231 and 241, a piezoelectric element 250, a weight 260, a power generation device 261, and a GPS device 262.
The arithmetic device 300 includes a generation unit 310 that generates a filter, and an arithmetic unit 320.

  As shown in FIG. 2, in the vibration sensor 200, a support 220 is fixed on an iron base 210. A piezoelectric element 250 is provided at the upper end of the support 220. One end of the piezoelectric element 250 is cantilevered by the upper end of the column 220.

A pair of upper and lower thin film electrodes 230 and 240 formed by applying silver paste on both surfaces of the piezoelectric element 250 are provided. The column 220 and the pair of thin film electrodes 230 and 240 are insulated.
A weight 260 is placed on the other end of the piezoelectric element 250 and on the thin film electrode 230.

A lead wire 231 is connected to the thin film electrode 230, a lead wire 241 is connected to the thin film electrode 240, and the lead wires 231 and 241 are connected to the arithmetic unit 300.
The potential difference output from the lead wires 231 and 241 is output as a vibration waveform by a processing device such as an arithmetic device.
In this embodiment, the lead wires 231 and 241 are used. However, the present invention is not limited to this, and a functional unit capable of transmitting and receiving with the arithmetic device 300 may be provided.

  The piezoelectric element 250 is formed of a stretched film (PVDF film) of polyvinylidene fluoride which is a polymer piezoelectric material.

  When the specific parameters are the elasticity E of the piezoelectric material, the secondary moment J of the cross section, the length L, the width b, and the height h, the spring constant k is expressed as follows.

^{k = 3EJ / L 3 (J} = bh 3/12) ··· (1)
Can be shown.

  The resonance frequency fo of the system composed of the piezoelectric element 250 and the weight 260 is expressed as follows.

  fo = √ (k / M) / 2π (2)

The resonance type vibration sensor 200 is formed so that at least one resonance frequency fo exists within a range of 60 Hz or more and less than 1000 Hz.
The resonance type vibration sensor 200 according to the present embodiment is formed so that there are four resonance frequencies fo between 100 Hz and 500 Hz. The reason for this is that abnormal sounds transmitted through the pipe network 110, particularly water leakage sounds, are often audible sounds, especially those below 1000 Hz.

  In this embodiment, the resonance type vibration sensor 200 is used. However, the present invention is not limited to this, and a conventional vibration sensor may be used.

  In addition, vibration sensor 200 according to the present embodiment transmits to GPS device 262 computing device 300 which position of the pipe network is installed. Further, the vibration sensor 200 can operate the vibration sensor 200 with the power generation device 261. For example, the power generation device 261 includes power generation using a fluid flowing in a pipe, geothermal power generation, and solar power generation when sunlight is inserted. As a result, the arithmetic device 300 can recognize the position of the vibration sensor 200. For example, the arithmetic device 300 can recognize the embedded position of the vibration sensor 200.

<Flowchart of water leakage position specifying method>
Next, the water leakage position specifying method will be described with a specific example.

In the water leakage position specifying method according to the present embodiment, vibration sensors 200 are installed in at least two places (point A and point B) of the pipe network 110, and abnormal sounds or vibrations caused by defects in the pipe network 110 are detected as vibration sensors. 200.
A filter is created using the coherence function of the waveform input to each vibration sensor 200. When creating this filter, the processing described later is performed to improve the accuracy of the abnormal sound generation position, the filter is created, and after applying the filter, the vibration transmission time difference Td is obtained from the cross-correlation function. This is a water leakage position specifying method for specifying an abnormal sound generation position from Td and vibration propagation velocity V.

  In FIG. 1, it is assumed that fluid leakage has occurred at a distance L from the vibration sensor 200 at point A. That is, the position of the distance L is an abnormal sound generation position (fluid leakage position). In this case, the leakage sound propagates a distance (L + N) longer than the distance L of the vibration sensor 200 at the point A by a distance N before reaching the vibration sensor 200 at the point B.

