JP2002174601A - Method and device for detecting damage on wall face - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for efficiently detecting a damage on the wall face of a structural body such as a tunnel. SOLUTION: The position of a strobe 5-1 is set by remote control to be positioned optically symmetrically to the position of a camera 1-1 in an image pickup part 1, and in this setting condition, light is emitted according to a command from an operation part. In this way, light from the strobe 5-1 is totally reflected in a part excepting a damaged part, and a while image due to too much exposure is taken by means of the camera 1-1. In the damaged part, the light from the strobe 5-1 is not totally reflected because it cannot reach the bottom of the damage, so that the image of a damaged part can be picked up.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting damage to a structure such as a tunnel wall, and more particularly to a method and apparatus for efficiently detecting cracks.

[0002]

2. Description of the Related Art Many tunnels of railways and roads are structures constructed of concrete, but cracks (cracks, voids, etc.) occur on the wall of the tunnel due to aging. If such cracks are left untreated, a part of the concrete will peel off and fall due to the vibration and wind pressure when a train or the like passes, causing a serious accident. for that reason,
It is necessary to detect and treat cracks on the walls of concrete structures at an early stage.

Conventionally, cracks on the wall of a tunnel are detected by a human hitting with a hammer or visually. Therefore, detection of cracks requires a great deal of labor and time.

In the case where cracks in a concrete structure such as a tunnel are to be detected by image processing, free lime (a state in which lime is melted out), dirt, graffiti, etc., are present on the tunnel wall in addition to the cracks. There are a number of such devices that exhibit a luminance distribution similar to that of a crack (hereinafter, these are collectively referred to as "dirt"), and there is a problem that it is difficult to separate the crack from the dirt.

[0005]

SUMMARY OF THE INVENTION The present invention solves such a conventional problem, and a method for detecting damage to a wall surface of a tunnel or the like which can efficiently detect damage to a wall surface of a structure such as a tunnel. And a device.

[0006]

SUMMARY OF THE INVENTION According to the present invention, in a case where damage is detected by image processing of a captured wall image, a light emitting means is set so that the position of the camera is optically symmetrical, and the wall surface is imaged. This makes it possible to easily separate damage and dirt on a wall surface in image processing.

[0007] Further, an imaging unit for imaging a wall surface, a distance sensor for measuring a distance between the wall surface and the imaging unit, a vehicle position sensor for measuring a distance from a tunnel entrance, and an imaging unit for referring to a vehicle position. An operation unit that outputs a trigger signal to, and issues an imaging command, a light emitting unit that emits light based on a command from the operation unit, a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and An image / data recording device that records a vehicle position obtained from a vehicle position sensor, and an analyzing device that analyzes a wall image based on the recorded wall distance and the vehicle position, thereby performing image processing. In doing so, damage to the wall surface and dirt can be separated, and damage to the wall surface can be accurately detected.

[0008] Further, an image pickup unit for picking up an image of a wall surface, a distance sensor for measuring the distance between the wall surface and the image pickup unit, a vehicle position sensor for measuring a distance from a tunnel entrance, and an image pickup unit for referring to the vehicle position. An operation unit that outputs a trigger signal to, and issues an imaging command, a light emitting unit that emits light based on a command from the operation unit, a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and An image / data recording device that records a vehicle position obtained from a vehicle position sensor, an analysis device that analyzes a wall image based on the recorded wall distance and the vehicle position, a storage device that stores an analysis result, and an analysis result. It is composed of an output device for outputting and a display device for displaying the analysis result, thereby separating wall damage and dirt in image processing,
Wall damage can be detected accurately.

Further, the amount of light emitted from the light emitting section is a quantity of light exceeding the line area of the image pickup section, whereby damage and dirt on a wall surface are reduced in image processing. Cutting and wall damage can be accurately detected.

[0010] The image pickup unit, the light emitting unit, and the distance sensor are provided in a single set, and are rotated and moved so as to scan a wall surface to record images and data of the wall surface. And by this,
It is possible to image the damage on the wall surface without omission.

