Strain analysis system, strain analysis method

Abstract

To easily obtain information on a structure in obtaining image data of the structure for strain analysis.SOLUTION: In a strain analysis system S, an imaging device 1 captures an image of a bridge 4 provided with a two-dimensional code 5 to obtain image data to record the data in a recording medium 3. A strain analysis device 2 obtains incidental information on the bridge 4 on the basis of captured image information of the two-dimensional code 5 included in the image data recorded in the recording medium 3, and extracts a plurality of measurement points preset in the two-dimensional code 5, and calculates a distance between the extracted respective measurement points to calculate a strain amount of the bridge 4 on the basis of the calculated distance between the respective measurement points.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a system and method for analyzing the strain of a structure.

Background Art

[0002] Structures such as bridges may undergo deformation in the members constituting the structure due to the action of static or dynamic forces caused by the weight of the structure itself or the load of automobiles moving on the structure. Therefore, the deterioration state of the structure is diagnosed by measuring the temporal change in the amount of deformation (strain amount) of the structure.

[0003] Conventionally, the measurement of the strain amount of a structure has generally been performed by installing a strain gauge on the surface of the measurement target position of the structure and detecting the measurement signal from the strain gauge. However, in the method of measuring the strain amount using such a strain gauge, the adhesion performance between the strain gauge and the structure surface deteriorates over time due to the natural environment to which the structure is exposed. For example, the installation state of the strain gauge on the structure can only be maintained for a certain period of about several months, and there is a problem that the strain amount cannot be measured after the passage of that period. In addition, when measuring the strain amount, it is necessary to connect to each other a cable for transmitting the measurement signal output from the strain gauge, a measurement device for detecting the measurement signal and collecting the detection result, the power supply of the strain gauge, etc., so there is also a problem that it takes time to prepare.

[0004] In order to solve the above problems, for example, the method of Patent Document 1 has been proposed. Patent Document 1 describes a technique for continuously photographing a structure to which a load is applied with a photographing device, measuring the deformation behavior of the structure using image measurement technology based on the obtained image data, and acquiring time-series observation data such as strain.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] When diagnosing the deterioration status of multiple structures installed in various geographically separated locations using the technology described in Patent Document 1, it is efficient to first photograph each structure, save the resulting image data on a recording medium for each structure, and then perform image analysis on them all at once later. The same applies when photographing multiple locations on a single structure and diagnosing the deterioration status using the image data from each location. However, when diagnosing the deterioration of structures using this procedure, a large number of image data files are saved depending on the number of times the images are taken, which may make it difficult to later determine which part of which structure each image data represents. This problem can be prevented by recording information about the structure and the location of the photograph along with the image data each time it is taken, but manually setting the information to be recorded by the photographer is time-consuming.

[0007] This invention has been made in consideration of the above points, and its main objective is to easily obtain information about a structure from image data of the structure used for strain analysis. [Means for solving the problem]

[0008] The strain analysis system according to the present invention includes an ancillary information acquisition unit that acquires ancillary information relating to a structure from image data obtained by photographing the structure for analyzing the strain of the structure, and a strain amount calculation unit that calculates the amount of strain of the structure based on the image data. An image data selection unit that selects one of the multiple image data based on the aforementioned supplementary information, The structure is provided with a two-dimensional code, the ancillary information acquisition unit acquires the ancillary information based on the captured image information of the two-dimensional code included in the image data, and the strain amount calculation unit Selected by the aforementioned image data selection unitFrom the captured image information of the two-dimensional code contained in the image data, a plurality of measurement points predetermined within the two-dimensional code are extracted, the distance between each extracted measurement point is calculated, and the strain amount is calculated based on the calculated distance between each measurement point. The strain analysis method according to the present invention involves photographing a structure that has a two-dimensional code attached to it. multiple Acquire image data, multiple The aforementioned image data each Based on the captured image information of the included two-dimensional code, ancillary information relating to the structure is obtained. Based on the aforementioned supplementary information, select one of the image data from the multiple image data, and select From the captured image information of the two-dimensional code contained in the image data, a plurality of measurement points predetermined within the two-dimensional code are extracted, the distance between each extracted measurement point is calculated, and the amount of strain of the structure is calculated based on the calculated distance between each measurement point. [Effects of the Invention]