  Accordingly, assuming that the distance between the vibration sensor 200 at the point A and the vibration sensor 200 at the point B is D, the transmission time difference Td at which the leakage sound arrives at the vibration sensor 200 at the point A and the vibration sensor 200 at the point B is The propagation speed V of the leaked sound and the distance between the two vibration sensors can be determined by the following equation, where D is the distance.

Td = N / V (3)
Also,
N = D-2L (4)
Can be shown.

By substituting equation (4) into equation (3),
L = (D−V · Td) / 2 (5)
It can be expressed as.
As described above, the distance L can be obtained.

<Abnormality judgment method for pipeline>
Hereinafter, a method for determining an abnormality of a pipeline using the abnormal sound generation identification device 100 will be described. FIG. 3 is a schematic diagram for explaining water leakage when the time zones are different, and FIG. 4 is a flowchart illustrating an example of the operation of the arithmetic device 300.

  In the first embodiment, measurement is performed in a plurality of time zones. For example, as shown in FIG. 3, measurement is performed during the daytime and at night. In other words, in general, the internal pressure of the fence network 110 varies with time. Specifically, at nighttime, the water usage is reduced, so the water pressure of the fence net 110 is increased.

As a result, the vibration level related to abnormal sound of water leakage tends to increase. On the other hand, during the daytime, the amount of water used is increased, and the water pressure of the fence net 110 is reduced. As a result, the vibration level related to abnormal sound of water leakage tends to decrease.
That is, in the present embodiment, the measurement is performed in the case of one water pressure of the fence net 110 and in the case of another water pressure different from the one water pressure. Hereinafter, the case of one water pressure of the fence net 110 is referred to as a first measurement step, and the case of another water pressure different from the one water pressure is referred to as a second measurement step.

(First measurement process)
First, the arithmetic device 300 outputs the potential difference output from the vibration sensor 200 as a vibration waveform.

As shown in FIG. 4, the vibration sensor 200 detects the vibration of the net 110 based on an instruction from the arithmetic device 300 at a predetermined time, for example, 14:00 in the daytime. The vibration sensor 200 measures the vibration of the screen 110 for a predetermined time and obtains vibration data (step S11). In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S12).

The arithmetic device 300 divides 100 seconds of vibration data into 20 parts every 5 seconds, and extracts 20 pieces of vibration data (step S13).
The arithmetic device 300 selects vibration data A having the minimum amplitude of the 20 pieces of vibration data (step S14).

(Second measurement process)
Next, the arithmetic device 300 measures the vibration of the screen 110 for a predetermined time based on an instruction from the arithmetic device 300 at a predetermined time, for example, at 2 o'clock at night, and obtains vibration data (step S21). . In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S22).

The arithmetic device 300 divides 100-second vibration data into 20 parts every 5 seconds, and extracts 20 vibration data (step S23).
The arithmetic device 300 selects vibration data B having the minimum amplitude of the 20 pieces of vibration data (step S24). That is, a region where the amplitude is minimized (minimum amplitude) is selected when divided by a predetermined time width.

In the first and second measurement steps of the present embodiment, the vibration data is divided into 20 pieces. However, the present invention is not limited to this, and vibration data every 5 seconds may be measured 20 times. .
Furthermore, in the first and second measurement steps of the present embodiment, vibration data having the minimum amplitude is selected. However, the present invention is not limited to this, and the influence of sudden vibration caused by vehicle traffic is eliminated. Any vibration data can be used.

The arithmetic device 300 calculates the difference AB between the vibration data of the vibration data A and the vibration data B (step S31).
In this case, by calculating the difference AB, it is possible to cancel the natural vibration of the pipe network 110 or the influence of the continuous vibration source caused by surrounding machines or the like.

  Next, the arithmetic device 300 determines whether or not the difference AB is lower than a threshold value (step S32). For example, when the threshold is zero and the difference AB is lower than the threshold, the arithmetic device 300 determines that water leakage has occurred (step S33). On the other hand, when the difference AB is equal to or greater than the threshold value, the arithmetic device 300 determines that no water leakage has occurred (step S34).

