JP3175878B2 - Pipeline internal state measurement method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the interior of various pipelines, such as underground communication pipelines and water and sewage pipelines, which are easily buried underground, by radiating sound waves from one side of the pipeline and measuring the reflected waves. The present invention relates to a method and an apparatus for measuring a state inside a pipeline for measuring a state.

[0002]

2. Description of the Related Art Conventionally, as a method for directly measuring the internal state of an underground communication pipeline, a method using a pipe camera shown in FIG. 8 is known.

In FIG. 8, 31 is a camera, 32 is a lighting device, 33 is a cable, 35 is a monitor device, 34 is a cable winding device, 101 is a dent, 102 is a foreign substance,
3 is a joint, and 200 is an operator.

FIG. 8 shows a measuring method in which a small camera 3 is placed in a tube.
1 and the lighting device 32 are inserted, and the operator 200 visually observes the state of the inside of the pipe, and determines whether or not there is any foreign matter in the pipe.
The purpose of this survey is to investigate the connection status and flatness of pipelines.

As a method for indirectly measuring the state inside a pipe such as a pipe for a heat exchanger, there is known a method utilizing reflection of a sound wave shown in FIG.

In FIG. 9, 141 is a transmitter, 142 is a receiver, 143 is a display, 145 is a steam pipe,
102 is a foreign substance, 104 is a hole, and 200 is an operator.

In the measurement method shown in FIG. 9, a sound wave is incident from a transmitter 141 installed at the end of a tube, and a temporal change of a reflected sound wave measured by a receiver 142 is displayed on a display 143. The data is analyzed by the operator 200.

[0008]

However, the measuring method using the pipe camera has an advantage that the state inside the pipe can be accurately grasped, but the camera 31, the lighting device 32, the monitor device 35, the cable 33, and the cable This is a large-scale device composed of the winding device 34, and has a drawback that it requires considerable labor and time to transport and insert the camera.

In the method using the reflection of the sound wave, the position of the object inside the tube from the end of the tube can be quantitatively measured from the time until the sound wave enters and the reflected sound wave from the object inside the tube is obtained. However, in order to identify the type of the reflective object, it is necessary to read information from the waveform displayed on the display, and there is a disadvantage that the operator 200 requires considerable skill.

Further, as shown in FIG. 10, the loudspeaker control signal and the waveform of the sound wave actually incident on the inside of the tube have different waveforms due to the influence of the dynamic characteristics of the sound wave generator. In such a case, it is difficult to distinguish the sound wave reflected from the object from the noise from the outside world, and it is impossible to measure the position of the reflecting object.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to make it possible to simplify the measurement and investigation of the state inside a pipeline and save labor.
Another object of the present invention is to provide a technique capable of measuring a reflected sound wave from an in-pipe object and a pipe end even when a pipe to be measured becomes long.

The above and other objects and a novel structure of the present invention will be apparent from the description of the present specification and the accompanying drawings.

[0013]

Means for Solving the Problems To achieve the above object, the means (1) of the present invention is a method for measuring the internal state of a pipeline.
There are incident sound waves from one side of the conduit to conduit, said tube
Receiving a time-varying reflected sound wave from the conduit body and the pipe end of the incident sound wave incident on the road, the conduit within the object from the incident sound <br/> wave in said conduit when and where the time until the reflected wave is obtained from the pipe end is measured and is the measured
Based between, as well as measure the position from one side of the conduit of the conduit within the object and the pipe end, reflected sound wave of the waveform from the duct body and the pipe end and the incident sound wave incident on the conduit based on the relationship between, and discriminates the conduit body and the tube.

[0014]

Further, in the means of (1), the incident wave waveform actually entering the sound wave of the conduit emanating from the speaker to be more driven by the speaker drive amplifier
When, using the error between the incident wave waveform with the ideal,
A speaker drive signal supplied to the speaker drive amplifier is modified to generate an incident sound wave having an arbitrary waveform .

Further, in the means of (1), the waveform of the incident sound wave type and position of the sound wave reflecting object inside the conduit enters the known tube path, reflected from the individual reflecting objects
Stored in the memory register by the acoustic wave in pairs, before
Acquiring a unique reflected acoustic dynamics serial line the inside of the reflecting object and the pipe end, then the waveform of <br/> incident sound wave which is incident on the measurement conduit, reflecting object inside the measured pipe and the relationship between the reflected sound wave of the waveform obtained from the pipe end, by comparing the reflected acoustic dynamics of the sound wave reflecting object and tube end acquired in the memory register, reflecting object inside the measured pipe and pipe end another species, as well as characterized by performing position location.

