JP7267557B2 - Track surrounding wall photographing device and track surrounding wall photographing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track surface photographing device and a track surface photographing method for photographing a surface surrounding a track with a plurality of moving cameras and detecting cracks formed on the surface.

The applicant of the present invention has already developed a wide-area surface imaging apparatus that can easily determine where cracks occur in an actual building, even if the surface is photographed with a large number of pixels. proposed (see, for example, Patent Document 1). More specifically, this wide-area surface imaging device captures images of a continuous tunnel wall surface using a plurality of cameras evenly installed along a semi-arc shape in order to photograph the tunnel wall surface.

In particular, the individual photographing planes of the cameras arranged adjacent to each other have an area in which they are superimposed on each other, and by irradiating this area with the laser pointer light, each of the individual photographing planes of the cameras arranged adjacent to each other has a To easily discriminate at which position of an actual building a crack occurs even on a photographing object surface photographed by increasing the number of pixels by reflecting the same laser pointer light. It has the advantage of being able to

Regarding this patent document 1, it is specifically assumed that the vehicle is mounted on the bed of a truck and photographed every time it is moved within a certain distance of 70 cm, and it is desirable to photograph the entire tunnel wall in a shorter time. was rare. Therefore, the applicant of the present application has proposed a tunnel peripheral wall photographing device capable of photographing the entire tunnel peripheral wall in a shorter time (see Patent Document 2).

Regarding the proposal of Patent Document 2, a group of cameras in which adjacent photographing areas of a plurality of cameras arranged along all or part of the vertical surface of the inner peripheral wall of the tunnel are adjusted so as to include a partial overlapping area. is moved along the longitudinal direction in the tunnel by a moving means such as a car, and continuous still images are obtained according to the continuous shooting speed by continuously photographing each camera of the camera group by the camera continuous shooting means. . Specifically, it is disclosed that cracks are determined in still images continuously shot at a speed of 15 km/h.

JP 2016-57579 A Utility Model Registration No. 3218047

Existing buildings such as tunnels are mainly present on public roads including expressways. Therefore, the inspection is carried out with all or part of the lanes in the relevant section closed to traffic or the number of lanes reduced. In this case, it is necessary to notify the section and time of road closure or lane reduction, and to warn drivers heading to the inspection site far before and just before the inspection site.

For this reason, it was the present condition that it was difficult to perform an inspection frequently. If the moving speed is at least 30 km/h or more, the moving speed is equivalent to that of a road cleaning vehicle that performs cleaning work at night or the like, so frequent inspections are possible. For this reason, it has been demanded to perform a crack determination inspection at a moving speed of 30 km/h or more.

However, subject blurring may occur in still images shot continuously at a speed of 30 km/h or more. In particular, during inspections in tunnels or at night, there are situations where the shutter speed of the camera cannot be increased, and this subject blurring may occur remarkably. For this reason, it is considered to increase the light source of the floodlight on the peripheral wall along with the camera group and increase the shutter speed. There is a possibility that the crack itself cannot be detected because the difference in illuminance between the two is not detected, and it is necessary to finely adjust the position of the projector.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a track surface photographing apparatus and a track surface photographing method capable of reliably detecting cracks even at a speed of 30 km/h or higher.

According to the first aspect of the present invention, there is provided an apparatus for photographing a peripheral wall of a track, which photographs a peripheral wall around a track with a plurality of moving cameras and detects cracks formed on the peripheral wall. hand,
a camera group arranged so that a part of the imaging area of the peripheral wall surface adjacent to the plurality of cameras arranged in the orthogonal direction of the running path includes an overlapping area;
camera group moving means for moving the camera group along the running path;
camera continuous shooting means for causing each camera of the camera group to shoot continuously;
means for correcting the width of cracks in the continuously shot images ;
The means for correcting the crack width includes:
A confirmation mark is attached in advance to the peripheral wall surface so as to face the horizontal camera of the camera group and is photographed by one of the camera group. It is characterized in that the blur amount is measured and the width of the crack is corrected using the subject blur amount .