A plurality of sets of the image pickup section, the light emitting section, and the distance sensor are provided, and each set records an image and data of a wall surface so as to pick up an image of a different portion of the wall surface. Thereby, it is possible to image the damage to the wall surface in a short time without omission.

When image processing is performed on a wall image picked up by an interlaced camera to detect damage, two interlaced cameras are used so that their scanning lines are set to be perpendicular to each other. In addition, it is characterized in that an image of a wall surface is taken, whereby even a small damage to the wall surface can be taken without omission.

[0013] Further, an image pickup unit using two interlaced cameras for picking up an image of a wall surface so that scanning lines thereof are perpendicular to each other, and a distance sensor for measuring a distance between the wall surface and the image pickup unit. A vehicle position sensor that measures a distance from a tunnel entrance, a vehicle position is referenced, a trigger signal is output to the imaging unit, an operation unit that issues an imaging command, and light is emitted based on a command from the operation unit. A light-emitting unit, an image / data recording device that records a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and a vehicle position obtained from the vehicle position sensor, and a recorded wall distance and vehicle position And an analysis device for analyzing the wall image based on the analysis result, a storage device for storing the analysis result, an output device for outputting the analysis result, and a display device for displaying the analysis result. Thus, isolate and damage and contamination of the wall in order to image processing, it is possible to detect accurately the small damaged wall.

Further, when damage is detected by image processing of a picked-up wall image, an image having periodicity appearing on the image is removed as a joint, whereby image processing is performed. The joints can be easily removed above.

When the wall width image and the length of the crack are measured by performing image processing on the wall image taken by the camera, the distance between the wall surface and the camera is measured by the distance sensor, and the camera focal length and the camera preset distance are set. CC which is ability
Determine the resolution from the number of D pixels, further assign a label to the crack appeared on the image, measure the number of pixels of the crack from the labeling image, measure the width and length of the crack from the number of pixels and the resolution. This makes it possible to measure the width and length of the crack from the crack image labeled on the image.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a wall damage detecting apparatus according to a first embodiment of the present invention. As shown in FIG. 1, a wall damage detection device according to a first embodiment of the present invention includes an imaging unit 1 such as a camera that images a wall surface, and a distance sensor 2 that measures a distance between the wall surface and the imaging unit 1. And a vehicle position sensor 3 for measuring the distance from the tunnel entrance, an operation unit 4 that outputs a trigger signal to the imaging unit 1 by referring to the vehicle position and issues an imaging command, and an optically symmetrical position of the camera. A light emitting unit 5 that emits strobe light or the like based on a command from the operation unit 4, a wall image captured by the imaging unit 1, a wall distance obtained from the distance sensor 2, and a vehicle obtained from the vehicle position sensor 3. An image / data recording device 6 for recording a position, an analyzing device 7 for analyzing a wall image based on the recorded wall distance and a vehicle position,
A storage device (for example, a DISK device) 8 for storing analysis results,
An output device (eg, Printer) 9 for outputting an analysis result;
And a display device (DISPLAY) 10 for displaying the analysis result.

In FIG. 1, based on an example in which a plurality of sets of an image pickup unit, a light emitting unit such as a strobe, and a distance sensor are provided, each set picks up an image of a different part of a wall such as a tunnel, and the image / data of the entire wall surface is obtained. As an alternative, an image pickup unit, a light-emitting unit such as a strobe, and a distance sensor are provided, and each is used to rotate and scan a wall such as a tunnel by using the unit. A configuration for recording images and data may be adopted. Further, a light emitting section 5 such as a strobe is provided with remote control means for remotely controlling the position and direction thereof. Section 5 is set.

