JP2017020864A - Apparatus and method for irradiating and detecting electromagnetic wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave irradiation/detection apparatus capable of minimizing an increase in measurement-related work or false detection of defects, which may be caused by a process of removing reflected waves reflected by a surface of a structure and a direct wave from an electromagnetic irradiation unit from an electromagnetic wave received by an electromagnetic detection unit.SOLUTION: An electromagnetic wave irradiation/detection apparatus comprises a transmitter unit for irradiating a structure with an electromagnetic wave, a receiver unit for receiving reflected waves of the electromagnetic wave, and a detection unit configured to detect the presence or absence of defects in the structure on the basis of the reflected waves. One of the transmitter unit and the receiver unit is set up at a location away from the surface of the structure, and the other is set up in contact with the structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electromagnetic wave irradiation / detection device and an electromagnetic wave irradiation / detection method, and more particularly to an electromagnetic wave irradiation / detection device and an electromagnetic wave irradiation / detection device for detecting the presence / absence of a defect inside a structure and the position of the defect from a position away from the surface of the structure. It relates to a detection method.

  In concrete structures such as bridges and tunnels, defects such as cracks and cavities occur due to aging. If these defects are left unattended, the structure itself may be destroyed or collapsed. Therefore, it is required to grasp and repair defects early.

  As techniques for nondestructively detecting the presence or absence of defects inside a structure, there are Patent Documents 1 to 6. These techniques utilize the property that microwave or millimeter wave electromagnetic waves pass through a dielectric material such as concrete forming a structure. The electromagnetic wave irradiation / detection device described in Patent Documents 1 to 6 irradiates the structure with electromagnetic waves and detects the electromagnetic waves reflected by the defects inside the structure, thereby determining the presence / absence of defects inside the structure and the positions of the defects. Detect nondestructively.

  Patent document 1 is disclosing the electromagnetic wave irradiation and detection apparatus with which it is equipped in the position away from the structure surface. The electromagnetic wave detection device described in Patent Document 1 receives an electromagnetic wave reflected by a structure surface and internal defects. Therefore, the electromagnetic wave detection device described in Patent Document 1 compares the waveform of the received reflected wave with the waveform of the reflected wave when there is no defect inside the structure, so that the reflected wave on the surface of the structure is obtained from the received waveform. Remove.

  Patent Documents 2 and 3 disclose electromagnetic wave irradiation / detection devices that move on the surface of a structure. The electromagnetic wave detection devices described in Patent Documents 2 and 3 receive an electromagnetic wave reflected by a structure surface and internal defects and a direct wave of the electromagnetic wave irradiated by the electromagnetic wave irradiation device. Therefore, the electromagnetic wave detection devices described in Patent Documents 2 and 3 subtract the average value of the received waveform at a plurality of positions from the received waveform, thereby causing an unnecessary signal to be reflected on the surface of the structure and a direct wave from the electromagnetic wave irradiation device. Remove.

  Patent Documents 4 and 5 disclose an electromagnetic wave irradiation / detection device that irradiates a structure with electromagnetic waves at an incident angle φ and receives electromagnetic waves irregularly reflected by defects inside the structure. Here, the reflected wave on the surface of the structure is reflected in the opposite direction to the electromagnetic wave irradiation device with the same reflection angle φ as the incident angle φ by specular reflection. Since the electromagnetic wave detection devices described in Patent Documents 4 and 5 are set so as not to receive the reflected wave on the surface of the structure, only the reflected wave irregularly reflected by a defect inside the structure is received.

  Patent Document 6 discloses an electromagnetic wave irradiation / detection device in which the polarization direction of the antenna is different between the electromagnetic wave irradiation device and the electromagnetic wave detection device. Here, the electromagnetic wave reflected on the surface of the structure is specularly reflected, and thus is in the same polarization state as before being reflected. Therefore, the electromagnetic wave detection device does not receive the electromagnetic wave reflected by the structure surface. On the other hand, the electromagnetic waves reflected by the defects inside the structure are irregularly reflected, and thus are in a polarization state different from that before reflection. For this reason, the electromagnetic wave detection apparatus described in Patent Document 6 receives only the electromagnetic waves irregularly reflected by defects inside the structure.