According to the second aspect of the present invention, there is provided a track peripheral wall photographing device including a first camera group as the camera group of claim 1, and a part of the photographing area of the first camera group. A second camera group having shooting areas adjacent in the running direction,
The camera continuous photographing means synchronizes the first camera group and the second camera group arranged side by side, and photographs the photographing area of the first camera group and the photographing area of the second camera group together. This is characterized in that the area is photographed continuously.

According to a third aspect of the present invention, there is provided a method for photographing a surrounding wall of a track, in which a plurality of moving cameras photograph the surrounding wall of the track and detect cracks formed on the wall. hand,
a step of moving, along the track, a group of cameras arranged in such a manner that part of the photographing areas of the peripheral wall surface adjacent to the plurality of cameras arranged in the orthogonal direction of the track includes an overlapping area;
a step of continuously photographing the peripheral wall surface while synchronizing the individual cameras of the camera group;
a step of correcting the width of cracks in the continuously shot images ;
Before, during, or after continuously photographing the peripheral wall surface, a confirmation mark affixed to the peripheral wall surface in advance so as to face the horizontally positioned camera of the camera group is photographed by one of the camera groups. Further comprising a step of shooting and measuring the amount of subject blur,
The step of correcting the width of the crack in the continuously shot images is characterized by using the subject blur amount .

In the method for photographing a track surrounding wall according to the invention recited in claim 4, a first camera group as the camera group recited in claim 3, and a part overlapping the photographing area of the first camera group Using a second camera group having shooting areas adjacent in the running direction,
By synchronizing the first camera group and the second camera group arranged side by side, the photographing area obtained by combining the photographing area of the first camera group and the photographing area of the second camera group is continuously photographed. It is characterized by further comprising a step of causing

ADVANTAGE OF THE INVENTION The present invention has an effect that it is possible to obtain a track peripheral wall photographing apparatus and a track wall photographing method capable of reliably detecting cracks even at a speed of 30 km/h or more.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing the configuration of a track peripheral wall imaging device of the present invention; FIG. 2 is an explanatory diagram showing the configuration of the main part of the track peripheral wall imaging device of FIG. 1 ; It is explanatory drawing which shows the structure of the track peripheral wall surface imaging device of FIG. 1, a figure is a top view, b figure is a front view. FIG. 4 is an explanatory view of photographing by the track peripheral wall surface photographing device shown in FIG. 3 ; FIG. 4 is an explanatory diagram of an image taken by the track peripheral wall surface imaging device shown in FIG. 3 ; FIG. 4 is an explanatory diagram showing an example of a confirmation mark, FIG. 1A being a still image in a normal state, and FIG.

In the present invention, there is provided a track peripheral wall photographing device for photographing the peripheral wall around the track with a plurality of moving cameras and detecting cracks formed on the track, wherein the plurality of cameras are arranged in the direction perpendicular to the track. A group of cameras in which a part of the photographing area of the surrounding wall surface adjacent to the cameras is arranged including an overlapping area, a camera group moving means for moving the camera group along the track, and each camera of the camera group are connected continuously and means for correcting the width of cracks in the continuously photographed images. a confirmation mark attached to the peripheral wall surface and photographed by one of the cameras, extracting the confirmation mark from the photographed image, measuring the amount of subject blur, and using the amount of subject blur, the width of the crack is corrected . This makes it possible to reliably detect cracks even at a speed of 30 km/h or more.

As the camera group of the present invention, a plurality of cameras arranged in the direction perpendicular to the track may be arranged so that part of the imaging area of the adjacent peripheral wall surface includes an overlapping area. Also, the camera group moving means of the present invention may be any device that moves the camera group along the track. For example, if the track is a tunnel where cars and trains running on rails can run, a semi-circular or quarter-circular shape along the tunnel wall surface can be used as a means of moving the camera group for trucks and trains. By arranging a plurality of cameras approximately evenly on the edge of the base, the camera can be easily installed. In addition, if it is the inner wall side of a bridge girder or the floor plate surface where automobiles and trains can run, it is possible to shoot by arranging a group of cameras downward from the side wall in the direction perpendicular to the track on the base held behind the truck bed. Just do it.

