How to check shaft condition

Abstract

The present invention aims to provide an unprecedented, revolutionary method for checking the state of a shaft. [Solution] A method for checking the condition of a vertical shaft 50 involves hanging a long, rigid body 1 having marking portions 1a arranged at equal intervals within the vertical shaft 50 from a position A1 of a specific XYZ coordinate at the upper opening of the shaft 50, and hanging a lightweight, wide measuring tape 5 having length scale portions 5a on its surface within the vertical shaft 50, photographing the vertical shaft 50 with an appropriate photographing means to create an image of the inside of the vertical shaft 50 that includes the marking portions 1a of the long body 1 and the length scale portions 5a of the measuring tape 5, and creating the three-dimensional point cloud 30 using this image, thereby checking changes in the condition of the vertical shaft 50.

Description

[Technical Field]

[0001] The present invention relates to a method for checking the state of a shaft. [Background technology]

[0002] Conventionally, when checking for changes in the condition of an underground structure surrounded by walls, such as damage or displacement of the inner wall surface of a tunnel, such as an adit, confirmation has been carried out using a three-dimensional point cloud generated by the three-dimensional point cloud generating device disclosed in Patent Document 1 (hereinafter referred to as the "conventional example").

[0003] This conventional example is equipped with a photographing unit that photographs the inner wall surface of a tunnel and a 3D point cloud generation unit that generates a 3D point cloud based on the images photographed by this photographing unit. The photographing unit moves inside the tunnel to photograph the inner wall surface, and the 3D point cloud is generated by the 3D point cloud generation unit based on the images photographed by this photographing unit. Note that a more accurate 3D point cloud can be obtained by assigning coordinates to the images photographed by the photographing unit.

[0004] Using this conventional example, 3D point clouds obtained at different times will be compared to identify changes in the condition of the tunnel's inner wall, such as damage or displacement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-62776 Summary of the Invention [Problem to be solved by the invention]

[0006] In addition to the tunnels mentioned above, there are other underground structures surrounded by walls, such as vertical shafts for collecting water that are installed in areas prone to landslides. There is also a demand for checking changes in the condition of these shafts using 3D point clouds. When generating a 3D point cloud for such a shaft, a camera unit is hung inside the shaft and moved down to photograph the inner wall surface, and a 3D point cloud is then generated by a 3D point cloud generation unit based on the images taken by this camera unit.

[0007] Furthermore, when trying to obtain coordinates (XYZ coordinates) within the shaft in order to make the three-dimensional point cloud of the shaft highly accurate, some shafts are as deep as 100m, and although coordinates near the top opening of the shaft can be easily obtained by GPS surveying, it is not possible to perform measurements using GPS inside the shaft, so highly accurate coordinates in the depth direction (Z coordinate) cannot be easily obtained.

[0008] Therefore, one easy way to obtain the Z coordinate in the depth direction within the shaft is to hang down a cloth tape measure with a scale (a weight is attached to the bottom end of the measure) and visually check the scale reflected in the image to obtain the Z coordinate. However, in reality, when hanging down this tape measure, it may twist along the way, stretch more than expected, or hit an obstacle (a staircase for ascending and descending within the shaft) and not hang down vertically, and so the Z coordinate may be obtained without realizing that the scale is displaying an inaccurate depth.

[0009] The present invention solves the above-mentioned problems and provides a revolutionary shaft condition checking method that has never been seen before. [Means for solving the problem]

[0010] The gist of the present invention will be explained with reference to the accompanying drawings.

[0011] This is a method for checking the state of a vertical shaft 50 by using a three-dimensional point cloud 30 created from an image of the inside of the vertical shaft 50 and the XYZ coordinates within the vertical shaft 50, and is characterized in that a rigid, elongated body 1 having marking portions 1a provided at equal intervals within the vertical shaft 50 is suspended from a specific XYZ coordinate position A1 at the upper opening of the vertical shaft 50, and a lightweight, wide measuring tape 5 having length scale portions 5a on its surface is suspended within the vertical shaft 50, the vertical shaft 50 is photographed using an appropriate photographing means to create an image of the inside of the vertical shaft 50 as an image including the marking portions 1a of the elongated body 1 and the length scale portion 5a of the measuring tape 5, and the three-dimensional point cloud 30 is created using this image to check the state of the vertical shaft 50.

[0012] The present invention also relates to a shaft state checking method as set forth in claim 1, characterized in that the marking portions 1a are provided on the elongated body 1 at 1 m intervals.