In order to achieve the above object, the means (2) according to the present invention is a method for measuring the internal state of a pipeline.
A measuring device, a speaker for generating sound waves inside the conduit, the incident sound wave emitted from the speaker, and the
Receiving a reflected sound wave from line inside and the tube end of the incident sound wave, and a microphone installed in front of the speaker, a temperature sensor for measuring the temperature inside the conduit, the speaker amplifies the speaker drive signal a speaker drive amplifier for supplying to a microphone amplifier for amplifying the reflected wave signal received by the microphone, a sensor amplifier for amplifying the sensor signal from the temperature sensor, and a processing unit, an analog-digital
Conversion unit and display unit that displays the measurement results of the internal state of the pipeline
And an operation unit that operates the pipeline internal state measurement device , wherein the arithmetic processing unit generates the speaker drive signal, and analyzes a reflected sound signal and a sensor signal ,
Type and position of the reflecting object and pipe end inside the pipe
Includes a CPU that performs a specific, and a memory register for storing said loudspeaker drive signal and the <br/> reflected sound wave signal, the
The analog-to-digital converter includes the microphone amplifier and
It converts the output signal of the sensor amplifier to a digital signal
De is supplied to the analog-digital converter to supply the arithmetic processing unit, said speaker driving amplifier converts the speaker drive signal generated by the CPU into an analog signal Te
And having a digital-to-analog converter.

[0018]

According to the above means, in analyzing and calculating the type and position of the object and the end of the pipe end from the measured reflected sound wave, the incident sound wave capable of distinguishing the reflected sound wave from the noise from the outside world. Can be used intentionally, so that it is possible to measure the reflected sound waves from the object inside the pipe and the pipe end even if the pipe to be measured is long, and to obtain the acoustic reflection characteristics inside the pipe in advance. So you can
The pipe length and the type identification and position measurement of the pipe body can be performed, thereby simplifying the measurement and investigation of the state inside the pipe and saving labor.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a method for measuring the internal state of an underground communication pipe, which is an embodiment of the method for measuring the internal state of a pipe using the acoustic method according to the present invention.

In FIG. 1, 1 is a speaker, 2 is a microphone, 3 is a temperature sensor, 20 and 30 are manholes, 21 is an underground communication line connecting manholes 20 and 30, 101 is a dent, 102 is a foreign substance, and 103 is a joint. , Pi (i = 0,
1, 2, 3) are the microphone 2, the reflection object in the tube and the position of the tube end, and li (i = 1, 2, 3) is the position of the object in the tube and the position of the tube end from the microphone 2.

In FIG. 1, a sound wave incident from a speaker 1 passes through P0 where a microphone 2 is located, and a reflected object P
1, P2, P3 and P4, and are measured again at the microphone 2.

At this time, the waveform of the sound wave measured by the microphone 2 is as shown in FIG.

FIG. 2 is a diagram schematically showing a measured waveform obtained from the pipeline in FIG.

In FIG. 2, ri (i = 0, 1, 2, 2)
3) The microphone 2, the reflecting object in the pipe and the pipe end position Pi
The waveform of the sound wave reflected from (i = 0, 1, 2, 3) is shown.

The position li (i = 1, 2, 3) of the object in the tube and the tube end from the microphone 2 is determined by the sound velocity V, the sound wave r0 passing through the microphone 2, the sound wave ri reflected from the reflecting object and the tube end. time difference ti (i = 1, 2, 3) from i = 1, 2, 3)
By obtaining 2,3), it can be obtained from the following equation.

[0027]

L i = ti × V (i = 1,2,3) / 2 (1) Here, the sound velocity of the gas is almost independent of the pressure and increases in proportion to the square root of the absolute temperature. The sound velocity V can be calculated from the pipe temperature T measured by the temperature sensor 3 using the following equation.

[0028]

(Equation 2)

According to the present embodiment, a sound wave enters the tube,
A reflected sound wave from an object inside the conduit is measured, and the distance of the reflected object can be recognized from the time delay of the reflected sound wave, and the difference between the objects in the tube can be recognized from the waveform of the reflected sound wave.

In the present embodiment, the dent 10 is inserted into an underground communication line 21 connecting the manholes 20 and 30 buried underground.
1, the case where there is the foreign matter 102 and the joint 103 is shown, but the measurement can be similarly performed in the case of a general pipeline.

