Roadside wall photography device

Abstract

To provide a tunnel wall photography device capable of appropriately photographing a tunnel wall surface even when the position or attitude of a photographing vehicle suddenly changes, or the cross-sectional shape of the tunnel wall suddenly changes, and the distance from two or more cameras mounted on the photographing vehicle to the tunnel wall changes while driving.SOLUTION: In a tunnel wall photography device 100 for photographing a tunnel wall surface 3 by mounting two or more cameras on a photographing vehicle 1, a camera 63 photographs mutually different photographing areas 31A to 31B on a tunnel wall surface 3, having mutually different photographing directions 20A to 20C as viewed from the traveling direction of the photographing vehicle 1, and the principal points 21 of the photographic lenses are arranged so as to coincide when viewed from the direction of travel, and the imaging areas 31A to 31B that are adjacent to each other have areas that overlap with each other.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a roadside wall surface photographing device, and more particularly to an improvement of a roadside wall surface photographing device that mounts two or more cameras on a photographing vehicle and photographs a roadside wall surface installed along the traveling route of the photographing vehicle.

Background Art

[0002] There has conventionally been known a tunnel wall surface photographing device that photographs a tunnel wall surface while traveling in a tunnel and analyzes the photographed image to detect cracks or the like generated on the tunnel wall surface (for example, Patent Document 1). In Patent Document 1, it is described that the tunnel wall surface is divided into two or more photographing areas in the tunnel circumferential direction, and each of these photographing areas is photographed using two or more cameras. Further, by overlapping adjacent photographing areas in the tunnel circumferential direction, the photographed images of each camera are synthesized to generate a wider synthesized image, and an inspection of the tunnel wall surface is performed based on this synthesized image.

[0003] Furthermore, there has conventionally been known a tunnel wall surface photographing device that controls the orientation of each camera according to the shape and dimensions of the tunnel and the traveling lane of the photographing vehicle (for example, Patent Document 2). If the distance from the camera to the tunnel wall surface changes, the photographing area of each camera on the tunnel wall surface also changes. Therefore, in order to appropriately divide and photograph the tunnel wall surface, it is necessary to adjust the position and orientation of each camera. Patent Document 2 describes calculating the photographing direction of each camera according to the shape and dimensions of the tunnel and the traveling lane of the photographing vehicle, and pre-adjusting the orientation of each camera.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] Generally, railway tracks and roads have a cant (a gradient in the direction of the vehicle width) corresponding to the radius of curvature of the curve. Therefore, if the cant changes inside a tunnel, the tilt of the filming vehicle changes, and the distance from each camera to the tunnel wall changes. Also, if the cross-sectional shape of the tunnel changes inside the tunnel, the distance from each camera to the tunnel wall will also change.

[0006] If the distance to the tunnel wall changes, the shooting area of ​​each camera on the tunnel wall changes, which could make it impossible to properly divide the tunnel wall. Specifically, the overlap between adjacent shooting areas may become excessive or insufficient, potentially reducing the resolution of the composite image or causing missing areas within the composite image.

[0007] Conventional tunnel wall imaging systems require the orientation of each camera to be adjusted in advance before traveling through the tunnel; it is not possible to adjust the orientation of each camera while traveling through the tunnel. Therefore, when the cant or tunnel cross-sectional shape changes rapidly inside the tunnel, it is not possible to take appropriate photographs both before and after the change. Consequently, in order to photograph the entire tunnel wall, it was necessary to travel through the same tunnel multiple times with different camera orientations.

[0008] Furthermore, even if it were possible to automatically adjust the direction of each camera while the vehicle was traveling through a tunnel, mechanically rotating the cameras would take time, resulting in the problem that there would be sections where proper filming could not be performed while the vehicle was in motion.

[0009] Furthermore, conventional tunnel wall imaging systems employ a structure in which two or more cameras are supported by independent pillars, allowing for independent adjustment of their height and orientation. As a result, the camera's shooting direction may change due to the acceleration and deceleration of the imaging vehicle or vibrations of the vehicle body. When such changes in shooting direction differ between cameras, the changes in the shooting area on the tunnel wall also differ between cameras, causing changes in the overlapping area of ​​adjacent shooting areas and affecting the accuracy of image synthesis.

[0010] Furthermore, because tunnels generally have a hot and humid environment, cameras are prone to condensation, and conventional tunnel wall imaging devices sometimes have the problem of not being able to capture clear images.

[0011] Furthermore, these challenges are not limited to photographing tunnel walls; they also apply to photographing sound barriers, for example, and to photograph roadside walls installed along routes such as railway tracks or roads.