As the camera continuous photographing means of the present invention, it is sufficient if it is capable of continuous photographing even at a speed of 30 km/h or more. As for the performance of the camera, if the continuous shooting function can shoot and save at a speed of 30 km / h or more, a camera with such performance may be used. It may function as a continuous shooting function by shooting.

Specifically, 30 km/h is 500 m/min and 833.3 cm/sec. Assuming that the width of one still image taken by one camera can capture 80 cm of the peripheral wall of the track, and the overlapping part of the adjacent still images is 5 cm × 2, the shooting is substantially 70 cm. width. Therefore, each camera of the camera group is continuously photographed by the camera continuous photographing means.

Specifically, if the camera can realize a continuous shooting function of 12 frames per second, it is possible to arrange multiple units in the direction perpendicular to the track direction, that is, in the vertical direction, and photograph the track wall surface. . For example, if the continuous shooting function of one camera is capable of taking 100 continuous shots, then it is sufficient to shoot with one set of cameras every 8.4 seconds.

If the time required to record 100 still images in a continuous shot is 8.4 seconds or less, the camera can move continuously at a speed of 30 km/h by switching the two groups of cameras every 8.4 seconds. If the time to record 100 consecutively shot still images in the recording means is 8.4×2=16.8 seconds or less, three sets of By switching the camera group in order every 16.8 seconds, it is possible to photograph the peripheral wall surface of the track while continuously moving at a speed of 30 km/h.

Further, in the case of a camera capable of realizing a continuous shooting function of six images per second, continuous shooting means can be configured by pairing a plurality of camera groups and driving them in synchronization. For example, two sets of camera groups are arranged side by side, and each camera of the second camera group is paired with each camera of the first camera group. The two paired cameras are set so as to photograph the inner wall regions adjacent to each other in the running direction. The two cameras that are paired are set to release the shutters at the same time by means of synchronization.

Assuming that the width of one still image captured by one camera can capture 80 cm of the peripheral wall of the track, and the overlapping portion of the adjacent still images is 5 cm × 2, pairing is possible. Still images taken by the two cameras have a substantially 140 cm shooting width. Under this condition, at a speed of 30 km/h, still images from the two paired cameras should be captured every 0.164 seconds.

The photographing intervals of the individual camera groups are synchronized by synchronizing means for the camera group in the vertical direction orthogonal to the track, and by continuous shooting means for the camera group in the horizontal direction along the track at intervals of 8.4 seconds. Continuous shooting or shooting every 0.084 seconds. In addition, assuming that the width of one still image taken by one camera can shoot 150 cm of the peripheral wall of the track, and the overlapping part of the adjacent still images is assumed to be 5 cm × 2, the actual shooting is 140 cm. If it is a width, the above-mentioned number of seconds, etc. can be doubled.

The still images of each group of cameras arranged in this way are shot at a speed of 30 km/h or more, so subject blur occurs while the shutter is opened and closed. In particular, it becomes conspicuous when the amount of light is insufficient and the shutter speed is slow. In this case, since the camera group itself is mounted on a moving vehicle and is moving at a speed of 30 km/h or more, pixels in the horizontal direction along the track become large. Specifically, for radial line segments with the same thickness, the thickness of horizontal lines in the same direction as the direction of movement does not change, but for vertical and diagonal line segments, only the horizontal component increases. Since the thickness of the line segment is increased, the thickness of the vertical line segment is also increased, and the thickness of the oblique line segment is thicker than that of the horizontal line segment and thinner than that of the vertical line segment.

For this reason, an image correcting means for correcting the traveling direction component of the continuously shot images is provided. Specifically, by performing correction to reduce the horizontal component of each pixel that constitutes a still image, subject blur is corrected even at speeds of 30 km/h or more, making it possible to reliably detect cracks. . The degree of subject blur differs depending on the difference in the amount of light at the shooting location, the moving speed of the camera group, and the like. Therefore, before, during, or after continuously photographing the peripheral wall surface, a step of photographing the confirmation mark with one of the cameras to measure the amount of subject blurring, and measuring the running direction component of the continuously photographed images. and a step of correcting using the subject blur amount when correcting.

In the present invention, there is provided a method for photographing a peripheral wall surface of a track by using a plurality of moving cameras to detect cracks formed on the peripheral wall surface of the track. A process of moving along the track a group of cameras arranged such that a part of the photographing area of the adjacent peripheral wall surface of the camera includes an overlapping area, and a process of continuously moving the peripheral wall surface while synchronizing the individual cameras of the camera group It comprises a step of continuously photographing and a step of correcting the traveling direction component of the continuously photographed images. This makes it possible to reliably detect cracks even at a speed of 30 km/h or higher.

FIG. 1 is an explanatory view showing the configuration of the roadway peripheral wall imaging apparatus of the present invention. FIG. 2 is an explanatory diagram showing the configuration of the main part of the track peripheral wall surface imaging device of FIG. 3A and 3B are explanatory diagrams showing the configuration of the track peripheral wall imaging apparatus of FIG. 1, where a is a plan view and b is a front view. 4A and 4B are explanatory diagrams of photographing by the track peripheral wall surface photographing device shown in FIG. 3. FIG. FIG. 5 is an explanatory diagram of an image captured by the track peripheral wall surface imaging device shown in FIG. 6A and 6B are explanatory diagrams showing an example of confirmation marks, FIG. 6A being a still image in a normal state, and FIG. 6B being a still image showing a state in which subject blur has occurred.

As shown in FIG. 1, the track peripheral wall surface imaging device 10 of the present embodiment includes a camera group 20 consisting of a plurality of cameras, a camera moving means 30 equipped with the camera group 20, and each camera 20 of the camera group 20. a camera synchronizing means 40 for synchronizing each camera, a camera continuous photographing means 50 for continuously photographing each synchronized camera, and a continuous photographing speed of the camera continuous photographing means 50 for continuously photographing in accordance with the speed of the camera moving means 30 and a photographing speed control means 60 for controlling so that the images partially overlap each other. Temporary recording means 70 for temporarily recording still images shot continuously by individual cameras; and an image correction means 90 for correcting subject blur of the still image.

In this embodiment, two groups of cameras 20a and 20b arranged in parallel in a direction orthogonal to the traveling direction are used in order to photograph the tunnel peripheral wall surface while traveling. The two groups of cameras 20a and 20b have the same configuration except for photographing adjacent photographing planes. Specifically, as the first camera group 20a, as shown in FIG. Two laser pointer support plates 23 are arranged alternately on the front and back. Each platform 22 and laser pointer support plate 23 support six cameras 20aa to 20af and laser pointer devices 25aa to 25ae shown in FIG. The other second camera group 20b has a similar configuration.

In this embodiment, the photographing plane 51 of one camera that constitutes the two groups of cameras 20a and 20b has a photographing range of 1,200×800 mm. 4 and 5, the cameras adjacent to each other in the first camera group 20a are directed in the shooting directions a to f in FIG. A region 52 is provided. Approximately the central portion of the overlapping photographing area 52 is adjusted so that the laser pointer light 53 of the laser pointer devices 25aa to 25ae is irradiated. Also in the second camera group 20b, an overlapping photographing area 52 is provided in which photographing planes ba1 to bf1 of adjacent cameras are overlapped, and a laser pointer light 53 is irradiated.

