JPH10311820A - Reflection signal classifying method for use in sound wave pipeline investigation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately determine where the subject of reflection is located in a pipeline by classifying reflection signals from sound waves sent out into the pipeline, when investigating the pipeline using the sound waves. SOLUTION: The timing of reception of the input signal of a reflected sound wave obtained by sending out a sound wave from an end P1 located in the area of a pipeline for investigation and the timing of reception of a reflected sound wave obtained by sending out a sound wave from an end P2 different from the end P1 are reversed in terms of time to set a condition in which the timing of reception of the latter reflected sound wave has the same starting point on a time axis as the time of transmission of the sound wave from the end P1, and then the latter timing of reception is compared with the former timing of reception. If the comparison results shows that the reflected sound waves exit at the coincident timing, the subject of reflection is determined to be located within the area between the ends P1, P2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for classifying reflected signals in a system for examining the inside of a pipe such as a buried pipe using sound waves.

[0002]

2. Description of the Related Art Pipes such as gas pipes and water pipes buried underground may be deteriorated due to corrosion due to long-term installation, or may be damaged by external force. Therefore, it is necessary to investigate the inside of the pipes and take measures for repairs such as repairs. 2. Description of the Related Art Conventionally, as one of the systems used for investigation inside a pipe of this type, there is a system in which a device such as a camera or a fiberscope is inserted into the pipe so that a state in the pipe can be directly visually recognized. However, the method of inserting such equipment requires ancillary equipment such as a cable to be inserted into the pipeline and insertion work, which may require a large amount of work and equipment for investigation. In addition, if there is a broken point, a branch, or the like in the middle of the pipeline, it is difficult to guide the equipment at that location, and there is a problem that the investigation over the entire pipeline cannot be performed accurately. Therefore, instead of such a method, a system is proposed in which a sound wave is transmitted from the end of the pipe and the state of reflection in the sound wave is observed to easily perform a state survey in the pipe from both ends or one end of the pipe. (Eg, JP-A-61-29757 and JP-A-61-202158). In the above publication, a sound generating means and a sound collecting means are arranged at an end of a pipe, and a sound wave transmitted from the sound generating means is detected to be reflected on a cross-sectional area changing portion generated in the pipe, and a cross-sectional area is detected. A technique capable of observing a position up to a changing portion is disclosed. Such technology is
It is possible not only to detect a cross-sectional area change portion in the pipe, but also to investigate the position of a joint or the like installed in the pipe by observing the position where the reflected sound wave is generated.

[0003]

SUMMARY OF THE INVENTION In the case of using a pipeline inspection system to investigate a pipeline including a branch from one end of the pipeline to another end different from this end, a survey is performed. Since sound waves reflected from a reflection source located at a position other than the section in the target pipeline may also appear in the received data related to the reflected sound waves, all of the objects that are the sources of each reflected sound wave from the received data itself are There is a case where an erroneous judgment that it exists in the survey section is made.

[0004] The above phenomenon will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating an example of a piping system and a timing chart illustrating a reception timing of a reception signal based on a reflected sound wave in the piping system. The configuration for conducting a pipeline survey on the pipeline S shown in FIG. 9 is as follows. A plurality of branch parts D1, D2 for the main pipe S
Are connected to the branch pipes S1 and S2. In the above main pipe S, the reflection object is the joints L1, L2, the branch parts D1, D2, and the ends of the branch pipes S1, S2. An end corresponding to point A, which is one of the ends of the branch pipes S1 and S2 (hereinafter, this end is referred to as an end P1), constitutes a part of the sonic pipe investigation means. A speaker 1 and a microphone 2 are arranged. The numbers shown in the figure indicate the distance between the reflection targets. When the section of the pipeline including the ends P1 and P2 of the branch pipes S1 and S2 in such a pipeline is to be investigated, the sound wave transmitted from the end P1 of the branch pipe S1 is as shown in the timing chart. Received as a reflected sound wave. In the timing chart, the reflection signals from the respective reflection units corresponding to the reflection sources are arranged on the time axis in proportion to the distance to the reflection target. That is, in the pipeline shown in FIG. 9, the branch portion D1, the joint portions L1 and L2, the branch portion D2, and the other end point B different from the above point A among the end portions of the pipeline are equivalent. The reflected signal is obtained in the traveling order of the sound waves, such as the end of the branch pipe S2 (hereinafter, this end is referred to as an end P2). Note that reference numerals shown in the timing chart mean the reflection target in the above-described pipeline. However, the direction of the reflection source is not clear in the reception timing that appears in the timing chart. That is, the joints L1 and L2 are not located on the same side of the branch part D1 but in opposite directions. For this reason, there is a risk that it may be determined that the joints L1 and L2 are located in the same direction only by the reception timing that appears in the timing chart, and there is a problem that an accurate arrangement position cannot be determined. In other words, there is a risk that the joint L2 may be erroneously determined to be located in the survey target section. For this reason, it is necessary to classify whether the signal output from the sound collection means indicates a reflection target within or outside the section.

On the other hand, when a sound wave is transmitted into a pipeline, multiple reflections occur in the pipeline, and a multiple reflection signal due to the multiple reflection may appear on received data. For this reason, it is not possible to determine whether the signal is a reflection signal from an actual reflection target or a multiple reflection signal by simply determining the presence or absence of a reflection signal on the received data.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional pipeline survey system, the object of the present invention is to classify reflected signals from sound waves transmitted into the pipeline and to reflect the reflected signals from the object to be reflected inside or outside the section. It is another object of the present invention to provide a method for classifying a reflected signal, which can classify whether the signal is a signal or not, and which can classify a reflected signal from an actual reflection target object into a multiple reflected signal which tends to be confused.

