JP2001099784A - Method for detecting crack on floor board of existing bridge and method for displaying the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for detecting cracks on a floor board of an existing bridge and a method for displaying it capable of having high reliability and operability by helping easy understanding of a condition of the cracks. SOLUTION: This method detects cracks on the floor board 20 of an existing bridge with both ends substantially supported by piers 21. A camera 31 takes as image of the bottom part of the floor board 20. Obtained image data are processed, and sampling and quantifying processing are provided to the cracks for each of divided small sections of the floor board 20, and output for each of the small sections is displayed. Information on the detected crack of the floor board 20 in all of the sections of the floor based 20 is obtained and is displayed together with a crack distribution diagram 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a crack in a floor plate made of reinforced concrete and a method for displaying a crack in a floor plate when an existing bridge such as a highway is inspected.

[0002]

2. Description of the Related Art At the time of maintenance, repair, reinforcement or replacement of an existing bridge, periodic inspections and surveys are conducted to ascertain the current state of damage to the floor plate of the bridge, and the durability of the bridge is determined based on the results. Need to be evaluated and diagnosed accurately. 2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 3-160349, a vehicle is equipped with a camera such as a CCD camera capable of photographing a digital image, and a road surface image is photographed by the camera while moving the vehicle. There is known a method of extracting an image representing a crack or a flaw on a road surface from stored image data, and detecting a crack or a flaw by emphasizing features of the image.

[0003]

However, in the above-mentioned conventional example, cracks and flaws are detected by image data captured by a camera, and are displayed as line images when they are displayed on a display or the like. However, there is a limit to the size of the display, and when the inspection range is wide such as a road, if the entire inspection range is displayed at one time on one screen of the display, the line image displayed on one screen of the camera is extremely large. There is a problem that the image is displayed small and the line image becomes unclear, and it is difficult to grasp the state of cracks and flaws. The present invention has been made in view of such circumstances,
Image processing of image data taken by the camera and output display for each subsection to create cracking information of the inspection area, making it easier to grasp the cracking situation and making the floorboard cracking in an existing bridge highly reliable and workable It is an object to provide a detection method and a display method thereof.

[0004]

According to the present invention, there is provided a method for detecting cracks in a floor plate of an existing bridge according to the present invention, the method comprising detecting cracks in a floor plate of an existing bridge having both ends substantially supported by piers. Then, the bottom of the floorboard is imaged by a camera, the obtained image data is subjected to image processing, and cracking is extracted and quantified for each of the subsections obtained by dividing the floorboard, and output display is performed for each subsection. As a result, crack information according to the degree of cracking can be obtained for each subsection, and for example, each subsection can be reduced or enlarged to detect the status of cracks and detailed status of the entire floorboard, and the inspection range can be improved. Even in the case of a wide area, it is possible to obtain highly reliable crack information which is safe and hardly causes an artificial error.

In the method for detecting cracks in a floor board of an existing bridge according to the present invention, the image data is obtained by capturing an image by mounting a camera on a bogie running in the X and Y directions arranged below the floor board, and obtaining data together with the running position of the bogie. May be configured. In this case, since the distance between the floorboard and the camera can be made constant, the image data can be obtained in a digital amount with little variation regardless of the distance from the river surface or the riverbank to the floorboard, for example. Further, in the method for detecting a crack in a floor plate of an existing bridge according to the present invention, the output display is toned to a different color or lightness according to the degree of the crack for each subsection, and further, the color or the gradation The crack information composed of lightness may be attached to each small section position of the floorboard. In this case, the degree of cracking becomes clear for each subsection, and it is possible to immediately take a countermeasure according to the degree of cracking.

According to the present invention, there is provided a method for displaying cracks in a floor plate of an existing bridge according to the present invention, which comprises displaying cracks in a floor plate of the existing bridge substantially supported at both ends by piers. An image is taken by a camera, the obtained image data is image-processed, and a crack is extracted and quantified for each subsection obtained by dividing the floorboard, an output is displayed for each subsection, and the output display is performed for each subsection. Each time it is toned to a different color or brightness depending on the degree of cracking,
Further, the crack information of the floorboard consisting of the color or lightness obtained by the gradation is obtained for all of a large number of continuous floorboards, and the crack information is displayed together with its distribution map,
In addition, all of the floorboards include further detailed data. In this case, crack information can be obtained for all of a large number of continuous floor boards, and one of the display devices can be obtained.
You can grasp the crack status of all floorboards on the screen.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIGS. 1A and 1B are side views showing a crack detecting device used in a method for detecting a crack in a floor plate of an existing bridge according to an embodiment of the present invention, and a distribution obtained by the crack detecting method. FIG. 2 is a perspective view showing a moving device of the crack detection device used in the crack detection method, FIG. 3 is a block diagram of the crack detection device used in the crack detection method, and FIG. 4 is a diagram showing the crack detection method. FIG. 5 is a flowchart showing the distribution of cracks used in the crack detection method.