FIG. 2 shows a configuration of an inspection car 20 for imaging the damage state of a wall surface of a tunnel or the like. Among the configurations of the wall damage detection device of the present invention shown in FIG. Has an image pickup unit 1, a distance sensor 2, a vehicle position sensor 3, an operation unit 4, a light emitting unit 5 such as a strobe (not shown), and an image / data recording device 6, and an operation unit 4 The vehicle travels while capturing a wall image of a tunnel or the like in accordance with a command from the vehicle. The captured wall image data includes vehicle position,
It is recorded in the image / data recording device 6 together with the wall surface distance (the distance between the imaging unit 1 and the wall surface).

Images recorded by running the inspection car 20
The data is returned to the center provided with the analysis device 7, the storage device (DISK device) 8, the output device 9, and the display device 10, and the wall image is analyzed based on the wall distance and the vehicle position recorded by the analysis device 7. . By performing image analysis by the analysis device 7, an analysis result such as “how much wall damage is present at which point in the tunnel” is stored in the storage device (DISK device) 8.

The output device (Printer) 9
Print out a sketch drawing describing the damage situation on the development plan of the wall of the tunnel. Further, by the display device 10,
Check the damaged image.

In FIG. 2, the operation unit 4 and the image / data recording device 6 are drawn out by a cable or the like because they cannot be drawn inside the inspection car 20. Actually, it is mounted in the inspection vehicle 20.
However, the operation unit 4 and the image / data recording device 6 are
It is possible to configure without installing in 20. Although not shown, the light emitting unit 5 such as a strobe is normally stored at a predetermined position in the inspection car 20 and is pulled out by remote control after arriving at the site, and is optically symmetric with the position of the camera. Is set to

FIG. 3 shows the positional relationship between the camera 1-1 of the image pickup section 1 and the light emitting section 5, for example, the strobe light 5-1 of the strobe light emitting section. Is set by remote control so as to be optically symmetric with the position of the camera 1-1, and the strobe 5-1 is irradiated in the set state based on a command from the operation unit 4. In this case, the light from the strobe 5-1 is totally reflected at a portion other than the damage, and a white image is captured by the camera 1-1. However, at the damaged part, the light of the strobe 5-1 does not reach the bottom of the damage and is not totally reflected, so that the damaged part can be imaged. Here, “optically symmetrically set” means that the strobe light reflected by the wall surface of the tunnel or the like is directly radiated to the camera of the imaging unit 1.

FIG. 4 shows an image in which the position of the strobe 5-1 is set as shown in FIG.
(A) to (d) of FIG. As shown in FIG.
In imaging with a light amount of 1/32 (the light amount is indicated by the ratio of the strobe light emission set to the total amount of strobe light emission), the amount of light is not enough to cause the plane portion of the wall surface such as the tunnel to be totally reflected, so that It will be seen that the damage to the wall such as the tunnel and other dirt are imaged together. FIG. 4 (b)
~ As shown in Fig. 4 (d), the light amount is 1/16, 1/8,
When the surface is gradually increased to 1/4, the dirt on the plane portion of the wall surface such as a tunnel is imaged white by total reflection. Since the strobe light does not easily reach the bottom of the damaged portion and does not reflect, the image can be captured in black.

The operation of the wall damage detecting apparatus according to the first embodiment of the present invention will be described with reference to FIGS.

The flow shown in FIG. 5 shows the pre-processing of the wall damage detecting device according to the first embodiment of the present invention. In step 51 of FIG. Confirm that there is a physical wall such as a tunnel including a damaged part such as a crack. Next, in step 52, an image to be imaged is input. In step 53, the input image is recorded in the image / data recording device 6. When an image is input in step 52, distance data is input in step 52 ', and
2 ", the vehicle position data is acquired. In step 53, the distance data and the vehicle position data are recorded in the image / data recording device 6 simultaneously with the image recording.

These steps are repeated as long as image data as an object to be imaged, in the case of the present invention, a wall surface of a tunnel or the like including a damaged portion such as a crack is physically present, and the image, distance data and vehicle position data are converted into image data.・ Record in the data recording device 6.