FIG. 3 shows an embodiment of a method for measuring the internal state of a pipeline using an acoustic method according to the present invention, which arbitrarily generates a waveform of a sound wave incident into the pipe in a method for measuring an internal state of an underground communication pipeline. It is a block diagram showing a technique.

FIG. 3 is a block diagram of the present invention.
It corresponds to the term.

From the speaker control signal memory register, k
The times th speaker control signal taken out u ^k, to generate sound waves to drive the speaker.

Here, u represents a vector obtained in a finite time and having discrete time series data as elements.

At this time, the incident waveform y ^k observed by the microphone is temporarily stored in the incident waveform memory register.

Here, y represents a vector obtained in finite time and having discrete time series data as elements.

Next, the target waveform y _d and the incident waveform y ^k are respectively fetched from the target incident waveform memory register and the incident waveform memory register, and their errors e ^k are obtained. ^k (mod)

[0038]

(Equation 3)

Is obtained.

[0040] However, E, e represents a vector, F _N is the discrete Fourier transform N × N matrix that performs, E = F _N e is the discrete Fourier transform of the error e, Yi, respectively Ui is y, the discrete Fourier u The i-th element of the transformation.

The error correction amount e ^k (m
The control signal is updated by the following equation from od).

[0042]

(4) u ^{k + 1} = u ^k + e ^k (mod) (7) The last updated speaker control signal u ^{k + 1} is stored in the speaker control signal memory register.

Here, the target waveform yd is used as the initial speaker control signal u ¹ .

FIG. 4 shows the relationship between the speaker control signal and the incident waveform when the incident waveform shaping method of this embodiment is used and when it is not used.

FIG. 5 shows a method of acquiring acoustic reflection dynamics of an in-pipe object and a pipe end in a method of measuring the internal state of an underground communication pipe which is an embodiment of the pipe internal state measuring method using the acoustic method according to the present invention. It is a figure which shows a flowchart.

FIG. 5 shows the third embodiment of the present invention.
It corresponds to the term.

Acquisition of the acoustic reflection dynamics of the in-pipe object and the pipe end is performed using the learning simulated conduit Obj1,2 ‥‥ n that reproduces an actually conceivable situation.

[0048] First, to select a target incident waveform y ^p _d randomly from different types of targets incident waveform stored in advance in the memory register, the y ^p speaker control signals to achieve a _d u ^p _d above Is created by the arbitrary waveform generation method described above.

Here, u and y represent vectors obtained by obtaining discrete time series data as elements, which are obtained in a finite time as described above.

[0050] The speaker control signal incident sound waves u ^p _d, measures the reflected waveform R ^p _d in the tube body obtained from the learning simulated conduit Obj1,2 ‥‥ n.

[0051] However, R ^p _d represents the reflected wave vector for a target waveform y ^p _d.

[0052] for each n the training simulation conduit Obj1,2 ‥‥, incident wave, the reflected wave ^{_{(y p d, R p d}} ) to be paired acoustic reflection dynamics database DB1,
Store in DB2 @ DBn.

FIG. 6 is a diagram showing a method for measuring the internal state of an underground communication pipe, which is an embodiment of the method for measuring the internal state of a pipe using the acoustic method according to the present invention, based on acoustic reflection dynamics. FIG. 4 is a diagram illustrating a flowchart of a method for performing recognition.

FIG. 6, like FIG. 5, corresponds to claim 3 of the present application.

Firstly, the target incident waveform y ^p _d selected from the memory register for target waveform, creating a speaker control signal u ^p _d to achieve a y ^p _d.

Next, by driving the speaker by the speaker control signal u ^p _d, measuring the reflected sound wave from the tube at that time. From the measured sound waves, reflected sound waves r1, r2 内 rq at the inside of the pipe and at the pipe end are extracted.

[0057] Then, the incident waveform y ^p _d and reflected waveform Ri (i
= 1,2 ‥‥ q-1) pairs _{^{(y p d, Ri) (}} i = 1,
2 ‥‥ q−1), and a pair of databases DB1, DB2ＲDBn (y ⁱ _d , R
ⁱ _d ) (i = 1, 2 ‥‥) using the following equation.

Here, y and R represent vectors as described above.

[0059]

Equation 5] J = ‖R ⁱ _d over Rj‖ (8) (i, j = 1,2 ‥‥) where each measurement pair _{^{(y p d, Ri) (}} i = 1,2 ‥‥ q
-1), data pairs for the evaluation value J to the minimum (y ⁱ _d, R
ⁱ _d ) Finally, the reflection object is recognized from the reflection as belonging to the database including (i = 1, 2 ‥‥).

FIG. 7 is a block diagram showing a schematic configuration of an apparatus for measuring the internal state of an underground communication pipe, which is an embodiment of the apparatus for measuring the internal state of a pipe using the acoustic method according to the present invention.

In FIG. 7, 1 is a speaker, 2 is a microphone, 3 is a temperature sensor, 41 is a speaker driving amplifier, 42
Is a microphone amplifier, 43 is a temperature sensor amplifier, 51 is a digital / analog converter, 52 and 53 are analog / digital converters, 6 is a time-varying gain controller, 7 is a memory register, 8 is a CPU, 9 is a display, 10 Is an operation switch. The memory register 7 includes a speaker control signal memory register, an incident waveform memory register, and a target incident waveform memory register.

In FIG. 7, in order to generate a sound wave into the tube, the digital value of the speaker drive signal data stored in the memory register 7 is converted to a digital / analog converter 5
1 converts the analog voltage value into a predetermined analog voltage value, drives the speaker 1 through the speaker drive amplifier 41, and generates a tube incident sound wave.

By arranging the microphone 2 at a right angle in front of the speaker 1, an incident sound wave emitted from the speaker 1 is received as a waveform of the same level as a reflected sound wave from inside the tube, and stored in the memory register 7.

The reflected sound wave received by the microphone 2 is amplified by a microphone amplifier 42 controlled by a time-varying gain controller 6 which changes the amplification factor with time, and then converted into a digital value by an analog / digital converter 52. It is stored in the memory register 7 in the arithmetic processing unit A.

At the same time, the temperature inside the pipe is measured by the temperature sensor 3 and amplified by the temperature sensor amplifier 43, then converted into a digital value by the analog / digital converter 53 and stored in the memory register 7 in the arithmetic processing section A. Is done.

Incident sound waves stored in the memory register 7;
The reflected sound wave and the temperature data in the pipe are stored in the CP
The type and position measurement result of the reflected sound wave processed by U8 are displayed on the display.

The measurement start / end and the analysis operation are performed by the operation switch 10 in accordance with the procedure shown on the display 9.

Although the present invention has been described in detail with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

[0069]

As described above, according to the present invention,
In analyzing and processing the type and position of the object inside the pipe and the end of the pipe from the measured reflected sound wave, the incident sound wave that can distinguish the reflected sound wave and noise from the outside world is intentionally used. Even if the measurement pipe becomes long, it is possible to measure the reflected sound waves from the pipe body and the pipe end.

Further, by acquiring the acoustic reflection characteristics inside the pipeline in advance, it is possible to specify the length of the pipeline and the type of the object in the pipeline.
Position measurement becomes possible.

As a result, it is possible to simplify the measurement and investigation of the state inside the pipeline and to save labor.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a method of measuring an internal state of an underground communication pipeline which is an embodiment of a method of measuring an internal state of a pipeline using an acoustic method according to the present invention.

FIG. 2 is a view schematically showing a measurement waveform obtained from the pipeline in FIG. 1;

FIG. 3 is a block diagram showing a method of arbitrarily generating a waveform of a sound wave incident on a pipe in a method for measuring an internal state of an underground communication pipe as an embodiment of the pipe internal state measuring method using an acoustic method according to the present invention. FIG.

FIG. 4 is a waveform chart showing a relationship between a speaker control signal and an incident waveform when the incident waveform shaping method of FIG. 3 is used and when it is not used.

FIG. 5 is a flowchart showing a method of acquiring acoustic reflection dynamics of an in-pipe object and a pipe end in a method of measuring an internal state of an underground communication pipe, which is an embodiment of the pipe internal state measuring method using an acoustic method according to the present invention. It is.

FIG. 6 shows a method for recognizing a reflecting object and a pipe end based on acoustic reflection dynamics in a method for measuring an internal state of an underground communication pipe, which is an embodiment of the pipe internal state measuring method using an acoustic method according to the present invention. FIG. 4 is a diagram showing a flowchart of the above.

FIG. 7 is a block diagram showing a schematic configuration of an apparatus for measuring an internal state of an underground communication pipe which is an embodiment of the apparatus for measuring an internal state of a pipe using an acoustic method according to the present invention.

FIG. 8 is a diagram showing a schematic configuration of a conventional method for directly measuring the internal state of an underground communication pipeline using a pipe camera.

FIG. 9 is a diagram showing a schematic configuration of a method for inspecting an internal state of a pipe using an acoustic method as a conventional technique.

FIG. 10 is a diagram schematically illustrating how a speaker control signal differs in actual generated sound wave waveform due to the influence of a speaker driving amplifier and speaker dynamics.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Speaker, 2 ... Microphone, 3 ... Temperature sensor, 41 ... Speaker drive amplifier, 42 ... Microphone amplifier, 43 ... Temperature sensor amplifier, 51 ... Digital / analog converter, 5
2, 53: analog / digital converter, 6: time-varying gain controller, 7: memory register, 8: CPU, 9
... Display, 10 ... Operation switch, 20, 30 ... Manhole, 21 ... Underground communication cable conduit, 31 ... Camera, 32 ... Lighting device, 33 ... Cable, 34 ... Cable winding device, 35 ... Monitor television, 141 ... Transmitter, 1
42 ... receiver, 143 ... display, 145 ... steam pipe, 101 ... dent, 102 ... foreign matter, 103 ... joint,
104: hole, 200: operator.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Yabuta 1-6-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-4-297815 (JP, A) JP-A Heisei 5-273335 (JP, A) JP-A-5-306923 (JP, A) JP-A-5-14962 (JP, U) Patent 3034330 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , (DB name) G01S 7/52-7/64 G01S 15/00-15/96

Claims (4)

(57) [Claims] 1. A sound wave is incident into a pipe from one side of the pipe,
Receiving a time-varying reflected sound wave from the conduit body and the pipe end of the incident sound wave incident on the conduit, the conduit
Incident sound waves the time until the reflected waves from said conduit body and the tube end is obtained by measuring from within, based on the measured time, the conduit of the conduit within the object and tube end as well as measure the position from one side of the front
The incident sound wave incident on the serial conduit from the relationship between the waveform of the reflected sound wave from said conduit body and the pipe end, the pipe internal state measurement, characterized in that to determine the line within the object and tube end Method. Is actually incident to wherein the sound waves emanating from a speaker that is driven by a speaker driver amplifier said conduit
The waveform of the incident sound wave and the waveform of the ideal incident sound wave
Using an erroneous difference between, modify the speaker drive signal supplied to the speaker drive amplifiers, line the internal state measuring method according to claim 1, characterized in that to generate the incident sound wave of an arbitrary waveform. 3. A waveform of the incident sound wave type and position of the sound wave reflecting object inside the conduit enters the known tube path, stored in pairs and reflection waves of the waveform from each reflecting object in the memory register to, acquire a unique reflected acoustic dynamics the conduit inside the reflecting object and the pipe end, then the waveform of the incident sound wave that will be incident on the measurement conduit, reflecting object inside the measured pipe and It compares the relationship between the reflected sound wave of the waveform obtained from the pipe end, and a reflected acoustic dynamics of the sound wave reflecting object and tube end acquired in the memory register
Te, the measured pipe internal reflection object and tube end another species,
2. The method according to claim 1 , wherein the position is specified.
Method of measuring the internal state of the pipeline. 4. A pipe internal state meter for measuring a pipe internal state.
A measuring device, receives a speaker for generating sound waves inside the conduit, the incident sound wave emitted from the speaker, and the reflected sound wave from line inside and the tube end of the incident <br/> waves,
A microphone installed in front of the speaker, a temperature sensor for measuring the temperature inside the conduit, a speaker drive amplifier is supplied to the speaker by amplifying a speaker drive signal, the reflected sound wave signal received by the microphone a microphone amplifier for amplifying a sensor amplifier for amplifying the sensor signal from the temperature sensor, and a processing unit, an analog-to-digital conversion unit, and a display unit for displaying the measurement result of the pipe internal state, the inside of the pipe Operation unit for operating the state measurement device
The arithmetic processing unit generates and arranges the speaker drive signals.
To, the conduit by analyzing the reflected ultrasonic signals and sensor signals
Specify the type of internal reflective object and pipe end, and specify the position.
And Cormorant CPU, and a memory register for storing said loudspeaker drive signal and the reflected sound wave signal, the analog-digital conversion unit, the operation to convert the output signal of the microphone amplifier and the sensor amplifier into a digital signal an analog-to-digital variable <br/> exchanger to supply to the processing unit, digital be supplied to the speaker drive amplifier converts the speaker drive signal generated by the CPU into analog signals
And an analog converter.