The photographing planes of the cameras of the first and second camera groups 20a and 20b arranged side by side are partly overlapped and adjacent to each other in the running direction. As shown in FIG. 5, a traveling direction overlapping photographing area 54 is provided in which the photographing surface aa1 of one camera of the first camera group and the photographing surface ba1 of one camera of the second camera group overlap each other. Similarly, the individual cameras arranged side by side in the running direction are also provided with overlapping running direction overlapping photographing areas 54 . By treating adjacent photographing areas sandwiching the traveling direction overlap photographing area 54 as one pair, cracks can be reliably detected even at a speed of 30 km/h or more.

A normal automobile is used as the camera moving means 30 of this embodiment. As shown in FIG. 3, the first camera group 20a shown in FIG. 2 and the second camera group 20b having the same configuration as the first camera group are connected to a carrier 31 of a carrier truck 30 as camera moving means. It is mounted approximately in the center of the Five balloon projectors 32 made of metal halide are arranged on luggage racks 31 in front of and behind the camera support 21, and a generator 33 for generating electricity supplied to each projector is arranged. These lights illuminate the inner wall of the tunnel brightly and uniformly.

Further, as the camera synchronizing means 40 shown in FIG. 1, a shutter remote controller is used for an existing camera. More specifically, in this embodiment, an infrared wireless shutter remote controller is used. This synchronizes the shutters of the individual cameras of the first camera group 20a and the second camera group 20b. Therefore, the photographing planes aa1, ba1 to af1, and bf1 shown in FIGS. 4 and 5 are photographed. As the camera continuous shooting means 50 of this embodiment, the continuous shooting function of each camera of the first camera group 20a and the second camera group 20b is used. Each camera used was capable of continuous photographing at 6 frames per second, and the number of images that could be continuously photographed was 100.

The photographing speed control means 60 of this embodiment adjusts the speed of the carrier truck 30 by adjusting the continuous photographing speed of the camera. That is, the continuous shooting function of each camera constituting the two camera groups 20a and 20b is capable of continuous shooting at 6 frames per second, and the number of images that can be continuously shot is 100 frames. Therefore, it is possible to perform continuous shooting for 100/6=16.66 seconds. In addition, since the two sets of camera groups 20a and 20b are synchronized and photographed, the width of one pair of still images can photograph 140 cm of the tunnel peripheral wall surface.

The actual width of the photographing area of 100 photographs is 140×100/100=140m, and this distance is photographed in 16.66 seconds, so the movement speed of the truck is 140/16.66×60×60. /1000 = 30.252 km/h. Therefore, in an actual filming site, the camera group is mounted on the loading truck 30, and ideally, the 140m wall of the tunnel should be photographed again every 16.66 seconds.

Therefore, third and fourth camera groups 20c and 20d, which have the same configuration as the first and second camera groups 20a and 20b, are further mounted on a carrier 31 as camera moving means 30 so that the first and second camera groups 20a and 20b When the continuous photographing of the camera groups 20a and 20b is completed, the third and fourth camera groups 20c and 20d are synchronized and continuously photographed. Still images of the first and second camera groups 20a and 20b are recorded in the temporary recording means 70 and the recording means 80 during the continuous shooting of the third and fourth camera groups 20c and 20d.

More specifically, as shown in FIG. 4, the cargo truck 30 is driven at a constant speed of 30.252 km/h toward the center line of the left lane of the tunnel 41 while the balloon light projector 32 (not shown) is illuminated. Then, when the measurement start point of the tunnel peripheral wall surface is reached, the individual cameras of the first and second camera groups 20a and 20b are synchronized to continuously shoot 100 frames at 6 frames per second to set the measurement end point. . As shown in FIGS. 4 and 5, two groups of photographing planes aa1, ba1 to af1, and bf1 are photographed by the first and second camera groups 20a and 20b on the tunnel peripheral wall on the opposite side of the traffic lane. be done.

Since the carrier truck 30 is traveling at a constant speed of 30.252 km/h, an overlapping photographing area 55 is generated in the traveling direction in the next group of still images obtained by continuous photographing at 6 frames per second. Further, by the next continuous shooting, the next still image is recorded while similarly generating an overlapping shooting area 55 in the traveling direction, and furthermore, by the same operation, 100 shooting planes aa100, ba100 to af100, which are continuously shot, bf100, and after that, the still images of the first and second camera groups 20a and 20b are temporarily recorded by the temporary recording means 70 while the third and fourth camera groups 20c and 20d are continuously shooting. Record in means 80 .

In this embodiment, a still image is shot at a speed of 30 km/h or more (=8.333 m/sec), but subject blur occurs while the shutter is opened and closed. In particular, it becomes conspicuous when the amount of light is insufficient and the shutter speed is slow. In this case, the pixels in the horizontal direction along the track become larger. Specifically, as shown in FIG. 6, the confirmation mark 91 in the normal state in FIG. There is no change in thickness for horizontal lines, but for vertical lines and diagonal line segments, only the horizontal component increases and the thickness of the line segment increases. , and the thickness of the diagonal line segment is thicker than that of the horizontal line segment and thinner than that of the vertical line segment.

Therefore, the image correcting means 90 corrects the running direction component of the continuously shot images. More specifically, by correcting each pixel constituting a still image to reduce the lateral component in the running direction, cracks can be reliably detected even at a speed of 30 km/h or more. The degree of subject blur differs depending on the difference in the amount of light at the photographing location, the difference in the moving speed of the camera group, and the like.

For this reason, a check mark 91 is affixed to a portion where cracks are not formed in the preliminary investigation stage on the peripheral wall surface to be inspected for cracks in advance, and confirmation is performed before, during, or after continuous photographing of the peripheral wall surface. The mark 91 may be photographed by one of the cameras to measure the amount of subject blur, and the amount of subject blur may be used when correcting the running direction component of the continuously shot images.

More preferably, cracks on the inner surface of the tunnel may be corrected by performing the following steps.
(1) Create two reference test patterns printed with lines of the correct width. For example, as shown in FIG. 6a, the same pattern has two widths of 0.2 mm and 0.4 mm.
(2) Attach these two types of reference test patterns to the tunnel wall. At this time, the sticking position should face the horizontal camera.
(3) Take continuous shots of the inside of the tunnel.
(4) Extract a reference test pattern from the captured image.

(5) Calculate the blur amount of the vertical line from the two types of pattern extraction results. (Example: Assume that 0.2 mm width → 0.8 mm width, 0.4 mm width → 1.2 mm width)
(6) Calculate the average blur and subtract it from the width of all vertical cracks photographed. (Example: (0.8-0.2)/2+(1.2-0.4)/2=(0.3+0.8)/2=0.55)
(7) Oblique cracks can be classified by angle and corrected. (Example: If the horizontal is 0 degrees, 0-22.5 degrees is uncorrected, and 22.5-67.5 degrees is subtracted from the average blur of the 45-degree line of the reference test pattern. 67. For 5-90 degrees, subtract 0.55 mm, which is the same as vertical.)
(8) For horizontal cracks, subtract 0.55mm from the length.

It is possible to cut noise by first performing a correction to cut shadows smaller than the thickness of the line segment (horizontal) in the running direction (horizontal) in the thin pattern in FIG. That is, by correcting each pixel constituting the still image to reduce the horizontal component in the running direction, the noise in the still image can be satisfactorily cut, and cracks can be reliably detected even at a speed of 30 km/h or more. becomes possible.

Further, as shown in FIG. 3, with respect to the camera groups 20 arranged on each of the two supports 21 on the loading platform 31, the first camera group 20 is first synchronized using camera continuous shooting control means (not shown). After recognizing the end of continuous shooting by the first cameras, continuous shooting by the second group of cameras is started, so that the entire tunnel wall can be photographed in a shorter time. It becomes possible. After the left lane in FIG. 4 is completed, the opposite lane is turned back and the peripheral wall surface on the opposite side of the tunnel is similarly photographed continuously.