[0013] Furthermore, the method for checking the state of a vertical shaft described in any one of claims 1 and 2 relates to a method for checking the state of a vertical shaft, characterized in that color display sections 1' of different colors are arranged alternately at 1 m intervals on the surface of the elongated body 1, and the boundaries between the color display sections 1' are configured as the marker sections 1a.

[0014] Furthermore, in the method for checking the state of a vertical shaft described in any one of claims 1 and 2, the method relates to a method for checking the state of a vertical shaft, characterized in that the long body 1 is suspended into the vertical shaft 50 from positions A1 and A2 of specific XYZ coordinates at multiple positions on the same plane at the upper opening of the vertical shaft 50, and the measuring tape 5 is suspended into the vertical shaft 50, and the vertical shaft 50 is photographed using an appropriate photographing means to create an image of the inside of the vertical shaft 50 as an image including the marker portion 1a of each of the long bodies 1 and the length scale portion 5a of the measuring tape 5.

[0015] Furthermore, in the method for checking the state of a vertical shaft described in claim 3, the long body 1 is suspended into the vertical shaft 50 from positions A1 and A2 of specific XYZ coordinates at multiple positions on the same plane at the upper opening of the vertical shaft 50, and the measuring tape 5 is suspended into the vertical shaft 50, and the vertical shaft 50 is photographed using an appropriate photographing means to create an image of the inside of the vertical shaft 50 as an image including the marker portion 1a of each of the long bodies 1 and the length scale portion 5a of the measuring tape 5. [Effects of the Invention]

[0016] Because the present invention is configured as described above, it is possible to easily and reliably obtain a highly accurate three-dimensional point cloud of the shaft, which in turn makes it possible to effectively confirm changes in the shaft's condition, making it an unprecedented, revolutionary method for checking the shaft's condition. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a front view showing the imaging unit 20 according to the present embodiment. [Figure 2] FIG. 2 is a front view showing the elongated body according to the present embodiment. [Figure 3] 10 is an explanatory diagram of a state in which the inside of a vertical shaft 50 is photographed using the photographing unit 20 according to the present embodiment. FIG. [Figure 4] 10 is an explanatory diagram of an image taken inside a vertical shaft 50 using the photographing unit 20 according to the present embodiment. FIG. [Figure 5] 3 is an explanatory diagram of a three-dimensional point cloud 30 generated by a three-dimensional point cloud generating unit according to the present embodiment. FIG. [Figure 6] 10 is an explanatory diagram of a shaft state confirmation method for confirming changes in the state of a shaft 50 using a three-dimensional point cloud 30 according to this embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] A preferred embodiment of the present invention will be briefly described below, illustrating the operation of the present invention with reference to the drawings.

[0019] In the present invention, when checking changes in the state of the shaft 50, a highly accurate three-dimensional point cloud 30 is created from images of the inside of the shaft 50 and the XYZ coordinates within the shaft 50.

[0020] Specifically, a rigid elongated body 1 having markings 1a provided at equal intervals within shaft 50 is suspended from position A1 of specific XYZ coordinates at the upper opening of shaft 50, and a lightweight, wide measuring tape 5 having length scales 5a on its surface is suspended within shaft 50. At this time, elongated body 1 is suspended with any markings 1a aligned with position A1 of the specific XYZ coordinates, while measuring tape 5 is suspended with any length scale 5a (for example, length scale 5a with sharp numerical values ​​in 1-meter increments) aligned with position B of the XYZ coordinates whose Z coordinate is the same as position A1.

[0021] This long body 1 is made of a hard material and does not twist or stretch, allowing it to hang vertically, and the markings 1a on the long body 1 are arranged at equal intervals, so that by looking at a photographed image, for example, it is possible to check whether the condition of the tape measure 5 is normal or abnormal by comparing it with the long body 1. In other words, if there is a clear misalignment between the markings 1a on the long body 1 and the length scale portion 5a of the tape measure 5, it can be confirmed that the tape measure 5 is abnormal.

