JP2020098101A - Structure soundness evaluation apparatus - Google Patents

Abstract

To easily evaluate soundness of structures while suppressing cost.SOLUTION: A structure soundness evaluation apparatus 1 is provided with an image pickup unit 10 for generating a picked-up image of a displacement measurement marker 120 installed in a structure 110 and a soundness evaluation unit 20 that evaluates soundness of the structure 110. The soundness evaluation unit 20 measures a position of the displacement measurement marker 120 from the picked-up image, generates structural displacement information that correlates imaging time points and the positions each other from a plurality of picked-up images with different imaging time points and to evaluate the soundness of the structure 110 based on the structure displacement information.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure soundness evaluation device.

For structures such as road bridges and railway bridges, soundness assessment is performed to understand the deterioration status.

For example, Patent Document 1 discloses a building diagnostic monitoring system that evaluates soundness using an acceleration sensor. Specifically, the recording unit receives and analyzes the detection data from the plurality of acceleration sensors in the building, and calculates the damage evaluation of the building based on the seismic intensity of each floor and the diagnostic algorithm included in the CPU.

On the other hand, Patent Document 2 discloses a structure displacement monitoring system that detects displacement of a structure and evaluates soundness. More specifically, the image capturing means captures an image of a region fixed to a member of the structure and including one or more markers, and acquires the captured image. The image analysis means performs image analysis processing on the image acquired by the imaging means, and obtains the position and shape of the marker included in the image. The deformation amount measuring unit measures the deformation amount of the member or the like based on the position and shape of the sign or the like obtained by the image analysis unit.

JP, 2013-254239, A JP, 2017-90281, A

However, when the acceleration sensor is used as in Patent Document 1, the cost of the acceleration sensor is required, and the routing of the data communication cable becomes complicated. On the other hand, in Patent Document 2, the soundness of the structure is evaluated by the interlayer displacement, but it is premised on the multipoint measurement, and it is difficult to easily carry out the soundness evaluation.

Therefore, an object of the present invention is to easily evaluate the soundness of a structure while suppressing the cost.

The following is a brief description of the outline of the typical inventions among the inventions disclosed in the present application.

A structure soundness evaluation apparatus according to a representative embodiment of the present invention includes an imaging unit that generates a picked-up image of a displacement measurement marker installed on a structure, and a soundness evaluation unit that evaluates the soundness of the structure. , Are provided. The soundness evaluation unit measures the position of the displacement measurement marker from the captured image, generates the structural displacement information in which the captured time and the position are associated with each other from the plurality of captured images with different capturing times, and outputs the structural displacement information. Based on this, the soundness of the structure is evaluated.

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows. According to the representative embodiment of the present invention, it is possible to easily evaluate the soundness of the structure while suppressing the cost.

It is a figure which shows an example of the structure soundness evaluation apparatus which concerns on Embodiment 1 of this invention. It is a flowchart figure which shows an example of the displacement measuring method which concerns on Embodiment 1 of this invention. It is a figure explaining the specific example of a displacement measurement marker. It is a figure explaining the specific example of mathematical processing. It is a figure explaining the specific example of the measurement result of the displacement in a comparative example.

(Embodiment 1)
Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and a person having ordinary skill in the art can easily think of appropriate modifications while keeping the gist of the invention, and are naturally included in the scope of the invention. Further, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part as compared with the actual mode, but this is merely an example, and the interpretation of the present invention will be understood. It is not limited.

In the specification and the drawings, the same elements as those described above with reference to the already-existing drawings are designated by the same reference numerals, and detailed description thereof may be appropriately omitted.

<Structure of structure soundness evaluation device>
The structure soundness evaluation apparatus according to the first embodiment measures the position of the displacement measurement marker from the captured image, and based on the structure displacement information that associates the imaging time with the position of the displacement measurement marker, the soundness of the structure It is a device to evaluate the degree.