As shown in FIGS. 1A and 2, a crack detecting apparatus 10 used in a method for detecting a crack in a floor plate of an existing bridge according to an embodiment of the present invention is substantially supported at both ends by piers 21. The bottom of the floor plate 20 of the existing bridge is photographed from bottom to top, and a camera 31 capable of storing the photographed image data in a digital amount, such as a CCD camera, and a clear screen can be obtained by the camera 31. And an illuminating device 32 for illuminating the imaging surface. The imaging device 30 is mounted on a moving device 40 that can move in the length direction (X direction) and the width direction (Y direction) of the floor plate 20 and is moved by a drive device that can be remotely controlled. Can be imaged. The moving device 40 is disposed below the floor plate 20 and has a traveling plate 41 whose height can be adjusted in the vertical direction, a traveling platform 42 capable of traveling on the traveling plate 41 in the X direction, and a Y platform on the traveling platform 42. Truck 4 that can travel in any direction
3 and the imaging device 30 is placed on the carriage 43 and the floor plate 2
0 is photographed from a substantially constant distance. As illustrated in FIG. 1B, the imaging device 30 includes a floor plate 20 (floor plate numbers P1, P2 to P2) between a plurality of arranged piers 21.
i) is divided into the length direction X and the width direction Y, respectively, into small sections (section addresses Q11, Q12 to Q1m, Q21 to Q21).
For each of Qn1 to Qmn), it is possible to sequentially move and capture an image according to the segment address. For example, the moving speed of the carriage 43 is about 1 m / sec, and the photographing speed of the camera 31 is 3 m / sec.
One frame is 1000 mm x 7 with approximately 0 frames / sec.
A range of a small section of about 00 mm can be photographed. Image data R0 for each frame obtained by the camera 31 is stored in the image storage medium 33 such as a video tape or a CD mounted on the carriage 43 together with the traveling position of the carriage 43.

As shown in FIG. 3, the image data R0 stored in the image storage medium 33 is divided into adjacent small sections (for example, Q11 and Q12, Q12 and Q13) by the image editing device 50.
Etc.), the editing process is performed to delete the overlapping portions of the image data R0 for each image data R0, and the required image data R with little noise
1 is taken out, and the image data R1 is subjected to image processing by an image processing device 60 such as a personal computer. In the image processing device 60, the image data R1 is subjected to density conversion processing for each of the small divisions of the floorboard 20 to smooth the image density, and is separated for each thickness of the crack line to extract and quantify the characteristic points of the crack. Processing is performed to calculate the characteristic amount of a crack, for example, the thickness and length of a line, for each small section. The characteristic amounts of the cracks are subjected to data processing for each of the small sections, and as shown in FIG. 1B, a distribution map 70 indicating the degree of the cracks is created. A distribution map 71 is formed and output and displayed on a display device 80 such as a CRT, a liquid crystal display, and a printer.

Here, a method for detecting and displaying a crack in a floor plate of an existing bridge according to an embodiment of the present invention will be described (see a flowchart shown in FIG. 4). (1) The entire bottom surface of the floor plate 20 is imaged while the imaging device 30 is mounted on the carriage 43 and moved, and the image data R0 is stored in the image storage medium 33 (step 1). (2) The image data R0 of the image storage medium 33 is input to the image editing device 50, and the adjacent small sections (for example, Q11 and Q1)
2, Q12 and Q13, etc.), the overlapping portions of the image data R0 are deleted, and the portions which are easily misjudged, such as the dark and dark portions and the dark lines generated by the overlapping, are removed, and the necessary portion of the image data R1 is removed (Step 2). (3) The image data R1 is input to the image processing device 60, and a density conversion process is performed (step 3). In the density conversion processing, since the image represented by the captured image data R1 varies from a bright image to a dark image, an average value of the image densities is obtained, and the processing is performed so that the average value becomes the central density of the image density. To reduce variations in image density.

