JP3262469B2 - Water leak detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects the location of underground objects such as water pipes and the like, and detects the presence or absence of water leakage caused by damage to piping, etc. It relates to a detection device.

[0002]

2. Description of the Related Art Conventionally, when detecting a water leak position, vibrations on the pipe are examined with ears at an exposed place such as a pipe valve to specify whether there is a water leak somewhere on the pipe. Was. In other words, the ears were used to confirm the vibration from the surface of the ground where the pipe was likely to be buried in the ground, to find a position where the water leaking sound could be best heard, and to dig there to examine the pipe.

However, this method requires skill. In addition, even when a vibration signal on a pipe is captured at two places where the pipe is exposed, such as a valve of the pipe, and a leaking position is estimated using a cross-correlation, a portion exposed on the pipe is formed. The condition was that there were two places separated by several meters or more.

[0004]

However, such a conventional detection method requires a high degree of skill in order to accurately determine whether or not the vibration heard from the pipe is a leak. In addition, estimating the location of the leak was a more difficult task.

The present invention solves such a problem associated with the conventional leak detection, and can accurately and promptly estimate the presence or absence of a leak and the location of a leak without requiring special skills. An object of the present invention is to provide a new leak detection device.

[0006]

In order to achieve the above object, a water leakage detection device according to the present invention detects the presence or absence of water leakage by capturing the vibration caused by water leakage from a pipe buried underground on the surface of the ground. A vibration detector for applying vibration to the pipe, and three acceleration sensors disposed on the ground surface to sense vibration from the vibration generator and vibration caused by water leakage. A pipe position detecting means for calculating a pipe position in the ground based on a vibration signal applied to the vibrator and a signal from the acceleration sensor; and three acceleration sensors arranged in accordance with the obtained pipe position. And a water leak direction detecting means for detecting a direction of occurrence of water leak based on a signal from the apparatus. The pipe position detecting means detects a vibration amplitude value of the vibration signal and the three acceleration sensors. Performs a cross-correlation processing with the vibration amplitude value cross-correlation function z1 (τ), z2 (τ), z3
(Τ) is determined, and from these cross-correlation functions, the vibration energy propagation speeds Ix (τ) and Iy (τ) in the X and Y directions formed by the three acceleration sensors are approximated, and these vibration energy propagation speeds Ix ( τ), X based on Iy (τ)
The vibration energy Wx and Wy in the direction and the Y direction are obtained,
It is characterized in that the direction of the pipe position is obtained by vector synthesis of these vibration energies Wx and Wy.

[0007]

[0008]

According to the water leakage detecting device of the present invention, the cross-correlation processing between the vibration signal on the ground surface and the excitation signal is performed to remove noise components other than the excitation signal and measure the vibration energy flux. By determining from which position the excitation signal originates, the pipe burial position is determined, and since water leakage can be detected at this pipe burying position, it is significantly more accurate and simpler than before, and It is possible to efficiently detect the water leakage position.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 to 3 are explanatory views showing a water leakage detection device according to a first embodiment of the present invention.

In the figure, a vibrator 2 and three acceleration sensors 3a, 3b,
3c is connected. The vibration exciter 2 is attached so as to contact an exposed portion of the pipe 4 buried underground. On the other hand, the acceleration sensors 3a, 3b, 3c are arranged at measurement positions on the ground surface 6 where the pipe 4 is buried underground.

Then, as shown in FIG. 2, when the detection operation is performed above the water leakage point 5, the water leakage point 5 can be detected. The arrangement of the acceleration sensors 3a, 3b, 3c is such that the acceleration sensor 3a is centered on the acceleration sensor 3b.
And 3c are selected to lie on orthogonal lines to each other. Here, it is assumed that the direction from the acceleration sensors 3a to 3b is the x direction and the direction from the acceleration sensors 3b to 3c is the y direction.

In this state, the vibrator 2 installed on the pipe 4 is operated to apply vibration to the pipe 4, and the vibration transmitted through the pipe 4 is simultaneously detected by the acceleration sensors 3a, 3b, 3c. The excitation signal of the vibrator 2 is y1, and the signals detected by the acceleration sensors 3a, 3b, 3c are y2, y, respectively.
3 and y4.