Here, the threshold according to the present embodiment is set based on the pressure and the disturbance factor. That is, the threshold value is set in consideration of the variation level of the vibration level from the vibration sensor 200 specified from the pressure difference in the pipe network 110 during a certain day and night and the disturbance factor.
Moreover, since the threshold value is set smaller than normal disturbances such as noise, when the difference result falls within the threshold value range, it can be specified that there is a location where water leakage occurs.

  Specifically, one area having the minimum amplitude is selected, and in the selected area, there is a possibility of water leakage, but it cannot be determined that water leaks. This is because, for example, there may be an influence of a water flow or the like. Therefore, it is possible to identify water leakage by selecting one region with the minimum amplitude in a state where the pressure is changed, calculating the difference between before and after the pressure change, and comparing the difference with the threshold value.

In the present embodiment, the threshold value of the vibration data difference AB is preferably 0, but may be a positive value when it is known in advance that the operation at night will be stopped by a pump or the like of the water supply facility. .
In addition, the first measurement process and the second measurement process may be detected each time as an abnormality, and steps S11 to S34 may be repeated over a plurality of days to perform abnormality detection and abnormality monitoring.
In this case, it is possible to set a threshold value based on the difference AB on the first day or the difference AB on the second day, which is particularly effective when there is mechanical vibration that stops at night.

(Second Embodiment)
Next, the second embodiment will be described. In the present embodiment, only differences between the second embodiment and the first embodiment will be described.
FIG. 5 is a flowchart illustrating another example of the operation of the arithmetic device 300.

(First measurement process)
As shown in FIG. 5, the vibration sensor 200 detects the vibration of the net 110 based on an instruction from the arithmetic device 300 at a predetermined time, for example, 14:00 in the daytime. The vibration sensor 200 measures the vibration of the screen 110 for a predetermined time and obtains vibration data (step S11). In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S12).

The arithmetic device 300 divides 100 seconds of vibration data into 20 parts every 5 seconds, and extracts 20 pieces of vibration data (step S13).
The arithmetic unit 300 selects a plurality of, for example, three pieces of vibration data C1, C2, and C3 from the minimum amplitude of the 20 pieces of vibration data (step S14a).
The arithmetic device 300 calculates the average vibration data C of the three vibration data C1, C2, and C3 (step S15).

(Second measurement process)
Based on the instruction from the arithmetic device 300, the vibration sensor 200 measures the vibration of the fence 110 for a predetermined time at 2 o'clock at night to obtain vibration data (step S21). In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S22).
The arithmetic device 300 divides 100-second vibration data into 20 parts every 5 seconds, and extracts 20 vibration data (step S23).
Further, the arithmetic unit 300 selects a plurality, for example, three pieces of vibration data D1, D2, D3 from the minimum amplitude of the 20 pieces of vibration data (step S24a).
The arithmetic device 300 calculates average vibration data D of the three vibration data D1, D2, and D3 (step S25).
The arithmetic device 300 calculates the difference CD between the average vibration data C and the average vibration data D (step S31).
In this case, by calculating the difference CD, it is possible to cancel the natural vibration of the pipe network 110 or the influence of the continuous vibration source due to surrounding machines or the like.

  Next, the arithmetic device 300 determines whether or not the difference CD is lower than a threshold value (step S32). For example, when the threshold value is zero and the difference CD is lower than the threshold value, the arithmetic device 300 determines that water leakage has occurred (step S33). On the other hand, when the difference CD is equal to or larger than the threshold value, the arithmetic device 300 determines that no water leakage has occurred (step S34).

(Third embodiment)
Subsequently, the third embodiment will be described. In the present embodiment, only the differences between the third embodiment and the first and second embodiments will be described. In the third embodiment, abnormality detection or abnormality monitoring of the pipe network 110 is performed on a plurality of days.
6 and 7 are flowcharts illustrating an example of the operation of the arithmetic device 300.

(First measurement process on the first day)
As shown in FIGS. 6 and 7, the vibration sensor 200 detects the vibration of the screen net 110 based on an instruction from the arithmetic device 300 at a predetermined time, for example, 14:00 on the first day. The vibration sensor 200 measures the vibration of the screen 110 for a predetermined time and obtains vibration data (step S11). In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S12).