[0022] An image of the inside of the shaft 50 is taken using an appropriate photographing device, and an image of the inside of the shaft 50 is created that includes the marking portion 1a of the elongated body 1 and the length scale portion 5a of the tape measure 5. Any marking portion 1a within the shaft 50 on the elongated body 1 is displayed in large on the tape measure 5a, which is wider than the elongated body 1, and the depth distance (Z coordinate) from position A1 can be confirmed based on the length scale portion 5, which is clearly displayed in the image. The XYZ coordinates of that position can be determined. Note that if the elongated body 1 were made wider and a large length scale portion were displayed on the elongated body 1, the tape measure 5 would be unnecessary. However, in practice, making the elongated body 1 wider would result in an extremely heavy device, which would impair workability and be unrealistic. Furthermore, the length scale portion would be too small to measure using the elongated body 1 alone due to its narrow width. Therefore, using the elongated body 1 in combination with the tape measure 5 achieves good workability.

[0023] A three-dimensional point cloud 30 is created from the image inside the shaft 50 and the XYZ coordinates inside the shaft 50 obtained as described above, and this three-dimensional point cloud 30 is used to confirm changes in the state of the shaft 50.

[0024] Therefore, without using particularly high-precision and expensive equipment, the coordinates within the shaft 50 can be accurately determined in a simple manner, resulting in a high-precision three-dimensional point cloud 30, thereby making it possible to easily confirm changes in the state of the shaft 50. [Example]

[0025] Specific embodiments of the present invention will be described with reference to the drawings.

[0026] This embodiment is a shaft condition confirmation method that confirms changes in the condition of a shaft 50 using a three-dimensional point cloud 30 created from an image inside the shaft 50 and the XYZ coordinates within the shaft 50, and this three-dimensional point cloud 30 is created using a three-dimensional point cloud creation device described below.

[0027] Specifically, this 3D point cloud creation device includes an appropriate photographing means (photographing unit 20) that mainly photographs the inside of the shaft 50, a 3D point cloud generation unit (not shown) that generates a 3D point cloud 30 based on the images photographed by this photographing unit 20, a long body 1, and a measuring tape 5.

[0028] The photographing unit 20 is a mobile terminal (smartphone) with communication and digital camera functions as shown in FIG. 1, and can acquire images using a built-in 3D model creation support function (for example, the 3D model creation support application "PIX4D Catch" / PIX4D is a registered trademark).

[0029] In addition, the photographing unit 20 has a built-in LiDAR sensor (Light Detection and Ranging / LiDAR is a registered trademark), and this LiDAR sensor is configured to add information about the distance between the photographing unit 20 and the subject (the inner wall surface of the shaft 50) to the image photographed using the 3D model creation support function.

[0030] Therefore, by processing an image containing distance information between the photographing unit 20 and the subject (the inner wall surface of the shaft 50) using the image processing function of the 3D point cloud generation unit described later, a highly accurate 3D point cloud 30 can be created.

[0031] In addition, in this embodiment, a lighting unit 22 disclosed in Patent No. 6596042 proposed by the present applicant is provided on a base 21 in which a storage unit 21a for storing and arranging the photographing unit 20 rotates horizontally 360 degrees (driven by a motor), and further, the base 21 on which the photographing unit 20 and lighting unit 22 are provided is suspended into the vertical shaft 50 from the upper opening of the vertical shaft 50 using a hanging device 23 disclosed in Patent No. 6089069.

[0032] Therefore, the photographing unit 20 can be raised and lowered within the shaft 50 by the hanging device 23, and can photograph the entire interior of the shaft 50 by rotating horizontally 360 degrees.

[0033] In addition, in this embodiment, an image display device (not shown) is provided that has a communication function that allows electronic data to be sent and received from the photographing unit 20, and has an image display monitor that displays images captured by the photographing unit 20 in real time while the photographing unit 20 is performing photographing work inside the vertical shaft 50.

[0034] The 3D point cloud generation unit is a portable electronic computer (PC) that has a communication function that allows it to send and receive electronic data to and from the photographing unit 20, and also has a built-in function that creates a 3D point cloud 30 from images captured by the photographing unit 20 (for example, the point cloud processing application "PIX4D Matic" / PIX4D is a registered trademark).

[0035] Therefore, a plurality of images (digital photographic data) of the interior of the shaft 50 are received from the photographing unit 50, and a highly accurate three-dimensional point cloud 30 is generated from these images using SfM (Structure from Motion) analysis technology.

[0036] The long body 1 is a narrow strip of approximately 1 cm wide and 100 m long made of an appropriate hard (metallic) material as shown in Figure 2, and is arranged so that it can be wound and stored in a winding device 1b.

[0037] Moreover, markings 1a are provided at equal intervals on the front and back surfaces of the elongated body 1.

