Leak location estimation device, leak location estimation method

Abstract

To provide a leakage position estimating device and a leakage position estimating method that allow a leakage position in a pipeline disposed on one side of a shield, to be easily specified from the other side of the shield.SOLUTION: A leakage position estimating device 30 receives an electromagnetic wave signal from a signal transmitting unit 26 at a wire tip disposed at a leakage position L1 in a pipeline 10 on one side of a floor 14, on the other side of the floor 14 according to coil shafts S1, S2, S3 in three directions of a first coil reception antenna 34A, a second coil reception antenna 34B, and a third coil reception antenna 34C. Further, the leakage position estimating device acquires an electromagnetic wave intensity K0 corresponding to an intensity of the third electromagnetic wave signals respectively received by the coil shafts S1, S2, S3 in the three directions, at a plurality of different spots, as respective position signal intensity information D1 together with a reception position, in order to estimate a position of the signal transmitting unit 26, as a leakage position L1, on the basis of multiple pieces of position signal intensity information D1.SELECTED DRAWING: Figure 7

Description

Technical Field

[0006] , , , ,

[0001] The present invention relates to a leakage position estimation device and a leakage position estimation method.

Background Art

[0002] Conventionally, when a leakage in a pipe supplying gas is detected, it is necessary to identify its position. Patent Document 1 below discloses a technique for detecting the flow velocity of a fluid in a pipe and identifying the leakage position of the fluid based on the change in the flow velocity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Thus, various techniques have been proposed for identifying the leakage position in a pipe. However, when the pipe itself is covered by a shielding object, for example, when it is covered by a floor or a wall inside a building, the leakage position cannot be directly observed. Therefore, it is necessary to identify the leakage position through the shielding object, and it is difficult to accurately identify the position. [[ID=3 ]]<,

[0005] In consideration of the above fact, an object of the present invention is to provide a leakage position estimation device and a leakage position estimation method capable of easily identifying the leakage position of a pipe arranged on one side of a shielding object from the other side of the shielding object.

Means for Solving the Problems

[0006] LeakageThe leak location estimation device includes: a search tool inserted into a pipe to identify the leak location within the pipe on one side of a shielding object; a receiver that receives electromagnetic wave signals output from a transmitting coil antenna at the tip of a wire positioned at the leak location using a first coil receiving antenna with its coil axis positioned in a first direction along the shielding surface of the shielding object, a second coil receiving antenna with its coil axis positioned in a direction intersecting the first direction along the shielding surface of the shielding object, and a third coil receiving antenna with its coil axis positioned in a direction intersecting the shielding surface; a storage unit that stores the electromagnetic wave intensity corresponding to the intensity of the electromagnetic wave signals received by the first coil receiving antenna, the electromagnetic wave signals received by the second coil receiving antenna, and the electromagnetic wave signals received by the third coil receiving antenna at multiple different locations, along with the reception position, as position signal intensity information; and an estimation unit that estimates the position of the transmitting coil antenna as the leak location based on the multiple position signal intensity pieces of information.

[0007] Leakage In the leak location estimation device, an electromagnetic wave signal output from a transmitting coil antenna located inside a pipe on one side of a shielding object is received by a receiver on the other side of the shielding object. The receiver has a first coil receiving antenna with its coil axis positioned in a first direction along the shielding surface of the shielding object, a second coil receiving antenna with its coil axis positioned in a direction intersecting the first direction along the shielding surface of the shielding object, and a third coil receiving antenna with its coil axis positioned in a direction intersecting the shielding surface. The electromagnetic wave intensity corresponding to the intensity of the electromagnetic wave signal received by each of the first, second, and third coil receiving antennas is stored in the storage unit as position signal intensity information along with the reception position, and the estimation unit estimates the position of the transmitting coil antenna as the leak location based on the multiple position signal intensity information.

[0008] When coil antennas are used for both transmission and reception, the distribution of electromagnetic waves is uneven near the transmitting coil antenna. Therefore, when receiving electromagnetic wave signals from the transmitting coil antenna, reception is performed using a first coil receiving antenna positioned with its coil axis aligned with the shielding surface of the shielding object, a second coil receiving antenna positioned with its coil axis intersecting the first direction, and a third coil receiving antenna positioned with its coil axis intersecting the shielding surface. By receiving with three coil axes in this way, the influence of uneven distribution of electromagnetic waves from the transmitting coil antenna positioned on one side of the shielding object is mitigated, making it easier to estimate the relationship between the position of the transmitting coil antenna and the intensity of the electromagnetic wave signal compared to the case with one axis. The estimation unit can then estimate the position of the transmitting coil antenna based on multiple position signal intensity information.

[0009] Furthermore, by using relatively inexpensive coil antennas for transmission and reception, the position of the transmitting coil antenna can be easily estimated.

[0010] Leakage In the leakage position estimation device, the angle between the first direction and the coil axis of the second coil receiving antenna is 80 degrees or more and 90 degrees or less, and the angle between the shielding surface and the coil axis of the third coil receiving antenna is 80 degrees or more and 90 degrees or less.

[0011] In this way, by setting the angle between the first direction and the coil axis of the second coil receiving antenna, and the angle between the shielding surface and the coil axis of the third coil receiving antenna, the effects of uneven distribution of electromagnetic waves from the transmitting coil antenna can be mitigated.

[0012] Leakage The leakage location estimation device uses the average intensity of the electromagnetic wave signals received at the same location by the first coil receiving antenna, the second coil receiving antenna, and the third coil receiving antenna as the electromagnetic wave intensity at that location.

[0013] LeakageAccording to the leakage location estimation device, the electromagnetic wave intensity is calculated by taking the average intensity of the electromagnetic wave signals received at the same point by receiving antennas with coil axes in three directions, thereby mitigating the effects of uneven distribution of electromagnetic waves from the transmitting coil antenna.

[0014] Leakage The leakage location estimation device estimates the leakage location as the center of symmetry of the electromagnetic wave intensity at a plurality of points within a receiving area that includes a plurality of points where the electromagnetic wave signal is received.

[0015] Leakage According to the leakage location estimation device, the leakage location can be estimated based on the fact that the intensity of the electromagnetic wave signal is symmetrically distributed around the transmitting coil antenna.

[0016] Leakage The leakage location estimation device, in which the estimation unit estimates the peak portion of the electromagnetic wave intensity at a plurality of points within a receiving area that includes a plurality of points where the electromagnetic wave signal is received, as the leakage location.

[0017] Leakage According to the leakage location estimation device, the leakage location can be estimated based on the fact that there is a peak in electromagnetic wave intensity near the transmitting coil antenna.

[0018] Claim 1The leakage location estimation method involves identifying the leakage location within the piping on one side of the shielding, placing a transmitting coil antenna at the tip of a wire at the leakage location, receiving the electromagnetic wave signal output from the transmitting coil antenna on the other side of the shielding using a first coil receiving antenna with its coil axis positioned in a first direction along the shielding surface of the shielding, a second coil receiving antenna with its coil axis positioned in a direction intersecting the first direction along the shielding surface of the shielding, and a third coil receiving antenna with its coil axis positioned in a direction intersecting the shielding surface, and acquiring the electromagnetic wave intensity corresponding to the intensity of the electromagnetic wave signal received by the first coil receiving antenna, the electromagnetic wave signal received by the second coil receiving antenna, and the electromagnetic wave signal received by the third coil receiving antenna at multiple different locations, along with the reception position, as position signal intensity information, and estimating the position of the transmitting coil antenna as the leakage location based on the multiple position signal intensity pieces of information.

[0019] Claim 1 In the leakage location estimation method, an electromagnetic wave signal output from a transmitting coil antenna placed inside a pipe on one side of the shielding object is received on the other side of the shielding object. Reception is performed by a first coil receiving antenna positioned in a first direction with its coil axis aligned with the shielding surface of the shielding object, a second coil receiving antenna positioned in a direction intersecting the first direction with its coil axis aligned with the shielding surface of the shielding object, and a third coil receiving antenna positioned in a direction intersecting the shielding surface. The electromagnetic wave intensity corresponding to the intensity of the electromagnetic wave signal received by each of the first, second, and third coil receiving antennas is acquired as position signal intensity information along with the reception position, and the position of the transmitting coil antenna is estimated as the leakage location based on the multiple position signal intensity information.

[0020] When a coil antenna is used for transmission and reception, there is unevenness in the electromagnetic wave distribution near the transmitting coil antenna. Therefore, when receiving an electromagnetic wave signal from the transmitting coil antenna, a first coil receiving antenna arranged in a first direction with its coil axis along the shielding surface of the shielding object, a second coil receiving antenna arranged in a direction intersecting the first direction with its coil axis along the shielding surface of the shielding object, and a third coil receiving antenna arranged in a direction intersecting the shielding surface are used for reception. By receiving with the coil axis as three axes in this way, the influence of the uneven distribution of electromagnetic waves from the transmitting coil antenna arranged on one side of the shielding object is mitigated, and compared with the case of one axis, it becomes easier to estimate the relationship between the position of the transmitting coil antenna and the intensity of the electromagnetic wave signal. And based on the plurality of position signal intensity information, the position of the transmitting coil antenna can be estimated.

[0021] Also, by using a coil antenna for relatively inexpensive transmission and reception, the position of the transmitting coil antenna can be easily estimated.

[0022] Claim 2 In the leakage position estimation method according to this, the angle formed by the first direction and the coil axis of the second coil receiving antenna is 80 degrees or more and 90 degrees or less, and the angle formed by the shielding surface and the coil axis of the third coil receiving antenna is 80 degrees or more and 90 degrees or less.

[0023] In this way, by setting the angle formed by the first direction and the coil axis of the second coil receiving antenna, and the angle formed by the shielding surface and the coil axis of the third coil receiving antenna, the influence of the uneven distribution of electromagnetic waves from the transmitting coil antenna can be mitigated.

[0024] Claim 3 In the leakage position estimation method according to this, the average intensity of the electromagnetic wave signals received at the same point by the first coil receiving antenna, the second coil receiving antenna, and the third coil receiving antenna is taken as the electromagnetic wave intensity at that point.

[0025] Claim 3According to the leakage location estimation method described herein, the electromagnetic wave intensity is calculated by taking the average intensity of the electromagnetic wave signals received at the same location by receiving antennas with coil axes in three directions, thereby mitigating the effects of uneven distribution of electromagnetic waves from the transmitting coil antenna.

[0026] Claim 4 The leakage location estimation method involves estimating the leakage location as the center of symmetry of the electromagnetic wave intensity at a plurality of points within a receiving area that includes a plurality of points where the electromagnetic wave signal is received.

[0027] Claim 4 According to the leakage location estimation method described herein, the leakage location can be estimated based on the fact that the intensity of the electromagnetic wave signal is symmetrically distributed around the transmitting coil antenna.

[0028] Claim 5 The leakage location estimation method involves estimating the leakage location as the peak portion of the electromagnetic wave intensity at a plurality of points within a receiving area that includes a plurality of points where the electromagnetic wave signal is received.

[0029] Claim 5 According to the leakage location estimation method described herein, the leakage location can be estimated based on the fact that there is a peak in electromagnetic wave intensity near the transmitting coil antenna. [Effects of the Invention]

[0030] According to the leak location estimation device and leak location estimation method of the present invention, the leak location in a pipe located on one side of a shielding object can be easily estimated from the other side of the shielding object. [Brief explanation of the drawing]