The flow shown in FIG. 6 shows the post-processing of the wall damage detecting device according to the first embodiment of the present invention. In step 61 of FIG. 6, the flow is obtained by the pre-processing of FIG. Enter the recorded image. Then, in step 62,
Perform normalization processing. In the normalization processing, an image captured by performing density conversion is converted into an image having a substantially constant luminance value distribution.

Next, at step 63, a smoothing process is performed.
In the smoothing process, noise removal is performed to smooth the shading variation on the image.

Next, in step 64, a ternarization process is performed. In the ternarization process, the image is black, white,
FIGS. 7A and 7B show three values of the intermediate level.
As shown in FIG. 7B, a gradation histogram is obtained for the original image data, and a first threshold value and a second threshold value are set in the gradation histogram.
A black level image and a white level image are generated as shown in FIG.

In step 65, the black level image and the white level image obtained by the ternarization processing are subjected to noise removal processing to remove isolated points.

Next, at step 66, joint removal processing is performed. When an image of a wall surface such as a tunnel is taken, joints are taken together with damages such as cracks. Joints are created at the boundary when a concrete panel with a predetermined area is attached to a wall surface of a tunnel or the like, and joints appear on the image periodically. Those having periodicity are determined to be joints and removed.

At step 67, a labeling process is performed. In the labeling process, the same label (number) is assigned to a block of connected black pixels (or white pixels), and different labels (numbers) are assigned to different connected components. This makes it possible to divide the label into a label for a damaged area such as a crack and a label for a stain.

This will be further described with reference to FIGS. 8 (a) and 8 (b). The input image in FIG. 8 (a) is a black level image (or white level image) obtained by the processing of steps 64-66. ), Which is represented by pixels binarized by “1” or “0”, and the labeling image in FIG. 8B is a set of “1” in FIG. For the lump of 1 "
Labels "A", "B" and "C" are assigned, and the label "A" is a label for a cracked portion, and the labels "B" and "C" are clumps for dirt and the like. it can. In this example, a symbol is attached as a label, but a number may be used.

Next, in step 68, the width and length of the crack are measured. Figure 8 shows the width of the crack.
An approximate value can be obtained from the width of a pixel to which a label is assigned as a crack as schematically shown in (b). More specifically, the distance data between the wall surface and the camera by the distance sensor 2 and a preset value are set. Camera focal length data,
The resolution is determined from the CCD pixel number data as the camera capability, and the number of pixels in the cracked portion is measured for the labeling image as shown in FIG. 8B, and the crack width and crack length are determined from the pixel number and the resolution. Is measured. Finally, data is output in step 69. This ends the post-processing.

(Second Embodiment) A wall damage detecting apparatus according to a second embodiment of the present invention is a first embodiment shown in FIG.
The configuration is basically the same as the configuration of the wall damage detection device according to the embodiment. However, with respect to the interlaced camera in the image pickup unit 1, in the second embodiment, two interlaced cameras are used as shown in FIG. is there.

This will be described in more detail below. An interlaced camera usually has one frame composed of two fields as shown in FIG.
In order to compose one frame by scanning the odd field in the first scan and the even field in the second scan, as shown in FIG. 10, small damage (approximately) is formed in parallel between the scan lines (interlaced scan). , 0.1 mm width or less), an image may not be captured by an interlaced camera.

Therefore, a wall damage detecting apparatus according to a second embodiment of the present invention uses two interlaced cameras as shown in FIG. 11 and is installed so that scanning lines are perpendicular to each other. is there. That is, the first interlaced camera 1-2 is installed in a normal scanning line direction, and the second interlaced camera 1-3 is installed in a direction in which the scanning lines are orthogonal thereto. I do. By doing so, as shown in FIG. 10, even if there is damage such as a small crack in parallel between the scanning lines and the first interlaced camera 1-2 cannot capture an image, the second interlaced camera 1-2 can not be imaged. It is possible to image the damage such as a small crack by the camera 1-3 of the system, so that it is possible to image the wall surface of the tunnel or the like without leakage, and it is possible to prevent the damage such as the crack from being overlooked.