<Imaging unit 10>
FIG. 1 is a diagram showing an example of a structure soundness evaluation apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the structure soundness evaluation device 1 includes an imaging unit 10 and a soundness evaluation unit 20. The imaging unit 10 is a functional block that images the imaging region 100 including the displacement measurement marker 120 installed on the structure 110 and generates a captured image. The image pickup unit 10 includes a lens 11, an image sensor 12, a calculation unit 13, a data storage unit 14, and a communication interface 15. For example, the image sensor 12, the calculation unit 13, the data storage unit 14, the communication interface 15, and the like may be connected to the internal bus or may be connected to each other by individual wiring. The imaging unit 10 is fixed at a predetermined position so that the lens 11 is directed to the imaging region 100.

The lens 11 focuses the light, which has arrived from the displacement measurement area A1 direction, on the image sensor 12. The image sensor 12 includes, for example, a CMOS image sensor in which CMOS (Complementary Metal Oxide Semiconductor) elements are arranged in an array, a CCD image sensor in which CCD (Charge Coupled Device) elements are arranged in an array, and the like. Each element of the image sensor 12 generates an electric signal according to the amount of light condensed by the lens 11. The image sensor 12 outputs the electric signal generated by each element to the arithmetic unit 13.

The calculation unit 13 generates a file of captured image data based on the electric signal generated by the image sensor 12. Information on the image capturing time may be added to the file of the captured image data. The calculation unit 13 may generate captured image data based on an image obtained by combining the captured image with the capturing time. The arithmetic unit 13 also controls the operation of each unit of the imaging unit 10.

The arithmetic unit 13 includes, for example, a microcomputer 13a and a RAM (Random Access Memory) 13b. In the RAM 13b, for example, the program read from the data storage unit 14 is expanded, and the expanded program is executed by the microcomputer 13a, whereby a function of generating captured image data is realized, and each unit of the image capturing unit 10 is realized. Controlled.

The data storage unit 14 includes a non-volatile memory such as a flash memory, and stores the captured image data generated by the calculation unit 13, distance information to the displacement measurement marker 120, programs, various setting information, and the like. Store. The captured image data and the distance information may be stored in the data storage unit 23 of the soundness evaluation unit 20 described later.

The communication interface 15 transmits and receives data to and from the communication interface 21 of the soundness evaluation unit 20. Data such as captured image data and control signals to the soundness evaluation unit 20 are transmitted from the imaging unit 10 via the communication interfaces 15 and 21. On the other hand, data such as a control signal is transmitted from the soundness evaluation unit 20 to the imaging unit 10 via the communication interfaces 21 and 15. The communication interface 15 and the communication interface 21 may be connected by wire or wirelessly. Further, the communication interface 15 and the communication interface 21 may send and receive data via an internal network or an external network such as the Internet.

<Soundness evaluation unit 20>
The soundness evaluation unit 20 is a functional block that measures the displacement of the displacement measurement marker based on the captured image data generated by the imaging unit 10 to measure the displacement measurement region, that is, the displacement of the ground, structures, and the like. As shown in FIG. 1, the soundness evaluation unit 20 includes a communication interface 21, a calculation unit 22, and a data storage unit 23. These may be connected to the internal bus or may be connected to each other by individual wiring.

The calculation unit 22 is a functional block that performs image processing on the captured image data and processing such as soundness evaluation of the structure. The arithmetic unit 22 includes, for example, a microcomputer 22a and a RAM 22b. In the RAM 22b, for example, a program read from the data storage unit 23 is expanded, and the expanded program is executed by the microcomputer 22a, thereby configuring image processing, processing such as soundness evaluation, and the soundness evaluation unit 20. The control of each unit is performed. The process related to the soundness evaluation will be described later in detail.

The data storage unit 23 includes, for example, a non-volatile memory such as a flash memory, the position of the displacement measurement marker measured from the captured image in the arithmetic unit 22, the captured time of each captured image, the soundness evaluation result, the program, various setting information, etc. Store each data of. Further, the data storage unit 23 may store the captured image data transmitted from the image capturing unit 10.

Although the imaging unit 10 and the soundness evaluation unit 20 are separately configured in FIG. 1, they may be integrally configured. In this case, for example, the arithmetic units 13 and 22 may be integrated, and the data storage units 14 and 23 may be integrated. Further, in this case, the communication interfaces 15 and 21 may be omitted. Further, as the image pickup unit 10, for example, a digital device such as a digital still camera or a digital video camera may be used. Further, as the soundness evaluation unit 20, for example, an information processing device such as a personal computer or a tablet terminal may be used.

