Reinforced concrete structure evaluation device, method, and program

Abstract

To accurately evaluate the deterioration and damage condition of a reinforced concrete structure by using an image of reflection wave intensity.SOLUTION: An acquisition unit 32 acquires a planar image group for each of multiple depths which includes planar images of reflection wave intensity for a reinforced concrete structure in which multiple reinforcing-bars extending in a first direction are arranged at predetermined intervals along a second direction orthogonal to the first direction. A selection unit 36 selects the depth of the planar image to be used for evaluation for each region on the basis of a statistical index calculated from pixel values of pixels included in each of the regions obtained by dividing the planar image into the multiple regions including one or more pixels. A calculation unit 38 calculates an evaluation value representing a change in the pixel value in the second direction of a composite image obtained by combining portions of the planar images corresponding to the selected depth for each region. An evaluation unit 40 evaluates the deterioration and damage condition of the reinforced concrete structure on the basis of the calculated evaluation value.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a reinforced concrete structure evaluation device, a reinforced concrete structure evaluation method, and a reinforced concrete structure evaluation program.

Background Art

[0002] Conventionally, the degree of deterioration damage inside a reinforced concrete structure has been quantitatively evaluated. For example, there has been proposed a reinforced concrete structure evaluation device that, at each position on the surface of a reinforced concrete structure, acquires a reflected wave intensity image representing the intensity of the reflected wave of electromagnetic waves irradiated from the surface toward the inside of the reinforced concrete structure by the pixel value of the pixel corresponding to each position. This device sets a range of evaluation targets in the acquired reflected wave intensity image, calculates statistical indicators of a type corresponding to the set range for the pixel values in the reflected wave intensity image, and uses the calculated values to evaluate the degree of deterioration damage of the reinforced concrete structure.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above prior art, the degree of deterioration damage of a reinforced concrete structure is evaluated using the variance of the reflected wave intensity image. However, depending on how the range of the evaluation target is set, there is a problem that the level of the variance calculated as the evaluation value does not necessarily match the degree of deterioration damage. For example, in the above prior art, when the variance within the range of the evaluation target is high, it is evaluated as sound, and when the variance is low, it is evaluated as having deterioration. However, when a portion with a large pixel value is included in a part of the evaluation target range of a deteriorated portion that originally has a low variance, the variance becomes high, and the evaluation target range may be evaluated as sound.

[0005] The present invention has been made in view of the above points, and aims to provide a reinforced concrete structure evaluation device, method, and program that can accurately evaluate the degree of deterioration and damage of a reinforced concrete structure using images of reflected wave intensity. [Means for solving the problem]

[0006] To achieve the above objective, the reinforced concrete structure evaluation device according to the present invention includes: an acquisition unit that acquires a group of planar images for each of a plurality of depths of a reinforced concrete structure, where a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, and the intensity of reflected electromagnetic waves irradiated from the surface toward the interior of the reinforced concrete structure at each position on the surface of the reinforced concrete structure is represented by the pixel values ​​of the pixels corresponding to each position; a selection unit that selects the depth of the planar image to be used for evaluation for each of the regions, based on a statistical index calculated from the pixel values ​​of the pixels included in each of the regions into which the planar image is divided into a plurality of regions containing one or more pixels; a calculation unit that calculates an evaluation value representing the change in pixel values ​​in the second direction of a combined image obtained by combining the portions of the planar image corresponding to the depth selected by the selection unit for each region; and an evaluation unit that evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit.

[0007] Furthermore, the reinforced concrete structure evaluation method according to the present invention is a reinforced concrete structure evaluation method executed by a reinforced concrete structure evaluation device including an acquisition unit, a selection unit, a calculation unit, and an evaluation unit, wherein the acquisition unit represents the intensity of reflected electromagnetic waves irradiated from the surface toward the interior of the reinforced concrete structure at each position on the surface of the reinforced concrete structure in which a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, in a planar image represented by the pixel value of the pixel corresponding to each position, and each of the plurality of depths of the reinforced concrete structure The method involves acquiring a set of planar images, a selection unit selecting the depth of the planar image to be used for evaluation for each region based on a statistical index calculated from the pixel values ​​of pixels included in each of the regions into which the planar image is divided into a plurality of regions containing one or more pixels, a calculation unit calculating an evaluation value representing the change in pixel values ​​in the second direction of a combined image obtained by combining the portions of the planar image corresponding to the depth selected by the selection unit for each region, and an evaluation unit evaluating the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit.

[0008] Furthermore, the reinforced concrete structure evaluation program according to the present invention is a program that causes a computer to function as an acquisition unit that acquires a group of planar images for each of several depths of a reinforced concrete structure, where a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, and the intensity of reflected electromagnetic waves irradiated from the surface toward the interior of the reinforced concrete structure at each position on the surface of the reinforced concrete structure is represented by the pixel values ​​of the pixels corresponding to each position; a selection unit that selects the depth of the planar image to be used for evaluation for each of the regions, based on a statistical index calculated from the pixel values ​​of the pixels included in each of the regions into which the planar image is divided into a plurality of regions containing one or more pixels; a calculation unit that calculates an evaluation value representing the change in pixel values ​​in the second direction of a combined image obtained by combining the portions of the planar image corresponding to the depth selected by the selection unit for each region; and an evaluation unit that evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit. [Effects of the Invention]

[0009] According to the reinforced concrete structure evaluation apparatus, method, and program of the present invention, the degree of deterioration and damage of a reinforced concrete structure can be accurately evaluated using images of reflected wave intensity. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of the reinforced concrete structure evaluation system. [Figure 2] This is a diagram illustrating the detection of reflection response waveforms. [Figure 3] This figure shows an example of the reflection response waveform detected for each detection point. [Figure 4] This is a diagram to explain the three-dimensional reflected wave intensity. [Figure 5] This is a block diagram showing the hardware configuration of a reinforced concrete structure evaluation device. [Figure 6]It is a block diagram showing an example of the functional configuration of a reinforced concrete structure evaluation device. [Figure 7] It is a diagram for explaining a group of planar images. [Figure 8] It is a diagram for explaining the calculation of wavelet transform coefficients. [Figure 9] It is a diagram for explaining the extraction of an evaluation target area. [Figure 10] It is a diagram for explaining the extraction of an evaluation target area. [Figure 11] It is a diagram for explaining the extraction of an evaluation target area. [Figure 12] It is a diagram for explaining the calculation of clarity. [Figure 13] It is a diagram for explaining the generation of a graph showing the relationship between the representative value of clarity and depth. [Figure 14] It is a diagram for explaining the selection of depth for each grid. [Figure 15] It is a diagram for explaining the selection of depth for each grid. [Figure 16] It is a diagram for explaining the generation of a patchwork image. [Figure 17] It is a diagram for explaining the expansion of a patchwork image. [Figure 18] It is a diagram for explaining the expansion of a patchwork image. [Figure 19] It is a diagram for explaining the evaluation value and evaluation image in the first embodiment. [Figure 20] It is a flowchart showing the flow of the reinforced concrete structure evaluation process. [Figure 21] It is a diagram for explaining an example of a mother wavelet used in wavelet transform. [Figure 22] It is a diagram for explaining the calculation of the evaluation value in the second embodiment. [Figure 23] It is a diagram for explaining the calculation of the evaluation value in the second embodiment. [Figure 24] It is a diagram for explaining the evaluation result in the second embodiment. [Figure 25]This figure illustrates another example of how to calculate the evaluation value in the second embodiment. [Figure 26] This figure illustrates another example of how to calculate the evaluation value in the second embodiment. [Figure 27] This figure illustrates the evaluation results in the second embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0012] In the following embodiments, we will describe the case in which the degree of deterioration and damage inside the reinforced concrete slab, which is a road surface structure, is evaluated. In the reinforced concrete slab, in each of the one or more layers, multiple reinforcing bars extending in the first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction. That is, the second direction is the direction in which areas where reinforcing bars are present and areas where they are not appear alternately.