The arithmetic device 300 divides 100 seconds of vibration data into 20 parts every 5 seconds, and extracts 20 pieces of vibration data (step S13).
The arithmetic device 300 selects the minimum level of 20 pieces of vibration data, for example, vibration data E (step S14b).

(Second measurement process on the first day)
Next, based on an instruction from the arithmetic device 300 at 2 o'clock at night on the first day, the arithmetic device 300 measures the vibration of the net 110 for a predetermined time and obtains vibration data (step S21). In the present embodiment, vibration data for 100 seconds is measured.
The vibration sensor 200 transmits the detected vibration data to the arithmetic device 300 (step S22).

The arithmetic device 300 divides 100-second vibration data into 20 parts every 5 seconds, and extracts 20 vibration data (step S23).
The arithmetic device 300 selects the minimum level of 20 pieces of vibration data, for example, vibration data F (step S24b).

Next, the arithmetic unit 300 calculates the difference G between the vibration data E and the vibration data F (step S31). Here, the difference G consists of EF.
Next, the arithmetic device 300 sets a threshold value H (step S32b). Here, the arithmetic device 300 sets the difference G to which a measurement error is added as the threshold value H. In the present embodiment, the measurement error is 3 dB.

(First measurement process on the second day)
The arithmetic device 300 performs steps S11, S12, and S13 based on an instruction from the arithmetic device 300 at a predetermined time, for example, at 14:00 on the second day, and has a minimum level of 20 vibration data, for example, vibration. Data I is selected (step S14c).

(Second measurement process on the second day)
The computing device 300 performs steps S21, S22, and S23 based on an instruction from the computing device 300 at a predetermined time, for example, at 2 o'clock on the second day, and performs a minimum level of 20 vibration data, for example, vibrations. Data J is selected (step S24c).

The arithmetic device 300 calculates a difference IJ between the vibration data I and the vibration data J (step S31c). Here, the difference IJ is obtained by subtracting the vibration data J from the vibration data I.
Next, the arithmetic device 300 determines whether or not the difference IJ is equal to or less than the threshold value H (step S32c).
When larger than the threshold value H, the arithmetic unit 300 determines that there is water leakage (step S33c).
When the threshold value is equal to or lower than the threshold value H, the arithmetic device 300 determines that there is no water leakage (step S34c).

(First measurement step and second measurement step on day n)
The arithmetic device 300 performs steps S11, S13, S14b, S21,..., S23, S24b, S31, S32b, S14c, S24c, S31c, and S34c on the nth day (n is an arbitrary positive integer). Repeatedly monitor for abnormalities.

  In the third embodiment, the threshold value H is defined based on the vibration data for the first day. However, the present invention is not limited to this, and the threshold value is re-defined based on the vibration data for the second day. Alternatively, an average of threshold values may be calculated based on vibration data for a plurality of days, and the average threshold value may be used.

  Note that the water leakage position specifying method can be applied to various pipe networks 110. For example, in addition to detecting leaks from water supply pipes, it is also used for detecting leaks in various pipes other than water supply, or for detecting leakage of fluids such as chemicals in pipes for chemicals in factories. be able to.

表１に示すように、差分ＡＢの予測は、振動データＡ−振動データＢ＝４０ｄＢ−２０ｄＢで、２０ｄＢである。計測誤差を考慮し、閾値Ｈを１８ｄＢと設定した。上記の閾値を用いて実際に漏水を検出できるか実験した。
測定結果を以下の表２に示す。

漏水による振動レベルは、振動データＡにおいては、２０ｄＢであり、振動データＢは、３０ｄＢであった。
また、最小領域振動最大レベルは、表１および表２における振動データＡの最大値、振動データＢの最大値を示す。 Example 1
Based on the first embodiment, threshold values were set as shown in Table 1 below.

As shown in Table 1, the prediction of the difference AB is 20 dB with vibration data A−vibration data B = 40 dB−20 dB. In consideration of measurement error, the threshold value H was set to 18 dB. It was experimented whether water leakage could actually be detected using the above threshold.
The measurement results are shown in Table 2 below.