<Soundness evaluation method>
Next, a structure soundness evaluation method using the structure soundness evaluation device of FIG. 1 will be described. FIG. 2 is a flowchart showing an example of the soundness evaluation method according to the first embodiment of the present invention. FIG. 2A is a flowchart relating to generation of structure displacement information in which the imaging time and the position of the displacement acquisition measurement marker are associated with each other. FIG. 2B is a flowchart related to the soundness evaluation of the structure.

<Generation of structural displacement information>
To generate the structure displacement information, the processes of steps S11 to S14 shown in FIG. 2A are executed. It is assumed that the image pickup unit 10 is installed and the lens 11 is positioned prior to the process of step S11. In step S11, the image capturing unit 10 captures an image of the image capturing area 100 including the displacement measurement marker 120 and generates captured image data for position measurement. The imaging unit 10 transmits the generated captured image data to the soundness evaluation unit 20. The captured image data is stored in the data storage unit 23 of the soundness evaluation unit 20 or the data storage unit 14 of the imaging unit 10. Further, the captured image data may be stored in an external storage or the like not shown.

In step S12, the calculation unit 22 performs image processing on the captured image data and extracts the displacement measurement marker 120 provided on the structure 110. Then, the calculation unit 22 measures the position of the extracted displacement measurement marker 120.

FIG. 3 is a diagram illustrating a specific example of the displacement measurement marker. Specifically, referring to FIG. 3, in the first position measurement, the calculation unit 22 extracts, for example, the displacement measurement marker 120 of FIG. 3 from the captured image. Well-known image processing is performed to extract the displacement measurement marker 120. The shape and pattern of the displacement measurement marker 120 are not limited to this.

Then, the calculation unit 22 sets a displacement measurement point 121 at an arbitrary position of the displacement measurement marker 120, and measures the position of the displacement measurement point 121 in the imaging region 100 as the position of the displacement measurement marker 120. The position of the displacement measurement marker 120 measured here is a value obtained in pixel units. Note that FIG. 3 shows an example in which the displacement measurement point 121 is set at a predetermined position on the lower right of the displacement measurement marker 120, but the displacement measurement point 121 may be set at a place other than this. The calculation unit 22 stores the measured position of the displacement measurement marker 120 in the RAM 22b in association with the imaging time or stores it in the data storage unit 23.

In step S13, the calculation unit 22 generates structure displacement information in which the imaging time and the position of the displacement measurement marker 120 are associated with each other. The calculation unit 22 reads the position of the displacement measurement point 121 and the corresponding imaging time stored in the RAM 22b or stored in the data storage unit 23, and, for example, associates the imaging time with the position of the displacement measurement point 121. The generated table is generated as structure displacement information. At this time, the calculation unit 22 may generate structure displacement information corresponding to each of a plurality of directions (for example, the vertical direction and the horizontal direction). Moreover, the calculation unit 22 may generate structure displacement information in directions other than these directions. The calculation unit 22 may store the generated structure displacement information in the RAM 22b or may store it in the data storage unit 23.

In step S14, it is determined whether the displacement measurement marker 120 is continuously imaged. The structure soundness evaluation apparatus 1 measures the change in the position of the displacement measurement point 121 in time series by imaging the displacement measurement marker 120 multiple times at different timings, and generates structure displacement information. For example, the imaging unit 10 or the soundness evaluation unit 20 counts the number of times the displacement measurement marker 120 is imaged, and determines whether the number of times N of imaging has reached a predetermined number of times of imaging N1. When the number of times of imaging has not reached the predetermined number of times of imaging (No), the processes of steps S11 to S13 are executed again.

In step S12 after the second time, the calculation unit 22 extracts the displacement measurement marker 120 and the displacement measurement point 121 set in step S11 of the first time, and measures the position of the displacement measurement point 121 in each captured image. Note that the calculation unit 22 may store the position of the displacement measurement point 121 and the corresponding imaging time in the data storage unit 23 each time the position measurement is performed, or the position of the displacement measurement point 121 for a plurality of times and the corresponding imaging time. The time may be collectively stored in the data storage unit 23.