JP 2005-233783 A JP 2007-033145 A JP 2008-039429 A JP 2007-121230 A JP 2007-121214 A JP 2007-121231 A

  The technique described in Patent Document 1 measures a reflected wave having no defect inside the structure, that is, a reflected wave including only the electromagnetic wave reflected on the structure surface, in order to remove the electromagnetic wave reflected on the structure surface. The results need to be prepared in advance. For this reason, there exists a problem that the effort of a measurement increases. In addition, depending on the situation, there is a problem that a structure having no defect cannot be prepared in the first place.

  In the techniques described in Patent Documents 2 and 3, when performing subtraction processing to remove the electromagnetic wave reflected on the structure surface and the direct wave from the electromagnetic wave irradiation device, a part of the electromagnetic wave reflected by the defect inside the structure is also removed at the same time. May end up. That is, there is a problem that an error occurs in the defect position detection. In the first place, in the case of a configuration in which the distance between the electromagnetic wave irradiation / detection device and the surface of the structure changes, there is a problem that the subtraction process cannot be performed.

  The techniques described in Patent Documents 4 to 6 are based on the assumption that irregular reflection does not occur on the structure surface, that is, specular reflection occurs on the structure surface. However, on the actual surface of the structure, irregular reflection may occur depending on the shape and state of the surface even when there is no assumed type of defect. In this case, the electromagnetic wave detection device erroneously receives the electromagnetic wave reflected on the structure surface as an electromagnetic wave reflected by a defect inside the structure. That is, there is a problem that a defect is erroneously detected even though there is no defect inside the structure.

  An object of the present invention is to provide an electromagnetic wave irradiation / detection device and an electromagnetic wave irradiation / detection method capable of solving the above-described problems.

  An electromagnetic wave irradiation / detection device according to an aspect of the present invention includes a transmitter that irradiates a structure with electromagnetic waves, a receiver that receives a reflected wave of the electromagnetic waves, and whether there is a defect in the structure based on the reflected waves. A detecting unit for detecting, wherein either one of the transmitting unit and the receiving unit is installed at a position away from the surface of the structure, and the other is in contact with the structure.

  The electromagnetic wave irradiation / detection device according to the present invention suppresses erroneous detection of defects caused by reflected waves from the structure surface without increasing the time and effort of measurement, and the presence or absence of defects from a position away from the structure surface. In addition, there is an effect that the position can be detected.

FIG. 1 is a block diagram showing a configuration of an electromagnetic wave irradiation / detection device 1 according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a detailed configuration of the electromagnetic wave irradiation / detection device 1 according to the first embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 2 according to the second embodiment of the present invention. FIG. 4 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 3 according to the third embodiment of the present invention. FIG. 5 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 4 according to the fourth embodiment of the present invention.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Note that, in each embodiment described in each drawing and specification, the same reference numerals are given to components having the same function.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration of an electromagnetic wave irradiation / detection device 1 according to the first embodiment of the present invention.

  Referring to FIG. 1, the electromagnetic wave irradiation / detection device 1 according to the first exemplary embodiment of the present invention includes a transmission unit 101, a reception unit 102, and a detection unit 100. The transmitter 101 is installed at a position away from the surface of the structure 103, and the receiver 102 is installed on the surface of the structure 103. By adopting such a configuration, the electromagnetic wave irradiation / detection device 1 has reflected waves 107 reflected from the surface of the structure 103 and a direct wave from the transmission unit 101 to the reception unit 102 (not shown) without increasing the measurement effort. ) Is suppressed, and the reflected wave 106 reflected by the defect inside the structure 103 can be received.

  Hereinafter, each component with which the electromagnetic wave irradiation and detection apparatus 1 in 1st Embodiment is provided is demonstrated.

The transmission unit 101 irradiates the structure 103 with a microwave or millimeter wave electromagnetic wave 105. Transmitting portion 101 is installed in a position away distance L _T from the surface of the structure 103 (i.e., a L _T ≠ 0).

The receiving unit 102 receives the reflected wave 107 in which the electromagnetic wave 105 is reflected by the surface of the structure 103 and the reflected wave 106 in which the electromagnetic wave 105 is reflected by the defect 104 inside the structure 103. The receiving unit 102 is installed on the surface of the structure 103 (that is, L _R = 0 when the distance from the surface of the structure 103 is L _R ). For this reason, the receiving unit 102 does not need to receive a direct wave (not shown) from the transmitting unit 101.

  The detection unit 100 detects the presence and position of the defect 104 based on the signals of the reflected wave 107 and the reflected wave 106 received by the receiving unit 102.