The vibration level due to water leakage was 20 dB in the vibration data A, and the vibration data B was 30 dB.
Further, the minimum region vibration maximum level indicates the maximum value of vibration data A and the maximum value of vibration data B in Tables 1 and 2.

As a result, the difference AB = vibration data A of the minimum area vibration maximum level−vibration data B of the minimum area vibration maximum level = 40 dB−30 dB = 10 dB.
Therefore, since the threshold value H is 18 dB> difference AB10 dB, it was possible to determine that water leakage occurred.

表３に示すように、差分ＡＢの予測は、振動データＡ−振動データＢ＝１０ｄＢ−５ｄＢで、５ｄＢである。計測誤差を考慮し、閾値Ｈを３ｄＢと設定した。
上記の閾値Ｈを用いて実際に漏水を検出できるか実験した。測定結果を以下の表２に示す。

漏水による振動レベルは、振動データＡにおいては、２０ｄＢであり、振動データＢは、３０ｄＢであった。
また、最小領域振動最大レベルは、表３および表４における振動データＡの最大値、振動データＢの最大値を示す。 (Example 2)
Based on the first embodiment, threshold values were set as shown in Table 3 below.

As shown in Table 3, the prediction of the difference AB is 5 dB with vibration data A−vibration data B = 10 dB−5 dB. In consideration of measurement errors, the threshold H was set to 3 dB.
It was experimented whether water leakage could actually be detected using the above threshold value H. The measurement results are shown in Table 2 below.

The vibration level due to water leakage was 20 dB in the vibration data A, and the vibration data B was 30 dB.
The minimum region vibration maximum level indicates the maximum value of vibration data A and the maximum value of vibration data B in Tables 3 and 4.

As a result, the difference AB = vibration data A of the minimum region vibration maximum level−vibration data B of the minimum region vibration maximum level = 20 dB−30 dB = −10 dB.
Therefore, since the threshold value H is 3 dB> difference AB-10 dB, it was possible to determine that water leakage occurred.

表５に示すように、１日から第Ｎ日まで振動データＡ，Ｂに基づいて漏水を検知した。
第Ｎ日は、差分ＡＢが閾値Ｈを下回ったために、漏水が生じたと判定することができた。なお、上記実施例３においては、第Ｎ日において、下回ったために漏水と判定したが、これに限定されず、複数日、または連日において、差分ＡＢが閾値Ｈより小さくなった場合に、漏水と判定してもよい。 (Example 3)
Example 1 was repeated for multiple days based on the first embodiment.

As shown in Table 5, water leakage was detected from vibration data A and B from day 1 to day N.
On the Nth day, since the difference AB was lower than the threshold value H, it was possible to determine that water leakage occurred. In Example 3 above, it was determined that the water leaked because it was lower on the Nth day. However, the present invention is not limited to this, and when the difference AB becomes smaller than the threshold H on multiple days or consecutive days, You may judge.

As described above, by using the difference AB, it is possible to cancel the inherent vibration in the pipeline or the disturbance noise of the machine or the like.
As a result, by using the differences AB, CD, G, IJ and the threshold value H from the vibration levels A, B, C, D1, D2, D3, E, and F, the vibration inherent to the pipeline due to the water flow, or the continuous machine, etc. It is possible to detect an abnormality in a pipe line that is less likely to cause erroneous determination depending on the presence or absence of a vibration source.

  In the present embodiment, as shown in FIG. 1, the vibration sensor 200 is provided in each of the vertical holes 120 at the point A and the point B. However, the present invention is not limited to this. The vibration sensor 200 may be provided. By providing the vibration sensor 200 in water, noise can be reduced.

  In the present invention, the pipe network 110 corresponds to a “pipe”, and when the water pressure in the pipe network 110 is low, or 14:00 in the daytime corresponds to a “first time zone”, and 100 seconds corresponds to a “predetermined time”. Steps S11 and S12 correspond to the “first measurement step”, when the water pressure in the pipe network 110 is high, or 2 o'clock corresponds to the “second time zone”, and step S21, The process of S22 corresponds to the “second measurement step”, the differences AB, CD, G, IJ correspond to the “vibration level difference”, the threshold value H or 0 corresponds to the “predetermined threshold value”, the step S32, The processes of S32b and S32c correspond to “determination process”, the process of step S13 corresponds to “first division process”, the process of step S23 corresponds to “second division process”, and steps S13, S14, and S14a. , S14b and S14c are “first extraction” The process of steps S23, S24, S24a, S24b, and s24c corresponds to a “second extraction step”, and the flowcharts of FIGS. 4 and 5 correspond to a “pipe abnormality detection method”. , 7 corresponds to a “pipeline abnormality monitoring method”.

  A preferred embodiment of the present invention is as described above, but the present invention is not limited thereto. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention. Furthermore, in this embodiment, although the effect | action and effect by the structure of this invention are described, these effect | actions and effects are examples and do not limit this invention.

100 Abnormal Sound Generation Identification Device 110 Pipe Network 200 Vibration Sensor 300 Arithmetic Device AB, CD, G, IJ Difference H Threshold

Claims (7)

An abnormality detection method for a pipeline that measures vibrations at a plurality of locations in a pipeline and identifies an abnormal location,
A first measurement step of measuring a vibration level over a predetermined time in a first time zone;
A second measurement step of measuring vibration over a predetermined time in a second time zone in which the water pressure in the pipeline is higher than the first time zone;
A vibration level difference calculating step for calculating a difference between a vibration level that has become a minimum region in the first measurement step and a vibration level that has become a minimum region in the second measurement step;
A method of detecting an abnormality of a pipe line, comprising: a determination step of determining an abnormality when a difference in the vibration level difference calculation step is less than a predetermined threshold value. A first dividing step of dividing the vibration level measured by the first measuring step;
A second dividing step of dividing the vibration level measured in the second measuring step,
The vibration level difference calculating step includes:
A first extraction step of extracting one or a predetermined number of vibration levels that have become a minimum region from among the plurality of vibration levels divided in the first division step;
A second extraction step of extracting one or a predetermined number of vibration levels that have become a minimum region from among the plurality of vibration levels divided in the second division step,
The pipe line abnormality detection method according to claim 1, wherein the vibration level difference calculation step calculates a difference from vibration levels of the first extraction step and the second extraction step.   The pipe line abnormality detection method according to claim 1 or 2, wherein the first measurement step, the second measurement step, the vibration level difference calculation step, and the determination step are repeated a plurality of times.   The pipe line abnormality detection method according to claim 1, wherein the predetermined threshold is zero. An abnormality monitoring method for a pipeline that measures vibration at a plurality of locations in a pipeline and identifies an abnormal location,
A first measurement step of measuring a vibration level over a predetermined time in a first time zone;
A second measurement step of measuring vibration over a predetermined time in a second time zone in which the water pressure in the pipeline is higher than the first time zone;
A vibration level difference calculating step for calculating a difference between a vibration level that has become a minimum region in the first measurement step and a vibration level that has become a minimum region in the second measurement step;
A determination step of determining an abnormality when the difference in the vibration level difference calculation step is less than a predetermined threshold,
The first measurement step, the second measurement step, the vibration level difference calculation step is repeated a plurality of times over a plurality of days,
The pipe line abnormality monitoring method, wherein the determination step determines that an abnormality occurs when a difference in the vibration level difference calculation step falls below a predetermined threshold value one or more times. A first dividing step of dividing the vibration level measured by the first measuring step;
A second dividing step of dividing the vibration level measured in the second measuring step,
The vibration level difference calculating step includes:
A first extraction step of extracting one or a predetermined number of vibration levels that have become a minimum region from among the plurality of vibration levels divided in the first division step;
A second extraction step of extracting one or a predetermined number of vibration levels that have become a minimum region from among the plurality of vibration levels divided in the second division step,
6. The pipe abnormality monitoring method according to claim 5, wherein the vibration level difference calculating step calculates a difference from vibration levels of the first extraction step and the second extraction step. The pipe line abnormality monitoring method according to claim 5 or 6, wherein the predetermined threshold is zero.

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