In the second and subsequent steps S13, for example, the calculation unit 22 reads the structure displacement information generated in the previous step S13 from the RAM 22b or the data storage unit 23, and measures the position of the displacement measurement point 121 measured this time and the corresponding imaging time. Is added to update the structure displacement information.

Note that the calculation unit 22 does not generate the structure displacement information until immediately before the final round, and in the final round, the structure displacement information is calculated using the positions and the imaging times of all the displacement measurement points 121 measured by the final round. May be generated. In this case, the process in step S13 is not performed until immediately before the final round, and the process in step S13 is performed only in the final round.

When the number of times of imaging reaches the predetermined number of times of imaging (Yes), a series of processes related to generation of structure displacement information and the like are completed.

Note that here, the case where the position measurement of the displacement measurement point 121 is performed every time a captured image is generated in step S12 has been described. However, after all imaging is completed, that is, the number of times of imaging is the predetermined number of times of imaging. After reaching, the position measurement of the displacement measurement point may be performed on all the captured images.

<Evaluation of soundness of structure>
Next, the soundness evaluation of the structure based on the structure displacement information will be described. In the soundness evaluation, for example, the processing of steps S21 to S22 shown in FIG. 2B is executed.

In step S21, mathematical processing is performed on the structure displacement information generated in step S13. The calculation unit 22 performs, for example, Fourier transform on the structure displacement information to generate structure amplitude information in which the amplitude and the frequency are associated with each other.

FIG. 4 is a diagram illustrating a specific example of mathematical processing. FIG. 4 shows the measurement result in the vertical direction of the displacement measurement marker. FIG. 4A is a diagram in which the structure displacement information before Fourier transform is graphed. In FIG. 4A, the horizontal axis represents the image capturing time and the vertical axis represents the position. In FIG. 4A, the elapsed time from the start of image capturing is shown as the image capturing time. Further, in FIG. 4A, the position of the displacement measurement marker is shown as the displacement from the reference position. In other words, the vertical axis of FIG. 4A shows the difference between the measured position and the reference position. FIG. 4B is a graph of the structure amplitude information after the Fourier transform. In FIG. 4B, the horizontal axis represents frequency and the vertical axis represents amplitude.

According to the structure displacement information shown in FIG. 4A, the displacement peak is detected near the times T1 and T2. On the other hand, according to the structure amplitude information shown in FIG. 4B, the peak of the amplitude is detected near the frequency F1. That is, it can be seen that the displacement measurement marker 120 vibrates at a frequency of about F1. The frequency when the displacement measurement marker 120 vibrates differs depending on the structure.

Here, the case where the Fourier transform is used as the mathematical process has been illustrated, but other than this, a process such as Laplace transform may be used for the mathematical process. In addition, the calculation unit 22 may perform different mathematical processes on the same structure displacement information depending on the purpose of use.

Further, when the structure displacement information corresponding to each of the plurality of directions is generated in step S13, the calculation unit 22 may perform mathematical processing on all the structure displacement information, or a part of the structure displacement information. Mathematical processing may be performed only on the object displacement information.

In step S22, the soundness of the structure is evaluated based on the structure amplitude information generated in step S21. The calculation unit 22 evaluates the soundness by, for example, calculating the full width at half maximum of the amplitude from the structure amplitude information and comparing the calculated full width at half maximum (hereinafter, referred to as the calculated full width at half maximum) with a predetermined half width threshold. To do. Specifically, if the calculated full width at half maximum is less than or equal to the full width at half maximum threshold, the calculation unit 22 evaluates that there is no problem with the soundness of the structure to be evaluated. On the other hand, if the calculated full width at half maximum is larger than the full width half maximum threshold value, the calculation unit 22 evaluates that there is a problem with the soundness of the structure to be evaluated.

Further, the soundness of the structure may be evaluated based on the amplitude of the structure amplitude information, the displacement of the structure displacement information, and the like. Further, the soundness of the structure may be evaluated by combining the evaluation result based on the structure amplitude information and the evaluation result based on the structure displacement information.