(Third Embodiment) A wall damage detecting device according to a third embodiment of the present invention is a first embodiment shown in FIG.
The configuration is basically the same as the configuration of the wall damage detection device according to the embodiment, and an inspection car for imaging the damage state of the wall surface such as a tunnel as shown in FIG. Assuming that a camera and a strobe light are used for the light emitting unit 5, the distance between the tunnel wall surface and the camera is 1 m to 1.
The distance is set to 5 m, the photographing range is used as a parameter using the zoom function of the camera 1, and the strobe is used to emit light while the tunnel wall is stationary, and an image is taken by the digital camera 1. Then, the captured image is taken into the image / data recording device 6, stored, and analyzed by the analysis device 7.

Here, the specifications of the camera, lens and strobe actually used are shown. (B) Camera specifications Number of pixels: 2000 x 1312 (2.74 million pixels) CCD size: 23.7 x 15.6 (mm) Saved file format: TIFF (uncompressed) Shutter speed・ ・ 1/1000 second (fixed) F-number ・ ・ ・ ・ ・ ・ ・ ・ ・ 5.6 (fixed) ISO ・ ・ ・ ・ ・ ・ ・ ・ ・ 200 (b) Lens specification Focal length ・ ・ ・ ・ ・ ・ ・ 28mm -105mm (AF zoom lens) (c) Strobe specification Light intensity: 1/32 (fixed) Flash time: approx. 1/19000 sec.

In the image of the side wall of the tunnel wall, the distance between the camera and the wall is 1.25 m, and the camera focal length is 2
When calculating the angle of view and image resolution from the imaging conditions of 8 mm and the camera pixel number of 2000 × 1312, 1.1 m × 0.7 m, 0.55 mm
/ Pixel.

From the image captured and stored as described above, a process for detecting damage such as a crack is performed by the analyzer 7. In the process of detecting a damage such as a crack, a ternary process is performed to extract features of the damage such as a crack.

The ternarization process is based on the luminance value of the image, and roughly cracks, wall backgrounds and other (free lime,
After repair, etc.).

FIG. 12 is a diagram showing a luminance histogram of a cracked image. As shown in FIG. 12, the tunnel wall surface image is a histogram in which almost all images have a substantially normal distribution. By setting the threshold 1 and the threshold 2 from the histogram, the black level, the white level, and the intermediate level 3 are set.
It divides into three areas and performs ternarization processing. The three areas roughly include:

Black level: cracks, joints, stains due to water leakage, etc. Intermediate level: wall background White level: cracks, free lime, repair, chalk, etc.

The cracked portion exists in the black level area and the white level area. Cracks in the white level region are those in which lime is melted or traced with chalk. Crack detection is performed from both the black level region and the white level region.

When performing ternarization, the threshold value is important. The threshold 1 and the threshold 2 are the rising position of the peak (point of the slope s1) and the falling position (point of the slope s2).
Detect and set.

In a histogram of an image having a black level crack, the luminance from the minimum luminance level to the peak rising level increases, and the area up to the threshold 1 increases (see FIG. 13B).

Conversely, an image having free lime and after repair has a histogram shape in which the average luminance level has a trailing edge to the maximum luminance level (see FIG. 13A).

When the image resolution is 0.5 (mm / pixel), for an image having a crack width of 0.3 mm or more, cracks and joints are extracted in the black level region, and the wall surface is extracted in the white level region. Noise components have been extracted.

In order to extract a crack having a width of 0.1 mm,
It is necessary to take an image with a resolution of 0.5 (mm / pixel) or more. In addition, lime has melted out from the cracked portion, and may be extracted together with the lime melted in the white level region.

In many cases, the histogram has a shape almost indicating a normal distribution, but the histogram of an image containing severe free lime or after repair does not always follow the normal distribution. In an image with severe free lime or after repair, a peak of the lime or the brightness value after repair appears in addition to the peak due to the background of the wall surface.