[0013] <First Embodiment> As shown in Figure 1, the reinforced concrete structure evaluation system 100 according to the first embodiment is composed of a reinforced concrete structure evaluation device 10, an electromagnetic wave device 50, and an image processing device 60.

[0014] The electromagnetic wave device 50 comprises a plurality of electromagnetic wave irradiating units and receiving units arranged on a line. The electromagnetic wave device 50 is installed, for example, at the rear lower part of the vehicle 90, such that the line direction of the electromagnetic wave device 50 is in the width direction of the road, and the direction of travel of the vehicle 90 is in a direction perpendicular to the width direction of the road (hereinafter referred to as the "axial direction"). The width direction corresponds to the first direction described above, and the axial direction corresponds to the second direction described above.

[0015] As shown in Figure 2, the electromagnetic wave device 50 scans the reflected wave intensity detection range 95 on the road surface in the direction of vehicle travel, irradiating electromagnetic waves from the surface towards the interior (depth) of the reinforced concrete slab, and receiving the reflected waves. This allows the reflected wave intensity corresponding to the depth to be detected at each position in the reflected wave intensity detection range 95. The reflected wave intensity corresponding to the depth is detected in the form of a reflected response waveform as shown in Figure 3 for each position (hereinafter referred to as "detection point"). One detection point may be, for example, 1 cm × 1 cm, and one line width may be 2.0 m. In this case, reflected response waveforms for 200 detection points are detected per line.

[0016] The depth corresponds to the time from irradiation of electromagnetic waves to reception of reflected waves. By extracting the reflected wave intensity corresponding to each desired depth from the reflected response waveform as shown in Figure 3, the reflected wave intensity for each depth of the reinforced concrete slab can be obtained. In other words, a reflected response waveform is detected for each detection point set in two dimensions with respect to the road surface, and multiple reflected wave intensity values ​​are obtained in the depth direction from the detected reflected response waveform, thereby obtaining three-dimensional reflected wave intensity within the reflected wave intensity detection range 95.

[0017] The electromagnetic wave device 50 outputs information on the reflection response waveform (reflection wave intensity according to depth) for each detection point acquired to the image processing device 60.

[0018] Furthermore, the electromagnetic wave device 50 is not limited to being attached to the vehicle 90, but may also be in other forms, such as being held by a worker or in the form of a handcart.

[0019] As described above, the information on the reflection response waveform of each detection point output from the electromagnetic wave device 50 represents the three-dimensional reflection wave intensity. Therefore, as shown in Figure 4, the image processing device 60 acquires information on the reflection wave intensity as planar data of the reflection wave intensity corresponding to the depth direction, longitudinal data of the reflection wave intensity along the axial direction, and cross-sectional data along the width direction. Based on the acquired information, the image processing device 60 extracts the reflection wave intensity for each depth, converts the reflection wave intensity into pixel values, and generates a planar image of the reflection wave intensity for each depth by performing a planar merging process on the pixels corresponding to each detection point. The image processing device 60 outputs the generated set of planar images of the reflection wave intensity for each depth to the reinforced concrete structure evaluation device 10.

[0020] In this embodiment, an example is described in which the reinforced concrete structure evaluation device 10 and the image processing device 60 are mounted on a vehicle 90, but the invention is not limited to this. The reinforced concrete structure evaluation device 10 and the image processing device 60 may be installed outside the vehicle, and information on the reflected response waveform acquired by the electromagnetic wave device 50 (details will be described later) may be transmitted from the electromagnetic wave device 50 to the image processing device 60.

[0021] Figure 5 is a block diagram showing the hardware configuration of the reinforced concrete structure evaluation device 10 according to the first embodiment. As shown in Figure 5, the reinforced concrete structure evaluation device 10 has a CPU (Central Processing Unit) 12, memory 14, storage device 16, input device 18, output device 20, storage medium reader 22, and communication I / F (Interface) 24. Each component is connected to each other so as to be able to communicate with each other via a bus 26.

[0022] The storage device 16 stores a reinforced concrete structure evaluation program for executing the reinforced concrete structure evaluation process described later. The CPU 12 is a central processing unit that executes various programs and controls each component. Specifically, the CPU 12 reads the program from the storage device 16 and executes the program using memory 14 as a working area. The CPU 12 controls each component and performs various calculations according to the program stored in the storage device 16.

[0023] Memory 14 is composed of RAM (Random Access Memory) and temporarily stores programs and data as a working area. Storage device 16 is composed of ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), etc., and stores various programs and data, including the operating system.

[0024] The input device 18 is a device for performing various types of input, such as a keyboard or mouse. The output device 20 is a device for outputting various types of information, such as a display or printer. By using a touch panel display as the output device 20, it may also function as the input device 18.

[0025] The storage medium reader 22 reads data stored on various storage media such as CD (Compact Disc)-ROM, DVD (Digital Versatile Disc)-ROM, Blu-ray disc, and USB (Universal Serial Bus) memory, and writes data to the storage media. The communication I / F 24 is an interface for communication with other devices, and standards such as Ethernet (registered trademark), FDDI, or Wi-Fi (registered trademark) are used.

[0026] Next, the functional configuration of the reinforced concrete structure evaluation device 10 according to the first embodiment will be described.

[0027] Figure 6 is a block diagram showing an example of the functional configuration of the reinforced concrete structure evaluation device 10. As shown in Figure 6, the reinforced concrete structure evaluation device 10 includes, as a functional configuration, an acquisition unit 32, an extraction unit 34, a selection unit 36, a calculation unit 38, and an evaluation unit 40. Each functional configuration is realized by the CPU 12 reading the reinforced concrete structure evaluation program stored in the storage device 16, expanding it into the memory 14, and executing it.

[0028] The acquisition unit 32 acquires a set of planar images of the reflected wave intensity for each depth, output from the image processing device 60. The acquisition unit 32 passes the set of planar images, as shown in the upper part of Figure 7, to the extraction unit 34 as three-dimensional array information in which the planar coordinates of pixels corresponding to the same position in each depth planar image are unified, as shown in the lower part of Figure 7. In the planar image in the upper part of Figure 7, the horizontal direction of the paper is the axial direction, and the vertical direction of the paper is the width direction. In the following figures as well, unless otherwise specified, the long side of each image is the axial direction, and the short side is the width direction.