  Here, as the structure 103, a dielectric (for example, concrete or wood) having a property of transmitting microwave or millimeter wave electromagnetic waves is assumed.

  Further, as the defect 104, an object different from the structure 103 such as a crack or a cavity is assumed. Since the uniformity of the structure 103 is impaired by the defect 104, the electromagnetic wave 105 is reflected by the defect 104. That is, the reflected wave 106 is generated.

Here, if the distance between the defect 104 and the surface of the structure 103 on the side irradiated with the electromagnetic wave 105 is d, the intensity of the defect 104 receiving the electromagnetic wave 105 is inversely proportional to (L _T + d) ² .

Similarly, the intensity at which the receiving unit 102 receives the reflected wave 106 is inversely proportional to (L _R + d) ² . Therefore, the intensity P _def of the reflected wave 106 received by the receiving unit 102 has a distance dependency represented by Expression (1).

On the other hand, the intensity at which the receiving unit 102 receives the reflected wave 107 is inversely proportional to (L _T + L _R ) ² . Therefore, the intensity P _sur of the reflected wave 107 received by the receiving unit 102 has a distance dependency represented by Expression (2).

From Expressions (1) and (2), the ratio between the intensity P _def of the reflected wave 106 received by the receiving unit 102 and the intensity P _sur of the reflected wave 107 received by the receiving unit 102 is given by Expression (3).

The ratio P _def / P _{sur in} Expression (3) is a value corresponding to the SN ratio, and the larger the value, the more the influence of the reflected wave 107 can be suppressed. There are two conditions for maximizing the S / N ratio given by equation (3), one for L _T = d and L _R = 0, and the other for L _T = 0 and L _R = d. is there.

In this embodiment, since L _R = 0, in the case of L _T = d, that is, the distance L _T between the surface of the structure 103 and the transmitter 101, and the surface of the structure 103 and the defect 104 When the distance d between is equal, the signal-to-noise ratio is maximized. Accordingly, the transmission unit 101 is preferably capable of adjusting the distance L _T from the surface of the structure 103 so as to maximize the SN ratio.

  In the present embodiment, the detection unit 100 is configured as an independent device, but the configuration of the detection unit 100 is not limited to this. For example, it may be incorporated in the reception unit 102 or the transmission unit 101.

  In the present embodiment, the detection unit 100 directly receives the reflected wave 107 and the reflected wave 106 received by the reception unit 102 from the reception unit 102, but the configuration of the detection unit 100 is not limited thereto. For example, the detection unit 100 may receive signals of the reflected wave 107 and the reflected wave 106 via the transmission unit 101 or another device.

  In this embodiment, one transmission unit 101, two reception units 102, one detection unit 100, and one detection unit 100 are provided. However, the number of these devices is limited to the above. Not.

  Hereinafter, with reference to FIG. 2, the details of each component of the electromagnetic wave irradiation / detection device 1 according to the first embodiment will be described.

  The transmission unit 101 includes an electromagnetic wave transmission unit 1011 and a synchronization signal transmission unit 1012.

  The electromagnetic wave transmission unit 1011 irradiates the structure 103 with a microwave or millimeter wave electromagnetic wave 105. The beam width or directivity of the electromagnetic wave 105 is desirably controllable by the electromagnetic wave transmission unit 1011 or another device (not shown) so that the reception unit 102 does not receive the beam width or directivity.

  The synchronization signal transmission unit 1012 transmits a synchronization signal to the reception unit 102 in order to synchronize with the reception unit 102. In the present embodiment, the synchronization signal includes information related to the time when the electromagnetic wave transmission unit 1011 transmits the electromagnetic wave 105.

Referring now to FIG. 1, in this embodiment, the transmission unit 101 is installed in a position away distance L _T from the surface of the structure 103 (i.e., a L _T ≠ 0). Therefore, even if the transmission unit 101 moves at high speed, there is little risk that the transmission unit 101 collides with the surface of the structure 103. Therefore, the transmission unit 101 may be mounted on a moving body (for example, a transportation device such as a flying body or a vehicle) and move at high speed. By irradiating the structure 103 with the electromagnetic wave 105 while the transmission unit 101 moves, the defect 104 existing inside the structure 103 can be detected in a wide range and at high speed. Moreover, the transmission part 101 may be mounted not only in a mobile body but in a mobile communication terminal.