[0012] This invention has been made in view of the above circumstances, and aims to provide a roadside wall imaging device that can properly image the roadside wall even when the distance from two or more cameras mounted on the imaging vehicle to the roadside wall changes during travel. In particular, it aims to provide a roadside wall imaging device that can properly image the roadside wall even when the position or orientation of the imaging vehicle on the road changes abruptly, or when the cross-sectional shape of the roadside wall changes abruptly. It also aims to suppress changes in the camera's imaging direction due to acceleration / deceleration of the imaging vehicle or vibration of the vehicle body. [Means for solving the problem]

[0013] A roadside wall photographing device according to a first embodiment of the present invention is a roadside wall photographing device that mounts two or more cameras on a photographing vehicle and photographs a roadside wall installed along the path of the photographing vehicle, wherein the cameras are arranged so that their photographing directions as viewed from the direction of travel of the photographing vehicle are different from each other, and they photograph different photographing areas on the roadside wall, and the principal points of the photographing lenses coincide as viewed from the direction of travel, and the adjacent photographing areas have overlapping areas.

[0014] By positioning the cameras so that the principal points of the cameras coincide when viewed from the direction of travel, it is possible to always ensure overlapping areas between adjacent shooting regions on the roadside wall, even if the distance from each camera to the roadside wall changes. Therefore, when using two or more cameras mounted on a moving vehicle to divide and photograph the roadside wall, even if the distance from each camera to the roadside wall changes due to a change in the position or orientation of the vehicle, or a change in the cross-sectional shape of the roadside wall, it is possible to continue photographing the roadside wall.

[0015] A roadside wall imaging device according to a second embodiment of the present invention, in addition to the above configuration, comprises a cylindrical mount that supports two or more cameras and is positioned such that its central axis coincides with the direction of travel, the cameras are positioned at different positions on the central axis, the principal point of the imaging lens is positioned on the central axis, and the cylindrical mount has an opening on the imaging axis of the camera.

[0016] By supporting two or more cameras with cylindrical mounts positioned so that their central axes coincide with the direction of travel, it is possible to suppress relative changes in the shooting direction between cameras due to the effects of the vehicle's acceleration and vibration. This makes it possible to secure overlapping areas between adjacent shooting regions on the roadside wall.

[0017] A roadside wall imaging device according to a third embodiment of the present invention comprises, in addition to the above configuration, two or more imaging units attached to the cylindrical frame, each having a camera, an imaging window, and an illumination device, wherein the camera is inserted into the cylindrical frame from the opening and images the imaging area through the imaging window provided in the imaging direction, and the illumination device is positioned outside the cylindrical frame and configured to illuminate the imaging area.

[0018] By adopting this configuration, a roadside wall imaging device can be obtained by attaching two or more imaging units to a cylindrical mount having two or more openings corresponding to the shooting direction of each camera.

[0019] A roadside wall photographing device according to a fourth embodiment of the present invention, in addition to the above configuration, comprises a pair of lighting devices in the photographing unit, the pair of lighting devices being arranged on either side of the photographing window and having a shape that extends in a direction perpendicular to the direction of travel.

[0020] By adopting this configuration, it is possible to ensure the intensity and spread of the illumination light while arranging the lighting devices of adjacent shooting units so that they do not interfere with each other.

[0021] A fifth embodiment of the present invention provides a roadside wall imaging device that, in addition to the above configuration, includes a dehumidifier that supplies dehumidified air into the cylindrical mount. By adopting such a configuration, condensation on the camera can be prevented. In particular, by supplying dehumidified air into a cylindrical mount on which two or more cameras are arranged, condensation on two or more cameras can be prevented simultaneously, thereby reducing the cost of condensation prevention.

[0022] According to the sixth embodiment of the present invention, a roadside wall surface photographing apparatus mounts three or more cameras on a photographing vehicle and photographs a roadside wall surface installed along the traveling path of the photographing vehicle. In the roadside wall surface photographing apparatus, a first cylindrical pedestal that extends in the traveling direction and supports two or more of the cameras, and a second cylindrical pedestal that is connected to the first cylindrical pedestal so as to be relatively rotatable with the central axis being aligned and supports one or more of the cameras are provided. The three or more cameras have different photographing directions when viewed from the traveling direction of the photographing vehicle, photograph different photographing areas on the roadside wall surface, the principal points of the photographing lenses are arranged on the central axis, and adjacent photographing areas have overlapping areas. By adopting such a configuration, various roadside wall surfaces can be photographed.

[0023] According to the seventh embodiment of the present invention, in addition to the above configuration, the first cylindrical pedestal supports two or more of the cameras for photographing the ceiling of the roadside wall surface and is rotatably fixed to the photographing vehicle, and the second cylindrical pedestal supports two or more of the cameras for photographing the side wall of the roadside wall surface and is rotatably fixed to the photographing vehicle.

[0024] By adopting such a configuration, when photographing a roadside wall in a railway or road having two or more traffic lanes, it is possible to correspond to both the case of traveling in the left lane and photographing the ceiling and the left side wall, and the case of traveling in the right lane and photographing the ceiling and the right side wall.