(4) In order to emphasize the data of the crack line of the image data R1, for example, an image having pixels of a 5 × 5 matrix is used to form an image which is continuous vertically, horizontally, diagonally to the right or diagonally to the left. A feature point process for determining a feature amount to be emphasized is performed (step 4). In the feature point processing, for example, the width of each of the vertical line (X direction), the horizontal line (Y direction), and the diagonal direction is set to 0.1 to 0.19, and the feature point A is set to 0.2 to 0.29. With the feature points B and 0.3 or more as feature points C, the image data R1 is passed through a filter that allows the image data of each feature point to pass. (5) Extract image data R2 as a line obtained by binarizing the image data R1 that has passed through the filter that passes each of the feature points A, B, and C according to the density of black and white using the average density as a threshold ( Step 5). (6) A line is drawn using the image data R2 as a line extracted and binarized at each of the feature points A, B, and C, and a line extraction process is performed (step 6). Therefore, the drawn line after the binarization is represented as a line having the same thickness as a thick line and a thin line. (7) The drawn line is colored for each feature point and gradation is made into a different color or brightness depending on the degree of the crack, and the type of the flaw is easily distinguished based on the crack information (step 7). For example, the line data extracted at the feature point A is colored green, the line data extracted at the feature point B is colored blue, and the line data extracted at the feature point C is colored red to determine the type of flaw. Make it easy to do.

(8) The length and area of the line data are calculated for each feature point to quantify the crack information (step 8). (9) The length and area of the line data obtained for each feature point are summed to obtain the total length and area of the crack for each image data R2 (step 9). (10) The total length of cracks and the total area data (crack information) for each image data R2 are stored as line images for each corresponding small section, and pasted at each small section position on the floorboard and displayed on the display device 80. (Step 10). (11) As shown in FIG. 5, the line image of each small section subjected to the image processing is reduced, and the line images are compared with each other according to the section address of the floor panel 20 to create a distribution map 70 of cracks for each floor panel number. (Step 11). The distribution map 70 compares the crack length or area of each line image with a predetermined evaluation length or area and, if the comparison result is within the evaluation criteria, displays a screen of a small section of the line image with a predetermined color in a predetermined color. Paint. For example, if the evaluation length a is 1 to 2 m and the crack length obtained by the image processing is 1.5 m, the color is green, and the evaluation length b
Is 2 to 4 m, and the crack length obtained by the image processing is 2.
If the length is 5 m, the color is blue, and if the evaluation length c is 4 m or more, and the crack length obtained by the image processing is 5.5 m, the color is red. The above process is performed on all floorboards 20 (P1 to Pi), and they are pasted together so that the division addresses are sequentially arranged in order, and a wide distribution map identified by color on one sheet or display screen of the display device 80. 71 is displayed, and the user can grasp the deteriorated portion, the frequency of deterioration, and the like of all the floor boards 20. (12) For all of the floorboards 20, for example, the display scale of a portion where the degree of damage / deterioration is particularly severe in the range of each small section is enlarged, and an image as a crack line for each small section of the enlarged distribution map 70 is displayed. The detailed data, which is the data R2, is displayed on the display device 80 as a line image so that it is easy to see visually (step 12).

As a result, cracks appearing on the surface of the floorboard 20 are emphasized and clarified by the density conversion process, and features such as the shape and size of the cracks are represented by counting by the crack extraction and quantification process. As shown in FIG. 1 (B), the state of cracks in the entire floorboard 20 is displayed as the distribution map 70, and it is possible to immediately take a countermeasure according to the degree of cracks. In particular, all floor boards 20 (P1 to P
Regarding i), displaying a line image for each subsection on the display device 80 cannot be displayed on one screen because the display area of the display device 80 is limited, but a distribution diagram in which the line image for each subsection is reduced is shown. Is obtained, and the distribution map 70 is pasted so that the adjacent division addresses are arranged successively in order, and is represented by a wide distribution map 71 including the evaluation for each subdivision, so that the entire image of the floorboard can be displayed on one screen. Can be seized with. When it is desired to know the state of the crack in detail, the display scale can be enlarged, and detailed data of the range of each subsection can be displayed as a line image on the enlarged distribution map 70, so that the data can be seen clearly and visually. . In addition, the output display is gradation-converted into different colors or lightness according to the thickness and length of the cracks for each small section by the density conversion processing, and furthermore, the gradation-colored light or lightness of the floor board 20 is displayed. By sticking to each small section position, it becomes easier to grasp the degree of cracking than to display a black and white line image.

[0014]

According to the method for detecting cracks in a floor plate of an existing bridge according to the present invention, the bottom of the floor plate is imaged by a camera, and the obtained image data is subjected to image processing to divide the floor plate into small sections. Crack extraction and quantification processing is performed, and output display is performed for each subsection, so that crack information according to the degree of cracking can be obtained for each subsection. It is possible to detect the condition of cracks and detailed conditions, and even if the inspection range is wide, it is possible to freely enlarge or reduce the small section screen and inspect it with an image corresponding to the screen. Therefore, it is possible to improve the reliability of the crack data, provide a workability, and provide a method for detecting a crack in a floor plate of an existing bridge at low cost. In particular, claim 2
In the method for detecting a crack in a floor plate of an existing bridge described above, the image data is configured by data obtained by capturing an image by mounting a camera on a bogie traveling in the X and Y directions arranged below the floor plate and obtaining a running position of the bogie. Therefore, it is possible to increase the safety and reliability of the detection operation by keeping the distance between the floorboard and the camera constant.

Further, in the method for detecting cracks in a floor plate of an existing bridge according to the third aspect, the output display is toned into different colors or lightness according to the degree of cracks in each of the small sections, Since the crack information consisting of the converted color or brightness is attached to each subsection position of the floorboard, the degree of cracking in each subsection becomes clear,
It is possible to immediately take measures according to the degree of cracking. The method for displaying cracks of floorboards in an existing bridge according to claim 4 obtains cracking information of floorboards for all of a large number of continuous floorboards, displays these cracking information together with a distribution map thereof, and furthermore, for all of the floorboards. In addition, because it includes expanded detailed data, it is possible to obtain a wide distribution map that includes crack information for all of a large number of continuous floorboards. Can be taken.

[Brief description of the drawings]

FIGS. 1A and 1B are a side view and a distribution diagram, respectively, showing a crack detection device used in a method for detecting a crack in a floor plate of an existing bridge according to an embodiment of the present invention. FIG.

FIG. 2 is a perspective view showing a moving device of the crack detection device used in the crack detection method.

FIG. 3 is a block diagram of a crack detection device used in the crack detection method.

FIG. 4 is a flowchart showing the crack detection method.

FIG. 5 is an explanatory diagram showing a distribution map of cracks used in the crack detection method.

[Explanation of symbols]

10: crack detection device, 20: floor plate, 21: pier, 3
0: imaging device, 31: camera, 32: lighting device, 33:
Image storage medium, 40: moving device, 41: running board, 42:
Running platform, 43: truck, 50: image editing device, 60: image processing device, 70: distribution map, 71: wide distribution map, 80:
Display device

Claims (4)

[Claims] 1. A method for detecting cracks in a floor plate of an existing bridge whose both ends are substantially supported by piers, wherein the bottom of the floor plate is imaged by a camera, and image data obtained is subjected to image processing. A method for detecting cracks in a floor plate of an existing bridge, wherein a crack is extracted and quantified for each of the small sections into which the floor board is divided, and an output is displayed for each of the small sections. 2. The method for detecting cracks in a floor plate of an existing bridge according to claim 1, wherein the image data is captured by mounting the camera on a bogie running in the X and Y directions disposed below the floor plate. A method for detecting cracks in a floor plate of an existing bridge, comprising a data obtained together with a running position of the floor. 3. The method for detecting cracks in a floor plate of an existing bridge according to claim 1 or 2, wherein the output display is toned to different colors or lightness according to the degree of cracks for each of the small sections. A method for detecting cracks in a floor plate of an existing bridge, wherein the information is formed by pasting the cracked information comprising the color or lightness that has been converted into gradations at each of the small section positions of the floor plate. 4. A method for displaying cracks in a floor plate of an existing bridge whose both ends are substantially supported by piers, wherein the bottom of the floor plate is imaged by a camera, and the obtained image data is subjected to image processing. Extraction and quantification processing of cracks is performed for each subsection obtained by dividing the floorboard, and output display is performed for each subsection, and the output display is different in color or according to the degree of cracks for each subsection. Lightness is toned, furthermore, crack information of the floorboard consisting of the color or lightness that has been grayed out is obtained for all of a large number of continuous floorboards, and these crack information is displayed together with its distribution diagram, and A method for displaying cracks on a floor plate of an existing bridge, further including enlarged detailed data for each of the floor plates.