  The receiving unit 102 will be described with reference to FIG. 2 again. The reception unit 102 includes an electromagnetic wave reception unit 1021, a synchronization signal reception unit 1022, and a signal transmission unit 1023. The receiving unit 102 includes an individual power source (not shown). However, when it is difficult to secure a power source, the receiving unit 102 may be wirelessly powered from the transmitting unit 101.

  The electromagnetic wave receiving unit 1021 receives the reflected wave 107 in which the electromagnetic wave 105 is reflected by the surface of the structure 103 and the reflected wave 106 in which the electromagnetic wave 105 is reflected by the defect 104 inside the structure 103. The electromagnetic wave receiving unit 1021 measures the time when the reflected wave 107 and the reflected wave 106 are received. The electromagnetic wave receiving unit 1021 transmits the signals of the reflected wave 107 and the reflected wave 106 and the information regarding the reception time of the reflected wave 107 and the reflected wave 106 to the signal transmitting unit 1023.

  The synchronization signal receiving unit 1022 receives the synchronization signal from the transmission unit 101. Based on the synchronization signal, the reception unit 102 can synchronize with the transmission unit 101. The synchronization signal receiving unit 1022 grasps the time when the electromagnetic wave 105 is transmitted based on the synchronization signal. The synchronization signal reception unit 1022 transmits information related to the transmission time of the electromagnetic wave 105 to the signal transmission unit 1023.

  The signal transmission unit 1023 transmits the information regarding the signal and reception time of the reflected wave 107 and the reflected wave 106 and the information regarding the transmission time of the electromagnetic wave 105 to the detection unit 100.

Referring now to FIG. 1, in this embodiment, the receiving unit 102 is installed on the surface of the structure 103 (i.e., when the distance from the surface of the structure 103 and L _R, L _R = 0 Is). In the present embodiment, the receiving unit 102 is fixedly installed on the surface of the structure 103, but the receiving unit 102 may be movable. When the receiving unit 102 is fixedly installed on the surface of the structure 103, it is necessary for the worker to be close to the structure 103 for installation once, but the worker inspects the structure 103 once installed. This eliminates the need for close proximity. That is, it is possible to perform an inspection from a remote location, thereby obtaining the advantage that the inspection work efficiency is improved. Further, since the remote inspection is possible, there is an advantage that there is no need for traffic regulation in the vicinity of the structure 103 (for example, bridge, road, tunnel, etc.) to be inspected.

  It is desirable that the apparatus fixedly installed on the surface of the structure 103 has low power consumption from the viewpoint of securing a power source. In general, the receiving unit 102 consumes less power than the transmitting unit 101. Therefore, this embodiment in which the receiving unit 102 is fixedly installed is a desirable configuration.

  The detection unit 100 will be described with reference to FIG. 2 again. The detection unit 100 includes a signal processing unit 1001 and a defect detection unit 1002. In the present embodiment, detection unit 100 is a server.

  The signal processing unit 1001 receives information regarding the signals and reception times of the reflected wave 107 and the reflected wave 106 and information regarding the transmission time of the electromagnetic wave 105. The signal processing unit 1001 performs signal processing for detecting the presence and position of the defect 104 based on the received signal. For example, the signal processing unit 1001 calculates the time from when the transmission unit 101 transmits the electromagnetic wave 105 to when the reception unit 102 receives the reflected wave 107 and the reflected wave 106.

The defect detection unit 1002 detects the presence and position of the defect 104 based on the signals of the reflected wave 107 and the reflected wave 106 and the information calculated by the signal processing unit 1001. Here, the intensity P _sur of the reflected wave 107 is reduced as compared with P _def of the reflected wave 106 due to the relationship of Expression (3). Therefore, the reflected wave 107 and reflected wave 106 signals substantially represent the reflected wave 106 signal. The defect detection unit 1002 detects the presence or absence of the defect 104 based on the signal of the reflected wave 106. When it is detected that the defect 104 is present, the defect detection unit 1002 detects the position of the defect 104 based on the information calculated by the signal processing unit 1001.

  In the present embodiment, the transmission unit 101 and the reception unit 102 and the reception unit 102 and the detection unit 100 are wirelessly connected. However, some or all of these may be connected by wire.

  The electromagnetic wave irradiation / detection device 1 according to the first embodiment includes a transmission unit 101 and a reception unit 102 separately. That is, the transmitter 101 is provided at a position away from the surface of the structure 103, and the receiver 102 is provided on the surface of the structure 103. Thereby, since the electromagnetic wave irradiation / detection device 1 can suppress the reception of the reflected wave 107 reflected by the surface of the structure 103, the presence / absence and position of the defect 104 inside the structure 103 can be determined more easily and accurately. Can be detected.

[Second Embodiment]
FIG. 3 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 2 according to the second embodiment of the present invention.

  Referring to FIG. 3, the electromagnetic wave irradiation / detection device 2 according to the second exemplary embodiment of the present invention includes a transmission unit 201, a reception unit 202, and a detection unit 200. The transmitter 201 is installed on the surface of the structure 103, and the receiver 202 is installed at a position away from the surface of the structure 103. Since the transmission unit 201, the reception unit 202, and the detection unit 200 have the same functions as the transmission unit 101, the reception unit 102, and the detection unit 100 in the first embodiment, detailed descriptions thereof are omitted. The electromagnetic wave irradiation / detection device 2 in the present embodiment is different in that the positional relationship between the electromagnetic wave irradiation / detection device 1 in the first embodiment and the transmission unit 101 and the reception unit 102 is different.

  Hereinafter, components included in the electromagnetic wave irradiation / detection device 2 according to the second embodiment will be described.

The transmitter 201 is installed on the surface of the structure 103 (that is, L _T = 0 when the distance from the surface of the structure 103 is L _T ). The transmission unit 201 includes an individual power source (not shown). However, when it is difficult to secure a power supply, the transmission unit 201 may be wirelessly powered from the reception unit 202.

  In the present embodiment, the transmission unit 201 is fixedly installed on the surface of the structure 103, but may be movable. When the transmission unit 201 is permanently fixed on the surface of the structure 103, the operator needs to be close to the structure 103 for installation once, but the operator inspects the structure 103 once installed. This eliminates the need for close proximity. That is, it is possible to perform an inspection from a remote location, thereby obtaining the advantage that the inspection work efficiency is improved. Further, since remote inspection is possible, there is an advantage that there is no need for traffic regulation in the vicinity of inspection points (bridges, tunnels, etc.).

The receiving unit 202 is installed at a position away from the surface of the structure 103 by a distance L _R (in this embodiment, L _R ≠ 0). Therefore, even if the receiving unit 202 moves at a high speed, there is little risk that the receiving unit 202 collides with the surface of the structure 103. Therefore, the receiving unit 202 may be mounted on a moving body (for example, a transportation device such as a flying body or a vehicle) and move at high speed. By receiving the reflected wave 106 reflected by the defect 104 inside the structure 103 while moving the receiving unit 202, the defect 104 existing inside the structure 103 can be detected in a wide range and at high speed. The receiving unit 202 is not limited to a mobile object, and may be mounted and transported in a mobile communication terminal or the like.

In the present embodiment, when L _R = d, that is, the distance L _R between the surface of the structure 103 and the receiving unit 202 is equal to the distance d between the surface of the structure 103 and the defect 104. If so, the signal-to-noise ratio is maximized. Therefore, it is desirable that the receiving unit 202 can adjust the distance L _R from the surface of the structure 103 so as to maximize the SN ratio.

  In the present embodiment, two transmission units 201, one reception unit 202, and one detection unit 200 are provided. However, the number of these devices is not limited to the above.

  The electromagnetic wave irradiation / detection device 2 according to the second exemplary embodiment includes the reception unit 202 at a position away from the surface of the structure 103 and the transmission unit 201 on the surface of the structure 103. With this configuration, the electromagnetic wave irradiation / detection device 2 can suppress the reception of the reflected wave 107 reflected from the surface of the structure 103, so that the presence / absence and position of the defect 104 in the structure 103 can be more easily and accurately. Can be detected.

[Third Embodiment]
FIG. 4 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 3 according to the third embodiment of the present invention.

  Referring to FIG. 4, the electromagnetic wave irradiation / detection device 3 according to the third exemplary embodiment of the present invention includes a transmission unit 301, a reception unit 302, and a detection unit 300. The transmitter 301 is installed at a position away from the surface of the structure 103, and the receiver 302 is installed inside the structure 103. Since the transmission unit 301, the reception unit 302, and the detection unit 300 have the same functions as the transmission unit 101, the reception unit 102, and the detection unit 100 in the first embodiment, detailed descriptions thereof are omitted. The electromagnetic wave irradiation / detection device 3 in the present embodiment is different in that the positional relationship between the electromagnetic wave irradiation / detection device 1 and the receiving unit 302 in the first embodiment is different.

  Hereinafter, components included in the electromagnetic wave irradiation / detection device 3 according to the third embodiment will be described.

The transmission unit 301 is installed at a position away from the surface of the structure 103 by a distance L _T (that is, L _T ≠ 0). For this reason, even if the transmission part 301 moves at high speed, there is little risk of colliding with the surface of the structure 103. Therefore, the transmission unit 301 may be mounted on a moving body (for example, a transportation device such as a flying body or a vehicle) and move at high speed. The structure 103 is irradiated with the electromagnetic wave 105 while moving the transmission unit 301, and the reception unit 302 receives the reflected wave 106 reflected by the defect 104 inside the structure 103, so that the defect 104 existing inside the structure 103 is removed. It is possible to detect a wide range and at high speed. The transmission unit 301 is not limited to a mobile body, and may be mounted and transported in a mobile communication terminal or the like.

  The receiving unit 302 is installed inside the structure 103. Therefore, the receiving unit 302 does not need to receive the reflected wave 107 reflected from the surface of the structure 103. That is, the receiving unit 302 can receive only the reflected wave 106 reflected by the defect 104 inside the structure 103 without being disturbed by the reflected wave 107. In addition, since the receiving unit 302 is fixedly installed inside the structure 103, once installed, the operator does not need to be close to inspect the structure 103. That is, it is possible to perform an inspection from a remote location, thereby obtaining the advantage that the inspection work efficiency is improved. Further, since remote inspection is possible, there is an advantage that there is no need for traffic regulation in the vicinity of inspection points (bridges, tunnels, etc.).

  It is desirable that the device installed in the structure 103 has low power consumption from the viewpoint of securing a power source. In general, the power consumption of the reception unit 302 is smaller than that of the transmission unit 301. Therefore, this embodiment in which the receiving unit 302 is installed inside the structure 103 is a desirable configuration.

  In the present embodiment, one transmission unit 301, two reception units 302, and one detection unit 300 are provided. However, the number of these devices is not limited to the above.

  The electromagnetic wave irradiation / detection device 3 according to the third embodiment includes the transmission unit 301 at a position away from the surface of the structure 103 and the reception unit 302 inside the structure 103. As a result, the receiving unit 302 does not need to receive the reflected wave 107 reflected from the surface of the structure 103, so that the electromagnetic wave irradiation / detection device 3 can more easily and accurately detect the presence / absence and position of the defect 104 inside the structure 103. Can be detected.

[Fourth Embodiment]
FIG. 5 is a block diagram showing a configuration of the electromagnetic wave irradiation / detection device 4 according to the fourth embodiment of the present invention.

  Referring to FIG. 5, the electromagnetic wave irradiation / detection device 4 according to the fourth exemplary embodiment of the present invention includes a transmission unit 401, a reception unit 402, and a detection unit 400. The transmitter 401 is installed inside the structure 103, and the receiver 402 is installed at a position away from the surface of the structure 103. Since the transmission unit 401, the reception unit 402, and the detection unit 400 have the same functions as the transmission unit 101, the reception unit 102, and the detection unit 100 in the first embodiment, detailed descriptions thereof are omitted. The electromagnetic wave irradiation / detection device 4 in the present embodiment is different in that the positional relationship between the electromagnetic wave irradiation / detection device 2 and the transmission unit 401 in the second embodiment is different.

  Hereinafter, components included in the electromagnetic wave irradiation / detection device 4 according to the fourth embodiment will be described.

  The transmission unit 401 is installed inside the structure 103. The transmission unit 401 irradiates the electromagnetic wave 105 toward the inside of the structure 103. Therefore, in the present embodiment, the interference wave reaching the reception unit 402 (the reflected wave 107 in the first and second embodiments) does not occur. The transmission unit 401 includes an individual power source (not shown). However, when it is difficult to secure a power source, the transmission unit 401 may be wirelessly powered from the reception unit 402.

  In the present embodiment, the transmission unit 401 is fixedly installed inside the structure 103. Therefore, although it is necessary for an installation worker to approach the structure 103 once for installation, it is not necessary for the operator to approach the structure 103 once the installation is performed. That is, it is possible to perform an inspection from a remote location, thereby obtaining the advantage that the inspection work efficiency is improved. Further, since remote inspection is possible, there is an advantage that there is no need for traffic regulation in the vicinity of inspection points (bridges, tunnels, etc.).

The receiving unit 402 is installed at a position away from the surface of the structure 103 by a distance L _R (ie, L _R ≠ 0). The receiving unit 402 receives only the reflected wave 106 reflected by the defect 104 inside the structure 103 without being disturbed by the reflected wave 107 in the first and second embodiments.

  In the present embodiment, the receiving unit 402 is located away from the surface of the structure 103. Therefore, there is little risk of collision with the surface of the structure 103 even if the receiving unit 402 moves at a high speed. Therefore, the receiving unit 402 may be mounted on a moving body (for example, a transportation device such as a flying body or a vehicle) and move at high speed. By receiving the reflected wave 106 reflected by the defect 104 inside the structure 103 while moving the receiving unit 402, it becomes possible to detect the defect 104 existing inside the structure 103 in a wide range and at high speed. The receiving unit 402 is not limited to a mobile body, and may be mounted and transported in a mobile communication terminal or the like.

  In the present embodiment, two transmission units 401, one reception unit 402, and one detection unit 400 are provided, but the number of these devices is not limited to the above.

  The electromagnetic wave irradiation / detection device 4 according to the fourth exemplary embodiment includes the reception unit 402 at a position away from the surface of the structure 103 and the transmission unit 401 inside the structure 103. As a result, the receiving unit 402 does not need to receive the reflected wave 107. Therefore, the electromagnetic wave irradiation / detection device 4 is easier and more accurate than the electromagnetic wave irradiation / detection device 2 of the second embodiment. The presence / absence and position of the defect 104 inside 103 can be detected.

  Although the present invention has been described with reference to each embodiment, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

  In addition, each component in each embodiment of the present invention can be realized by a computer and a program as well as its function in hardware. The program is provided by being recorded on a computer-readable recording medium such as a magnetic disk or a semiconductor memory, and is read by the computer when the computer is started up. The read program causes the computer to function as a component in each of the embodiments described above by controlling the operation of the computer.

[Industrial applicability]
As an application example of the present invention, there is an electromagnetic wave irradiation / detection device for nondestructively and remotely detecting a defect of a structure.

1, 2, 3, 4 Electromagnetic wave irradiation / detection device 101, 201, 301, 401 Transmission unit 102, 202, 302, 402 Reception unit 100, 200, 300, 400 Detection unit 1011 Electromagnetic wave transmission unit 1012 Synchronization signal transmission unit 1021 Electromagnetic wave Receiver 1022 Synchronization signal receiver 1023 Signal transmitter 1001 Signal processor 1002 Defect detector 104 Defect 105 Electromagnetic wave 106 Reflected wave 107 Reflected wave

Claims (10)

A transmitter for irradiating the structure with electromagnetic waves;
A receiver for receiving the reflected wave of the electromagnetic wave;
A detection unit that detects the presence and position of a defect in the structure based on the reflected wave, and
Either one of the transmitting unit or the receiving unit is installed at a position away from the surface of the structure, and the other is in contact with the structure.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the device that contacts the structure is installed on a surface of the structure.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the device that contacts the structure is installed inside the structure.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the device installed at a position distant from the surface of the structure is capable of adjusting a distance from the surface of the structure.   5. The distance according to claim 4, wherein the distance is set based on a ratio between an intensity of the electromagnetic wave reflected by the defect received by the receiving unit and an intensity of the electromagnetic wave reflected by the surface of the structure. Electromagnetic wave irradiation / detection device.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the device installed at a position away from the surface of the structure is mounted on a moving body.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the transmission unit transmits a synchronization signal to the reception unit and synchronizes with the reception unit.   The electromagnetic wave irradiation / detection device according to claim 1, wherein the transmission unit wirelessly feeds power to the reception unit. Irradiating the structure with electromagnetic waves from a position away from the surface of the structure;
Receiving the reflected wave of the electromagnetic wave in contact with the structure;
Detecting the presence / absence and position of a defect in the structure based on the reflected wave. Irradiating the structure with electromagnetic waves in contact with the structure;
Receiving the reflected wave of the electromagnetic wave at a position outside the structure and away from the surface;
Detecting the presence / absence and position of a defect in the structure based on the reflected wave.

Images