[0038] This marking section 1a is made up of color display sections 1' of different colors arranged alternately at 1m intervals on the surface of the elongated body 1, with the boundaries between the color display sections 1' forming the marking section 1a. Specifically, a silver base is painted with easy-to-recognize colors such as blue, red, white, or yellow at 1m intervals.

[0039] As with the measuring tape 5 described later, length scales (scale lines) are provided on both the front and back surfaces of the elongated body 1.

[0040] A weight 1d is provided at the tip (lower end when hanging) of the elongated body 1.

[0041] As shown in Figure 3, the measuring tape 5 is a wide strip of cloth (a woven fabric that is softer and lighter than the elongated body 1) approximately 6 cm wide and 100 m long, and is lighter and wider than the elongated body 1 described above.

[0042] Furthermore, length scale portions 5a (scale lines and numbers) are provided on the front and back surfaces of the measuring tape 5.

[0043] A weight 5b is provided at the tip (lower end when hanging) of the tape measure 5.

[0044] A method for checking the status of a vertical shaft 50 will now be described, in which a three-dimensional point cloud 30 of the vertical shaft 50 is generated using the three-dimensional point cloud creation device of this embodiment configured as described above, and this three-dimensional point cloud 30 is used to check changes in the status of the vertical shaft 50.

[0045] A metal mesh-like cover 51 is provided at the upper opening of a shaft 50 and has a plurality of positions on the same plane, with a long body 1 hanging from specific XYZ coordinate positions A1 and A2 into the shaft 50 to a position where the lower end cone 1d is located near the bottom, and a measuring tape 5 hanging from the shaft 50 to a position where the lower end cone 5b is located near the bottom. At this time, the long body 1 hangs down with any of the markings 1a aligned with the specific XYZ coordinate positions A1 and A2 (inserted into any of the mesh holes 51a with a maximum diameter of about 3 cm and the opening edge of the mesh hole 51a), while the measuring tape 5 hangs down along the inner wall surface of the shaft 50 with any of the length scales 5a (for example, length scales 5a with sharp numerical values ​​in 1-meter increments) aligned with position B (the end of the cover 51) of the XYZ coordinates that has the same Z coordinate as positions A1 and A2.

[0046] Each elongated body 1 is made of a hard material (metal) and does not twist or stretch, allowing it to hang vertically, and the markings 1a on the elongated body 1 are arranged at equal intervals, so that by looking at the photographed image, it can be confirmed whether the condition of the tape measure 5 is normal or abnormal by comparing it with the elongated body 1. In other words, if there is a clear misalignment between the markings 1a on the elongated body 1 and the length scale portion 5a of the tape measure 5, it can be confirmed that the tape measure 5 is abnormal.

[0047] The photographing unit 20 is lowered by the hanging device 23 and rotated horizontally 360 degrees to photograph the entire inner wall surface of the shaft 50, the long body 1 (mark portion 1a) and the measure 5 (length scale portion 5a) (at this time, the worker is checking the state inside the shaft 50 in real time while looking at the image displayed on the image display monitor of the image display device outside the shaft 50). The multiple image data photographed by this photographing unit 20 are sent to the 3D point cloud generation unit, and the above-mentioned positions A1, A2 and B are also photographed. The X and Y coordinates of the marks 1a on each of the elongated bodies 1 are obtained by GPS (GNSS) surveying to determine the X, Y, and Z coordinates at positions A1 and A2, and the depth distance (Z coordinate) from positions A1 and A2 to positions A1' and A2' of the marks 1a on each of the elongated bodies 1 within the shaft 50 is confirmed based on the length scale 5 that is provided in large display on a measuring tape 5a that is wider than each of the elongated bodies 1 and is clearly displayed on the image, and the X, Y, and Z coordinates of each of positions A1' and A2' within the shaft 50 are determined (see Figure 4). Note that the measuring tape 5 is made of cloth (woven fabric) and has a weight 5b attached to its lower end, so it stretches slightly, but this is an error that can be handled empirically.

[0048] Furthermore, in this embodiment, as described above, two elongated bodies 1 are hung down to determine the XYZ coordinates within the shaft 50; in other words, by providing multiple coordinate axes, the orientation of the shaft 50 (three-dimensional point cloud 30) can be identified; however, it is also possible to use only one elongated body 1 by also using the tape measure 5 as a landmark when determining the XYZ coordinates within the shaft 50.