[0025] According to the eighth embodiment of the present invention, in addition to the above configuration, the internal spaces of the first and second cylindrical pedestals communicate with each other, and a dehumidifying device for sending dehumidified air into the internal space is provided. By adopting such a configuration, it is possible to prevent the cameras from condensing. In particular, by sending dehumidified air into the communicating internal space, condensation of three or more cameras can be prevented collectively, so that the cost for preventing condensation can be suppressed.

[0026] According to a ninth embodiment of the present invention, the roadside wall surface photographing apparatus further includes a slide mechanism that slides the first and second cylindrical mounts in the traveling direction to transition between a storage position and a photographing position. In the storage position, the three or more cameras are arranged on the floor surface of the photographing vehicle. In the photographing position, the cameras supported by the second cylindrical mount are arranged to protrude in the traveling direction from the floor surface.

[0027] By adopting such a configuration, it is possible to photograph a low region of the roadside wall surface, particularly a region lower than the floor surface of the photographing vehicle.

[0028] According to a tenth embodiment of the present invention, the roadside wall surface photographing apparatus further includes that the photographing vehicle is a railway vehicle in addition to the above configuration.

[0029] According to an eleventh embodiment of the present invention, the roadside wall surface photographing apparatus further includes that the photographing vehicle is an automobile in addition to the above configuration.

[0030] According to a twelfth embodiment of the present invention, the roadside wall surface photographing apparatus further includes that the roadside wall surface is a tunnel lining surface in addition to the above configuration.

[0031] According to a thirteenth embodiment of the present invention, the roadside wall surface photographing apparatus further includes that the roadside wall surface is a soundproof wall surface in addition to the above configuration.

Effect of the Invention

[0032] According to the present invention, even when the distance from the two or more cameras mounted on the photographing vehicle to the roadside wall surface changes during traveling, the roadside wall surface can be appropriately photographed. In particular, even when the position or posture of the photographing vehicle on the traveling road changes suddenly, or when the cross-sectional shape of the roadside wall surface changes suddenly, the roadside wall surface can be appropriately photographed. Further, it is possible to suppress the change in the photographing direction of the camera due to the acceleration / deceleration of the photographing vehicle or the vibration of the vehicle body.

Brief Description of the Drawings

[0033] [Figure 1]Figure 1 shows an example of the shooting directions 20A to 20C of two or more cameras mounted on the shooting vehicle 1. [Figure 2] This is an explanatory diagram showing an example of a shooting area 31A to 31C on the tunnel wall surface, which is captured by two or more cameras under predetermined conditions. [Figure 3] This is an explanatory diagram showing an example of the imaging areas 31A to 31C on the tunnel wall surface that are captured by two or more cameras when the cant changes. [Figure 4] This is an explanatory diagram showing an example of the imaging areas 31A to 31C on the tunnel wall surface, which are captured by two or more cameras when the cross-sectional shape of the tunnel changes. [Figure 5] This diagram shows an example of the arrangement of shooting areas 311-319, illustrating the case where the vehicle is driving in the left lane inside the tunnel and the left side of the ceiling and left wall are being photographed. [Figure 6] This diagram shows an example of the arrangement of shooting areas 311-319, illustrating the case where the vehicle is driving in the right lane inside the tunnel and the right side of the ceiling and the right side wall are being photographed. [Figure 7] This figure shows one example configuration of a tunnel photography device 100 according to an embodiment of the present invention. [Figure 8] This diagram shows one example configuration of cylindrical frames 51-53. [Figure 9] This diagram shows one example configuration of the imaging unit 6. [Figure 10] This is a perspective view showing how the imaging unit 6 is attached to the cylindrical mounts 51-53. [Figure 11] This is a perspective view showing the imaging unit 6 attached to the cylindrical mounts 51-53. [Figure 12] This diagram schematically shows a cross-section when the lens 631 is cut through a cross-section passing through its principal point 21. [Figure 13] This is a perspective view showing an example of the rotational movement of the cylindrical frames 51-53, and corresponds to Figure 5. [Figure 14] This is a perspective view showing an example of the rotational movement of the cylindrical frames 51-53, and corresponds to Figure 6. [Figure 15] This is an explanatory diagram of the sliding operation of the in-vehicle unit 5, showing the unit 5 in the storage position. [Figure 16] This is an explanatory diagram of one example configuration for preventing condensation in the in-vehicle unit 5. [Modes for carrying out the invention]

[0034] The following embodiments describe a tunnel wall imaging device, but the application of the present invention is a roadside wall imaging device that images roadside walls installed along the path of an imaging vehicle. Roadside walls include, but are not limited to, the ceiling and side walls of a tunnel. For example, soundproof walls are also included as roadside walls. Furthermore, the following embodiments describe a case where the imaging vehicle is a railway vehicle, but the imaging vehicle according to the present invention is not limited to a railway vehicle, and includes, for example, an automobile.

[0035] Figures 1 to 4 are explanatory diagrams illustrating the outline of a tunnel wall imaging device according to an embodiment of the present invention. Figure 1 shows an example of the imaging directions 20A to 20C of two or more cameras mounted on the imaging vehicle 1. Figures 2 to 4 are explanatory diagrams showing an example of the imaging areas 31A to 31C on the tunnel wall surface captured by two or more cameras. In all figures, (a) shows the case of the tunnel wall imaging device 100 according to this embodiment, and (b) shows the case of a conventional tunnel wall imaging device 101 for comparison with the present invention.

[0036] The tunnel wall imaging device 100 is a device in which an imaging vehicle 1 equipped with two or more cameras (not shown) travels inside the tunnel and images the tunnel wall 3 to detect cracks and other defects on the tunnel wall 3. Each camera has different imaging directions 20A to 20C. Therefore, each camera forms different imaging fields 30A to 30C and images different imaging areas 31A to 31C on the tunnel wall 3.

[0037] The shooting directions 20A to 20C are the directions of the shooting axes of each camera, all of which are perpendicular to the direction of travel of the shooting vehicle 1, and have different vertical angles to each other. The shooting field of view 30A to 30C is the space that each camera can shoot, and is determined by the camera's installation position, shooting directions 20A to 20C, and the focal length (field of view) of the shooting lens, forming a fan-shaped space when viewed from the direction of travel of the shooting vehicle 1. The shooting area 31A to 31C is the tunnel wall 3 within the shooting field of view 30A to 30C, and is the area on the tunnel wall 3 that is photographed by each camera.

[0038] In the tunnel wall imaging device 100 according to the present invention shown in Figure 1(a), the principal points 21 of the imaging lenses of each camera are arranged to coincide when viewed from the direction of travel of the imaging vehicle 1. In other words, the principal points 21 of each imaging lens are located on a common axis parallel to the direction of travel of the imaging vehicle 1. The principal point of a lens is the point where the optical axis and principal surface of the lens intersect. Therefore, the imaging axis of each camera starts from the common principal point 21 and extends toward different imaging directions 20A to 20C.

[0039] In the comparative example tunnel wall imaging device 101 shown in Figure 1(b), each camera is positioned according to the imaging area 31A to 31C, and the principal points 21A to 21C of the imaging lenses of each camera are not positioned to coincide when viewed from the direction of travel of the imaging vehicle 1. Therefore, the imaging axes of each camera start from different principal points 21A to 21C and extend toward different imaging directions 20A to 20C.

[0040] Figure 2 shows how the tunnel wall 3 is divided into two or more shooting areas 31A to 31C under predetermined shooting conditions. Each camera's shooting field of view 30A to 30C is pre-adjusted so that adjacent shooting areas 31A to 31C have an appropriate overlapping area. For example, the shooting field of view 30A to 30C of each camera is pre-adjusted considering shooting conditions such as the cross-sectional shape of the tunnel and the lane (driving position in the vehicle width direction) of the vehicle being photographed 1. Therefore, in either case (a) or (b) in the figure, the tunnel ceiling and left wall can be divided into two or more shooting areas 31A to 31C such that adjacent shooting areas 31A to 31C have an overlapping area.

[0041] Figure 3 shows what happens when the cant changes while the camera vehicle 1 is in motion, causing the camera vehicle 1 to tilt significantly. As the camera vehicle 1 tilts towards the left wall of the tunnel, the distance from each camera to the tunnel wall 3 becomes shorter compared to the case in Figure 2. In the conventional example shown in Figure 3(b), the change in cant makes it impossible to secure overlapping areas between the camera areas 31A and 31C. In contrast, in this embodiment shown in Figure 3(a), overlapping areas between the camera areas 31A and 31C are secured even when the cant changes.

[0042] Figure 4 shows what happens when the cross-sectional shape of the tunnel changes. Due to the change in the cross-sectional shape of the tunnel, the distance from each camera to the tunnel wall 3 becomes shorter compared to the case in Figure 2. In the conventional example shown in Figure 4(b), the change in the cross-sectional shape of the tunnel makes it impossible to secure an overlapping area between the shooting areas 31A to 31C. In contrast, in this embodiment shown in Figure 4(a), even if the cross-sectional shape of the tunnel changes, an overlapping area between the shooting areas 31A to 31C is secured.

[0043] In conventional tunnel wall imaging devices 101, the principal points 21A to 21C of the imaging lenses do not coincide. Therefore, even if an overlapping area is secured between imaging regions 31A to 31C under assumed imaging conditions, if the imaging conditions change and the distance from each camera to the tunnel wall 3 becomes shorter, it becomes impossible to secure an overlapping area between imaging regions 31A to 31C. To prevent this problem, it is conceivable to widen the overlapping area under assumed conditions, but this would require widening the field of view of each camera or increasing the number of cameras. However, widening the field of view of each camera leads to a decrease in the resolution of the captured images, and increasing the number of cameras leads to an increase in cost.

[0044] In contrast, in the tunnel wall imaging device 100 according to this embodiment, the principal point 21 of the imaging lens is aligned, so even if the distance from each camera to the tunnel wall 3 changes, the overlapping area between imaging regions 31A to 31C can always be secured. For this reason, even if the cant changes or the cross-sectional shape of the tunnel changes, the tunnel wall 3 can be divided into appropriate imaging regions 31A to 31C and imaged. Moreover, this does not lead to a decrease in resolution or an increase in cost. Furthermore, each camera is equipped with autofocus control according to the distance to the tunnel wall 3, so imaging can continue even if the distance to the tunnel wall changes.

[0045] A composite image of the tunnel wall 3 is generated by combining the images captured by each camera. In the conventional tunnel wall imaging device 101, the tilt-shift effect (distortion of the captured image due to perspective) differs for each camera, and it was necessary to correct the tilt-shift effect of each captured image before combining them. In contrast, the tunnel wall imaging device 100 according to the present invention avoids different tilt-shift effects between adjacent cameras by aligning the principal points 21 of the imaging lenses. Therefore, the image synthesis process can be made easier.

[0046] Figures 5 and 6 show an example of the arrangement of the shooting areas 311 to 319 according to this embodiment. The tunnel wall shooting device 100 operates with a shooting vehicle 1 equipped with two or more cameras, which travels through the tunnel, with each camera taking pictures at regular intervals. For example, each camera takes a picture simultaneously every 0.5 mm the shooting vehicle 1 moves forward.

[0047] Furthermore, the tunnel wall imaging device 100 simultaneously images the ceiling and either the left or right side wall. For example, if there are two or more driving lanes in the tunnel, it images the ceiling in the lane in which the imaging vehicle 1 is traveling and the side wall closest to that lane. Figure 5 shows the case where the vehicle is driving in the left lane of the tunnel and the left portion of the ceiling and the left wall are photographed, while Figure 6 shows the case where the vehicle is driving in the right lane of the tunnel and the right portion of the ceiling and the right wall are photographed.

[0048] In the diagram, shooting fields 301-305 are for ceiling photography, and shooting fields 306-309 are for side wall photography. The cameras for ceiling photography and side wall photography use different focal lengths of their lenses. For ceiling photography, a longer focal length lens is used compared to side wall photography, and the field of view for ceiling photography (301-305) is narrower than that for side wall photography (306-309). Generally, the distance from the shooting vehicle 1 to the ceiling is longer than the distance to the side wall, and by using a longer focal length lens in the ceiling photography camera than in the side wall photography camera, it is possible to obtain roughly the same resolution in the images of the ceiling and side wall.

[0049] If the filming vehicle 1 is an automobile and the two lanes in the tunnel are traveling in opposite directions, then the exact same filming vehicle 1 can be used to film both while traveling in the left lane and while traveling in the right lane. However, if the two lanes are traveling in the same direction, the filming direction of the camera used to film the side wall must be changed depending on whether the vehicle is in the left or right lane. Furthermore, if the filming vehicle 1 is a railway vehicle, it cannot be turned 180 degrees like an automobile, so regardless of the direction of travel in each lane in the tunnel, the filming direction of the camera used to film the side wall must be changed depending on whether the vehicle is in the left or right lane.

[0050] Comparing Figures 5 and 6, the shooting fields 301-305 for the ceiling remain unchanged in their relative position to the shooting vehicle 1, while the shooting fields 306-308 for the side walls rotate integrally around the principal point 21 of the shooting lens. Furthermore, the shooting field 309 for the lowest part rotates independently of the shooting fields 306-308 for the side walls, also around the principal point 21.

[0051] If a configuration were adopted in which all shooting fields 301-309 rotate as a single unit, changing the driving lane would cause the ceiling shooting fields 301-305 to be directed towards the side wall, and the side wall shooting fields 306-309 to be directed towards the ceiling, making it impossible to obtain images with appropriate resolution. For this reason, the ceiling shooting fields 301-305 are fixed, while the side wall shooting fields 306-309 are rotated.

[0052] Furthermore, if a configuration is adopted in which the side wall shooting fields 306-309 rotate integrally, when the driving lane is changed, the shooting field 309 for the bottom of the side wall will be directed towards the top of the side wall. Here, the bottom of the side wall is photographed by a dedicated camera that can photograph without being obstructed by the floor. For this reason, while the shooting fields 306-308 for the side walls rotate integrally, the shooting field 309 for the bottom of the side wall rotates independently of these.

[0053] Figure 7 shows an example configuration of a tunnel wall imaging device 100 according to an embodiment of the present invention. The tunnel wall imaging device 100 consists of an imaging vehicle 1 equipped with two or more cameras. The imaging vehicle 1 comprises two or more bogies 40 that run on the railway tracks, a vehicle body floor 41 supported by the bogies 40, a sliding mechanism 42, and an on-board unit 5 having a number of cameras.

[0054] The on-board unit 5 is mounted on the vehicle floor 41 via a sliding mechanism 42 and can be slid in the direction of travel relative to the vehicle floor 41. By sliding the on-board unit 5 and positioning the camera outside the vehicle floor 41, the lowest part of the tunnel's side wall can also be photographed.

[0055] The vehicle-mounted unit 5 comprises a base frame 500 attached to a sliding mechanism 42, support columns 501 to 503 extending upward from the base frame 500, frame support parts 511 to 513 provided at the upper ends of the support columns 501 to 503, and frame units 521 to 523 supported by the frame support parts 511 to 513.

[0056] Mounting units 521 to 523 are configured by attaching one or more imaging units 6 to a single cylindrical mounting base 51 to 53. Mounting unit 521 is a mounting unit for ceiling imaging, with five imaging units 6 attached to a cylindrical mounting base 51 for imaging the ceiling of the tunnel wall 3. Mounting unit 522 is a mounting unit for side wall imaging, with three imaging units 6 attached to a cylindrical mounting base 52 for imaging the side walls of the tunnel wall 3. Mounting unit 523 is a mounting unit for bottom imaging, with one imaging unit 6 attached to a cylindrical mounting base 53 for imaging the bottom of the side wall.

[0057] Figure 8 shows an example configuration of cylindrical mounts 51-53. Each of the cylindrical mounts 51-53 is cylindrical in shape and is connected to one another so that their central axes 50 coincide. The connected cylindrical mounts 51-53 are positioned so that their central axes 50 coincide with the direction of travel of the imaging vehicle 1. In addition, one or more openings 55 are provided on the side of each cylindrical mount 51-53, and four unit fixing grooves 56 are formed near each opening 55.

[0058] The cylindrical frames 51-53 are rotatably supported by frame support sections 511-513. Furthermore, the cylindrical frames 51-53 can rotate relative to each other. That is, the cylindrical frame 52 for the side wall is rotatable relative to the cylindrical frame 51 for the ceiling. Also, the cylindrical frame 53 for the lowest section is rotatable independently of the cylindrical frames 51 and 52 for the ceiling and side walls. The cylindrical frames 51-53 may be directly connected, or they may be connected via the frame support sections 512 and 513. The rotational drive of the cylindrical frames 51-53 is performed by a rotational drive unit (not shown) within the frame support sections 511-513.

[0059] The opening 55 is an opening for mounting the imaging unit 6 and is formed on the circumferential surface of the cylindrical mounts 51-53, which are in the direction of camera shooting when viewed from the central axis 50. The imaging unit 6 can be fitted into the opening 55 without creating any gaps.

[0060] The unit fixing groove 56 is an engaging recess for defining the mounting position of the imaging unit 6. By forming three or more unit fixing grooves 56 with different circumferential or axial positions, and inserting and engaging the projections of the imaging unit 6 into each, the imaging unit 6 can be fixed to the cylindrical mounts 51-53 in the desired position, and the imaging direction can be precisely defined. In this case, a pair of unit fixing grooves 56 are formed so as to sandwich the opening 55 in the circumferential direction, and two sets of such a pair of unit fixing grooves 56 are arranged with different positions on the central axis 50.

[0061] Figure 9 shows an example configuration of the imaging unit 6, where (a) is a view from the direction of travel of the imaging vehicle 1, and (b) is a view from the imaging area. Figure 10 is a perspective view showing how the imaging unit 6 is attached to the cylindrical mounts 51-53. Figure 11 is a perspective view showing the imaging unit 6 attached to the cylindrical mounts 51-53.

[0062] The shooting unit 6 consists of a unit support frame 60, a clamp 61, a camera support plate 62, a camera 63, a lighting fixing frame 64, and a lighting device 65.

[0063] The unit support frame 60 is a member that supports the clamp 61, the camera support plate 62, and the lighting fixing frame 64. The unit support frame 60 has a roughly H-shaped planar shape with both ends in the longitudinal direction branched off, and is positioned outside the cylindrical mounts 51-53 so as to face the sides of the cylindrical mounts 51-53 and extend tangentially to those sides. In addition, a shooting window 60W is formed approximately in the center of the unit support frame 60. The shooting window 60W is made of a transparent material such as an acrylic plate and can transmit incident light to the camera 63.

[0064] The clamp 61 is a means for attaching the imaging unit 6 to the cylindrical mounts 51-53, and is composed of an upper clamp 610 and a lower clamp 611, with the upper clamp 610 fixed to the unit support frame 60. The cylindrical mounts 51-53 are sandwiched between the pair of clamps 610 and 611, and the pair of clamps 610 and 611 are fastened together with bolts, thereby fixing the imaging unit 6 to the cylindrical mounts 51-53. In addition, the upper clamp 610 has four protrusions 61P formed on it.

[0065] The projection 61P is a protrusion formed on the inner surface of the upper clamp 610 facing the side surface of the cylindrical mount 51-53, and is formed in a position corresponding to the unit fixing groove 56. It has a tapered shape with a decreasing cross-sectional area towards the tip. By engaging three or more projections 61P with the unit fixing groove 56 of the cylindrical mount 51-53, the imaging unit 6 can be mounted so that the imaging direction is predetermined.

[0066] The camera support plate 62 is a component that supports the camera 63. One end of the camera support plate 62 is fixed to the unit support frame 60, and the other end is inserted through the opening 55 and positioned in the internal space of the cylindrical mounts 51-53.

[0067] The camera 63 consists of an image sensor 630 and a photographic lens 631. The image sensor 630 is a photoelectric conversion element such as a CCD or CMOS image sensor that generates image data. The photographic lens 631 is an optical lens for forming an image on the image sensor 630.

[0068] The position of the photographic lens 631 is pre-adjusted so that its principal point 21 coincides with the central axis 50 of the cylindrical mounts 51-53. During shooting, autofocus control is performed without moving the principal point of the photographic lens 631 by moving the image sensor 630 based on the distance to the shooting area measured by the distance sensor 66. The distance sensor 66 is a sensor that measures the distance to the shooting area and is mounted near the shooting window 60W of the unit support frame 60.

[0069] The lighting fixing frame 64 is a member that supports the lighting device 65, and a pair of lighting fixing frames 64 are attached to both ends of the unit support frame 60 so that their angles can be adjusted. The lighting device 65 is a linear light source that illuminates the shooting area and extends in a direction perpendicular to the central axis 50.

[0070] The imaging unit 6 is installed by inserting the camera support plate 62 into the openings of the cylindrical mounts 51-53 and fastening the lower clamp 611 to the upper clamp 610 so as to sandwich the cylindrical mounts 51-53. At this time, the projection 61P of the upper clamp 610 engages with the unit fixing groove 56, and the imaging unit 6 is installed in the desired position.

[0071] Figure 12 schematically shows a cross-section when the camera lens 631 is cut by a plane perpendicular to the axial direction 50 passing through its principal point 21. The illumination light from the lighting device 65 is reflected in the shooting area, passes through the shooting window 60W, and is focused onto the image sensor 630 by the camera lens 631. The mounting position of the camera lens 631 on the camera support plate 62 is adjustable, and the principal point of the camera lens 631 is pre-adjusted to coincide with the central axis 50 of the cylindrical mounts 51-53.

[0072] Figures 13 and 14 are perspective views showing an example of the rotational movement of the cylindrical mounts 51-53. Figure 13 corresponds to Figure 5, and Figure 14 corresponds to Figure 6. Comparing Figures 13 and 14, the shooting direction of the ceiling mount unit 521 is generally the same, but the shooting directions of the side wall and bottom mount units 522 and 523 are significantly different.

[0073] The shooting direction of the ceiling camera can be adjusted by rotating the cylindrical mount 51 for the ceiling. The shooting direction of the side wall camera can be changed to the left or right, passing through the ceiling, by rotating the cylindrical mount 52 for the side wall. The shooting direction of the bottom camera can be changed to the lower left or lower right, passing through the ceiling, by rotating the cylindrical mount 53 for the bottom. These changes in shooting direction are made in advance before shooting begins.

[0074] Figure 13 shows the scene when driving in the left lane of the two driving lanes provided inside the tunnel and photographing the left side of the tunnel wall 3. The photographing unit 6 (side wall mount unit 522) attached to the cylindrical mount 52 for the side wall is pointed to the left, and the photographing unit 6 (lowest mount unit 523) attached to the cylindrical mount 53 for the lowest part is pointed to the lower left.

[0075] Figure 14 shows the conditions when driving in the right lane inside the tunnel and photographing the right side of the tunnel wall 3. The photographing unit 6 (side wall mount unit 522) attached to the cylindrical mount 52 for the side wall is pointed to the right, and the photographing unit 6 (lowest mount unit 523) attached to the cylindrical mount 53 for the lowest part is pointed to the lower right.

[0076] In this way, by driving along each of the two traffic lanes and taking photographs, it is possible to photograph the entire tunnel wall 3.

[0077] Figure 15 is an explanatory diagram of the sliding operation of the in-vehicle unit 5, showing the unit 5 in the storage position. In contrast, Figure 7 shows the unit 5 in the shooting position.

[0078] In the storage position, all cameras are positioned on the vehicle floor 41, preventing, for example, parts from falling during travel and ensuring safety during non-filming situations. In contrast, in the filming position, some cameras, such as the camera mounted on the cylindrical base 53 for the lowest section, are positioned outside the vehicle floor 41, allowing for filming of the lowest part of the tunnel's side wall without obstruction from the vehicle floor 41. The on-board unit 5 can slide in the direction of travel using a sliding mechanism 42, allowing it to transition between the storage position and the filming position. [Explanation of symbols]

[0079] 1. Filming vehicle 20A~20C Shooting direction 21,21A~21C Principal point 3 Tunnel wall 30A~30C, 301~309 Field of view 31A~31C, 311~319 Imaging area 40 bogies 41 Vehicle floor 42. Slide mechanism 5. In-vehicle unit 50 center axis 500 Base Frame 501~503 Post 51-53 Cylindrical base 511-513 Support section of the mounting frame 521-523 Mounting Unit 55 Opening 56 Unit fixing groove 6. Shooting Unit 60 Unit Support Frame 60W shooting window 61 Clamp 610 Upper clamp 611 Lower clamp 61P protrusion 62 Camera support plate 63 Cameras 630 Image Sensors 631 Shooting Lens 64 Lighting Fixing Frame 65 Lighting devices 66 Distance Sensor 70 Dehumidifier 71 Air supply tube 100 Tunnel wall imaging device

Claims

1. In a roadside wall photographing device equipped with two or more cameras on a photographing vehicle, which photographs roadside walls installed along the path of the photographing vehicle, The cameras are arranged such that their shooting directions, as viewed from the direction of travel of the vehicle, are different from each other, and they capture different shooting areas on the roadside wall, and the principal points of the shooting lenses coincide when viewed from the direction of travel. The adjacent imaging areas have overlapping areas, Furthermore, it includes a cylindrical mount that supports the two or more cameras, with its central axis aligned with the direction of travel. The cameras are arranged such that their positions on the central axis are different from each other. The principal point of the aforementioned photographic lens is located on the central axis, The roadside wall imaging device is characterized in that the cylindrical frame has an opening in the direction of the camera's shooting.

2. The camera and lighting device are provided, and the camera comprises two or more shooting units that are mounted on the cylindrical frame, The camera is inserted into the cylindrical frame through the opening and captures the shooting area through the shooting window provided in the shooting direction. The roadside wall imaging apparatus according to claim 1, characterized in that the lighting device is located outside the cylindrical frame and illuminates the imaging area.

3. The aforementioned shooting unit has a pair of the aforementioned lighting devices, The roadside wall photographing device according to claim 2, characterized in that the pair of lighting devices are arranged on either side of the photographing window and have a shape that extends in a direction perpendicular to the direction of travel.

4. The roadside wall imaging device according to claim 2, further characterized by being equipped with a dehumidifier that supplies dehumidified air into the cylindrical frame.

5. In a roadside wall photographing device equipped with three or more cameras on a photographing vehicle, which photographs roadside walls installed along the path of the photographing vehicle, A first cylindrical mount extending in the direction of travel and supporting two or more of the cameras, The system comprises a first cylindrical mount connected to the first cylindrical mount so as to be rotatable relative to it with its central axis aligned, and a second cylindrical mount supporting one or more of the cameras, The three or more cameras have different shooting directions as viewed from the direction of travel of the shooting vehicle, and each captures different shooting areas on the roadside wall, with the principal point of the shooting lens positioned on the central axis. A roadside wall imaging device characterized by having overlapping regions in the imaging areas that are adjacent to each other.

6. The first cylindrical frame supports two or more cameras for photographing the ceiling of the roadside wall and is rotatably fixed to the photographing vehicle. The roadside wall imaging device according to claim 5, characterized in that the second cylindrical frame supports two or more cameras for imaging the side walls of the roadside wall and is rotatably fixed to the imaging vehicle.

7. The internal spaces of the first and second cylindrical frames are in communication with each other. The roadside wall surface imaging device according to claim 5, characterized in that it is equipped with a dehumidifying device that sends dehumidified air into the internal space.

8. The first and second cylindrical mounts are provided with a sliding mechanism that slides them in the direction of travel, transitioning between a storage position and a shooting position. In the aforementioned storage position, the three or more cameras are positioned on the floor of the filming vehicle. The roadside wall imaging device according to claim 5, characterized in that, in the aforementioned shooting position, the camera supported by the second cylindrical frame is positioned to protrude from the floor surface in the direction of travel.

9. The roadside wall photographing device according to claim 1 or 5, characterized in that the photographing vehicle is a railway vehicle.

10. The roadside wall surface imaging device according to claim 1 or 5, characterized in that the imaging vehicle is an automobile.

11. The roadside wall photographing device according to claim 1 or 5, characterized in that the roadside wall surface is the tunnel lining surface.

12. The roadside wall imaging device according to claim 1 or 5, characterized in that the roadside wall surface is a soundproof wall surface.

Images