[0009] According to the present invention, information about a structure can be easily obtained from image data of the structure used for strain analysis. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic diagram showing a measurement system including a strain analysis system according to the first embodiment of the present invention. [Figure 2] A block diagram showing the configuration of an imaging device according to the first embodiment of the present invention. [Figure 3] A block diagram showing the configuration of a strain analysis apparatus according to the first embodiment of the present invention. [Figure 4] A diagram showing an example of a two-dimensional code. [Figure 5] A flowchart showing the flow of the supplementary information acquisition process performed in the strain analysis apparatus according to the first embodiment of the present invention. [Figure 6] A flowchart showing the flow of strain analysis processing performed in a strain analysis apparatus according to the first embodiment of the present invention. [Figure 7] A schematic diagram showing a measurement system including a strain analysis system according to a second embodiment of the present invention. [Figure 8] Flowchart showing the flow of strain analysis processing executed in the strain analysis device according to the second embodiment of the present invention. [Figure 9] Block diagram showing the configuration of the strain analysis device according to the third embodiment of the present invention. [Figure 10] Flowchart showing the flow of two-dimensional code reproduction processing executed in the strain analysis device according to the third embodiment of the present invention. [Figure 11] Diagram showing a modified example of a two-dimensional code. [Figure 12] Block diagram showing the configuration of the imaging device according to a modified example of the present invention.

Mode for Carrying Out the Invention

[0011] <First Embodiment> Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 6.

[0012] (Strain Analysis System) FIG. 1 is a diagram showing an outline of a measurement system including a strain analysis system S according to the first embodiment of the present invention. The strain analysis system S of the present embodiment is a system that performs strain analysis on a bridge 4 as a structure to be analyzed, and includes an imaging device 1 and a strain analysis device 2.

[0013] The imaging device 1 photographs a two-dimensional code 5 installed at a predetermined analysis target position on the bridge 4 and acquires image data. The acquired image data is recorded on a recording medium 3 stored in the imaging device 1. Note that the shooting distance and the shooting angle when the imaging device 1 photographs the two-dimensional code 5 are preferably set so that the shooting image information of the two-dimensional code 5 included in the image data acquired by shooting has a resolution required for strain analysis.

[0014] The recording medium 3 on which the image data is recorded by the imaging device 1 is removed from the imaging device 1 after the shooting is completed and attached to the strain analysis device 2. At this time, the strain analysis device 2 acquires various information (hereinafter referred to as attached information) about the bridge 4 described by the two-dimensional code 5. Then, the strain analysis device 2 calculates the amount of strain of the bridge 4 based on the image data recorded on the recording medium 3 and diagnoses the deterioration state of the bridge 4. The details of the processing by the strain analysis device 2 will be described later.

[0015] As described above, in the strain analysis system S of the present embodiment, the transfer of image data between the imaging device 1 and the strain analysis device 2 is performed via the recording medium 3. That is, an operator who performs the deterioration diagnosis of the bridge 4 using the strain analysis system S can input the image data for analyzing the strain of the bridge 4 to the strain analysis device 2 by transferring the recording medium 3 on which the image data is recorded from the imaging device 1 to the strain analysis device 2. Therefore, it is not always necessary to place the strain analysis device 2 near the installation location of the bridge 4, and the strain analysis device 2 may be installed at a location away from the installation location of the bridge 4.

[0016] In FIG. 1, as the strain analysis system S, a system for performing strain analysis with the bridge 4 as the analysis target has been described. However, it is also possible to use other structures other than the bridge 4 as the analysis target. Furthermore, it is also possible to use a plurality of structures as the analysis target. That is, by photographing the two-dimensional code installed on various structures with the imaging device 1, recording the obtained image data on the recording medium 3, transferring the recording medium 3 from the imaging device 1 to the strain analysis device 2, and causing the strain analysis device 2 to read the image data recorded on the recording medium 3, a strain analysis system S for performing strain analysis of various structures including the bridge 4 can be realized.