The flow of vibration energy on the ground surface can be determined by the following method using the vibration intensity method. The signal detected on the ground surface includes, in addition to the excitation signal from the exciter 2, a noise component caused by vibration of the road surface or the like. Remove this noise component,
In order to extract only the excitation signal and detect the propagation direction of the signal, as the statistical processing in the time series of the signal, the excitation signal vibration amplitude y1 (t) of the vibration exciter 2 and the acceleration sensor 3a on the ground surface , 3b, 3c, cross-correlation processing is performed according to the following equation between the vibration amplitude values y2 (t), y3 (t), y4 (t), and the cross-correlation function z1 (τ), z2 (τ) and z3 (τ) are obtained.

Z1 (τ) = ∫y1 (t) y2 (t−τ) dt (1a) z2 (τ) = ∫y1 (t) y3 (t−τ) dt ... (1b) z3 (Τ) = ∫y1 (t) y4 (t−τ) dt (1c) The cross-correlation function obtained in this way is closely related to the vibration component on the pipe.

Here, the vibration energy propagation velocity between two points in the x direction is represented by Ix (τ), and the spatial differential along the x axis is approximated by the spatial difference as follows. Ix (τ) = z1 (τ) −z2 (τ) (2) As a result, the vibration energy Wx flowing in the x direction at the positions of the acceleration sensors 3a and 3b on the ground surface is z2 (τ)
Is multiplied by Ix (τ) and integrated by time τ.

Wx = ∫z2 (τ) Ix (τ) dτ (3) Similarly, the vibration energy propagation velocity between two points in the y direction is represented by Iy (τ), and the vibration energy flowing in the y direction Is Wy, Wy is obtained as follows.

Iy (τ) = z3 (τ) −z2 (τ) (4) Wy = ∫z2 (τ) Iy (τ) dτ (5) In this way, the x direction and y From the vibration energy Wx and Wy flowing in the directions, by vector-combining the two, it is possible to know in which direction the vibration generated by the vibrator 2 passes through the ground surface at the measurement position.

From these results, the direction of the pipe buried underground is predicted, and the same measurement as shown in FIG. 2 is performed many times on the ground surface to determine the pipe burying position. can do.

After determining the pipe burying position, the exciter 2 installed on the pipe is stopped, and the acceleration sensors 3a, 3b, 3c on the ground surface are installed above the pipe burying position as shown in FIG. Then, by performing the same measurement in a state where the vibration from the vibrator 2 is not given, that is, obtaining the vibration energies Wx and Wy flowing in each of the x-direction and the y-direction and vector-combining both. Thus, it is possible to confirm in which direction the vibration caused by the water leakage at the water leakage point 5 passes on the pipe position.

From this result, it is possible to predict the direction of the water leak in the pipe and perform the same measurement as many times as necessary on the pipe burying position, thereby specifying the water leak position on the pipe.

FIG. 3 is a block diagram showing a specific configuration of the water leakage detection device shown in FIG. In FIG. 3, signals from the acceleration sensors 3a, 3b, 3c undergo an amplification and filtering process at an input unit 1e. In this input signal, the vibration due to water leakage is considerably smaller than the vibration caused by the vibration of the vibrator 2, and therefore, in the input unit 1e,
By changing the amplification factor based on the amplitude value etc. of the input signal,
It is desirable that the vibration from the vibrator 2 be taken in reliably.

The signal from the input section 1e is input to an input conversion section 1d.
After being converted into a digital value, the signal is supplied to the signal processing section 1c and subjected to statistical calculation processing according to the above-described calculation formula. As this arithmetic processing means, a high-speed DSP (D
It can be performed using an digital signal processor or the like.

The signal processing unit 1c as an operation means
Is displayed on the display unit 1a as the flow direction of the vibration energy and the value of the vibration energy intensity via the central processing unit 1b.

On the other hand, when the operation section 1f is operated by the operator, a command to start the calculation is sent to the signal processing section 1c, and when the embedded position of the pipe 4 is detected, the vibration of the vibrator 2 is detected. A command to start the vibration operation and a command to stop the vibration operation of the vibrator 2b when water leakage is detected are sent.

When the start of the vibrating operation of the vibrator 2 is commanded,
The central processing unit 1b instructs the signal generation unit 1g to generate an excitation signal, and after the excitation signal is amplified by the signal output unit 1h, is supplied to the exciter 2 and is applied to the input unit 1e.