[0007]

In order to achieve this object, according to the first aspect of the present invention, there is provided a sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe. The time from when the pulsed sound wave is transmitted to when the sound is collected after the pulsed sound wave is transmitted using a pipe line survey device having a sound collecting unit that collects the pulsed sound wave reflected in the pipe line from the sound velocity value In a sound wave type pipe line survey system for examining a situation inside a pipe line, when a pair of branch pipes are included in a pipe line to be investigated by the above survey system, a sound wave is transmitted from one end point A of the above section and obtained. A first step of storing received data relating to the reflected sound wave to be obtained, and changing the state of reflection at another end point B different from the above-mentioned end point A, and transmitting the sound wave from the above-mentioned end A to obtain a sound wave. A second step of storing received data related to the reflected sound wave; The received data obtained in the first and second steps are compared to specify the position of the other end B, and the sound wave of at least the other end B obtained from the received data is obtained. A third step of determining a propagation time;
A fourth step of storing reception data on reflected sound waves obtained by transmitting sound waves from the other end point B;
Of the received data obtained in the step, the time portion from the other end point B to the end point A obtained in the third step is extracted, and the received data in the time portion is temporally inverted. ,
A fifth step of converting the starting point to be the end point A and comparing the received data with the received data obtained in the first step. In the fifth step, at the same timing on the time axis, It is characterized in that it is determined that the obtained reception signal is from a reflection target located in a section from the end point A to the other end point B.

According to a second aspect of the present invention, there is provided a sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a pulsed sound wave reflected in the pipe at one end of the pipe. A sound wave type pipe line survey for investigating the state of the inside of a pipe from the time from when the above-mentioned pulsed sound wave is transmitted to when the sound is collected and a sound velocity value using a pipe line survey device having sound collecting means. In the system, when the pipeline section to be investigated by the survey system is a pipe that does not include a branch pipe, first data that stores received data related to a reflected sound wave obtained by transmitting a sound wave from one end point A of the section is stored. And a second step of changing a reflection state of another end point B different from the end A point and storing received data relating to a reflected sound wave obtained by transmitting a sound wave from the end A point. And the first and second
Comparing the received data obtained in the step
A third step of specifying the position of a point and obtaining the propagation time of the sound wave to at least the other end B point obtained from the received data; and transmitting the sound wave from the other end B point. A fourth step of storing the received data relating to the reflected sound waves to be received, and the received data obtained in the fourth step being converted from the other end B to the end A obtained in the third step. Of the time portion, and temporally inverts the received data of the time portion, converts the data so that the start point is the end point A, and compares the data with the received data obtained in the first step. The fifth step is that the received signal obtained at the same timing on the time axis is a reflection target located in a section including the end point A and the other end B point. Received from different objects and received at a different timing. Signal is characterized to determine the multiple reflection signal generated in a section including the said end point A and the other end point B.

According to a third aspect of the present invention, there is provided a sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a pulsed sound wave reflected in the pipe at one end of the pipe. A sonic pipe line survey for investigating the state of the inside of a pipeline from the time from when the above-mentioned pulsed sound wave is transmitted until the sound is collected and a sound velocity value using a pipeline survey device having sound collecting means. In a system including one branch point in a pipeline including one end point A and another end B point different from the end A point, the above end A point A first step of storing received data relating to a reflected sound wave obtained by transmitting a sound wave from the second step, and a second step of storing received data relating to a reflected sound wave obtained by transmitting a sound wave from the end point B;
A third step of specifying the branch portion from the received data obtained in the first and second steps, and comparing the received data obtained in the two steps with each other using the branch portion as a reference point for comparison; In the third step, the received signal obtained at the same timing with respect to the comparison reference point is a point A of the end and another end B different from the end A. It is characterized in that it is determined that the object is from a reflection target other than the section including the point.

According to a fourth aspect of the present invention, there is provided a sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a pulsed sound wave reflected in the pipe at one end of the pipe. A sonic pipe line survey for investigating the state of the inside of a pipeline from the time from when the above-mentioned pulsed sound wave is transmitted until the sound is collected and a sound velocity value using a pipeline survey device having sound collecting means. In the system, in the case of a pipeline including at least two branch portions in a pipeline including one end point A and another end B point different from the end A point, the end A A first step of storing received data relating to reflected sound waves obtained by transmitting a sound wave from a point, and a second step of storing received data relating to reflected sound waves obtained by transmitting a sound wave from the end point B.
And one of the branch portions is specified from the reception data obtained in the first and second steps, and the reception data obtained in both the steps is matched with one of the branch portions as a comparison reference point. And comparing the received data obtained in the first and second steps with the third step for comparison, and identifying the other of the branched parts, and using the other of the branched parts as a comparison reference point in the two steps. And a fourth step of matching and comparing the received data thus obtained. In the third step,
A received signal obtained at the same timing with respect to one of the branch portions, which is the comparison reference point, has a point A at one end and another point A different from the end A at one of the branches. It is determined that the light source is from a reflection target located in one of the sections other than the section including the end point B, and in the fourth step, the same as the other of the branch portions serving as the comparison reference points is determined. It is determined that the received signal obtained at the timing is from a reflection target outside the section including the point A of the end and the point B of the other end with the other of the branch portions as a boundary. It is characterized by.

The invention according to claim 5 is the invention according to claim 3 or 4.
In the invention described above, the specification of the branch portion serving as the comparison reference point is performed by storing first reception data relating to a reflected sound wave obtained by transmitting a sound wave from one end point A of the section.
And a second step of changing the reflection state of the other end point B different from the end point A, and storing reception data on reflected sound waves obtained by transmitting sound waves from the end point A. A third step of comparing the received data obtained in the first and second steps to specify the position of the other end B point, and transmitting a sound wave from the other end B point A fourth step of storing the received data relating to the reflected sound waves obtained by the above-mentioned method, and obtaining the received data obtained in the fourth step from the other end point B in the third step. The time part up to the point A is taken out, the received data of the time part is temporally inverted, converted so that the starting point is the end point A, and
And a fifth step of comparing the received data obtained at the same timing on the time axis and corresponding to the enlarged reflected sound wave in the fifth step. It is characterized as a signal from

According to a sixth aspect of the present invention, there is provided a method for classifying a reflected signal in a sound wave type pipeline survey system according to one of the first, second and fifth aspects, wherein the reflection state of the other end point B is determined. The change is performed by switching the open / close state of the other end B point.

According to a seventh aspect of the present invention, there is provided a method for classifying a reflected signal in a sonic pipe line survey system according to any one of the first, second and fifth aspects, wherein the reflection state of the other end point B is determined. The characteristic is changed by selecting the non-reflection state and the reflection state of the other end B point.

[0014]

According to the first aspect of the present invention, based on received data relating to a reflected sound wave by transmitting a sound wave from one end point A of the survey target section and another end B point different from the end A point. The propagation time portion of the sound wave between the two end portions is extracted, and the reception data regarding the reflected sound wave from the other end point B is inverted on the time axis within the propagation time portion of the extracted sound wave, and the data is inverted on the time axis. Is converted so that the start point of the end point is the same as one end point A. The reception data regarding the reflected sound waves from one end A point which is the same starting point on the time axis and another end B point different from this end A point are compared with each other, and the reception data obtained at the same timing is compared. It is determined that the signal is a signal from a reflection target located in the section from the end point A to the point B.

According to the second aspect of the present invention, when a pipe that does not include a branch pipe is to be inspected, a point A at one end of the section to be inspected and a point B at another end different from the end A are used. Extracting the propagation time portion of the sound wave between both ends based on the received data related to the reflected sound wave due to the sound wave transmission,
In the propagation time portion of the extracted sound wave, the received data related to the reflected sound wave from the other end point B is inverted on the time axis so that the start point in time is the same as one end point A. Convert. One end A that is the same starting point on the time axis
The received data regarding the reflected sound waves from the point and the other end point B different from the end point A are compared with each other, and the received signal obtained at the same timing is within the section from the end point A to the point B. It is determined that the signal is from the reflection object located,
It is determined that the signals received at different timings are multiple reflection signals generated in the section including the end points A and B.

According to the third aspect of the present invention, in the case of a pipeline including one branch portion between one end point A and another end B point which is different from the end A, from each of the ends, The received data regarding the reflected sound wave from the end point A and the received data regarding the reflected sound wave from the end point B are compared using the branch portion obtained with reference to the received data regarding the reflected sound wave as a comparison reference point. By the comparison, it is determined that the reception signal having the same timing is from the reflection target located outside the section between the end point A and the end point B.

According to a fourth aspect of the present invention, in the case of a pipeline including at least two branch portions between one end point A and another end B point different from the end A, each end A , The branch portion closest to each end is determined from the received data related to the reflected sound waves from point B, and located at the boundary between the section between the end point A and the end point B and the outside of the section. The data is translated and shifted on the time axis using the branch portion as a comparison reference point, and the reception signals whose reception timings match from the comparison reference point are located outside the section including the end points A and B. It is determined as being from the reflection target.

According to the fifth aspect of the present invention, the first and the fourth
Of the received data obtained in the step, the received data obtained in the fourth step is inverted on the time axis, and the same start point is set on the time axis as the first received data and compared. At the same timing on the time axis, and by considering the received signal corresponding to the enlarged reflected sound wave as a signal from the branching unit, the branching portion can be specified more simply than when only the enlarged reflected sound wave is selected. Can be done accurately.

According to the present invention, the phase of the reflected sound wave is inverted by switching to the open / close state at the end B, and the other end B can be easily identified by comparing received data. Can be.

According to the seventh aspect of the present invention, by eliminating the generation of the reflected sound wave at the end point B, the other end point B can be easily recognized by comparing the received data.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. In the drawings after FIG. 1, the same components as those shown in FIG. 9 are denoted by the same reference numerals. FIG. 1 is a schematic diagram showing a schematic configuration of a sound wave type pipeline inspection device used in a reflection signal classification method according to the present invention. In FIG. 1, a sound wave type pipeline inspection device 10 includes at least a speaker 11 as a sound generator. , A microphone 12 as a sound collecting means, a CPU 13 as a control unit, a display 14,
A converter 15, amplifiers 16 and 17, and A / D converter 1
8 is provided. In addition, in addition to the above-described members, the sound wave type pipe line survey device 10 may also use a sound speed correction unit or the like for changing a sound speed value that changes depending on the pipe temperature, the type of pipe gas, and the temperature. The display 14 is C
Devices that can visually observe the reception timing of reflected sound waves, such as an RT monitor, an LED display panel, a liquid crystal display, a plasma display, and electroluminescence, are used.

On the other hand, a pipe using the above-described sonic pipe line survey device 10 has branch portions D1 and D2 shown in FIG. 9, and has two branch portions, in other words, a pipe including a pair of branch pipes. Roads are targeted. The following steps are performed to determine the reflection signal in the section including the ends P1 and P2 of the pipeline S using the above-described acoustic pipeline inspection device 10. The reference numerals shown in the timing chart described later correspond to the reference numerals of the branch pipe, the branch portion, and the joint in the pipeline S shown in FIG.

(1) First Step In this step, an end P1 of the branch pipe S1 corresponding to one of the ends (point A) of the pipe S (hereinafter, this end is represented by a symbol P1). And a received signal corresponding to the reflected sound wave is stored as data. That is, in FIG. 2, a speaker 11 forming a part of the sonic type pipe line survey device 10 and a microphone 12 in front of the speaker 11 are arranged at an end P1 of the branch pipe S1 in the pipe S, respectively.
1 transmits a pulsed sound wave. The sound wave transmitted from the speaker 11 is collected by the microphone 12 at the timing shown in the timing chart of FIG. 2 in the same order as described in FIG. 9, and a reception signal is obtained.

(2) Second Step In this step, a sound wave is transmitted from the end P1 of the pipe S, and the end of the branch pipe S2 corresponding to an end (point B) at a position different from the end P1. The state of reflection is changed by opening and closing P2 (hereinafter, this end is represented by reference numeral P2), and received data relating to the reflected sound wave is stored.

(3) Third Step In this step, the received data obtained in the first step and the second
And the position of the end P2 is specified from the reflection signal whose phase is inverted as shown in FIG. 3 based on the change in the reflection state among the reflection signals. . When the position of the end P2 is specified, the propagation time of the sound wave to that position is obtained.

(4) Fourth Step In this step, a sound wave is transmitted from the end P2 specified in the third step, and received data on the reflected sound wave is stored. In carrying out this step, as shown in FIG. 4, the speaker 11 and the microphone 12 of the sonic pipe line survey device 10 are arranged at the end P2 of the branch pipe S2. As is apparent from the timing chart shown in FIG.
1, the branch portion D1, the joint portion L2, and the end portion P1 of the branch pipe S1 are reflected in the traveling order of the sound waves, and a received signal corresponding to the reflected wave is obtained as data.

(5) Fifth Step In this step, the time portion up to the end P2 obtained in the third step is extracted from the timing data of the received signal obtained in the fourth step, The received data of the portion is temporally inverted, and the inverted data is compared with the timing data obtained in the first step. That is, as shown in FIG. 5, the reception timing (the timing chart shown in FIG. 4) of the reflected sound wave obtained in the fourth step is temporally shifted by the end P1 side as shown in the lower part of FIG. Invert the start point and the end point on the time axis so as to be the start point for observation, and use the same time axis progress condition as the first step,
For the section from the end P1 to the end P2, a comparison is performed to determine the reflection target in the section. In the inversion operation in this case, the input timing of the received signal related to the reflected sound wave is used as data, and a change in the phase of the signal is ignored. In the comparison, the reception signals existing at the same timing are from the reflection target located in the pipeline including the branch pipes S1 and S2 respectively provided from the end P1 to the end P2 in the pipeline S. Is determined. The reason is as follows.

In FIG. 2, the reflected sound wave in the section from the end P1 including the branch pipes S1 and S2 to the end P2 is:
It is obtained according to the distance between the reflection object corresponding to the reflection source and the sound collecting means 12. In other words, when the reflection target is positioned at a distance as shown in FIG. 2, the time until the sound wave transmitted from the end P1 is reflected by each part and collected, and the sound wave transmitted from the end P2. This is different from the time required for reflected sound waves to be collected at each part. By setting the reception timing of the reflected sound wave by transmitting the sound waves from the ends P1 and P2 to the same starting point on the timing, as shown in FIG. 5, the reflection target is reflected in the section of the pipeline from the ends P1 to P2. If there is an object, the reception timing of the sound wave matches. Thereby, it can be determined that the reflection target object corresponding to the coincident reception timing is located in the section between the ends P1 and P2.

Next, an embodiment of the present invention will be described. The invention according to claim 2 is the one end A of the pipeline.
It is based on the premise that no branch pipe is included in the pipeline from the point to the other end B point different from the end A point,
FIG. 6 shows a schematic diagram of the pipeline S 'and a timing chart showing the reception timing of the reflected signal in the pipeline. The numbers in FIG. 6 indicate the distance (the number indicated by the suffix m) and the output timing (the number indicated by the suffix s) of the reflection signal output from the sound collecting means. This means that the sound speed is 5 m / s.

The embodiment shown in FIG. 6 is characterized in that a multiple reflection signal due to multiple reflection in a pipe line not including a branch pipe is distinguished from a reflection signal from an object to be reflected in the pipe line. In FIG. 6, between an end P3 corresponding to one (point A) of the ends of the conduit S 'and an end P4 corresponding to another end (point B) different from the end P3. When the reflection target L3 exists, the sound generating means and the sound collecting means of the sound wave type pipe line survey device 10 are arranged at the end P3, and the sound waves transmitted from the sound generating means are collected by the sound collecting means. The timing at which the reflection signal is output corresponds to the time for the sound wave to reciprocate the distance to the reflection target L3 and the other end P4, as shown in the timing chart shown in the lower part of FIG. On the other hand, when multiple reflections occur between the reflection target L3 and the sound generator in the pipeline S ′ shown in FIG. 6, a multiple reflection signal due to the multiple reflections appears on the received data. That is, as an example, if multiple reflections occur between the sounding means disposed at the end P3 and the reflection target L3, and if the number of reciprocations of the sound waves due to the multiple reflections is two, the reception data of The time obtained by multiplying the reciprocating time between one end P3 and the reflection target L3 by the number of reciprocations (2) of the sound wave by reflection (FIG. 6)
A multiple reflection signal is obtained at the time point (timing position indicated by 4s in (A)). When such a multiple reflection signal is generated, it is difficult to determine the classification of the signal on the received data, and therefore, there is a possibility that the multiple reflection signal is erroneously determined to be from a reflection target in that section. .

Therefore, in this embodiment, the multiple reflection signal is determined by the following procedure. End (corresponding to P3 in the figure) corresponding to one of the ends (point A) in the conduit S '
The first step of storing the received data of the sound wave signal according to the reflection of the sound wave transmitted from the terminal P3 corresponds to another end (point B) different from the end P3 due to the transmission of the sound wave from the end P3. A second step of changing the reflection state at the end (hereinafter, denoted by reference numeral P4 in the drawing) and storing the reception data regarding the reflected sound wave, and comparing the reception data obtained in the first and second steps. The third step of determining the position of the end P4 and determining the propagation time of the sound wave to that position, the sound wave transmitted from the end P4 and reflected by the pipe S 'from the end P4 to the end P3 A fourth step of storing the received data relating to the end part P3 obtained in the third step.
A fifth part in which a time portion in which the sound wave propagates from the end to the end P4 is taken out, temporally inverted, converted so as to coincide with the end P3, and the received data obtained in the first step is compared. Each step is performed. In the fifth step, it is determined that the received signals obtained at the same timing are from the reflection target in the section, and the signals obtained at different timings are determined as the multiple reflection signals due to the multiple reflection. It has become.

Hereinafter, the determination method will be described. FIG. 6B is a timing chart of the received data when the above-described fourth step is performed. In this step, the received data from the end P4 of the pipeline S ′ is stored. FIG.
(C) is a timing chart of the received data when the fifth step is performed. The upper timing chart is a timing chart relating to the reflected signal of the sound wave transmitted from the end P3, and the lower timing chart is Is obtained by temporally inverting the timing chart relating to the reflected signal of the sound wave transmitted from the end P4 and converting the start point on the time axis to the end P3. FIG. 6 (C)
In, when the same start point is set on the time axis and the reception timing of the reflection signal is compared with the end P3 as a reference, the reflection signal from the reflection target L3 that actually exists in the section of the pipeline S ′ is: Appear at the same timing. Therefore, reflected signals appearing at different timings can be determined to be multiple reflected signals due to multiple reflections occurring in the section of the pipeline S ′.

According to the present embodiment, the reflected signal in the pipe can be classified into a multi-reflected signal due to multiple reflection and a reflected signal from an existing reflecting object. Accurate determination can be made without erroneous determination.

Next, a third embodiment will be described. The invention according to claim 3 is a method for producing a section corresponding to a section between one end A and another end B different from the end A in the case of a pipeline including one branch. It is characterized in that a signal from an external reflection target can be determined. FIG. 7 shows a schematic diagram of a pipe in the case where a branch pipe S1 is provided in a part of the pipe S, and received data relating to reflected sound waves for this pipe. An end (hereinafter, this end is referred to as an end P1) corresponding to one of the ends (point A) of the pipe S with the branch portion D of the branch pipe S1 as a boundary, and in FIG.
(A) is added to an end (point B) corresponding to another end (point B) different from the end P1 (hereinafter referred to as an end P2, and in FIG. 7, (B) is added). The following first to third steps are executed in order to determine the reflection target existing outside the section (for convenience, indicated by reference numeral Z0).

(1) First Step In this step, a sound wave is transmitted from the end P1 of the pipe S, and a received signal corresponding to the reflected sound wave is stored as data. That is, a speaker 11 forming a part of the sound wave type pipeline inspection device 10 and a microphone 12 are arranged in front of the speaker 11 at an end P1 of the pipeline S, and the speaker 11 emits pulsed sound waves. As shown in FIG. 7B, the sound wave transmitted from the speaker 11 is collected by the microphone 12 at a timing according to the propagation order of the sound wave, and a reception signal is obtained.

(2) Second Step In this step, the reception data relating to the reflected sound wave due to the transmission of the sound wave from the other end P2 different from the end P1 is stored. That is, FIG. 7A
The same sound wave type pipeline survey device 10 as shown in FIG. 1 is arranged, and a pulsed sound wave is transmitted from the speaker 11. Speaker 11
As shown in FIG. 7C, the sound wave transmitted from the microphone 12 is collected by the microphone 12 at a timing according to the propagation order of the sound wave, and a received signal is obtained.

(3) Third Step In this step, the propagation time of the sound wave from the received data obtained in the first and second steps to the branch part D is obtained. That is, the reflected sound waves obtained in the second step are in the order of the branch portion D, the joint portion L1, the joint portion L2, and the end portion P1, as shown in FIG. 7D. For this reason, on the reception data regarding the reflected sound wave from the end portion P2, the reflected sound wave from the enlarged diameter portion is regarded as the reflected sound wave from the branched portion D, and the reception timing at which the reflected sound wave from the branched portion D is obtained is determined. The first reference point
And the received data in the second step are compared. That is,
In the pipeline S shown in FIG. 7A, since the object to be reflected (L2) located outside the section (Z0) between the end P1 and the end P2 is to be determined, the branch D is used as a reference. given that,
Regardless of the transmission of the sound waves from the end portions P1 and P2 at different positions, the reciprocating time of the sound wave from the branch portion D to the reflection target L2 located outside the target section pipeline (with the branch portion D in FIG. The time during which the sound wave reciprocates over the distance to the reflection target L2) is the same. Accordingly, the reception data obtained in the first step (data having the end P1 as a sound generating section) and the reception data obtained in the second step (reception data having the end P2 as a sound generating section) are divided into two parts. It can be determined that the received signal having the coincident timing with the reference to the reception timing of D is the reflection target located outside the section. In this embodiment, FIG.
As is clear from the timing chart shown in (D),
With respect to the reception data obtained in the first step, the branch portion D in the reception data obtained in the second step is translated and shifted on the time axis so as to be a starting point for comparing reception timings. The start points on the time axis are matched, and the received signals generated at the same timing are observed. In this case,
Time from the branch portion D to the joint portion L2 (in the figure, for convenience,
(The propagation time of the sound wave between the reflecting members is indicated by a numeral using the distance)), so that the joint L2 can be determined as a reflection target (L2) located outside the section.

Next, an embodiment of the present invention will be described. The invention according to claim 4 is a reflective object located outside the section when at least two branch portions are included between one end point A and another end B point different from the end A point. Is characterized by being able to determine the presence of FIG. 8 shows an end (hereinafter, referred to as an end A) corresponding to one end A point.
This end portion is denoted by reference numeral P1) and branches from the end portion P1 to an end portion corresponding to an end point B (hereinafter, this end portion is denoted by reference numeral P2) via two branch portions. Tube S
1, a schematic view of a pipeline S having S2 and received data on reflected sound waves in the pipeline S are shown. In the pipe line S shown in FIG. 8, a first pipe including branch pipes S1 and S2 is provided.
And a second section (for convenience, a section located on the right side of the branch section D1) corresponding to one of sections other than the first section Z1 with the branch section D1 as a boundary. A third section corresponding to the other of the sections other than the first section Z1 with the boundary indicated by the reference sign Z2) and the branch portion D2.
(For convenience, a section located on the left side of the branch portion D2 is indicated by a symbol Z3). In the present embodiment, first, the reflection target L2 located in the second section that is outside the section of the first section Z1 and the third object that is not shown but is outside the other section with respect to the first section Z1. Section Z3
Is determined. Hereinafter, the determination method will be described.

In the determination method of this embodiment, the following first to fourth steps are performed. (1 ′) First Step In this step, a branch pipe S corresponding to one end of the pipe S
A sound wave is transmitted from one end P1, and a received signal corresponding to the reflected sound wave is stored as data. In other words, the speaker 1 forming a part of the sonic pipe line survey device 10 is provided at the end P1 of the branch pipe S1 corresponding to one of the ends (point A) of the pipe S.
1 and a microphone 12 are arranged in front of the microphone 1, and pulse-like sound waves are transmitted from the speaker 11. The sound wave transmitted from the speaker 11 is collected at the timing shown in FIG. 8B and is obtained as a reception signal.

(2 ') Second Step In this step, a sound wave is transmitted from an end P2 other than one of the ends (P1) of the pipe S, and a received signal corresponding to the reflected sound is stored as data. I do. In other words, the end P2 of the branch pipe S2 corresponding to one other than one of the ends (point A) in the pipe S
On the other hand, a speaker 11, which is a part of the above-mentioned sound wave type pipeline survey device 10, and a microphone 12 are arranged in front of the speaker 11, and the speaker 11 emits pulsed sound waves. The sound wave transmitted from the speaker 11 is shown in FIG.
Sound is collected at the timing shown in (C) and is obtained as a received signal.

(3 ') Third Step In this step, the position of the branch D1 is specified, and the received data obtained in the first and second steps are compared using the position of the branch D1 as a comparison reference point. Then, the reflection target whose reception timing is matched is outside the first section Z1, that is, the branching section D1.
Is determined as a reflection target located in a second section Z2 corresponding to a section outside the first section Z1 with. When specifying the position of the branch portion D1 to make such a determination, the characteristics (for example, the shape and size of the waveform) of the reflected sound wave from the branch portion are stored in advance, and the characteristics correspond to the characteristics. The branching part is specified by selecting a reflected sound wave to be performed. When the branch portion D1 is used as a comparison reference point, the end portions P1 at different positions from each other,
Regardless of the transmission of the sound wave from P2, the reciprocating time of the sound wave from the branch portion D1 to the reflection target L2 located in the second section Z2 matches, so that the reception signal having the matching timing is the second signal. It can be determined that the object is a reflection target located in the section Z2, that is, outside the section of the first section Z1.
In the present embodiment, as is apparent from the timing chart shown in FIG. 8C, the branching unit D1 in the reception data obtained in the second step is compared with the reception data obtained in the first step by the reception timing. Are shifted in parallel on the time axis so as to be a starting point for comparing the received signals, and the received signals generated at the same timing are observed. In this case, the time from the branch portion D1 to the joint portion L2 (in the figure, for convenience, the moving time of the sound wave between the respective reflecting members is indicated by a number using a distance), so that this time is equal. The joint L2 is determined as a reflection target located in the second section Z2.

(4 ') Fourth step In this step, the same processing as in the third step is performed by comparing the received data obtained in the first and second steps with the branch part D2 as a comparison reference point. Then, the reflection target located in the third section Z3 corresponding to the outside of the first section Z1 having the branch portion D2 as a boundary is determined. According to this embodiment, by only a simple operation of shifting by translating the reception timing of the reflected signal even when the number of branch pipes is increased on the time axis, it is possible to determine the presence of a reflection object .

Next, a fifth embodiment of the present invention will be described. The invention according to claim 5 provides the above-described claim 3,
According to the fourth aspect of the present invention, it is possible to specify the branch portion as the comparison reference point not only by the characteristics (for example, the shape and size of the waveform) of the reflected sound wave from the portion but also by the reception timing. Features. That is,
As an embodiment of the invention described in claim 5, the following steps which are the first to fifth steps are used. (1 ″) First Step In this step, from the end P1 of the branch pipe S1 corresponding to one of the ends (point A) of the pipe S (hereinafter, this end is represented by a symbol P1) A sound wave is transmitted, and a received signal corresponding to the reflected sound wave is stored as data. That is, in FIG. 2, a speaker 11 forming a part of the sonic type pipe line survey device 10 and a microphone 12 in front of the speaker 11 are arranged at an end P1 of the branch pipe S1 in the pipe S, respectively.
1 transmits a pulsed sound wave. The sound wave transmitted from the speaker 11 is collected by the microphone 12 at the timing shown in the timing chart of FIG. 2 in the same order as described in FIG. 9, and a reception signal is obtained.

(2 '') Second Step In this step, a sound wave is transmitted from the end P1 of the pipe S, and a branch pipe S2 corresponding to an end (point B) different from the end P1 is formed. The reflection state is changed by opening and closing the end portion P2 (hereinafter, this end portion is represented by reference numeral P2), and received data relating to the reflected sound wave is stored.

(3 ″) Third Step In this step, the received data obtained in the first step and the second
And the position of the end P2 is specified from the reflection signal whose phase is inverted as shown in FIG. 3 based on the change in the reflection state among the reflection signals. . When the position of the end P2 is specified, the propagation time of the sound wave to that position is obtained.

(4 '') Fourth Step In this step, a sound wave is transmitted from the end P2 specified in the third step, and received data relating to the reflected sound wave is stored. In carrying out this step, as shown in FIG. 4, the speaker 11 and the microphone 12 of the sonic pipe line survey device 10 are arranged at the end P2 of the branch pipe S2. As is apparent from the timing chart shown in FIG.
1, the branch portion D1, the joint portion L2, and the end portion P1 of the branch pipe S1 are reflected in the traveling order of the sound waves, and a received signal corresponding to the reflected wave is obtained as data.

(5 ″) Fifth Step In this step, a time portion up to the end P2 obtained in the third step is extracted from the timing data of the received signal obtained in the fourth step. The received data in the time portion is temporally inverted, and the inverted data is compared with the timing data obtained in the first step. That is, as shown in FIG. 5, the reception timing (the timing chart shown in FIG. 4) of the reflected sound wave obtained in the fourth step is temporally shifted by the end P1 side as shown in the lower part of FIG. Invert the start point and the end point on the time axis so as to be the start point for observation, and use the same time axis progress condition as the first step,
For the section from the end P1 to the end P2, a comparison is performed to determine the reflection target in the section. In the inversion operation in this case, the input timing of the received signal related to the reflected sound wave is used as data, and a change in the phase of the signal is ignored, but the characteristics of the reflected sound wave at the branching section (for example, The magnitude is stored, and attention is paid to the received signal corresponding to the characteristic of the reflected sound wave, and further, to the received signal obtained at the same timing on the time axis. When attention is paid to the characteristics of the reflected sound waves and the reception timing, as is apparent from FIG. 5, the reception signals existing at the same timing are branched pipes S1 and S2 respectively provided between the ends P1 and P2 in the pipe S and Branch pipe S
1, a reflection object (D1, D2) located in a pipeline including S2.
2, L1) is obtained, and the reflection target (L2) located outside the pipeline including these ends P1, P2 can be excluded. Therefore, the reflection object (L1) is added by further adding the characteristics of the reflected sound wave in the pipeline including the ends P1 and P2 and the positional relationship of the reflection object (D1, D2, L1) as determination conditions. Can be excluded,
It is possible to determine that the remaining received signal is from the branch units D1 and D2.

In each of the above embodiments, the reflection state of the end P2 which is the other end (point B) different from the end P1 which is one (point A) of the ends of the pipeline. The example in which the open / closed state is switched is given as an example of changing, but the present invention is not limited to this, and the reflection state is changed by selecting the non-reflective state and the reflective state at the other end (point B). You may. In this case, in order to achieve a non-reflection state, a configuration or the like that can cancel a sound wave by transmitting a sound wave having an opposite phase to a sound wave from a glass wool, a muffler, or a sound generating unit is selected. As described above, in the change of the reflection state by selecting the non-reflection state and the reflection state, the case where the reception signal appears on the reception data regarding the reflection sound wave obtained by the transmission of the sound wave from the end and the case where the reception signal does not appear Since it is possible to classify, it is possible to specify the position of the end whose reflection state is changed from the timing when the state change occurs.

[0049]

According to the first aspect of the present invention, the reception timing of the reflected signal of the sound wave transmitted from the end point A, which is one of the ends, and the other end different from the end A point. Reception data on the reflected sound wave of the sound wave transmitted from the point B is inverted on the time axis and received by a simple process of converting the start point on the time to be the same as one end point A. It is possible to easily determine that the received signal obtained at the same timing between the data is a reflection target located in the section from the end point A to the end point B.

According to the second aspect of the present invention, when a survey using a sound wave is performed on a pipe that does not include a branch pipe, a multiple reflection signal due to multiple reflections generated in the pipe and a reflection from the object to be reflected. Since it is possible to classify the reflected signal by the sound wave, it is possible to accurately determine the presence or absence of the reflection target.

According to the third aspect of the present invention, in the case of a pipe including one branch between one end A and another end B different from the end A, the branch By setting a comparison reference point between the received data regarding the reflected sound waves obtained by transmitting the sound waves from the end points A and B, and comparing the data, the position outside the section between the end points A and B is determined. Can be determined to be from the reflection target located at. This makes it possible to accurately determine the reflected sound waves from outside the section even when the reflected sound waves are generated from the inside and outside of the section at the branch point.

According to the fourth aspect of the present invention, in the case of a pipe including at least two branch portions between one end A and another end B different from the end A, the end A And a branch section located at the boundary between the pipeline connecting the other end point B and a pipeline adjacent to this pipeline, and using the assumed reception timing of the branch section as a comparison reference point. Only by comparing the received data regarding the reflected sound waves from the end points A and B, it is possible to classify the reflection signals from the reflection target located outside the section connecting the end points A and B. . Thus, even when there are a plurality of branch portions, it is possible to accurately determine the reflected sound waves from outside the section.

According to the fifth aspect of the present invention, the reception data concerning the reflected sound wave by transmitting the sound wave from one point A of the end obtained in the first step, and the end part obtained in the fourth step. Of the received data of the reflected sound wave transmitted from the other end point B other than the point A, the reception data obtained in the fourth step is inverted on the time axis to obtain the first data. By setting the same start point on the time axis with the received data and comparing them, at the same timing on the time axis, and by regarding that the received signal corresponding to the enlarged reflected sound wave corresponds to the branch portion, The branching portion can be specified more accurately than when only the enlarged reflected sound wave is selected.

According to the sixth aspect of the present invention, by switching to the open / closed state at the end point B, the phase of the reflected sound wave is inverted so that the end part can be easily identified when comparing received data. The reflected signal can be handled accurately.

According to the seventh aspect of the present invention, by eliminating the generation of the reflected sound wave at the end B, the end can be easily identified when comparing the received data with each other. Can be done accurately.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining an apparatus used in a method for classifying reflected signals according to the first aspect of the present invention.

FIG. 2 is a schematic diagram of a pipeline to be investigated in which the reflected signal classification method according to the first embodiment is implemented, and a reception timing of a reflected sound wave obtained when the first step is performed in the pipeline. It is a timing chart for explaining.

FIG. 3 is a timing chart for explaining a reception timing of a reflected sound wave when a reflection condition is changed in the reflected signal classification method according to the third aspect of the present invention.

FIG. 4 is a schematic diagram of a pipeline showing a configuration for performing a third step in the reflected signal classification method according to the first embodiment of the present invention, and a description will be given of a reception timing of a reflected sound wave obtained from the pipeline. FIG.

FIG. 5 is a timing chart for explaining a fourth step in the reflected signal classification method according to the first embodiment;

FIG. 6 is a schematic diagram of a pipeline for explaining an embodiment of the invention described in claim 2, and a timing chart showing a reception timing of a reflected signal obtained in the pipeline.

FIG. 7 is a schematic diagram of a pipeline for explaining an embodiment of the invention described in claim 3, and a timing chart showing reception timing obtained by the pipeline.

FIG. 8 is a schematic diagram of a pipeline for explaining an embodiment of the invention described in claim 4, and a timing chart showing reception timing obtained by the pipeline.

FIG. 9 is a timing chart illustrating an example of a pipeline and a reception timing of a sound wave signal obtained when a part of the pipeline is set as a survey target section.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 sound wave type pipeline investigation device 11 sound generation means 12 sound collection means S pipeline S1, S2 branch pipe D, D1, D2 branch part L1, L2 joint part P1 end P2 corresponding to one end (A) point P2 An end corresponding to another end (B) point different from the end P1 Z1 A first section Z2 A second section corresponding to outside the first section Z3 A third section corresponding to outside the first section

Claims (7)