[0049] The three-dimensional point cloud generation unit creates a three-dimensional point cloud 30 from the image inside the shaft 50 and the XYZ coordinates inside the shaft 50 obtained as described above (see Figure 5), and this three-dimensional point cloud 30 is used to confirm changes in the state of the shaft 50.

[0050] Specifically, for example, as shown in Figure 6, three-dimensional point clouds 30 are obtained at different times, such as years or months, and these three-dimensional point clouds 30 are compared and examined to check for changes in the condition of the inner wall surface of the shaft 50, such as damage (cracks), displacement (movement of the shaft 50), and deformation (bending and deformation of the shaft 50).

[0051] Therefore, according to this embodiment, without using particularly high-precision and expensive equipment, the coordinates within the shaft 50 can be accurately determined in a simple manner, and a high-precision three-dimensional point cloud 30 can be obtained, thereby making it possible to easily confirm changes in the state of the shaft 50.

[0052] In addition, in this embodiment, the marking portions 1a are provided on the elongated body 1 at 1 m intervals, making it easy to confirm the depth position of the marking portions 1a and allowing the coordinates within the shaft 50 to be determined accurately, thereby reliably achieving the aforementioned effects in this respect as well.

[0053] In addition, in this embodiment, color display sections 1' of different colors are arranged alternately at 1 m intervals on the surface of the elongated body 1, and the boundaries between the color display sections 1' are configured as marker sections 1a, making it easy to confirm the depth position of the marker sections 1a, thereby reliably achieving the aforementioned effects in this respect as well.

[0054] In addition, in this embodiment, long bodies 1 are suspended into the shaft 50 from positions A1 and A2 of specific XYZ coordinates at multiple positions on the same plane at the upper opening of the shaft 50, and a measuring tape 5 is suspended into the shaft 50.The shaft 50 is photographed using an appropriate photographing means to create an image of the inside of the shaft 50 as an image including the marker portion 1a of each long body 1 and the length scale portion 5a of the measuring tape 5.Therefore, the XYZ coordinates on the same horizontal plane within the shaft 50 can be determined using the marker portion 1a of each long body 1 and the length scale portion 5a of the measuring tape 5, and by providing multiple coordinate axes, the orientation of the shaft 50 (three-dimensional point cloud 30) can be identified, thereby reliably achieving the aforementioned effects in this respect as well.

[0055] The present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate. [Explanation of symbols]

[0056] A1 position A2 position 1 Long body 1' Color display section 1a Marking section 5. Major 5a Length scale 30 3D point clouds 50 Shaft

Claims

1. A method for checking the condition of a vertical shaft to check changes in the condition of the shaft using a three-dimensional point cloud created from an image of the inside of the shaft and the XYZ coordinates within the shaft, comprising: hanging a rigid, elongated body having marker portions set at equal intervals within the shaft from a specific XYZ coordinate position at the upper opening of the shaft; hanging a lightweight, wide measuring tape with length scale markings on its surface within the shaft; photographing the shaft with an appropriate photographing means to create an image of the inside of the shaft as an image including the marker portions of the elongated body and the length scale portion of the measuring tape; and creating the three-dimensional point cloud using this image to check changes in the condition of the shaft.

2. 2. A method for checking the state of a vertical shaft according to claim 1, wherein the marking portions are provided on the elongated body at intervals of 1 m.

3. A method for checking the status of a vertical shaft as described in any one of claims 1 and 2, characterized in that color display sections of different colors are arranged alternately at 1 m intervals on the surface of the elongated body, and the boundaries between the color display sections are configured as the marker sections.

4. A method for checking the status of a vertical shaft as described in any one of claims 1 and 2, characterized in that the long bodies are hung down into the vertical shaft from specific XYZ coordinate positions at multiple positions on the same plane at the upper opening of the vertical shaft, the measuring tape is hung down into the vertical shaft, and the vertical shaft is photographed using an appropriate photographing means to create an image of the inside of the vertical shaft as an image including the marker portions of each of the long bodies and the length scale portion of the measuring tape.

5. A method for checking the status of a vertical shaft as described in claim 3, characterized in that the long bodies are hung down into the vertical shaft from specific XYZ coordinate positions at multiple positions on the same plane at the upper opening of the vertical shaft, the measuring tape is hung down into the vertical shaft, and the vertical shaft is photographed using an appropriate photographing means to create an image of the inside of the vertical shaft as an image including the marker portions of each of the long bodies and the length scale portion of the measuring tape.

Images