[0017] Furthermore, while Figure 1 shows that only one analysis target location is set on the bridge 4, and the image capture device 1 is shown photographing the two-dimensional code 5 installed at this analysis target location, multiple analysis target locations may be provided on the bridge 4. In other words, the strain analysis system S of this embodiment can perform strain analysis of the bridge 4 by photographing the two-dimensional codes 5 installed at multiple locations on the bridge 4 with the image capture device 1, and using the installation location of each two-dimensional code 5 as the analysis target location.

[0018] (Configuration of the imaging device) Figure 2 is a block diagram showing the configuration of an imaging device 1 according to a first embodiment of the present invention. The imaging device 1 includes a processor 11, a memory 12, an optical unit 13, an imaging unit 14, a recording medium interface unit 15, and an operation unit 16.

[0019] The processor 11 is an arithmetic processing unit composed of a CPU (Central Processing Unit), MPU (Micro Processing Unit), PLD (Programmable Logic Device), ASIC (Application Specific Integrated Circuit), etc. The memory 12 acts as the main memory of the processor 11. The processor 11 can realize the functions of the imaging control unit 111 and the recording control unit 112 by executing a predetermined program in cooperation with the memory 12.

[0020] The optical unit 13 is composed of a combination of multiple lenses and forms an image of the subject being photographed by the imaging device 1 onto the imaging unit 14. The imaging unit 14 is composed of an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) and captures the image of the subject formed by the optical unit 13 to generate image data including the captured image information of the subject. The recording medium interface unit 15 stores the recording medium 3 in the imaging device 1 and reads and writes data to the recording medium 3 according to the control of the processor 11. The operation unit 16 is composed of various operating members such as switches and touch panels and receives various operations input from the operator holding the imaging device 1 and outputs the operation content to the processor 11.

[0021] The imaging control unit 111 controls the operation of the optical unit 13 and the imaging unit 14, causing the imaging device 1 to perform imaging. The recording control unit 112 controls the reading of data from the recording medium 3 and the writing of data to the recording medium 3 via the recording medium interface unit 15. Through the control of this recording control unit 112, image data 31 is recorded on the recording medium 3.

[0022] Image data 31 is data acquired by the imaging device 1 by photographing the portion of the bridge 4 containing the two-dimensional code 5, and includes captured image information of the two-dimensional code 5. Information such as the date and time of shooting and various shooting conditions may also be included in the image data 31. For example, if the image data 31 is an image file such as a bitmap or JPEG, the date and time of shooting can be recorded as the creation date and time of the image file. Alternatively, information such as the date and time of shooting and various shooting conditions can be included in the image data 31 using well-known metadata such as Exif (Exchangeable image file format) information.

[0023] The imaging device 1 records the image data 31 acquired for the bridge 4 in the manner described above onto the recording medium 3 using the recording control unit 112. Similarly, image data 31 is acquired for other structures besides the bridge 4 and recorded onto the recording medium 3.

[0024] (Configuration of the strain analysis system) Figure 3 is a block diagram showing the configuration of a strain analysis apparatus 2 according to a first embodiment of the present invention. The strain analysis apparatus 2 includes a processor 21, a memory 22, a storage 23, a recording medium interface unit 25, and an input / output unit 26.

[0025] The processor 21 is an arithmetic processing unit composed of a CPU (Central Processing Unit), MPU (Micro Processing Unit), PLD (Programmable Logic Device), ASIC (Application Specific Integrated Circuit), etc. The memory 22 acts as the main memory of the processor 21. By working in cooperation with the memory 22 to execute a predetermined program, the processor 21 can realize the following functions: an ancillary information acquisition unit 211, an image data selection unit 212, a strain amount calculation unit 213, and a degradation diagnosis unit 214. The storage 23 acts as an auxiliary storage device for the processor 21.