FIG. 14 is a diagram showing a histogram shape having a strong free lime peak and lime peaks around the peak. At this time, the optimal threshold value 2 is the falling position of the wall surface background peak.

By setting various threshold values in this way, it is possible to extract free lime and after repair. In addition to the free lime on the wall of the tunnel and stains caused by water leakage, it is also possible to extract not only cracks and free lime but also damage to the free lime wall, such as after dirt or graffiti.

[0055]

As is clear from the above description, the wall damage detecting device of the present invention performs image processing on a wall image of a tunnel or the like and detects the image, so that damage such as cracks on the wall of a tunnel or the like can be efficiently performed. It is possible to detect.

In the wall damage detecting device of the present invention, a light emitting portion such as a strobe is set so that the position of the camera is optically symmetric, and an image of a wall such as a tunnel is taken. Damage and dirt can be easily separated.

Further, the wall damage detection apparatus of the present invention uses two interlaced cameras so that their scanning lines are set to be perpendicular to each other, and images a wall surface of a tunnel or the like. Thus, even a small damage to a wall surface such as a tunnel can be imaged without omission.

Further, the wall damage detecting device of the present invention measures the distance between the tunnel wall surface and the camera by the distance sensor, obtains the resolution from the preset camera focal length and the number of CCD pixels, which is the camera's capability, and further measures the resolution on the image. A label is assigned to the cracked portion that appears in the image, the number of pixels of the cracked portion is measured from the labeling image, and the width and length of the crack are measured from the number of pixels and the resolution. The crack width and length can be measured from the crack image labeled by the above.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wall damage detection device according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a configuration of an inspection car for imaging a damage state of a wall surface such as a tunnel,

FIG. 3 is a diagram showing a positional relationship between a camera of an imaging unit and a strobe of a strobe light emitting unit;

FIG. 4 shows an example of an image in which the position of the strobe is set as shown in FIG. 3 and damage to a wall surface such as a tunnel is captured.
32, (b) an image example when the light amount is reduced to 1/16, (c) an image example when the light amount is reduced to 1/8, and (d) an image example when the light amount is reduced to 1/4. Image example,

FIG. 5 is a flowchart showing pre-processing of the wall damage detection device according to the first embodiment of the present invention;

FIG. 6 is a flowchart showing post-processing of the wall damage detection device according to the first embodiment of the present invention;

FIG. 7 is a diagram for explaining a ternarization process in step 64 of FIG. 6;

FIG. 8 is a diagram for explaining a labeling process in step 67 of FIG. 6;

FIG. 9 is a diagram for explaining a frame in the interlaced mode;

FIG. 10 shows an example of damage that cannot be imaged by an interlaced camera,

FIG. 11 is a diagram showing a method of installing an interlaced camera according to a second embodiment of the present invention;

FIG. 12 is a diagram showing a luminance histogram of a cracked image;

13A is a diagram illustrating a histogram shape of an image having free lime and after repair, and FIG. 13B is a diagram illustrating a histogram shape of an image having a black level crack.

FIG. 14 is a diagram showing a histogram shape having a strong free lime peak and lime peaks around the peak.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 imaging unit 1-1 camera 1-2 first camera 1-3 second camera 2 distance sensor 3 vehicle position sensor 4 operation unit 5 light emitting unit such as strobe 5-1 strobe 6 image / data recording device 7 analysis device 8 Storage device (DISK device) 9 Output device (Printer) 10 Display device (DISPLAY) 20 Inspection car

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G06T 1/00 300 G06T 1/00 300 F term (reference) 2D055 LA06 LA16 2F065 AA49 AA60 BB05 CC40 DD06 FF42 FF67 GG08 GG13 HH12 JJ03 JJ05 JJ08 JJ26 MM08 MM22 PP01 PP05 QQ03 QQ06 QQ08 QQ23 QQ24 QQ34 QQ42 QQ43 SS02 SS04 SS06 SS13 2G051 AB02 AC15 BB02 BC02 BC07 CA04 CA07 CB01 CD05 EA11 EA12 DA03 EA14 EA01 EA14 EB01