[0031] [Figure 1] This diagram shows a partial configuration of a building in which the leak location estimation device of this embodiment is used. [Figure 2A] This is a schematic diagram of the search tool used in this embodiment. [Figure 2B] This diagram shows the process of using a detection tool to locate the leak in a pipe. [Figure 3A]This is a schematic diagram of the transmitter used in this embodiment. [Figure 3B] This diagram shows the signal transmitting unit of the transmitter positioned at the leakage point. [Figure 4A] This is a perspective view of the leak location estimation device of this embodiment, as seen from the camera side. [Figure 4B] This is a perspective view of the leak location estimation device of this embodiment, as seen from the display unit side. [Figure 5] This is a block diagram showing the control system of the leak location estimation device of this embodiment. [Figure 6] This figure shows the state in which the leak location estimation device of this embodiment is receiving signals near the leak location. [Figure 7] This is a flowchart of the leak location estimation processing program executed by the controller. [Figure 8] This figure shows the state in which half of the target image has been scanned on the display unit of the leak location estimation device of this embodiment. [Figure 9] This figure shows the state in which the entire surface of the target image has been scanned and displayed on the display unit of the leak location estimation device of this embodiment. [Figure 10] This is a flowchart of the symmetry center estimation process in this embodiment. [Figure 11] (A) is a diagram showing the state in which intensity information is displayed in each square of the target image, and (B) is a diagram showing the state in which valid information is displayed. [Figure 12] (A) is a diagram illustrating the procedure for determining the symmetrical position in the X direction based on valid information, and (B) is a diagram showing the intersection of the symmetrical positions in the X and Y directions. [Figure 13] This is a flowchart of the peak position estimation processing program executed by the controller. [Modes for carrying out the invention]

[0032] Embodiments of the leak location estimation device and method according to the present invention will be described below. In this embodiment, the case of detecting a gas leak inside a building will be described as an example.

[0033] As shown in Figure 1, the target piping 10 is laid along the walls 12 and floor 14 of the building and supplies gas to a gas consumption appliance (not shown). The wall 12 has an inner wall 12A and an outer wall 12B that are parallel to each other. The inner wall 12A is located on the interior side and partitions the interior of the room, and the outer wall 12B partitions the exterior from the inside of the wall 12D. The inner wall 12A and the floor 14 correspond to the shielding of the present invention. In this embodiment, an inspection opening 12C is provided in the outer wall 12B, and an opening 10A of the piping 10 is provided at a position corresponding to the inspection opening 12C. Access to the inside of the piping 10 is possible from this inspection opening 12C and opening 10A.

[0034] The piping 10 is installed on one side of the inner wall 12A and floor 14. The other side of the inner wall 12A and floor 14 is the room, i.e., the workspace R.

[0035] The leak location L1 of the piping 10 can be identified in advance using a search tool 16 in the following manner. As shown in Figure 2A, the search tool 16 has an air tube 16A and a balloon 16B. The balloon 16B is attached to the end of the air tube 16A. One end of the air tube 16A is connected to the inlet of the balloon 16B, and air can be supplied to the balloon 16B from the other end using a blowing means such as a rubber bulb 16C.

[0036] As shown in Figure 2B, the search for the leak location L1 with the search tool 16 involves deflating the balloon 16B and inserting the air pipe 16A from the balloon 16B side into the pipe 10 through the inspection port 12C. Then, air is sent at an arbitrary position to seal the pipe 10 with the balloon 16B, and the airtightness downstream of the sealing position is checked to determine whether or not there is a leak downstream of the sealing position. By repeating this process while changing the position of the balloon 16B, the position of the balloon 16B that maintains an airtight state and the position of the balloon 16B that does not maintain an airtight state are brought closer together, and the position of the balloon 16B that maintains an airtight state and is closest to the consumer equipment can be determined to be the leak location L1. The distance from the inspection port 12C to the leak location L1 can be confirmed by the insertion length of the air pipe 16A of the search tool 16.

[0037] Next, the transmitter 20 will be described.

[0038] As shown in Figure 3A, the transmitter 20 includes a power supply unit 22, a wire 24, and a signal transmitting unit 26. The signal transmitting unit 26 is located at the end of the wire 24 and consists of an antenna including a coil 26A (transmitting coil antenna). The axial direction S of the coil 26A is aligned with the extension direction of the wire 24 (the extension direction of the pipe 10). The maximum diameter 26R of the coil 26A is set to be smaller than the inner diameter of the pipe 10. By flowing current from the power supply unit 22, electromagnetic waves are generated from the signal transmitting unit 26, and these electromagnetic waves are transmitted as a signal.

[0039] As shown in Figure 3B, the transmitter 20 inserts a wire 24 into the piping 10 from the signal transmitting unit 26 side through the inspection port 12C and the opening 10A. By making the insertion length of the wire 24 the same as the insertion length when the search tool 16 detects the leak location L1, the signal transmitting unit 26 can be positioned at the leak location L1.

[0040] Next, the leak location estimation device 30 of this embodiment will be described. As shown in Figures 4A and 4B, the leak location estimation device 30 of this embodiment has a main unit 32, a receiver 34, a connecting bar 36, a camera 38, a positioning device 48, and a display unit 50.

[0041] The connecting bar 36 is rod-shaped, with a receiver 34 attached to its tip. The main body 32 is attached to the base end of the connecting bar 36 via a mounting part 37.

[0042] The receiver 34 includes a first coil receiving antenna 34A, a second coil receiving antenna 34B, and a third coil receiving antenna 34C, and receives electromagnetic wave signals from the signal transmitting unit 26. The coil axis S1 of the first coil receiving antenna 34A is positioned at an angle (approximately 90° in this embodiment) with respect to the extending direction of the connecting bar 36. The coil axis S2 of the second coil receiving antenna 34B is positioned at the same angle as the first coil receiving antenna 34A with respect to the extending direction of the connecting bar 36, and is positioned perpendicular to the first coil receiving antenna 34A. The coil axis S3 of the third coil receiving antenna 34C is positioned perpendicular to the first coil receiving antenna 34A and the second coil receiving antenna 34B. In the measurement work described later, the coil axis S1 of the first coil receiving antenna 34A and the coil axis S2 of the second coil receiving antenna 34B are positioned near the floor 14 in a direction along the floor surface (parallel to the floor surface).

[0043] A microcontroller 35 is provided near the receiver 34 of the connecting bar 36. The microcontroller 35 is composed of a CPU, ROM, RAM, etc. (not shown) and is connected to the first coil receiving antenna 34A, the second coil receiving antenna 34B, and the third coil receiving antenna 34C. The microcontroller 35 acquires the intensity K1 of the first electromagnetic wave signal received by the first coil receiving antenna 34A, the intensity K2 of the second electromagnetic wave signal received by the second coil receiving antenna 34B, and the intensity K3 of the third electromagnetic wave signal received by the third coil receiving antenna 34C, which are acquired at each point, and calculates the average value (intensity average) as the electromagnetic wave intensity K0 at that location. The calculation can be performed using the formula K0 = (K1 + K2 + K3) / 3. The microcontroller 35 has a communication function (Wi-Fi, Bluetooth, etc.) and transmits the electromagnetic wave intensity K0 to the controller 40, which will be described later.

[0044] In this embodiment, the first coil receiving antenna 34A, the second coil receiving antenna 34B, and the third coil receiving antenna 34C are positioned close to each other, and the first, second, and third electromagnetic wave signals received at the same timing are treated as the electromagnetic wave intensity K0 at the same position. If the first coil receiving antenna 34A, the second coil receiving antenna 34B, and the third coil receiving antenna 34C are separated to the extent that position correction is required, the reception timing and position of each antenna are corrected to calculate the electromagnetic wave intensity K0.

[0045] The main unit 32 is roughly rectangular in shape when viewed from the front, and is a thin rectangular parallelepiped. The main unit 32 comprises a housing 39, a controller 40, a camera 38, a positioning device 48, and a display unit 50. The controller 40, the positioning device 48, and the display unit 50 are housed inside the housing 39. The housing 39 is transparent in the part corresponding to the display unit 50 so that the information displayed on the display unit 50 can be seen from the outside. The display unit 50 is located on one side 32A of the main unit 32, and the camera 38 is located on the other side 32B of the main unit 32 opposite to the display unit 50. Images captured by the camera 38 are transmitted via the controller 40 and displayed on the display unit 50. The receiver 34 is captured within the image range of the camera 38. Within the image captured by the camera 38, the position of the receiver 34 is identified, and the electromagnetic wave intensity K0 received at that position, along with the position information P1 determined by the positioning device 48, is stored in the memory unit 45 (described later) as position signal intensity information D1.

[0046] The housing 39 forms the outer shape of the main body 32, and the mounting portion 37 is attached so as to sandwich the housing 39 in the thickness direction. The mounting portion 37 has a pocket 37A into which the connecting bar 36 is inserted, and a fixing portion 37B that is fixed to the housing 39.

[0047] The positioning device 48 determines the position of the receiver 34 and outputs position information P1 to the controller 40. Positioning can be performed using GPS, LiDAR, etc. Alternatively, a marker or QR code (not shown) may be attached to the receiver 34 for recognition by the camera 38.

[0048] As shown in Figure 5, the controller 40 is electrically connected to the camera 38, the positioning device 48, and the display unit 50. The controller 40 is also communicated with the microcontroller 35. Figure 5 is a block diagram showing an example of the electrical configuration of the controller 40 according to this embodiment.

[0049] As shown in Figure 5, the controller 40 includes a CPU (Central Processing Unit) 41, a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, an input / output interface (I / O) 44, and a storage unit 45.

[0050] The CPU 41, ROM 42, RAM 43, and I / O 44 are connected to each other via the bus 46. Each functional unit, including the memory unit 45, is connected to the I / O 44. These functional units are able to communicate with the CPU 41 via the I / O 44.

[0051] For the storage unit 45, for example, an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory may be used. The storage unit 45 stores control programs for controlling each part of the leakage location estimation device 30, as well as various data. These control programs and various data may also be stored in the ROM 42.

[0052] In this embodiment, a position estimation processing program and the like are stored as part of the control program. Furthermore, data used in this processing, such as position signal strength information D1, electromagnetic wave strength K0, and position information P1, are stored.

[0053] Next, the operation of the leak location estimation device 30 of this embodiment will be described.

[0054] The leakage location estimation device 30 is used within the workspace R, as shown in Figure 6. The signal transmitting unit 26 of the transmitter 20 is placed in advance at the leakage location L1, and current is supplied from the power supply unit 22. As a result, an electromagnetic wave signal is transmitted from the signal transmitting unit 26.

[0055] The worker positions the receiver 34 of the leak location estimation device 30 at a low position near the floor 14 where the leak location L1 is estimated to be located, with the coil axis S1 of the first coil receiving antenna 34A and the coil axis S2 of the second coil receiving antenna 34B aligned with the floor surface, and turns on the power supply (not shown). Upon turning on the power supply, image acquisition by the camera 38 begins, and the image (target image G) acquired at a predetermined rate is displayed on the display unit 50.

[0056] Furthermore, the receiver 34 begins receiving electromagnetic wave signals, and the positioning device 48 determines the position of the receiver 34. In addition, the camera 38 and LiDAR begin acquiring spatial shape data, a spatial map is created, and self-position estimation is performed. Then, the controller 40 executes the leakage location estimation processing program shown in Figure 7.

[0057] The leakage location estimation processing program divides the target image G into a grid and sequentially acquires the electromagnetic wave intensity K0 at the location corresponding to each grid cell. Therefore, the operator moves (scans) the receiver 34 along the grid of the target image G to acquire the electromagnetic wave intensity K0. The electromagnetic wave intensity K0 is the average value of the intensity K1 of the first electromagnetic wave signal, the intensity K2 of the second electromagnetic wave signal, and the intensity K3 of the third electromagnetic wave signal, and is calculated by the microcontroller 35. The target image G is an image corresponding to a target area that is pre-set to include the leakage location L1 based on the insertion length of the wire 24 of the transmitter 20, and each grid cell is a pixel on the target image G.

[0058] In step S10, the position information P1 of the receiver 34, which has been positioned by the positioning device 48, is acquired. In step S12, the electromagnetic wave intensity K0 transmitted from the microcontroller 35 is acquired. In step S14, position signal intensity information D1 is created by associating the acquired position information P1 with the electromagnetic wave intensity K0, and this information is stored in the storage unit 45.

[0059] Next, in step S16, the electromagnetic wave intensity K0 is displayed on the display unit 50. The electromagnetic wave intensity K0 is displayed by displaying it at the corresponding position in each of the grid sections of the target image G displayed on the display unit 50, based on the position information P1 (mapping display). In Figures 8 and 9, the electromagnetic wave intensity K0 is represented by shades of gray, with darker areas indicating lower intensity and lighter (white) areas indicating higher intensity.

[0060] The operator confirms that the electromagnetic wave intensity K0 is displayed at the corresponding location, then displays it in the next square and moves the position of the receiver 34.

[0061] Next, in step S18, it is determined whether scanning in the target area is complete, that is, whether the electromagnetic wave intensity K0 for all squares has been acquired. If the determination is negative, the process proceeds to step S20 to determine whether the receiver 34 has moved (moved to the next position by the operator). If the position change is not complete, the process waits until it is completed. If the position change is complete, the process returns to step S10 and the above process is repeated. This makes it possible to obtain the electromagnetic wave intensity K0 at each square position in the target image G. Figure 8 shows that the acquisition of electromagnetic wave intensity K0 for approximately half of the positions in the target image G has been completed, and Figure 9 shows that the acquisition of electromagnetic wave intensity K0 for all squares in the target image G has been completed.

[0062] If the judgment is affirmed in step S18, the process proceeds to step S30, where the symmetry center estimation process shown in Figure 10 is executed.

[0063] In the symmetry center estimation process, first, in step S32, the average value of the electromagnetic wave intensity K0 for all cells in the target image G is calculated, and in step S34, only the portion above the average value is retained as the effective region. Figure 11(A) shows the electromagnetic wave intensity K0 for all cells on the target image G, and Figure 11(B) shows the electromagnetic wave intensity K0 only for the effective region remaining after the processing in step S34.

[0064] Next, in step S36, the symmetrical position of the electromagnetic wave intensity K0 in the X direction in the target image is calculated. To calculate the symmetrical position, the "distance × electromagnetic wave intensity K0" is determined for each cell (pixel) on both sides (left and right) from an arbitrary position in the X direction of the effective area (shown by the vertical lines and × in Figure 12(A)), and the sum of the calculated values ​​on one side (left) and the sum on the other side (right) are compared across the line. The position where the difference between the sum on one side and the sum on the other side is smallest is defined as the symmetrical position of the electromagnetic wave intensity K0 in the X direction in the target image.

[0065] Next, in step S38, the symmetrical position of electromagnetic wave intensity K0 in the Y direction of the target image is calculated. The symmetrical position is calculated in the same way as in step S36, by finding the "distance × electromagnetic wave intensity K0" for each grid cell (pixel) on both sides (upper and lower) from an arbitrary position in the Y direction of the effective area, and comparing the sum of the calculated values ​​on one side (upper) with the sum of the values ​​on the other side (lower). The position where the difference between the sum of one side and the sum of the other side is smallest is taken as the symmetrical position of electromagnetic wave intensity K0 in the Y direction of the target image.

[0066] Next, in step S40, the intersection of the calculated symmetrical position in the X direction and the symmetrical position in the Y direction is determined as the center of symmetry. In Figure 12(B), this is the position marked with ×. After the process in step S40, the symmetry center estimation process is completed, and the program proceeds to step S22 shown in Figure 7, where the symmetry center is displayed on the display unit 50 as the estimated leakage position, and the leakage position estimation processing program is terminated.

[0067] According to the leakage location estimation processing program of this embodiment, the leakage location L1 can be easily estimated based on the location signal intensity information D1.

[0068] Here, we will explain the angles of the coil axis S of the transmitter 20 and the coil axes S1, S2, and S3 of the leakage location estimation device 30. The signal transmitting unit 26 of the transmitter 20 is inserted into the piping 10 located beneath the floor 14, but its orientation is unknown. When the angle between the coil axis S and the receiving coil axis becomes large, due to the relationship of electromagnetic wave distribution, in some locations, the received electromagnetic wave intensity may weaken even at close distances from the signal transmitting unit 26. Therefore, in this embodiment, coil axes S1 and S2, which are arranged parallel to the floor surface of the floor 14, are set at an angle of 90° to each other. In addition, a coil axis S3 is set to be arranged perpendicular to the floor surface of the floor 14. By setting three axes in this way and using the electromagnetic wave intensity received by each coil axis, the effect of unevenness in the electromagnetic wave distribution caused by the angle between the coil axis S and the receiving coil axis can be reduced.

[0069] In this embodiment, the electromagnetic wave intensity K0 was obtained for each grid cell, but it is not necessary to obtain the electromagnetic wave intensity K0 according to the grid cells; it may be obtained at any position. The symmetry center estimation process may be performed based on the electromagnetic wave intensity K0 at any position.

[0070] In this embodiment, the leakage location L1 was estimated by determining the center of symmetry through a symmetry center estimation process. However, the peak portion PE of the electromagnetic wave intensity K0 within the target image G may also be estimated as the leakage location L1. Here, "peak portion PE" refers to the portion where the electromagnetic wave intensity K0 of the corresponding grid area is clearly higher than that of the surrounding grid areas. When the peak portion PE is estimated as the leakage location L1, the peak location estimation processing program shown in Figure 13 is executed.

[0071] Steps S10 to S20 are executed as described above. If the determination in step S18 is affirmative, the program proceeds to step S22, where the peak portion PE is displayed on the display unit 50 as the estimated leak location, and the leak location estimation processing program is terminated.

[0072] In this way, by identifying the leak location L1, the opening formed by breaking the floor 14 during repairs can be reduced, and work costs can be suppressed.

[0073] In this embodiment, the electromagnetic wave intensity K0 of the electromagnetic wave signal is displayed on the display unit 50 of the leakage location estimation device 30, but the target image G may be displayed on the display unit of another terminal.

[0074] Furthermore, in this embodiment, the first coil receiving antenna 34A, the second coil receiving antenna 34B, and the third coil receiving antenna 34C are arranged so that the coil axis S1 and coil axis S2 are orthogonal, and the coil axis S3 is orthogonal to the coil axes S1 and S2. However, it is not always necessary for the three axes to be orthogonal. However, it is preferable that the angle between the coil axis S1 and coil axis S2 is 80 degrees or more and 90 degrees or less, and the angle between the coil axis S3 and the coil axes S1 and S2 is 80 degrees or more and 90 degrees or less. [Explanation of symbols]

[0075] 12A Inner wall (shielding object) 14 Floor (shield) 26. Signal Transmitter (Transmitting Coil Antenna) 30 Leak location estimation device 34 Receiver 34A First coil receiving antenna 34B Second coil receiving antenna 34C Third Coil Receiving Antenna 40 Controller (Estimation Unit) 45 Storage section D1 Position signal strength information K0 Electromagnetic wave intensity L1 Leak location PE peak section

Claims

1. Identify the location of the leak within the piping on one side of the shielding, The transmitting coil antenna at the tip of the wire is positioned at the aforementioned leakage location. The electromagnetic wave signal output from the transmitting coil antenna is received on the other side of the shielding object by a first coil receiving antenna whose coil axis is positioned in a first direction along the shielding surface of the shielding object, a second coil receiving antenna whose coil axis is positioned in a direction intersecting the first direction along the shielding surface of the shielding object, and a third coil receiving antenna whose coil axis is positioned in a direction intersecting the shielding surface. The electromagnetic wave intensity corresponding to the intensity of the electromagnetic wave signal received by the first coil receiving antenna, the electromagnetic wave signal received by the second coil receiving antenna, and the electromagnetic wave signal received by the third coil receiving antenna at multiple different locations is acquired as position signal intensity information, along with the reception position. Based on the multiple position signal strength information, the position of the transmitting coil antenna is estimated as the leakage location. Method for estimating the location of a leak.

2. The leakage location estimation method according to claim 1, wherein the angle between the first direction and the coil axis of the second coil receiving antenna is 80 degrees or more and 90 degrees or less, and the angle between the shielding surface and the coil axis of the third coil receiving antenna is 80 degrees or more and 90 degrees or less.

3. The average intensity of the electromagnetic wave signals received at the same location by the first coil receiving antenna, the second coil receiving antenna, and the third coil receiving antenna is defined as the electromagnetic wave intensity at that location. The method for estimating the location of a leak according to claim 1.

4. Within a receiving area including multiple points where the electromagnetic wave signal is received, the center of symmetry of the electromagnetic wave intensity at the multiple points is estimated to be the leakage location. A method for estimating the location of a leak according to any one of claims 1 to 3.

5. Within a receiving area including multiple points where the electromagnetic wave signal is received, the peak portions of the electromagnetic wave intensity at the multiple points are estimated to be leakage locations. A method for estimating the location of a leak according to any one of claims 1 to 3.

Images