[0026] The recording medium interface unit 25 is connected to the recording medium 3 and reads and writes data to the recording medium 3 in accordance with the control of the processor 21. The input / output unit 26 is configured using various operating elements such as a mouse, keyboard, and touch panel, as well as various display devices, and receives various operations input from the operator performing analysis processing using the strain analysis device 2, outputs the operation content to the processor 21, and presents the analysis processing results to the operator.

[0027] The ancillary information acquisition unit 211 acquires ancillary information 32 about the bridge 4 by reading the two-dimensional code 5 contained in the image data 31 recorded on the recording medium 3. The acquired ancillary information 32 is recorded on the recording medium 3 in association with the image data 31. Alternatively, the ancillary information 32 may not be recorded on the recording medium 3, but temporarily recorded in the memory 22 or on the storage 23. The ancillary information 32 is information about the bridge 4 acquired by the ancillary information acquisition unit 211 by reading the two-dimensional code 5 from the captured image information of the two-dimensional code 5 contained in the image data 31, and includes information such as a unique ID pre-assigned to the bridge 4, the type of structure to which the bridge 4 belongs, the material of the members used in the bridge 4, the installation location and construction date of the bridge 4, and the location of the two-dimensional code 5 on the bridge 4. Furthermore, when the strain analysis device 2 uses image data 31 to diagnose the deterioration state of the bridge 4, any information other than that mentioned above may be included in the two-dimensional code 5 and used as supplementary information 32, if it is useful in determining which structure the image data 31 was taken of. In addition, information such as the date and time of shooting and various shooting conditions may be obtained from the image data 31 and included in the supplementary information 32.

[0028] The image data selection unit 212 selects image data 31 recorded on the recording medium 3 based on the supplementary information 32 acquired by the supplementary information acquisition unit 211. When image data 31 of various structures, including bridges 4, are recorded on the recording medium 3 by the imaging device 1, the operator specifies the structure to be analyzed using the input / output unit 26, and the image data selection unit 212 selects the image data 31 of that structure from the multiple image data 31 based on the supplementary information 32. As a result, the operator can easily identify the image data 31 necessary for strain analysis of the structure within the recording medium 3 and load it into the strain analysis device 2 simply by specifying the structure to be analyzed.

[0029] The strain calculation unit 213 calculates the strain of the bridge 4, which is a structure, based on the image data 31 recorded on the recording medium 3. Details of the strain calculation method used by the strain calculation unit 213 will be described later.

[0030] The deterioration diagnosis unit 214 diagnoses the deterioration state of the bridge 4 based on the strain amount calculated by the strain amount calculation unit 213. The diagnosis result of the deterioration state by the deterioration diagnosis unit 214 is output by the input / output unit 26 and presented to the worker.

[0031] (Example of a QR code) Figure 4 shows an example of a two-dimensional code 5 installed on a bridge 4. The two-dimensional code 5 is composed of a combination of multiple element points 51 provided at predetermined intervals. Each element point 51 is integrally formed with the bridge 4, for example, by engraving a metal member such as steel that makes up the bridge 4. However, the two-dimensional code 5 may also be formed by methods other than engraving, such as painting or printing, as long as it is integrally formed with the bridge 4. Furthermore, if the two-dimensional code 5 can be photographed by the imaging device 1 in a state where it can be easily identified, the two-dimensional code 5 may be protected by methods such as attaching a transparent protective film to the two-dimensional code 5. In this way, it is possible to suppress the deterioration of the two-dimensional code 5 over time due to exposure of the bridge 4 to the natural environment, which would make it difficult to identify.

[0032] The arrangement pattern of the two-dimensional code 5 shown in Figure 4 is merely an example, and any other arrangement pattern is possible. Here, the arrangement pattern of the two-dimensional code 5 is determined by converting the character information representing the supplementary information 32 according to a predetermined conversion rule. This conversion rule can be one defined in a well-known two-dimensional code standard. The supplementary information acquisition unit 211 can read the supplementary information 32 from the captured image information of the two-dimensional code 5 using the two-dimensional code standard used when determining the arrangement pattern of the two-dimensional code 5.

[0033] (Processing by strain analysis equipment) Figure 5 is a flowchart showing the flow of the supplementary information acquisition process performed in the strain analysis apparatus 2 according to the first embodiment of the present invention. When the recording medium 3 on which image data 31 is recorded is connected to the recording medium interface unit 25, the processor 21 of the strain analysis apparatus 2 executes the supplementary information acquisition process shown in the flowchart of Figure 5.

[0034] In step S11, one of the image data 31 recorded on the recording medium 3 is selected. Below, we will explain the case where, when a worker takes a picture of the part of the bridge 4 where the two-dimensional code 5 is installed, using the imaging device 1 as the subject, image data 31 for analyzing the strain of the bridge 4 is acquired and recorded on the recording medium 3, and similar image data 31 for other parts of the bridge 4 and other structures is also recorded on the recording medium 3, and the image data 31 capturing the two-dimensional code 5 is selected in step S11 from among these image data 31. In this case, as described above, the selected image data 31 includes the captured image information of the two-dimensional code 5.

[0035] In step S12, the ancillary information acquisition unit 211 reads the two-dimensional code 5 from the image data 31 selected in step S11. Here, in accordance with well-known two-dimensional code standards, the ancillary information 32 regarding the bridge 4 is acquired by reading the character information written on the two-dimensional code 5 from the captured image information of the two-dimensional code 5 contained in the image data 31.

[0036] In step S13, the supplementary information 32 acquired in step S12 is recorded on the recording medium 3, or on the memory 22 or storage 23.

[0037] In step S14, it is determined whether all image data 31 recorded on the recording medium 3 have been selected in step S11. If all image data 31 have been selected and supplementary information 32 has been acquired and recorded for each image data 31, the supplementary information acquisition process shown in the flowchart of Figure 5 is terminated. On the other hand, if there are unselected image data 31, the process returns to step S11, and after selecting one of the unselected image data 31 in step S11, the processes of steps S12 and S13 are repeated. This allows supplementary information 32 to be acquired for each image data 31.

[0038] Figure 6 is a flowchart showing the flow of strain analysis processing performed in the strain analysis apparatus 2 according to the first embodiment of the present invention. In this embodiment, the processor 21 of the strain analysis apparatus 2 has already performed the supplementary information acquisition processing described in the flowchart of Figure 5. When an operator instructs the strain analysis apparatus 2 to perform strain analysis processing using the input / output unit 26, the processor 21 of the strain analysis apparatus 2 executes the strain analysis processing shown in the flowchart of Figure 6.

[0039] In step S21, the operator selects a structure to be analyzed from among various structures whose image data 31 is recorded on the recording medium 3, according to the operator's instructions. In the following, it is assumed that the bridge 4 in Figure 1, on which the two-dimensional code 5 is installed, has been selected as the structure to be analyzed.

[0040] In step S22, the image data selection unit 212 selects image data 31 corresponding to the structure selected in step S21 from among the image data 31 of various structures recorded on the recording medium 3. Here, the ancillary information 32 acquired for each image data 31 by the ancillary information acquisition process described above is referenced, and it is identified which ancillary information 32 represents information about the bridge 4, which is the structure selected as the target of analysis. At this time, the image data selection unit 212 may automatically identify the ancillary information 32 that represents information about the bridge 4, or the contents of each ancillary information 32 may be displayed on the input / output unit 26 to present to the operator, and the operator may select which ancillary information 32 represents information about the bridge 4. Then, the image data 31 corresponding to the identified ancillary information 32 is selected as image data 31 that includes the captured image information of the two-dimensional code 5 installed on the bridge 4. This makes it possible to select the image data 31 to be processed from among the image data 31 of various structures recorded on the recording medium 3.