The acceleration sensors 3a, 3b, 3c are installed on the ground surface 6, and the vibrator 2 is installed at an exposed portion of the pipe 4, for example, at a position close to the valve 7. 4 to 6 show a water leakage detecting device according to a second embodiment of the present invention.

In this embodiment, an acceleration sensor 2a attached to the pipe 4 at a position close to the vibrator 2 is added to the configuration of the water leakage detection device in the first embodiment shown in FIG.

The use of the acceleration sensors 3a, 3b, 3c is the same as in the first embodiment. Acceleration sensor 2
a and the vibrator 2 are attached so as to come into contact with the exposed portion of the pipe 4 buried underground. On the other hand, the acceleration sensors 3a, 3b, and 3c correspond to the ground surface 6 where the pipe 4 is buried.
At the measurement position. Then, as shown in FIG. 5, when the detection operation is performed above the water leakage point 5, the water leakage point 5
Can be detected.

In this example, the acceleration sensor 2a detects a signal given to the pipe 4 by the vibrator 2 and a signal given to the pipe due to an external factor such as water leakage.
Used as y1. Other configurations and operations are the same as those of the first embodiment shown in FIG.

FIG. 6 is a block diagram showing a specific configuration of the water leakage detection device shown in FIG. The leak detection device of this example also has an input unit 1e, an input conversion unit 1d, a signal processing unit 1c having arithmetic means, a central processing unit 1b, a display unit 1a, an operation unit 1f, a signal A generator 1g and a signal output unit 1h are provided.

However, in this embodiment, the signal output unit 1h
The operation is the same as that of FIG. 3 except that the vibration signal detected by the acceleration sensor 2a is input to the input unit 1e instead of the vibration signal input to the input unit 1e.
Therefore, as shown in FIG. 5, when the detection operation is performed above the water leakage point 5, the water leakage point can be specified from the vibration caused by the water leakage.

[0032]

As described above, according to the present invention, a water leak detection operation, which has been performed by relying on the ears of a skilled person, can be performed reliably and quickly without requiring any skill. Moreover, there is a remarkable effect that highly accurate detection can be performed even in a situation where there is only one exposed portion on the pipe.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a water leakage detection device according to a first embodiment of the present invention as being in a state of detecting a pipe position.

FIG. 2 is an explanatory diagram showing each acceleration sensor of the water leakage detection device in FIG. 1 as being in a state of detecting a water leakage position.

FIG. 3 is a block diagram illustrating a configuration of a water leakage detection device in FIG. 1;

FIG. 4 is an explanatory view showing a water leakage detection device according to a second embodiment of the present invention as being in a state of detecting a pipe position.

FIG. 5 is an explanatory diagram showing each acceleration sensor of the water leakage detection device in FIG. 4 as being in a state of detecting a water leakage position.

FIG. 6 is a block diagram illustrating a configuration of a water leakage detection device in FIG. 4;

[Explanation of symbols]

 1 Main unit 1a Display unit 1b Central processing unit 1c Signal processing unit 1d Input conversion unit 1e Input unit 1f Operation unit 1g Signal generation Unit 1h Signal output unit 2 Exciter 2a, 3a, 3b, 3c Acceleration sensor 4 Piping 5 Water leaking point 6 Ground surface

Claims (1)

(57) [Claims] An apparatus for detecting the presence or absence of water leakage by detecting vibrations caused by water leakage from a pipe buried underground on the surface of the ground, wherein a vibration for applying vibration to said pipe is provided. Vessel, three acceleration sensors arranged on the ground surface for sensing vibration from the shaker and vibration caused by water leakage, and based on a vibration signal applied to the shaker and a signal from the acceleration sensor. A pipe position detecting means for calculating a pipe position in the ground by calculation, and a water leak direction detecting means for detecting a direction of water leak based on signals from three acceleration sensors arranged according to the calculated pipe position , The pipe position detecting means includes a vibration amplitude value of the vibration signal and
Vibration amplitude value detected by the three acceleration sensors
And a cross-correlation function z1
(Τ), z2 (τ) and z3 (τ) are obtained,
From the function, the X direction and the three acceleration sensors
Energy propagation velocity Ix (τ) in the Y and Y directions, Iy
(Τ), and these vibration energy propagation speeds Ix
(Τ) and Iy (τ) based on the vibration energy in the X and Y directions.
Energy Wx and Wy are obtained, and these vibration energies W
By combining x and Wy in a vector,
A water leak detection device for determining a direction .