In the present embodiment, an example is shown in which two groups of cameras, ie, the first and second camera groups 20a and 20b and the third and fourth camera groups 20c and 20d, continuously take pictures. However, if it takes a long time to record a still image, a fifth and sixth camera group may be added to perform continuous shooting.

10 ... Tunnel surrounding wall imaging device,
20a... First camera group,
20b... second camera group,
20c... the third camera group,
20d... Fourth camera group,
20aa to 20af... camera,
21 ... camera support,
22 ... camera platform,
23 ... laser pointer support plate,
24 ... installation table,
25 ... laser pointer device (25aa to 25ae),
30 ... Camera moving means (cargo truck),
31 ... loading platform,
32 ... balloon floodlight,
33 ... generator,
40 ... camera synchronization means,
41 Tunnel,
50 ... camera continuous shooting means,
51 ... shooting surface,
52 ... overlapping imaging area,
53 ... laser pointer light,
54 ... traveling direction overlapping photographing area,
aa1 to af1 ... photographing surface,
ba1 to bf1 ... photographing surface,
aa2 to af2 ... photographing surface,
ba2 to bf2 ... shooting surface,
aa100 to af100 ... photographing surface,
ba100 to bf100 ... shooting surface,
60 ... photographing speed control means,
70 Temporary recording means,
80 ... recording means,
90 ... image correction means,
91 ... confirmation mark,

Claims (4)

A track wall surface photographing device for photographing the wall surface around the track with a plurality of moving cameras and detecting cracks formed on the wall surface,
a camera group arranged so that a part of the imaging area of the peripheral wall surface adjacent to the plurality of cameras arranged in the orthogonal direction of the running path includes an overlapping area;
camera group moving means for moving the camera group along the running path;
camera continuous shooting means for causing each camera of the camera group to shoot continuously;
means for correcting the width of cracks in the continuously shot images ;
The means for correcting the crack width includes:
A confirmation mark is attached in advance to the peripheral wall surface so as to face the horizontal camera of the camera group and is photographed by one of the camera group. 1. A track peripheral wall photographing device , characterized in that the amount of blurring of a subject is measured, and the width of the crack is corrected using the amount of subject blurring . As the camera group, a first camera group and a second camera group having a photographing area that partially overlaps the photographing area of the first camera group and is adjacent to the traveling direction,
The camera continuous photographing means synchronizes the first camera group and the second camera group arranged side by side, and photographs the photographing area of the first camera group and the photographing area of the second camera group together. 2. The track peripheral wall photographing device according to claim 1, wherein the region is continuously photographed. A track wall surface imaging method for photographing a wall surface around a track with a plurality of moving cameras and detecting cracks formed on the wall surface,
a step of moving, along the track, a group of cameras arranged in such a manner that part of the photographing areas of the peripheral wall surface adjacent to the plurality of cameras arranged in the orthogonal direction of the track includes an overlapping area;
a step of continuously photographing the peripheral wall surface while synchronizing the individual cameras of the camera group;
a step of correcting the width of cracks in the continuously shot images ;
Before, during, or after continuously photographing the peripheral wall surface, a confirmation mark affixed to the peripheral wall surface in advance so as to face the horizontally positioned camera of the camera group is photographed by one of the camera groups. Further comprising a step of shooting and measuring the amount of subject blur,
A method of photographing a track peripheral wall , wherein the step of correcting the width of the crack in the continuously photographed images uses the amount of blurring of the subject . As the camera group, using a first camera group and a second camera group having an imaging area that partially overlaps the imaging area of the first camera group and is adjacent to the driving direction,
By synchronizing the first camera group and the second camera group arranged side by side, the photographing area obtained by combining the photographing area of the first camera group and the photographing area of the second camera group is continuously photographed. 4. The method for photographing a track peripheral wall surface according to claim 3, further comprising a step of causing the image to be captured.

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