[0041] In step S23, the strain calculation unit 213 extracts measurement points to be used for measuring the strain of the bridge 4 from the captured image information of the two-dimensional code 5 contained in the image data 31 selected in step S22. Here, a predetermined number of element points 51 that are located at pre-set positions within the two-dimensional code 5 are extracted as measurement points for measuring the strain of the bridge 4 from among the multiple element points 51 that make up the two-dimensional code 5. For example, element points 51 located at the four corners or the center of the two-dimensional code 5 can be extracted as measurement points for measuring strain.

[0042] In step S24, the strain calculation unit 213 calculates the distance between each measurement point extracted in step S23. Here, for example, the distance between each measurement point can be calculated by finding the length between each measurement point on the image and converting it to a distance in real space. However, in this embodiment, since there is no information in the captured image information that serves as a reference for the distance in real space, the absolute value of the distance between each measurement point cannot be correctly determined unless the shooting distance is known. Therefore, the distance between each measurement point calculated here is relative, assuming a constant shooting position, and does not represent the absolute distance in real space. Alternatively, the length between each measurement point on the image may be used directly without converting it to a distance in real space, and the subsequent processing may be carried out.

[0043] In step S25, the strain calculation unit 213 measures the change over time in the distance between each measurement point calculated in step S24. For example, for various structures including the bridge 4, the strain analysis device 2 stores the distances between measurement points calculated at predetermined intervals in the past for each structure and each measurement point, and the change over time in the distance between measurement points is measured by arranging these distances in chronological order and calculating the difference between them. At this time, the change over time may be measured after statistically processing the past distances between measurement points. Alternatively, a well-known method such as the digital image correlation (DIC) method may be used.

[0044] In step S26, the deterioration diagnosis unit 214 calculates the strain amount of the two-dimensional code 5, that is, the strain amount of the part of the bridge 4 where the two-dimensional code 5 is provided, based on the change in the distance between measurement points calculated in step S25. Here, for example, the strain amount can be calculated by dividing the change in the distance between each measurement point by the original distance before the change.

[0045] In step S27, the deterioration diagnosis unit 214 diagnoses the deterioration state of the bridge 4 based on the strain calculation result obtained in step S26. Here, for example, if the magnitude of the strain is above a predetermined threshold, or if the strain is rising rapidly, it can be diagnosed that the bridge 4 is in a deteriorated state. At this time, the threshold for determining the deterioration state may be changed depending on the type of structure. In addition to this, deterioration diagnoses of various structures, including the bridge 4, can be performed using any method with the strain calculation result.

[0046] In step S28, the results of the deterioration state diagnosis performed in step S27 are output. For example, the results of the deterioration state diagnosis can be output by displaying a predetermined screen showing the deterioration state diagnosis results on the input / output unit 26 to the operator, or by transmitting them externally from the strain analysis device 2.

[0047] After executing the process in step S28, the strain analysis process shown in the flowchart in Figure 6 is terminated.

[0048] According to the first embodiment of the present invention described above, the following effects are achieved.

[0049] (1) The strain analysis system S includes an ancillary information acquisition unit 211 that acquires ancillary information 32 related to the bridge 4 from image data 31 obtained by photographing the bridge 4, which is a structure, for analyzing the strain of the bridge 4, and a strain amount calculation unit 213 that calculates the amount of strain of the bridge 4 based on the image data 31. The bridge 4 is provided with a two-dimensional code 5, and the ancillary information acquisition unit 211 acquires the ancillary information 32 based on the captured image information of the two-dimensional code 5 included in the image data 31 (step S12). The strain amount calculation unit 213 extracts a plurality of measurement points that have been set in advance within the two-dimensional code 5 from the captured image information of the two-dimensional code 5 included in the image data 31 (step S23), calculates the distance between each extracted measurement point (step S24), and calculates the amount of strain based on the calculated distance between each measurement point (step S25). In this way, information about the structure can be easily obtained as supplementary information 32 from the image data 31 of the structure used for strain analysis.

[0050] (2) The supplementary information 32 may include at least one of the following: a unique ID pre-assigned to the bridge 4, the type, material, installation location or construction date of the bridge 4, and the location of the two-dimensional code 5 on the bridge 4. In this way, it is easy to determine from the supplementary information 32 which structure, among the various structures including the bridge 4, the image data 31 was taken of.

[0051] (3) The strain analysis system S includes an image data selection unit 212 that selects one of several image data 31 recorded on the recording medium 3 based on the supplementary information 32 (step S22). The strain amount calculation unit 213 calculates the strain amount of the bridge 4 using the image data 31 selected by the image data selection unit 212. In this way, even if image data 31 of various structures, including the bridge 4, are recorded on the recording medium 3, the image data 31 to be used for calculating the strain amount can be reliably selected.

[0052] (4) The strain calculation unit 213 measures the change in distance between each measurement point over time (step S25) and calculates the strain amount based on the measurement results of this change over time (step S26). In this way, the amount of strain in the bridge 4 caused by the change over time can be accurately determined.

[0053] (5) The strain analysis system S includes a deterioration diagnosis unit 214 that diagnoses the deterioration state of the bridge 4 based on the amount of strain (step S27). In this way, it is possible to appropriately diagnose whether or not the bridge 4 is in a deteriorated state based on the amount of strain of the bridge 4.

[0054] <Second Embodiment> A second embodiment of the present invention will be described below with reference to Figures 7 and 8. In this embodiment, an example will be described in which, when photographing the two-dimensional code 5, a gauge that serves as a reference for the distance between measurement points included in the two-dimensional code 5 is also photographed.

[0055] Figure 7 shows a schematic diagram of a measurement system including a strain analysis system S according to a second embodiment of the present invention. In this embodiment, a strain analysis is performed on a bridge 4, which is a structure, using the same strain analysis system S as in the first embodiment.

[0056] In this embodiment, the imaging device 1 photographs a two-dimensional code 5 installed at a predetermined analysis target location on the bridge 4 and acquires image data 31. At this time, the worker holds a gauge 6 having multiple scale lines drawn at predetermined intervals near the two-dimensional code 5 and uses the imaging device 1 to photograph the two-dimensional code 5. As a result, the recording medium 3 records image data 31 including the image information of the two-dimensional code 5 and the image information of the gauge 6.

[0057] The recording medium 3 on which the above image data 31 is recorded is removed from the imaging device 1 after the shooting is completed, as in the first embodiment, and mounted on the strain analysis device 2. The strain analysis device 2 calculates the amount of strain of the bridge 4 based on the image data 31 recorded on the recording medium 3 and diagnoses the deterioration state of the bridge 4.

[0058] As in the first embodiment described above, when any of the multiple element points 51 included in the two-dimensional code 5 are used as measurement points for strain measurement, there is no information in the captured image information that serves as a reference for distance in real space. Therefore, the absolute value of the distance between each measurement point cannot be determined by this alone. For this reason, in the first embodiment, it is necessary to fix the imaging device 1 in a certain position and take multiple images at predetermined time intervals, and to measure the change in distance between measurement points between the image data 31 obtained in each image to determine the amount of strain. For these reasons, the first embodiment is suitable for cases where multiple images are taken in a short time, such as 10 minutes, and the amount of strain is calculated from the change in distance between measurement points within that time.

[0059] On the other hand, in the second embodiment, by photographing the gauge 6 together with the two-dimensional code 5, the absolute value of the distance between each measurement point in the two-dimensional code 5 can be determined based on the known length between each scale line of the gauge 6. Therefore, even without fixing the imaging device 1 in a fixed position or setting the imaging device 1 in exactly the same position each time a photograph is taken, the amount of strain can be determined from the change in the absolute distance between the measurement points of each image data 31 obtained by taking photographs at predetermined time intervals. Accordingly, the second embodiment is suitable when the imaging device 1 is set up in an arbitrary position, and photographs are taken for a longer period than in the first embodiment, for example, at one-year intervals, and the amount of strain is calculated from the change in the distance between measurement points during that time.