The calculation unit 22 may notify the user of these evaluation results by displaying them on a display device (not shown), for example. Further, the arithmetic unit 22 may cause the structure soundness evaluation device 1 to issue an alarm when it is diagnosed that there is a problem in soundness.

[Comparative example]
Here, a comparative example will be described. As a comparative example, a displacement measurement result when a vibrometer is used will be described. FIG. 5 is a diagram illustrating a specific example of the displacement measurement result in the comparative example. FIG. 5 shows displacement measurement results for the same structure as in the case of FIG. FIG. 5A shows displacement measurement results of the structure when sampling is performed at a frequency of 100 Hz. FIG. 5B shows a conversion result obtained by performing a Fourier transform on the displacement measurement result of FIG.

Comparing the structure displacement information of FIG. 4A and the displacement measurement result of FIG. 5A, the structure displacement information measured from the captured image is almost the same as the displacement measurement result using the vibrometer. ing. Therefore, the structure amplitude information of FIG. 4(b) has almost the same result as the conversion result of FIG. 5(b). However, although the results of FIGS. 4 and 5 are almost the same in the drawings, since the position of the displacement measurement marker can be measured in pixel units in a digital device, the structure according to the present embodiment can be obtained. The measurement accuracy of the soundness evaluation device is higher than the measurement accuracy of the vibrometer according to the comparative example.

<Effects of this embodiment>
According to the present embodiment, the calculation unit 22 measures each position of the displacement measurement marker 120 from the plurality of captured images, and generates the structure displacement information in which the imaging time and the position of the displacement measurement marker 120 are associated with each other. To do. Then, the calculation unit 22 evaluates the soundness of the structure to be evaluated based on the structure displacement information. According to this configuration, it is not necessary to use an acceleration sensor or a measuring instrument such as the vibrometer described in the comparative example in soundness evaluation. Further, since only one displacement measurement point 121 is required to detect the position of the displacement measurement marker 120, it is possible to easily evaluate the soundness of the structure while suppressing the cost. In addition, the installation work of the structure soundness evaluation device is made efficient.

Further, according to the present embodiment, the calculation unit 22 generates structure displacement information corresponding to each of a plurality of directions (for example, vertical direction and horizontal direction). According to this configuration, since the soundness of the structure can be evaluated from a plurality of directions, the soundness can be evaluated more accurately.

Further, according to the present embodiment, the calculation unit 22 performs mathematical processing on the structure displacement information and converts the structure displacement information into predetermined information. For example, the calculation unit 22 performs a Fourier transform on the structure displacement information and converts the structure displacement information into structure amplitude information in which the frequency and the amplitude are associated with each other. According to this configuration, it is possible to acquire information useful for soundness evaluation from the structure displacement information, and thus it is possible to effectively perform soundness evaluation of the structure.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1... Structural soundness evaluation apparatus, 10... Imaging part, 20... Soundness evaluation part, 100... Imaging area, 110... Structure, 120... Displacement measurement marker, 121... Displacement measurement point

Claims (6)

An imaging unit that generates a captured image of the displacement measurement marker installed on the structure,
A soundness evaluation unit for evaluating the soundness of the structure,
Equipped with
The soundness evaluation unit measures the position of the displacement measurement marker from the captured image, and generates structure displacement information in which the captured time and the position are associated with each other, from the plurality of captured images having different captured times. , Evaluating the soundness of the structure based on the structure displacement information,
Structural soundness evaluation device. In the structure soundness evaluation device according to claim 1,
The soundness evaluation unit generates the structure displacement information corresponding to each of a plurality of directions,
Structural soundness evaluation device. The structure soundness evaluation device according to claim 2,
The soundness evaluation unit respectively generates the structural displacement information in the vertical direction and the horizontal direction,
Structural soundness evaluation device. In the structure soundness evaluation device according to claim 1,
The soundness evaluation unit performs mathematical processing on the structure displacement information,
Structural soundness evaluation device. The structure soundness evaluation device according to claim 4,
The mathematical process is a Fourier transform,
Structural soundness evaluation device. The structure soundness evaluation device according to claim 5,
The soundness evaluation unit performs a Fourier transform on the structure displacement information to generate structure amplitude information in which amplitude and frequency are associated with each other,
Structural soundness evaluation device.

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