[Claims] 1. A sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a sound collecting means for collecting a pulsed sound wave reflected in the pipe at one end of the pipe. A sound wave type pipe line survey system for examining the state of the inside of the pipe line from the time from the transmission of the pulsed sound wave to the collection of sound using the provided pipe line survey device and the sound velocity value, In the case where a pair of branch pipes are included in the pipeline to be investigated by the first method, a first step of storing reception data regarding reflected sound waves obtained by transmitting a sound wave from one end point A of the section; A second step of changing the reflection state of another end point B different from the point and storing received data relating to a reflected sound wave obtained by transmitting a sound wave from the end point A; Compare the received data obtained in step 2 A third step of determining the position of the end B point of the above, and obtaining the propagation time of the sound wave to at least the other end B point obtained from the received data; A fourth step of storing reception data relating to the reflected sound waves obtained by transmission; and obtaining the reception data obtained in the fourth step from the other end point B in the third step. The time portion up to the point A is extracted, the received data of the time portion is temporally inverted, converted so that the starting point is the end point A, and compared with the received data obtained in the first step. In the fifth step, the received signal obtained at the same timing on the time axis is shifted from the end A to the other end B.
A reflection signal classification method in a sound wave type pipeline survey system, wherein the reflection signal is determined as being from a reflection target object located in a section up to a point. 2. A sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a sound collecting means for collecting a pulsed sound wave reflected in the pipe at one end of the pipe. A sound wave type pipe line survey system for examining the state of the inside of the pipe line from the time from the transmission of the pulsed sound wave to the collection of sound using the provided pipe line survey device and the sound velocity value, A first step of storing received data on reflected sound waves obtained by transmitting a sound wave from one end point A of the section when the pipeline section to be investigated by the method does not include a branch pipe; A second step of changing the reflection state of the other end point B different from the point A and storing received data relating to a reflected sound wave obtained by transmitting a sound wave from the end point A; Compare the received data obtained in the second step A third step of specifying the position of the other end B point and obtaining the propagation time of the sound wave to at least the other end B point obtained from the received data; A fourth step of storing reception data relating to reflected sound waves obtained by transmitting the sound waves, and the reception data obtained in the fourth step being obtained in the third step from the other end B point. The time portion up to the end A is taken out, the received data in the time portion is temporally inverted, converted so that the start point is the end A, and the received data obtained in the first step is obtained. In the fifth step, the reception signal obtained at the same timing on the time axis includes a section including the end point A and the other end point B. Is determined to be from a reflective object located within A reflected signal classification in a sound wave type pipeline survey system, wherein a received signal transmitted is determined as a multiple reflection signal generated in a section including the end point A and the other end point B. Method. 3. A sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a sound collecting means for collecting a pulsed sound wave reflected in the pipe at one end of the pipe. In a sound wave type pipe line survey system for examining the state of the inside of a pipe line from the time from when the above-mentioned pulsed sound wave is transmitted to when the sound is collected and the sound velocity value using a pipe line survey device provided, In the case of a pipeline including one point A and another branch point B which is different from the end A point, a sound wave is transmitted from the end A point. A first step of storing received data relating to the obtained reflected sound wave; a second step of storing received data relating to the reflected sound wave obtained by transmitting the sound wave from the end point B; and the first and second steps. Identify the above branch from the received data obtained in the process, and A third step of comparing the received data obtained in the two steps as a comparison reference point, and comparing the received data with each other. In the third step, the reception data obtained at the same timing with respect to the comparison reference point is provided. The sound wave type tube is characterized in that it is determined that the signal is from a reflection target other than a section including one point A of the end and another end B different from the end A. Classification method of reflected signal in road survey system. 4. A sound generating means for transmitting a pulsed sound wave from one end of a pipe into the pipe, and a sound collecting means for collecting a pulsed sound wave reflected in the pipe at one end of the pipe. In a sound wave type pipe line survey system for examining the state of the inside of a pipe line from the time from when the above-mentioned pulsed sound wave is transmitted to when the sound is collected and the sound velocity value using a pipe line survey device provided, In the case of a pipeline including at least two branch portions in a pipeline including one point A and another end B point different from the end A point, a sound wave is transmitted from the end A point. A first step of storing received data relating to reflected sound waves obtained by the above, a second step of storing received data relating to reflected sound waves obtained by transmitting a sound wave from the end point B, and the first and second steps Identify one of the above branches from the received data obtained in step A third step of comparing the received data obtained in the two steps with each other using one of the branch parts as a comparison reference point, and comparing the received data obtained in the first and second steps with the branch A fourth step of identifying the other of the parts and comparing the received data obtained in the two steps with matching using the other of the branched parts as a comparison reference point. A received signal obtained at the same timing with respect to one of the above-mentioned branch portions as a reference point is a point A at one of the above-mentioned ends and another end different from the above-mentioned point A at one of the above-mentioned branch portions as a boundary. It is determined that it is from a reflection target located in one of the sections other than the section including the point B, and in the fourth step, at the same timing with respect to the other of the branch portions serving as the comparison reference points. The obtained received signal is A reflection in a sound wave type pipe line survey system, wherein the reflection is determined to be from a reflection target object outside a section including one end point A and another end point B with the other end as a boundary. Signal classification method. 5. The invention according to claim 3 or 4, wherein the branch portion serving as the comparison reference point is specified by receiving data relating to a reflected sound wave obtained by transmitting a sound wave from one end point A of the section. A first step of storing the reflected data of the reflected sound wave obtained by transmitting the sound wave from the end point A by changing the reflection state of the other end point B different from the end point A. A second step of storing; a third step of comparing the received data obtained in the first and second steps to specify the position of the other end B; and the other end B A fourth step of storing received data relating to reflected sound waves obtained by transmitting sound waves from a point; and receiving data obtained in the fourth step in the third step from the other end B point. The time portion up to the end point A thus obtained is extracted, and the reception data of the time portion is obtained. A fifth step of inverting the data in time, converting the start point to be the end point A, and comparing the received data with the received data obtained in the first step. A received signal obtained at the same timing on the time axis and corresponding to an enlarged reflected sound wave is regarded as a signal from a branch portion, and a reflected signal classification method in the sound wave type pipeline inspection system. 6. The reflection signal classification method in the sonic pipe line survey system according to claim 1, wherein the reflection state of the other end B is determined by using the other end B. A reflected signal classification method in a sound wave type pipeline inspection system, wherein the reflected signal is changed by switching between open and closed states of points. 7. The reflection signal classification method in the sonic pipeline inspection system according to claim 1, wherein the reflection state of the other end B is determined by using the other end B. A reflected signal classification method in a sound wave type pipeline survey system, wherein the method is changed by selecting a non-reflection state and a reflection state of a point.