[0029] The extraction unit 34 detects the joint portions of the reinforced concrete slab from each of the planar images acquired by the acquisition unit 32, and extracts the areas between the detected joints as the evaluation target region. Specifically, the extraction unit 34 generates a full-layer overlay image by taking the sum or average of the pixel values ​​in the depth direction of pixels with the same planar coordinate. As shown in Figure 8, the extraction unit 34 calculates the wavelet transform coefficient for each pixel for each axial line of the full-layer overlay image (dashed line in the upper part of Figure 8). Then, the extraction unit 34 generates a wavelet transform result by mapping the calculated wavelet transform coefficient to each pixel.

[0030] As shown in Figure 9, the extraction unit 34 calculates the sum of wavelet transform coefficients for each column of the wavelet transform result and identifies the maximum value of the sum. Note that in Figure 9, the wavelet transform coefficients are represented by simplified numerical values ​​for simplicity of explanation. The extraction unit 34 shifts the pixel positions of each row in the axial direction by a predetermined amount and calculates the sum of wavelet transform coefficients for each column of the shifted wavelet transform result as well. As shown in Figure 10, the extraction unit 34 detects the shift amount that maximizes the maximum value in the relationship between the shift amount and the maximum value of the sum of wavelet transform coefficients for each column. Then, as shown in Figure 11, for the left edge and right edge of the planar image, the extraction unit 34 identifies the joint portion based on the column where the sum is maximized for the detected shift amount (indicated by L and R in Figure 11) and the shift amount. The extraction unit 34 extracts the area between the identified joint portions as the evaluation target region (the white area in the lower part of Figure 11). Note that the shift amount may differ between the left edge and the right edge of the evaluation target region.

[0031] The selection unit 36 ​​selects the depth of the planar image to be used for evaluation for each region, based on a statistical index calculated from the pixel values ​​of pixels contained in each of the regions into which the evaluation target region of the planar image has been divided into multiple regions containing one or more pixels. In the first embodiment, as an example, each grid when the evaluation target region of the planar image is divided into a grid is defined as the above region. In the first embodiment, wavelet transform coefficients calculated based on the pixel values ​​of pixels contained in the grid are used as the statistical index.

[0032] Let's explain this in detail with reference to Figure 12. In Figure 12, the upper part of each of (A) to (E) shows a planar image or an image with the calculated values ​​mapped, and the lower part shows the pixel value or calculated value of each pixel along the axial line indicated by a solid line within each of the images shown in the upper part.

[0033] The selection unit 36 ​​calculates the wavelet transform coefficient for each pixel, as shown in Figure 12(B), for each axial line of the planar image, as shown in Figure 12(A). The mother wavelet used to calculate the wavelet transform coefficient can be any shape, such as a general shape or a Mexican hat shape. If the range of pixel values ​​in the planar image is 0 to x (for example, 0 to 100), the range of the wavelet transform coefficient is -x to x (for example, -100 to 100). The selection unit 36 ​​calculates the squared value of the calculated wavelet transform coefficient, as shown in Figure 12(C). The range of the squared value is 0 to x 2 (For example, 0 to 10000). The squared value is calculated in order to detect both downward-convex and upward-convex peaks in the peak detection described later. The selection unit 36 ​​performs a logarithmic transformation on the squared value of the calculated wavelet transform coefficient, as shown in Figure 12 (D). The range of the value after logarithmic transformation is 0 to log(x 2 The range is (+1) (for example, 0 to 10). The selection unit 36 ​​also calculates a value (hereinafter referred to as "clarity") obtained by applying a Gaussian filter to the logarithmically transformed value, as shown in Figure 12 (E). The range of clarity is 0 to log(x), similar to the value after logarithmically transformation. 2 (+1) However, the range may be narrowed (for example, 0 to 6) due to the smoothing of the waveform peaks. Note that Gaussian filtering is just one example of waveform smoothing; instead of Gaussian filtering, mean filter, low-pass filter using Fourier transform, etc., may be applied.

[0034] The selection unit 36 ​​divides the evaluation area of ​​the planar image into, for example, a grid of 15 pixels vertically x 15 pixels horizontally, and calculates a representative value of clarity within each grid. The representative value may be, for example, the average value or median of clarity within the grid. The selection unit 36 ​​generates a graph showing the relationship between the representative value of clarity and depth in grids with the same planar coordinates for each depth in the planar image. The selection unit 36 ​​also performs a Gaussian filter on the generated graph. Figure 13 shows an example of a graph generated for a certain grid (indicated by the thick frame in the upper part of Figure 13). The upper part of Figure 13 shows the clarity for each depth (a), (b), (c), and (d), the lower left part of Figure 13 shows the graph showing the relationship between the representative value of clarity and depth for that grid, and the lower right part of Figure 13 shows the result of applying a Gaussian filter to that graph.

[0035] The selection unit 36 ​​detects the maximum value of the graph obtained by applying a Gaussian filter to the relationship between the representative value of clarity and depth as a peak. If there are multiple layers of reinforcing bars in the reinforced concrete slab, the selection unit 36 ​​detects a number of peaks equal to the number of reinforcing bar layers. In the first embodiment, the case in which two peaks corresponding to the upper and lower reinforcing bars are detected will be described. In this case, as shown in the lower right figure of Figure 13, the selection unit 36 ​​detects two peaks in descending order of clarity value.

[0036] As shown in Figure 14(A), the selection unit 36 ​​plots the peaks detected for all grids in a three-dimensional space of the depth corresponding to the peak, the axial position of the grid, and the widthwise position to obtain the distribution of peaks. From the distribution of peaks, the selection unit 36 ​​generates a histogram of the number of detected peaks against depth, as shown in Figure 14(B), and determines the range corresponding to the upper reinforcement (shaded area) and the range corresponding to the lower reinforcement (shaded area) from the shape of the histogram. For example, the selection unit 36 ​​determines the range corresponding to the upper reinforcement as the range where the sum of the number of detected peaks corresponding to each depth included in a predetermined range is the largest, and the range corresponding to the lower reinforcement as the range where the sum is the second largest. Depths that do not correspond to the depth where reinforcement exists, such as depths near the road surface, are excluded from the range for determining the range.

[0037] As shown in Figures 14(C) to (F), the selection unit 36 ​​selects the average of the depths within the range corresponding to the upper reinforcement and the range corresponding to the lower reinforcement, in a graph showing the relationship between the representative value of clarity and depth for each grid, as the depth for that grid.

[0038] In Figure 14(C), the graph showing the relationship between the representative value of clarity and depth shows peaks corresponding to the upper and lower reinforcement bars, but in some grids, there are no clear peaks. Figure 14(D) shows a case where there is a peak for the upper reinforcement bars but not for the lower reinforcement bars, (E) shows a case where there is a peak for the lower reinforcement bars but not for the upper reinforcement bars, and (F) shows a case where neither peak exists.

[0039] Therefore, as shown in Figure 15, the selection unit 36 ​​arranges the selected depths for each grid for both the upper and lower reinforcement bars, corresponding to the planar coordinates of the grid. Note that "×" represents a grid where no peak exists. For example, the selection unit 36 ​​may determine that no peak exists if the variance of the representative clarity values ​​corresponding to each depth within the range is less than or equal to a predetermined value. The selection unit 36 ​​interpolates the depths for grids where no peak exists based on the depths of the surrounding grids. As a result, depths for all grids are selected, as shown in the lower part of Figure 15.

[0040] The calculation unit 38 generates a patchwork image by combining portions of the planar images at depths selected by the selection unit 36 ​​for each grid. The patchwork image is an example of the combined image of the present invention. Specifically, as shown in the upper diagram of Figure 16, the calculation unit 38 uses the depth selected for each grid and the group of planar images to identify the depth selected by the selection unit 36 ​​for each grid, and selects a planar image of the identified depth from the group of planar images of all depths.

[0041] The calculation unit 38 extracts the portion of the selected planar image that corresponds to the relevant grid. As shown in the middle diagram of Figure 16, the calculation unit 38 generates a patchwork image by combining the extracted portions of the planar image for all grids. In the first embodiment, since the selection unit 36 ​​has selected the depth for the upper reinforcement and the depth for the lower reinforcement, the calculation unit 38 generates a patchwork image of the upper reinforcement and a patchwork image of the lower reinforcement, as shown in the lower diagram of Figure 16. Note that the calculation unit 38 is not limited to selecting a single planar image corresponding to the specified depth, but may also select a predetermined number of planar images (for example, 5 images) corresponding to a predetermined number of depths before and after the specified depth. In this case, the calculation unit 38 generates a predetermined number of patchwork images.

[0042] The calculation unit 38 calculates an evaluation value using wavelet transform coefficients based on the pixel values ​​of pixels in the patchwork image. In this case, the calculation unit 38 may calculate the evaluation value using an expanded patchwork image obtained by adding pixels with interpolated pixel values ​​between pixels in the axial direction of the patchwork image.

[0043] Here, referring to Figure 17, we will explain the evaluation values ​​for the patchwork image with and without expansion. In the example in Figure 17, it is assumed that the patchwork image includes deteriorated and damaged areas (dashed lines) as shown in the upper part of Figure 17.

[0044] In the case of expansion, for example, as shown in Figure 18, the calculation unit 38 calculates an interpolation curve for each axial line of the patchwork image based on the pixel values ​​of the patchwork image before expansion, using quadratic spline interpolation or the like. The calculation unit 38 sets one or more pixels to be interpolated between the pixels before expansion (black circles in Figure 18) (marked with an "x" in Figure 18), and identifies the pixel values ​​of the set pixels from the interpolation curve. The calculation unit 38 expands the patchwork image by adding pixels with the identified pixel values ​​between the pixels before expansion (B in Figure 17).

[0045] The calculation unit 38 calculates the wavelet transform coefficient for each pixel for each axial line of the expanded patchwork image, similar to when the clarity is calculated by the selection unit 36, squares the calculated wavelet transform coefficients, and performs a logarithmic transformation. Then, the calculation unit 38 calculates an evaluation value by applying a Gaussian filter to the logarithmic transformed value for each line. Furthermore, if the calculation unit 38 has generated a predetermined number of patchwork images corresponding to a predetermined number of depths before and after the specified depth, it calculates the above evaluation value for each patchwork image, and sets the maximum evaluation value in the depth direction of pixels with the same planar coordinates as the evaluation value for each pixel in the patchwork image.

[0046] As shown in Figure 17, the calculation unit 38 calculates an evaluation value for each pixel of the expanded patchwork image. In the example in Figure 17, the distribution of evaluation values ​​is such that pixels with lower evaluation values ​​are represented with darker colors, and pixels with higher evaluation values ​​are represented with lighter colors. As shown in Figure 17, the calculation unit 38 calculates the evaluation value for each pixel of the patchwork image before expansion by downsampling pixels so that the evaluation value corresponding to the expanded patchwork image matches the size of the patchwork image before expansion. In the example in Figure 17, in a reinforced concrete slab, there are areas where the rebar is densely packed, such as the girder section of a bridge (the axial area shown as A in Figure 17). As shown in Figure 17, without expanding the patchwork image, there are areas where the evaluation value is low even though there is no deterioration or damage in the densely packed rebar section. On the other hand, when the evaluation value is calculated after expanding the patchwork image, the evaluation value is appropriately calculated even in the areas where the rebar is densely packed.

[0047] Furthermore, the calculation unit 38 may apply mother wavelets of different widths to the patchwork image of the upper reinforcement and the patchwork image of the lower reinforcement when calculating the wavelet transform coefficients. Specifically, the patchwork image of the lower reinforcement will be a blurrier image than the patchwork image of the upper reinforcement. Therefore, the width of the mother wavelet applied to the patchwork image of the lower reinforcement is made wider than the width of the mother wavelet applied to the patchwork image of the upper reinforcement.

[0048] The evaluation unit 40 evaluates the degree of deterioration and damage of the reinforced concrete slab based on the evaluation values ​​calculated by the calculation unit 38. Specifically, for each grid of the patchwork image, the evaluation unit 40 selects a representative value of the evaluation value of each pixel included in the grid. Here, the representative value may be selected from among the evaluation values ​​in the grid that have the lowest evaluation, in order to avoid overlooking deterioration and damage. The evaluation unit 40 evaluates the degree of deterioration and damage for each grid based on a comparison between the selected representative value of the evaluation value and a predetermined threshold. The threshold is set in advance to the threshold that maximizes the degree of agreement between the area below the threshold and the correct deterioration and damage location when the area with an evaluation value above the threshold and the area below the threshold are classified while varying the threshold in a planar image where the correct degree of deterioration and damage is known.

[0049] Furthermore, the evaluation unit 40 displays an evaluation image in which each grid of the patchwork image is represented in a display manner corresponding to the evaluation result for each grid. For example, as shown in Figure 19, the evaluation unit 40 may display an evaluation image in which each grid of the patchwork image is color-coded according to the representative value of the evaluation value selected for each grid. Alternatively, for example, the evaluation unit 40 may display an evaluation image in which grids where the representative value of the evaluation value selected for each grid is below a threshold are color-coded.

[0050] Next, the operation of the reinforced concrete structure evaluation system 100 according to the first embodiment will be described.

[0051] The electromagnetic wave device 50 scans the reflected wave intensity detection range 95 on the road surface in the direction of vehicle travel, irradiating electromagnetic waves from the surface towards the interior (depth) of the reinforced concrete slab, and receiving the reflected waves. As a result, the electromagnetic wave device 50 detects the reflected wave intensity corresponding to the depth at each position in the reflected wave intensity detection range 95. The electromagnetic wave device 50 then outputs information of the reflected response waveform (reflected wave intensity according to depth) for each acquired detection point to the image processing device 60.

[0052] Next, the image processing device 60 acquires information output from the electromagnetic wave device 50, extracts the reflected wave intensity for each depth based on the acquired information, converts the reflected wave intensity into pixel values, performs a planar merging process on the pixels corresponding to each detection point, and generates a set of planar images of the reflected wave intensity for each depth. Then, the image processing device 60 outputs the generated set of planar images of the reflected wave intensity for each depth to the reinforced concrete structure evaluation device 10.

[0053] The reinforced concrete structure evaluation device 10 performs reinforced concrete structure evaluation processing. Figure 20 is a flowchart showing the flow of reinforced concrete structure evaluation processing performed by the CPU 12 of the reinforced concrete structure evaluation device 10. The CPU 12 reads the reinforced concrete structure evaluation program from the storage device 16, loads it into memory 14, and executes it. As a result, the CPU 12 functions as each functional component of the reinforced concrete structure evaluation device 10, and the reinforced concrete structure evaluation processing shown in Figure 20 is executed.

[0054] First, in step S10, the acquisition unit 32 acquires a set of planar images of the reflected wave intensity for each depth, which are output from the image processing device 60. Then, the acquisition unit 32 passes the set of planar images to the extraction unit 34 as information for a three-dimensional array in which the planar coordinates of pixels corresponding to the same position in the planar images of each depth are unified.

[0055] Next, in step S12, the extraction unit 34 detects the joint portions of the reinforced concrete structure from each of the planar images received from the acquisition unit 32, and extracts the area between the detected joints as the evaluation target area.

[0056] Next, in step S14, the selection unit 36 ​​calculates the clarity for each grid based on wavelet transform coefficients calculated from the pixel values ​​of pixels contained in each of the grids into which the evaluation area of ​​the planar image has been divided. The selection unit 36 ​​also generates a graph in which a Gaussian filter is applied to the relationship between the representative clarity value and depth in grids with the same planar coordinates for each depth in the planar image. Then, the selection unit 36 ​​selects the depth of the planar image to be used for evaluation for each grid based on the peaks detected from this graph.

[0057] Next, in step S16, the calculation unit 38 generates a patchwork image by combining the portions of the planar image with depths selected by the selection unit 36 ​​for each grid. The calculation unit 38 also expands the patchwork image by adding pixels with interpolated pixel values ​​between pixels in the axial direction of the patchwork image.

[0058] Next, in step S18, the calculation unit 38 calculates the wavelet transform coefficient for each pixel for each axial line of the expanded patchwork image, squares the calculated wavelet transform coefficient, and performs a logarithmic transformation. Then, the calculation unit 38 calculates an evaluation value by applying a Gaussian filter to the logarithmic transformed value for each line, and calculates the evaluation value for each pixel of the patchwork image before expansion by downsampling pixels to match the size of the patchwork image before expansion.

[0059] Next, in step S20, the evaluation unit 40 selects a representative value for the evaluation value of each pixel included in each grid of the patchwork image, and evaluates the degree of deterioration and damage for each grid based on a comparison between the selected representative value and a predetermined threshold. Then, the evaluation unit 40 displays an evaluation image representing each grid of the patchwork image in a display mode corresponding to the evaluation result for each grid, and the reinforced concrete structure evaluation process is completed.

[0060] As described above, according to the reinforced concrete structure evaluation system of the first embodiment, the reinforced concrete structure evaluation device acquires a set of planar images of the reflected wave intensity at each depth at various locations on the surface of the reinforced concrete structure. The reinforced concrete structure evaluation device also selects the depth of the planar image to be used for evaluation for each grid, based on a statistical index calculated from the pixel values ​​of pixels included in each of the grids into which the planar image has been divided. Then, the reinforced concrete structure evaluation device calculates an evaluation value using wavelet transform coefficients based on a combined image obtained by combining the portions of the planar images at the depths selected for each grid, and evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value. This makes it possible to accurately evaluate the degree of deterioration and damage of a reinforced concrete structure using images of reflected wave intensity.

[0061] In the first embodiment, the clarity and evaluation value were described as calculated by logarithmically transforming and smoothing the squared value of the wavelet transform coefficient calculated from the pixel value, as shown in Figure 12. However, the invention is not limited to this. For example, the clarity or evaluation value may be calculated by taking the envelope value of the waveform (corresponding to (B) in Figure 12) that shows the wavelet transform coefficient for one line in the axial direction calculated for each pixel of a planar image or patchwork image.

[0062] Furthermore, in the first embodiment, the mother wavelet applied when calculating the wavelet transform coefficient may be a mother wavelet (A in Figure 21) with a width corresponding to the axial width of the reinforcing bar portion in the planar image or patchwork image, as shown in Figure 21. Alternatively, the mother wavelet may be a mother wavelet (B in Figure 21) with a width that responds to the edges of the reinforcing bar portion in the planar image or patchwork image. These mother wavelets may also be applied selectively.

[0063] <Second Embodiment> Next, a second embodiment will be described. In the reinforced concrete structure evaluation system according to the second embodiment, components similar to those in the reinforced concrete structure evaluation system 100 according to the first embodiment are denoted by the same reference numerals and detailed descriptions are omitted.

[0064] As shown in Figure 1, the reinforced concrete structure evaluation system 200 according to the second embodiment comprises a reinforced concrete structure evaluation device 210, an electromagnetic wave device 50, and an image processing device 60.

[0065] The hardware configuration of the reinforced concrete structure evaluation device 210 according to the second embodiment is the same as that of the reinforced concrete structure evaluation device 10 according to the first embodiment shown in Figure 5, so a description will be omitted.

[0066] Next, the functional configuration of the reinforced concrete structure evaluation device 210 according to the second embodiment will be described.

[0067] As shown in Figure 6, the reinforced concrete structure evaluation device 210 includes, as a functional configuration, an acquisition unit 32, an extraction unit 34, a selection unit 36, a calculation unit 238, and an evaluation unit 240. Each functional configuration is realized when the CPU 12 reads the reinforced concrete structure evaluation program stored in the storage device 16, expands it into the memory 14, and executes it.

[0068] Here, for example, let's assume that the location indicated by (1) on the line to be processed in the patchwork image shown in Figure 22 is in a healthy state. In this case, as shown by A in Figure 22, the change in pixel value with respect to the axial position of the location indicated by (1) on the line to be processed (axial position - pixel value) shows peaks at intervals corresponding to the predetermined spacing of the reinforcing bars. Therefore, frequency analysis is performed by treating the axial position as the time axis, and as shown by B in Figure 22, the graph of axial position - pixel value is converted into a frequency distribution (frequency - intensity). From the frequency distribution, peaks are detected around specific frequencies corresponding to the period of the reinforcing bar spacing.

[0069] On the other hand, the area indicated by (2) on the line being processed in the patchwork image shown in Figure 22 is considered to be in a state of degradation. In this case, as shown by C in Figure 22, no periodicity of peaks is observed in the axial position-pixel value graph. Therefore, as shown by D in Figure 22, no peaks at specific frequencies are detected in the frequency distribution. Furthermore, the area indicated by (3) on the line being processed in the patchwork image shown in Figure 22 is considered to have a mixture of pixel values ​​from periodically appearing reinforcing bars and pixel values ​​from other reflections. In this case, the axial position-pixel value is as shown by E in Figure 22. In the frequency distribution obtained by frequency analysis of this axial position-pixel value, as shown by F in Figure 22, a distribution is observed at a specific frequency that appeared in the frequency distribution of the healthy area, and in a frequency range lower than that frequency. Also, the intensity (magnitude of the distribution) at a specific frequency is lower than the intensity at a specific frequency in the healthy area.

[0070] Therefore, the calculation unit 238 calculates a value obtained by frequency analysis of the change in pixel value with respect to the pixel position of each pixel along the axial line of the patchwork image as an evaluation value. Specifically, the calculation unit 238 creates an axial position-pixel value graph showing the change in pixel value with respect to the pixel position within each analysis frame, while sliding an analysis frame of a predetermined width by a predetermined distance along the axial direction of the patchwork image. Then, as shown in Figure 23, the calculation unit 238 detects peaks from the axial position-pixel value graph and counts the distance (number of pixels) between peaks as the period of the peak. Furthermore, the calculation unit 238 converts the period to frequency, for example, at a rate of 1 ms per pixel. In this case, for example, if the period is 8 pixels, the frequency will be 125 Hz. Then, the calculation unit 238 creates a frequency distribution by voting the converted frequency in a frequency-intensity histogram. The calculation unit 238 detects peaks from the created frequency distribution and calculates the frequency of the detected peak and the intensity at that frequency as evaluation values ​​for the range specified by the analysis frame. The calculation unit 238 calculates an evaluation value for each line of the patchwork image using the above process, thereby obtaining the evaluation values ​​as a planar distribution.

[0071] The evaluation unit 240 evaluates the degree of deterioration and damage to the reinforced concrete slab based on whether the frequency indicated by the evaluation value calculated by the calculation unit 238 falls within a predetermined frequency range based on a predetermined frequency. The reference frequency may be a frequency calculated in advance for sound areas. For example, the reference frequency may be 125 Hz and the frequency range may be 125 Hz ± 10 Hz. In this case, the evaluation unit 240 evaluates an area as sound if the peak frequency indicated by the evaluation value is within the range of 115 to 135 Hz, and evaluates an area as deteriorated if it is less than 115 Hz or more than 135 Hz. Furthermore, even if the frequency indicated by the evaluation value is within the predetermined frequency range, the evaluation unit 240 may evaluate an area as showing a tendency towards deterioration if the intensity of that frequency is below a predetermined value. Note that the above reference frequency and frequency range are examples, and appropriate values ​​should be set according to the spacing of the reinforcing bars as an index for evaluation based on the peak frequency.

[0072] The evaluation unit 240 represents the evaluation results for each range of the analysis frame as a planar distribution. Figure 24 shows an example of the evaluation results for a patchwork image that includes deteriorated areas (solid lines in the upper part of Figure 24). In the example evaluation results in Figure 24, healthy areas are represented in black, deteriorated areas in white, and areas showing a tendency towards deterioration in gray. In the example in Figure 24, the deteriorated areas in the patchwork image and the deteriorated areas indicated by the evaluation results generally coincide.

[0073] The operation of the reinforced concrete structure evaluation system 200 according to the second embodiment is omitted because the processing in steps S18 and S20 of the reinforced concrete structure evaluation process (Figure 20) performed by the reinforced concrete structure evaluation device 210 is the same as the processing of the calculation unit 238 and evaluation unit 240 described above.

[0074] As described above, according to the reinforced concrete structure evaluation system of the second embodiment, the reinforced concrete structure evaluation device calculates a value obtained by frequency analysis of the change in pixel value with respect to the pixel position of each pixel along the second direction line of the combined image, and evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value. This makes it possible to accurately evaluate the degree of deterioration and damage of the reinforced concrete structure using an image of reflected wave intensity.

[0075] In the second embodiment described above, the representation of healthy and deteriorated areas in the evaluation results can be adjusted by changing the width of the analysis frame and the slide width used to calculate the evaluation value. Specifically, widening the width of the analysis frame creates a gradient at the boundary between healthy and deteriorated areas, while narrowing the width of the analysis frame makes the boundary between healthy and deteriorated areas clearer. Furthermore, widening the slide width results in a coarser resolution of the evaluation results, while narrowing the slide width results in a higher resolution.

[0076] Furthermore, while the second embodiment described above explains how to calculate evaluation values ​​based on the period of the peak for each analysis frame in axial position-pixel value, the method is not limited to this. For example, spatial frequency analysis may be performed for each axial line of the patchwork image, and evaluation values ​​may be calculated based on the frequency distribution for each pixel position.

[0077] Specifically, the calculation unit sets each line in the axial direction of the patchwork image as a line to be processed, and creates an axial position-pixel value graph for each line to be processed, as shown in Figure 25A. The calculation unit treats the axial distance of the created axial position-pixel value graph as the time axis, for example, at a rate of 1ms per pixel, and performs a time-frequency transformation. Short-time Fourier transform, wavelet transform, S-Transform, etc., can be applied as time-frequency transformation methods. As a result, an axial position-frequency distribution, which is the frequency distribution of pixel value changes at each position in the axial direction, is obtained, as shown in Figure 25B. Note that in the axial position-frequency distribution shown in Figure 25B, the intensity of the frequency is represented by the shade of color.

[0078] The evaluation unit evaluates the periodicity of pixel values ​​corresponding to reinforcing bars arranged at predetermined intervals, based on the axial position-frequency distribution obtained by the calculation unit. For example, as shown in Figure 26, the evaluation unit evaluates areas where the distribution is around a predetermined reference frequency (e.g., 120 Hz) as sound areas, and areas where there is no clear distribution as deteriorated areas.

[0079] More specifically, the evaluation unit evaluates a location as sound if the intensity of each frequency within a predetermined frequency range, including the reference frequency, at each location in the axial position-frequency distribution is above a threshold, and as deteriorated if the intensity is below the threshold. In the example in Figure 26, the areas indicated by solid lines within the axial position-frequency section are where the frequency intensity is below the threshold. The evaluation unit may also evaluate locations as deteriorated if the intensity of frequencies outside the predetermined frequency range is above the threshold, as shown by dashed lines within the axial position-frequency distribution in Figure 26. Furthermore, the evaluation unit may also evaluate locations as deteriorated if, as shown by dashed lines within the axial position-frequency distribution in Figure 26, the intensity of frequencies within the predetermined frequency range is above the threshold, but the intensity of frequencies outside the predetermined frequency range is also above the threshold. The reference frequency and frequency range mentioned above should be set to appropriate values ​​according to the spacing of the reinforcing bars.

[0080] The evaluation unit expresses the evaluation results based on the axial position-frequency distribution as a planar distribution. Figure 27 shows an example of the evaluation results for a patchwork image that includes deteriorated areas (indicated by solid lines in the upper part of Figure 27). In the example evaluation results in Figure 27, healthy areas are represented in black, deteriorated areas in white, and areas showing a tendency towards deterioration in gray. In the example in Figure 27, the deteriorated areas in the patchwork image and the deteriorated areas indicated by the evaluation results generally coincide.

[0081] Furthermore, the processing that the CPU reads and executes in the above embodiment may be executed by various processors other than the CPU. Examples of such processors include PLDs (Programmable Logic Devices) such as FPGAs (Field-Programmable Gate Arrays) whose circuit configuration can be changed after manufacturing, and dedicated electrical circuits such as ASICs (Application Specific Integrated Circuits) which have a circuit configuration specifically designed to execute a particular process. The above processing may be executed by one of these various processors, or by a combination of two or more processors of the same or different types (for example, multiple FPGAs, and a combination of a CPU and an FPGA). More specifically, the hardware structure of these various processors is an electrical circuit that combines circuit elements such as semiconductor elements.

[0082] Furthermore, although the above embodiment describes a configuration in which the program is pre-stored (installed) in a storage device, the invention is not limited to this. The program may be provided in a form recorded on a storage medium such as a CD-ROM, DVD-ROM (Digital Versatile Disc Read Only Memory), or USB (Universal Serial Bus) memory. Alternatively, the program may be provided in a form that is downloaded from an external device via a network.

[0083] The following additional information is disclosed.

[0084] (Additional note 1) An acquisition unit acquires a set of planar images for each of the multiple depths of a reinforced concrete structure, wherein, at each position on the surface of a reinforced concrete structure in which multiple reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, the intensity of the reflected electromagnetic waves irradiated from the surface toward the interior of the reinforced concrete structure is represented by the pixel value of the pixel corresponding to each position, and the acquisition unit acquires a set of planar images for each of the multiple depths of the reinforced concrete structure. A selection unit that selects the depth of the planar image to be used for evaluation for each region, based on a statistical index calculated from the pixel values ​​of pixels included in each of the regions into which the planar image is divided into multiple regions, each containing one or more pixels. A calculation unit calculates an evaluation value representing the change in pixel values ​​in a second direction of a combined image obtained by combining portions of the planar image corresponding to the depth selected by the selection unit for each region, An evaluation unit that evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit, Reinforced concrete structure evaluation device including [specific component].

[0085] (Additional note 2) The reinforced concrete structure evaluation device according to Appendix 1, wherein the selection unit uses wavelet transform coefficients calculated based on the pixel values ​​of pixels included in the region as the statistical index.

[0086] (Additional note 3) The reinforced concrete structure evaluation apparatus according to Appendix 2, wherein the selection unit uses a value obtained by logarithmically transforming the squared value of the wavelet transform coefficient calculated for each pixel of the planar image, and then applying a Gaussian filter to that value for each line in the second direction, as the statistical index.

[0087] (Additional note 4) The reinforced concrete structure evaluation apparatus according to Appendix 2, wherein the selection unit uses the value obtained by taking the envelope of the waveform representing the wavelet transform coefficient for one line in the second direction calculated for each pixel of the planar image as the statistical index.

[0088] (Additional note 5) The reinforced concrete structure evaluation device according to any one of the appendix items 1 to 4, wherein the selection unit selects the depth corresponding to the peak of the representative value in a graph showing the relationship between the representative value of the statistical index within the region and the depth for each region.

[0089] (Additional note 6) The reinforced concrete structure evaluation device according to Appendix 5, wherein the selection unit detects the maximum value of a graph obtained by applying a Gaussian filter to the relationship between the representative value and the depth as the peak.

[0090] (Additional note 7) The reinforced concrete structure evaluation apparatus according to Appendix 5 or Appendix 6, wherein the selection unit interpolates the peaks in the region where no peaks are detected using peaks detected in the surrounding region.

[0091] (Additional note 8) The reinforced concrete structure evaluation apparatus according to any one of the appendix items 1 to 7, wherein the calculation unit calculates the wavelet transform coefficient for each pixel of the combined image as the evaluation value.

[0092] (Additional note 9) The reinforced concrete structure evaluation apparatus according to Appendix 8, wherein the calculation unit calculates the evaluation value by performing a Gaussian filter on the logarithmic transformation of the squared value of the wavelet transform coefficient calculated for each pixel of the combined image, for each line in the second direction.

[0093] (Additional note 10) The reinforced concrete structure evaluation apparatus according to Appendix 9, wherein the calculation unit calculates the value obtained by taking the envelope of the waveform representing the wavelet transform coefficient for one line in the second direction calculated for each pixel of the combined image as the evaluation value.

[0094] (Additional note 11) If there are multiple layers in the aforementioned reinforced concrete structure that contain reinforcing steel, The selection unit selects the depth corresponding to each of the layers in which the reinforcing bars are present. The calculation unit uses a mother wavelet of a width corresponding to the layer to calculate the wavelet transform coefficient for each of the combined images corresponding to each of the layers. A reinforced concrete structure evaluation device as described in any one of the appendices 8 to 10.

[0095] (Additional note 12) The calculation unit is a reinforced concrete structure evaluation device according to Appendix 11, wherein the width of the mother wavelet is increased for deeper layers.

[0096] (Additional note 13) The reinforced concrete structure evaluation apparatus according to any one of appendices 8 to 12, wherein the calculation unit selectively uses a mother wavelet with a width corresponding to the width in the second direction of the region showing the reinforcement in the combined image, and a mother wavelet with a width that responds to the edge of the region showing the reinforcement in the combined image to calculate the wavelet transform coefficient.

[0097] (Additional note 14) The reinforced concrete structure evaluation device according to any one of the appendix items 1 to 7, wherein the calculation unit calculates as the evaluation value a value obtained by frequency analysis of the change in pixel value with respect to the pixel position of each pixel along the second direction line of the combined image.

[0098] (Additional note 15) The reinforced concrete structure evaluation apparatus according to Appendix 14, wherein the calculation unit calculates the evaluation value based on the peak frequency and intensity at the peak frequency of a waveform showing the change in pixel value with respect to the pixel position within the analysis frame, while sliding an analysis frame of a predetermined width by a predetermined distance along the second direction of the combined image.

[0099] (Additional note 16) The reinforced concrete structure evaluation apparatus according to Appendix 14, wherein the calculation unit performs spatial frequency analysis on each line in the second direction of the combined image and calculates the evaluation value based on the frequency distribution for each pixel position of each pixel.

[0100] (Additional note 17) The reinforced concrete structure evaluation device according to any one of the appendix items 1 to 16, wherein the evaluation unit evaluates the degree of deterioration and damage for each region of the combined image based on a comparison between the lowest evaluation value among the evaluation values ​​of each pixel included in the region and a predetermined threshold.

[0101] (Additional note 18) The reinforced concrete structure evaluation device according to any one of the appendix items 1 to 17, wherein the evaluation unit displays an evaluation image in which each region of the combined image is represented in a display manner corresponding to the evaluation result for each region.

[0102] (Additional note 19) The reinforced concrete structure evaluation device according to Appendix 18, wherein the evaluation unit displays an evaluation image in which each region of the combined image is color-coded according to the lowest evaluation value among the evaluation values ​​of each pixel included in the region.

[0103] (Additional note 20) The acquisition unit includes an extraction unit that detects the joint portions of the reinforced concrete structure from each of the planar images acquired by the acquisition unit and extracts the area between the detected joints as the evaluation target area. The reinforced concrete structure evaluation apparatus according to any one of the appendix items 1 to 19, wherein each of the selection unit, the calculation unit, and the evaluation unit performs processing on the evaluation target area extracted by the extraction unit.