Claims (10)

[Claims] 1. A wall damage, characterized in that when detecting a damage by image processing of a picked-up wall image, a light emitting means is set so that a camera position is optically symmetric so as to image a wall surface. Detection method. 2. An imaging unit for imaging a wall surface, a distance sensor for measuring a distance between the wall surface and the imaging unit, a vehicle position sensor for measuring a distance from a tunnel entrance, and referring to a vehicle position, the imaging unit An operation unit that outputs a trigger signal to, and issues an imaging command, a light emitting unit that emits light based on a command from the operation unit, a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and An image / data recording device for recording a vehicle position obtained from a vehicle position sensor, and an analyzing device for analyzing a wall image based on the recorded wall distance and vehicle position. 3. An image pickup unit for picking up an image of a wall surface, a distance sensor for measuring a distance between the wall surface and the image pickup unit, a vehicle position sensor for measuring a distance from a tunnel entrance, and referring to a vehicle position, the image pickup unit. An operation unit that outputs a trigger signal to, and issues an imaging command, a light emitting unit that emits light based on a command from the operation unit, a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and An image / data recording device that records a vehicle position obtained from a vehicle position sensor, an analysis device that analyzes a wall image based on the recorded wall distance and the vehicle position, a storage device that stores an analysis result, and an analysis result. A wall damage detection device including an output device for outputting and a display device for displaying an analysis result. 4. The light-emitting unit according to claim 2, wherein a light-emitting amount of the light-emitting unit exceeds a linear region of the image-capturing unit.
A wall damage detection device according to claim 3. 5. The apparatus according to claim 1, wherein the imaging unit, the light emitting unit, and the distance sensor are provided in a single set, and are rotated and moved so as to scan a wall surface, thereby recording image / data of the wall surface. The wall surface damage detection device according to claim 2. 6. A plurality of sets of the image pickup unit, the light emitting unit, and the distance sensor are provided, and each set records an image and data of a wall surface so as to image a different part of the wall surface. The wall surface damage detection device according to any one of claims 2 to 4, wherein 7. When detecting damage by performing image processing on a wall image captured by an interlaced camera, two interlaced cameras are used so that their scanning lines are set to be perpendicular to each other. A method for detecting a damage to a wall surface, wherein a wall surface is imaged. 8. An imaging unit which uses two interlaced cameras to image a wall surface and whose scanning lines are set to be perpendicular to each other, and a distance sensor which measures a distance between the wall surface and the imaging unit. A vehicle position sensor that measures a distance from a tunnel entrance, a vehicle position is referenced, a trigger signal is output to the imaging unit, an operation unit that issues an imaging command, and light is emitted based on a command from the operation unit. A light-emitting unit, an image / data recording device that records a wall image captured by the imaging unit, a wall distance obtained from the distance sensor, and a vehicle position obtained from the vehicle position sensor, and a recorded wall distance and vehicle position An analysis device that analyzes wall images based on
A wall damage detection device including a storage device for storing an analysis result, an output device for outputting the analysis result, and a display device for displaying the analysis result. 9. The method according to claim 1, wherein when detecting damage by performing image processing on a captured wall image, an image having periodicity appearing on the image is removed as joints. 4. A method for detecting wall damage according to item 1. 10. When a wall surface image captured by a camera is image-processed to measure a crack width and its length, a distance sensor measures a distance between the wall surface and the camera, and sets a predetermined camera focal length and a camera focal length. CCD is the ability
Determine the resolution from the number of pixels, further assign a label to the cracked part that appeared on the image, measure the number of pixels of the cracked part from the labeling image, and measure the width and length of the crack from the number of pixels and the resolution. The wall surface damage detection method according to claim 1 or 7, wherein: