JP7152864B2 - Structural damage detection sensor and damage detection system - Google Patents

Description

TECHNICAL FIELD The present invention relates to sensors and systems for detecting damage to structures such as railway vehicles.

Patent Literature 1 discloses a method for detecting the occurrence of fatigue cracks in a structure. In this method, an RFID tag is attached to a turbine blade, and when a crack occurs in the turbine blade, the RFID becomes inoperable due to the crack, and the RFID tag cannot be read by an RFID reader. I have to. However, if the usage environment is severe, the RFID tag may become inoperable due to factors other than cracks, and it may be erroneously determined that a crack has occurred when no crack actually occurs. there is a possibility.

Patent Literature 2 discloses a linear detector for detecting the occurrence of fatigue cracks in structures. In this device, a detection wire is adhered to a portion of the structure where stress tends to concentrate, and the detection device body is connected to the detection wire. When a fatigue crack occurs in the structure, the detection wire is disconnected, and the detection device main body that detects the disconnection emits an LED and incorporates an IC tag, etc., so that the administrator can receive crack information. ing. According to this configuration, it is possible to prevent erroneous determination because the possibility of disconnection of the detection line due to factors other than cracks is low.

JP 2010-203433 A Japanese Patent No. 4801651

However, in the configuration of Patent Document 2, when a fatigue crack occurs in a portion of the structure that is deviated from the position where the detection line is arranged, the crack cannot be detected because the detection line is not disconnected. There is a problem that the fatigue crack detection range is narrow. In addition, there is also the problem that an external power source is required because the configuration is such that a fatigue crack is detected by disconnection of a detection wire that is constantly energized.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a configuration that can reliably detect whether or not a structure has been damaged without an erroneous determination and that can achieve a wide detection range.

A structural damage detection sensor according to an aspect of the present invention is a sensor attached to a structure for detecting damage to the structure, the sensor sheet being connected to the structure and having a portion to be broken formed therein. and at least one detection circuit formed on the sensor sheet and crossing the portion to be broken, and at least one detection circuit electrically connected to the detection circuit and capable of rewriting self detection information when the detection circuit is disconnected An RFID tag and at least one antenna circuit electrically connected to the RFID tag.

According to the above configuration, if the damage detection sensor is attached to a portion of the structure where damage (for example, fatigue cracks, bolt breakage, detachment of car body parts, detachment of lids of important equipment, etc.) may occur, When the sensor sheet is damaged, the sensor sheet is distorted and the part to be broken is broken, and the detection circuit is disconnected. Then, since the information of the RFID tag is rewritten, by reading the information of the RFID tag wirelessly through the antenna circuit, it is possible to reliably detect whether or not the structure has been damaged without erroneous determination. Moreover, even if damage to the structure occurs at a position other than the detection circuit, if the strain due to the damage is transmitted to the sensor sheet, the sensor sheet has a fragile portion to be broken, so that the portion to be broken will be removed. , and the detection circuit is disconnected. That is, even if the structure is damaged at a position different from the detection circuit, the damage is transmitted to the sensor sheet, so that the sensor sheet can break the detection circuit by the breaking portion. Therefore, a wide detection range can be realized in the damage detection sensor.

A structure damage detection system according to an aspect of the present invention includes the damage detection sensor described above, and an RFID reader that wirelessly receives the ID information of the RFID tag of the damage detection sensor and the detection information via the antenna circuit. a database that stores correspondence relationships between the ID information and positions in the structure; and the ID information read by the RFID reader and the detection information are received via a network, and the received ID information and the database are received. a server for matching the sensed information with the identification information of the structure to associate the sensed information with a location on the structure.

According to the above configuration, in the server, the detection information rewritten due to disconnection of the detection circuit due to the occurrence of damage in the structure is associated with the position in the structure. The position can be easily grasped, and maintenance work can be facilitated.

Advantageous Effects of Invention According to the present invention, it is possible to provide a configuration that can reliably detect whether or not a structure has been damaged without erroneous determination and that can realize a wide detection range.

1 is a schematic diagram of a structure damage detection system according to a first embodiment; FIG. FIG. 2 is a plan view of the breakage detection sensor shown in FIG. 1; FIG. 2 is a diagram illustrating association of ID information, detection information, and position information in the server shown in FIG. 1; FIG. It is a top view of the breakage detection sensor which concerns on 2nd Embodiment. It is a top view of the damage detection sensor which concerns on 3rd Embodiment. It is a top view of the damage detection sensor which concerns on 4th Embodiment. It is a sectional view of the damage detection sensor concerning a 5th embodiment. FIG. 11 is a cross-sectional view of a breakage detection sensor according to a sixth embodiment; FIG. 11 is a plan view of a breakage detection sensor according to a seventh embodiment;

Embodiments will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram of a damage detection system 1 for a structure 10 according to an embodiment. As shown in FIG. 1, the damage detection system 1 is a system that detects damage to a structure 10 due to aging factors, which is caused by repeated external forces (for example, repeated stress or vibration) acting on the structure 10 . The damage detection system 1 detects damage to the structure 10 using RFID (Radio frequency identifier), and contributes to reducing the maintenance burden of the structure 10 . The structure 10 is, for example, a railroad vehicle (a bogie or a vehicle body thereof), but may be other structures such as a transport device such as an aircraft or a ship, or a bridge. A plurality of damage detection sensors 11 are respectively attached to a plurality of locations of the structure 10 where stress concentration is likely to occur. A damage detection system 1 includes a plurality of damage detection sensors 11 , an RFID reader 2 , a data processing device 3 , a server 4 and a database 5 .

The RFID reader 2 reads a signal including identification information and detection information of an RFID tag 23 (described later) of the breakage detection sensor 11 without contact. The RFID reader 2 may be installed in the vicinity of the structure 10, or may be a portable type carried by the worker. The data processing device 3 processes the signal read by the RFID reader 2 and transmits it to the server 4 via the network N (for example, the Internet). Note that the network is not limited to the Internet, and may be LAN, WAN, satellite communication lines, mobile phone networks, or other various communication networks. The database 5 stores in advance the correspondence relationship between the ID information of the RFID tag 23, which will be described later, and the position information indicating the position on the structure 10 where the RFID tag is installed. The server 4 performs arithmetic processing on the signal received from the data processing device 3 while referring to the database 5, and transmits the result of the arithmetic operation to an external facility such as an operation command center. The processed data of the server 4 is accumulated and saved in the database 5 .

FIG. 2 is a plan view of the breakage detection sensor 11 shown in FIG. As shown in FIG. 2, the damage detection sensor 11 is attached to a portion of the structure 10 where stress is likely to concentrate. The damage detection sensor 11 includes a sensor sheet 21 , a detection circuit 22 (tamper detection circuit), an RFID tag 23 and an antenna circuit 24 . The sensor sheet 21 is connected to the structure 10 by being adhered to the structure 10 . The sensor sheet 21 is formed with a linear breakable portion 21a that is more fragile than other portions. In this embodiment, the portion to be broken 21a is a perforation. Note that the breakable portion 21a is not limited to perforations as long as it forms a portion of the sensor sheet 21 that is preferentially broken.

The detection circuit 22 is formed on the sensor sheet 21 and crosses the breaking portion 21a. That is, the detection circuit 22 is a closed circuit arranged so as to break when the sensor sheet 21 breaks at the breaking portion 21a. RFID tag 23 is electrically connected to detection circuit 22 . The RFID tag 23 is a passive RDID tag that does not require a power source. The RFID tag 23 is configured to rewrite its own detection information when the detection circuit 22 is disconnected. That is, the RFID tag 23 stores its own ID information and detection information indicating whether or not the detection circuit 22 connected to itself is disconnected. For example, the RFID tag 23 stores "0" as the detection information when the detection circuit 22 is disconnected, and stores "1" as the detection information when the detection circuit 22 is not disconnected. Antenna circuit 24 is electrically connected to RFID tag 23 . The RFID tag 23 generates electricity based on a signal received via the antenna circuit 24 and wirelessly transmits ID information and detection information to the outside via the antenna circuit 24 .

The damage detection sensor 11 adheres to the structure 10 the back surface of the sensor sheet 21 opposite to the surface on which the RFID tag 23 and the antenna circuit 24 are provided. At that time, the breakage detection sensor 11 is attached to the structure 10 so that the expected fracture portion 21a is aligned with the assumed fatigue crack X of the structure 10 . Then, when a fatigue crack occurs in the structure 10, the sensor sheet 21 is distorted, and the sensor sheet 21 is broken at the breaking portion 21a, and the detection circuit 22 is broken. Then, since the information of the RFID tag 23 is rewritten, by reading the information of the RFID tag 23 wirelessly through the antenna circuit 24, whether or not the fatigue crack has occurred in the structure 10 can be reliably detected without erroneous judgment. be able to.

Moreover, even if the fatigue crack of the structure 10 occurs at a position other than the detection circuit 22, when the strain due to the fatigue crack is transmitted to the sensor sheet 21, the sensor sheet 21 has a fragile scheduled breakage portion 21a. , the sensor sheet 21 is broken at the breaking portion 21a, and the detection circuit 22 is broken. That is, even if the fatigue crack of the structure 10 occurs at a position different from that of the detection circuit 22, the fatigue crack is transmitted as strain to the sensor sheet 21, and the detection circuit 22 can be broken by the breaking portion 21a. Therefore, a wide detection range can be realized in the damage detection sensor 11 .

FIG. 3 is a diagram for explaining association of ID information, detection information, and position information in the server 4 shown in FIG. As shown in FIGS. 1 and 3 , the server 4 refers to the database 5 to obtain the correspondence relationship between the ID information of the RFID tag 23 and the positional information regarding the position of the RFID tag 23 in the structure 10 . The server 4 acquires a combination of the ID information and detection information (detection signal) read from the damage detection sensor 11 by the RFID reader 23 via the data processor 3 and the network N. FIG.

Then, the server 4 associates the detection information with the position information of the RFID tag 23 based on the correspondence acquired from the database 5 and the combination of the ID information and the detection information acquired from the damage detection sensor 11 . The server 4 transmits the associated detection information and position information to the driving command center, and the driving command center notifies the driver and the like of the information. With such a configuration, it is possible to easily grasp the position where the damage occurs in the structure 10, and to facilitate the maintenance work.

(Second embodiment)
FIG. 4 is a plan view of the breakage detection sensor 111 according to the second embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 4, in the breakage detection sensor 111 of the second embodiment, a sensor sheet 121 is provided with a plurality of (for example, three in FIG. 4) linear portions to be broken 121a. The detection circuit 22 traverses all of the plurality of planned breaking portions 121a. Therefore, even if only one portion to be broken 121a among the plurality of portions to be broken 121a is broken and the rest of the portions to be broken 121a are not broken, the detection circuit 22 is broken.

Therefore, even if the fatigue crack of the structure occurs at a different position than expected, the fatigue crack is transmitted as strain to the sensor sheet 21, and the detection circuit 22 can be disconnected by at least one expected breakage portion 121a. Therefore, a wide detection range can be realized in the damage detection sensor 111 . Since the rest of the configuration is the same as that of the above-described first embodiment, description thereof will be omitted.

(Third embodiment)
FIG. 5 is a plan view of the breakage detection sensor 211 according to the third embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 5, in the damage detection sensor 211 of the third embodiment, the detection circuit 222 repeatedly traverses the breaking portion 21a of the sensor sheet 21 in a meandering manner. According to this configuration, even when the sensor sheet 21 is broken only at the part to be broken 21a, the possibility that the detection circuit 222 is broken can be increased, and the detection sensitivity is improved. Since the rest of the configuration is the same as that of the above-described first embodiment, description thereof will be omitted.

(Fourth embodiment)
FIG. 6 is a plan view of the breakage detection sensor 311 according to the fourth embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 6, in the damage detection sensor 311 of the fourth embodiment, multiple detection circuits 222 , multiple RFID tags 23 and multiple antenna circuits 24 are mounted on one sensor sheet 321 . In the example of FIG. 6, three detection circuits 222, three RFID tags 23, and three antenna circuits 24 are provided, but the number is not particularly limited. Each detection circuit 222 is electrically connected to each RFID tag 23 independently. Each RFID tag 23 is electrically connected to each antenna circuit 24 independently.

Each detection circuit 222 traverses the breakable portion 321 a at different positions on the sensor sheet 321 . Each detection circuit 222 is arranged in order from one side of the portion to be broken 321a toward the other side. The detection circuit 222 traverses the breaking portion 321a in a meandering manner as in the third embodiment, but may have a non-serpentine shape as in the first embodiment. A plurality of RFID tags 23 and antenna circuits 24 are dispersedly arranged on the sensor sheet 321 so as to be divided into one side and the other side with the portion to be broken 321a interposed therebetween. In the example of FIG. 6, the plurality of RFID tags 23 and the antenna circuits 24 are alternately arranged on one side and the other side of the portion to be broken 321a.

According to such a configuration, even when the sensor sheet 321 is broken only at a part of the breaking portion 321a, one of the plurality of detection circuits 222 is broken, thereby increasing the possibility of breaking detection. and the sensitivity of the damage detection sensor 311 is improved. Further, since the plurality of detection circuits 222 formed at mutually different positions on the sensor sheet 321 are electrically connected to the plurality of RFID tags 23 respectively, the positions of the disconnected circuits among the plurality of detection circuits 222 and From the number, the degree of progression of fatigue cracks in the structure can be grasped step by step. Since the rest of the configuration is the same as that of the above-described first embodiment, description thereof will be omitted.

(Fifth embodiment)
FIG. 7 is a cross-sectional view of a breakage detection sensor 411 according to the fifth embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 7, in the breakage detection sensor 411 of the fifth embodiment, the sensor sheet 421 includes a sensor support portion 421b in which a portion to be broken 421a is formed, and an RFID support portion on which the RFID tag 23 and the antenna circuit 24 are mounted. and a portion 421c.

The antenna circuit 24 is arranged such that the distance between the adhesive surface 421 d (the back surface to which the structure 10 is attached) of the sensor sheet 421 and the antenna circuit 24 is greater than the distance between the adhesive surface 421 d and the detection circuit 22 . are placed. Specifically, the sensor sheet 421 is formed such that the RFID support portion 421c is thicker than the sensor support portion 421b. Note that the RFID support portion 421c may be hollow and thickened instead of being solid and thickened. According to such a configuration, when the structure 10 is made of metal, the antenna circuit 24 is separated from the surface of the structure 10, so that radio quality can be stabilized. Since the rest of the configuration is the same as that of the above-described first embodiment, description thereof will be omitted.

(Sixth embodiment)
FIG. 8 is a cross-sectional view of a breakage detection sensor 511 according to the sixth embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 8, in the breakage detection sensor 511 of the sixth embodiment, the sensor sheet 521 includes a sensor support portion 521b formed with a portion to be broken 521a, and an RFID support portion on which the RFID tag 23 and the antenna circuit 24 are mounted. and a portion 521c. The antenna circuit 24 is arranged such that the distance between the adhesive surface 521 d (the back surface to which the structure 10 is attached) of the sensor sheet 521 and the antenna circuit 24 is greater than the distance between the adhesive surface 521 d and the detection circuit 22 . are placed.

Specifically, the sensor sheet 521 has a bent portion 521e between the sensor support portion 521b and the RFID support portion 521c, and is folded so that the RFID support portion 521c overlaps the sensor support portion 521b. The RFID tag 23 is mounted on the surface of the RFID support portion 521c facing the sensor support portion 521b, and the antenna circuit 24 is mounted on the surface of the RFID support portion 521c opposite to the sensor support portion 521b. The RFID tag 23 and the antenna circuit 24 are electrically connected through the through hole of the RFID support portion 521c. Note that the RFID tag 23 may be arranged on the same side as the antenna circuit 24 . Further, instead of connecting the sensor support portion 521b and the RFID support portion 521c at the bent portion 521e, the sensor support portion 521b and the RFID support portion 521c may be separated from each other.

The RFID support portion 521c is fixed to the sensor support portion 521b by a connection member 525 (for example, a hook-and-loop fastener, an adhesive, or the like), and is maintained in a state of being superimposed on the sensor support portion 521b. According to such a configuration, when the structure 10 is made of metal, the antenna circuit 24 is separated from the surface of the structure 10, so that radio quality can be stabilized. Since the rest of the configuration is the same as that of the above-described first embodiment, description thereof will be omitted.

(Seventh embodiment)
FIG. 9 is a plan view of a breakage detection sensor 611 according to the seventh embodiment. In addition, the same code|symbol is attached|subjected about the structure which is common in 1st Embodiment, and description is abbreviate|omitted. As shown in FIG. 9, the damage detection sensor 611 of the seventh embodiment includes a base sheet 626. As shown in FIG. The base sheet 626 has a sensor support portion 626a on which the sensor sheet 621 is superimposed, and an RFID support portion 626b arranged at a position different from the sensor sheet 621 and on which the RFID tag 23 and the antenna circuit 24 are mounted. In the sensor sheet 621, cut portions are formed as the portions to be broken 621a, but perforations or the like may be formed as the portions to be broken 621a.

A detection circuit 622 electrically connected to the RFID tag 23 crosses the breaking portion 621a. The sensor sheet 621 is partially fixed to the base sheet 626 on both sides of the breakable portion 621a (for example, the cut portion). As an example, the sensor sheet 621 is partially fixed to the base sheet 626 by micro-resistance welding W on both sides of the portion to be broken 621a. At least the sensor support portion 626 a of the base sheet 626 has an adhesive surface to be attached to a structure on the back surface opposite to the sensor sheet 621 .

According to such a configuration, when a fatigue crack occurs in the structure and the sensor support portion 626a of the base sheet 626 is distorted, the strain is transmitted to the sensor sheet 621, and the breakable portion 621a is stably broken. can be generated. When the damage detection sensor 611 is attached to the structure, the sensor sheet 621 does not need to come into contact with the structure. can be done easily. Further, since the RFID tag 23 and the antenna circuit 24 are mounted on the base sheet 626 instead of the sensor sheet 621 to be broken, the RFID tag 23 and the antenna circuit 24 are stably held, and stable wireless communication can be performed. . In addition, the aspect using this base sheet 626 may be applied to the configuration of each of the above-described other embodiments.

It should be noted that the present invention is not limited to the above-described embodiments, and its configuration can be changed, added, or deleted. For example, some features or methods in one embodiment may be applied to other embodiments, and some features in an embodiment are optionally separate from other features in that embodiment. Extractable. In addition to being used to detect fatigue cracks, each of the above-described damage detection sensors may be used to detect damage phenomena such as bolt breakage, detachment of vehicle body parts, detachment of lids of important equipment, and swelling.

1 damage detection system 2 RFID reader 3 data processor 4 server 5 database 10 structure 11, 111, 211, 311, 411, 511, 611 damage detection sensor 21, 121, 321, 421, 521, 621 sensor sheet 21a, 121a , 321a, 521a, 621a portion to be broken 22, 222 detection circuit 23 RFID tag 24 antenna circuit

Claims (3)

A sensor attached to a structure for detecting damage to the structure,
a sensor sheet connected to the structure and formed with one portion to be broken;
at least one detection circuit formed on the sensor sheet and crossing the portion to be broken;
at least one RFID tag that is electrically connected to the detection circuit and whose detection information is rewritten when the detection circuit is disconnected;
at least one antenna circuit electrically connected to the RFID tag;
wherein the at least one sensing circuit, the at least one RFID tag, and the at least one antenna circuit comprise a plurality of sensing circuits, a plurality of RFID tags, and a plurality of antenna circuits, respectively;
The plurality of detection circuits are electrically connected to the plurality of RFID tags, respectively, and cross the one planned breaking portion at different positions ,
The damage detection sensor for a structure , wherein the detection circuit meanders across the planned breaking portion . 2. The structural damage detection sensor according to claim 1 , wherein the portion to be broken has a perforation, a thin portion, or a notch. A breakage detection sensor according to claim 1 or 2 ;
an RFID reader that wirelessly receives the ID information of the RFID tag of the damage detection sensor and the detection information via the antenna circuit;
a database storing a correspondence relationship between the ID information and a position in the structure;
a server that receives the ID information read by the RFID reader and the detection information via a network, compares the received ID information with the ID information in the database, and associates the detection information with a position in the structure; A structural failure detection system comprising:

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