[0104] (Additional note 21) The reinforced concrete structure evaluation apparatus according to any one of the appendix 1 to 20, wherein the calculation unit calculates the evaluation value using the expanded combined image obtained by adding pixels with interpolated pixel values ​​between pixels in the second direction of the combined image. [Explanation of Symbols]

[0105] 10,210 Reinforced Concrete Structure Evaluation Device 12 CPU 14 memory 16 Storage device 18 Input device 20 Output device 22 Storage medium reader 24 Communication I / F 26 bus 32 Acquisition Department 34 Extraction part 36 Selection Section 38, 238 Calculation Unit 40,240 Evaluation Department 50 Electromagnetic wave equipment 60 Image Processing Devices 90 vehicles 95 Reflected wave intensity detection range 100, 200 Reinforced Concrete Structure Evaluation System

Claims

1. An acquisition unit acquires a set of planar images for each of the multiple depths of a reinforced concrete structure, wherein a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, and the intensity of the reflected electromagnetic waves irradiated from the surface toward the interior of the reinforced concrete structure is represented by the pixel value of the pixel corresponding to each of the positions on the surface of the reinforced concrete structure, and A selection unit that selects the depth of the planar image to be used for evaluation for each region, based on a statistical index calculated from the pixel values ​​of pixels included in each of the regions into which the planar image is divided into a plurality of regions, each containing one or more pixels. A calculation unit calculates an evaluation value representing the change in pixel values ​​in a second direction of a combined image obtained by combining portions of the planar image corresponding to the depth selected by the selection unit for each region, An evaluation unit that evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit, Reinforced concrete structure evaluation device including [specific component].

2. The reinforced concrete structure evaluation device according to claim 1, wherein the selection unit selects, for each region, the depth corresponding to the peak of the representative value in a graph showing the relationship between the representative value of the statistical index within the region and the depth.

3. The reinforced concrete structure evaluation apparatus according to claim 2, wherein the selection unit detects the maximum value of a graph obtained by applying a Gaussian filter to the relationship between the representative value and the depth as the peak.

4. The reinforced concrete structure evaluation device according to claim 2, wherein the selection unit interpolates the peaks in the region where no peaks are detected using peaks detected in the surrounding region.

5. The reinforced concrete structure evaluation device according to any one of claims 1 to 4, wherein the calculation unit calculates the wavelet transform coefficient for each pixel of the combined image as the evaluation value.

6. The reinforced concrete structure evaluation apparatus according to claim 5, wherein the calculation unit calculates the evaluation value by performing a Gaussian filter on the logarithmic transformation of the squared value of the wavelet transform coefficient calculated for each pixel of the combined image, for each line in the second direction.

7. The reinforced concrete structure evaluation apparatus according to claim 6, wherein the calculation unit calculates the value obtained by taking the envelope of the waveform representing the wavelet transform coefficient for one line in the second direction calculated for each pixel of the combined image as the evaluation value.

8. If there are multiple layers in the aforementioned reinforced concrete structure that contain reinforcing steel, The selection unit selects the depth corresponding to each of the layers in which the reinforcing bars are present. The calculation unit uses a mother wavelet of a width corresponding to the layer to calculate the wavelet transform coefficient for each of the combined images corresponding to each of the layers. The reinforced concrete structure evaluation device according to claim 5.

9. The reinforced concrete structure evaluation apparatus according to claim 5, wherein the calculation unit selectively uses a mother wavelet having a width corresponding to the width in the second direction of the region showing the reinforcing bars in the combined image, and a mother wavelet having a width that responds to the edge of the region showing the reinforcing bars in the combined image to calculate the wavelet transform coefficient.

10. The reinforced concrete structure evaluation device according to any one of claims 1 to 4, wherein the calculation unit calculates, as the evaluation value, a value obtained by frequency analysis of the change in pixel value with respect to the pixel position of each pixel along the second direction line of the combined image.

11. The reinforced concrete structure evaluation apparatus according to claim 10, wherein the calculation unit calculates the evaluation value based on the peak frequency and intensity at the peak frequency of a waveform showing the change in pixel value with respect to the pixel position within the analysis frame, while sliding an analysis frame of a predetermined width by a predetermined distance along the second direction of the combined image.

12. The reinforced concrete structure evaluation apparatus according to claim 10, wherein the calculation unit performs spatial frequency analysis on each line in the second direction of the combined image and calculates the evaluation value based on the frequency distribution for each pixel position of each pixel.

13. The reinforced concrete structure evaluation device according to any one of claims 1 to 4, wherein the evaluation unit evaluates the degree of deterioration and damage for each region of the combined image based on a comparison between the lowest evaluation value among the evaluation values ​​of each pixel included in the region and a predetermined threshold.

14. The reinforced concrete structure evaluation device according to any one of claims 1 to 4, wherein the evaluation unit displays an evaluation image in which each region of the combined image is represented in a display manner corresponding to the evaluation result for each region.

15. A reinforced concrete structure evaluation method performed by a reinforced concrete structure evaluation device including an acquisition unit, a selection unit, a calculation unit, and an evaluation unit, The acquisition unit acquires a set of planar images representing the intensity of reflected electromagnetic waves irradiated from the surface toward the interior of a reinforced concrete structure at each position on the surface of the reinforced concrete structure, where a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction, and the intensity of reflected electromagnetic waves irradiated toward the interior of the reinforced concrete structure is represented by the pixel value of the pixel corresponding to each position, and the acquisition unit acquires a set of planar images for each of the plurality of depths of the reinforced concrete structure. The selection unit divides the planar image into multiple regions, each containing one or more pixels, and based on a statistical index calculated from the pixel values ​​of the pixels in each of the regions, it selects the depth of the planar image to be used for evaluation for each region. The calculation unit calculates an evaluation value representing the change in pixel values ​​in the second direction of the combined image obtained by combining the portions of the planar image corresponding to the depth selected by the selection unit for each region. The evaluation unit evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit. Evaluation methods for reinforced concrete structures.

16. Computers, A planar image is obtained in which the intensity of reflected electromagnetic waves irradiated from the surface toward the interior of a reinforced concrete structure at each position on the surface of a reinforced concrete structure in which a plurality of reinforcing bars extending in a first direction are arranged at predetermined intervals along a second direction perpendicular to the first direction is represented by the pixel value of the pixel corresponding to each position, and the acquisition unit acquires a group of planar images for each of the plurality of depths of the reinforced concrete structure. A selection unit selects the depth of the planar image to be used for evaluation for each region, based on a statistical index calculated from the pixel values ​​of pixels included in each of the regions into which the planar image is divided into a plurality of regions containing one or more pixels. A calculation unit calculates an evaluation value representing the change in pixel values ​​in a second direction of a combined image obtained by combining portions of the planar image corresponding to the depth selected by the selection unit for each region, and An evaluation unit evaluates the degree of deterioration and damage of the reinforced concrete structure based on the evaluation value calculated by the calculation unit. A reinforced concrete structure evaluation program designed to function as such.

Images