[0060] Figure 8 is a flowchart showing the flow of strain analysis processing performed in the strain analysis apparatus 2 according to the second embodiment of the present invention. In this embodiment, the processor 21 of the strain analysis apparatus 2 has already performed the ancillary information acquisition processing described in the first embodiment, and when the operator instructs the strain analysis apparatus 2 to perform strain analysis processing using the input / output unit 26, the processor 21 of the strain analysis apparatus 2 performs the strain analysis processing shown in the flowchart of Figure 8.

[0061] In the flowchart of Figure 8, the same step numbers are used for the parts that perform the same processing as in the flowchart of Figure 6 described in the first embodiment. Below, we will explain the parts that differ from the flowchart of Figure 6, and omit the explanation of the others.

[0062] After performing the processing in step S23, in step S24A, the strain amount calculation unit 213 calculates the distance between each measurement point extracted in step S23 based on the captured image information of the gauge 6 included in the image data 31 selected in step S22. Here, the distance between each measurement point is calculated by utilizing the fact that each scale line of the gauge 6 is drawn at known predetermined intervals. This makes it possible to calculate the distance between each measurement point more accurately compared to the first embodiment.

[0063] After performing the process in step S24A, steps S25 and beyond perform the same processing as shown in the flowchart in Figure 6.

[0064] According to the second embodiment of the present invention described above, the image data 31 includes captured image information of a two-dimensional code 5 and captured image information of a gauge 6 having a plurality of scale lines drawn at predetermined intervals, and the strain amount calculation unit 213 calculates the distance between each measurement point based on the captured image information of the gauge 6 (step S24A). In this way, the distance between each measurement point can be calculated accurately.

[0065] <Third Embodiment> A third embodiment of the present invention will be described below with reference to Figures 9 to 10. In this embodiment, when the two-dimensional code 5 cannot be read from the image data 31 due to deformation of the two-dimensional code 5, and therefore the supplementary information 32 cannot be obtained, an example will be described in which the amount of deformation of the two-dimensional code 5 is calculated, the two-dimensional code 5 is reproduced based on the calculation result, and the supplementary information 32 is obtained. In this context, the case in which the two-dimensional code 5 cannot be read refers to a case in which the amount of deformation of the two-dimensional code 5 due to the strain of the bridge 4 is large, and therefore the two-dimensional code 5 cannot be read normally. In addition to this, there are cases in which the two-dimensional code 5 cannot be read normally due to partial or total dirt, discoloration, disappearance, etc. of the two-dimensional code 5, but in such cases, the two-dimensional code 5 cannot be reproduced even if this embodiment is applied, and therefore the supplementary information 32 cannot be obtained.

[0066] Figure 9 is a block diagram showing the configuration of the strain analysis device 2B according to the third embodiment of the present invention. In this embodiment, the strain analysis system S is equipped with the strain analysis device 2B in place of the strain analysis device 2.

[0067] The strain analysis device 2B has the same configuration as the strain analysis device 2 described in the first embodiment. The processor 21 in the strain analysis device 2B works in cooperation with the memory 22 to execute a predetermined program, thereby realizing the functions of the ancillary information acquisition unit 211, image data selection unit 212, strain amount calculation unit 213, and degradation diagnosis unit 214, as well as the two-dimensional code reproduction unit 215.

[0068] The two-dimensional code reproduction unit 215 determines the amount of deformation of the two-dimensional code 5 from the captured image information of the two-dimensional code 5 contained in the image data 31, and reproduces the two-dimensional code 5 based on this deformation amount. Details of how the two-dimensional code reproduction unit 215 reproduces the two-dimensional code 5 will be described later.

[0069] When the two-dimensional code 5 is reproduced by the two-dimensional code reproduction unit 215, the ancillary information acquisition unit 211 reads the two-dimensional code 5 and acquires the ancillary information 32. The ancillary information 32 acquired by the ancillary information acquisition unit 211 from the reproduced two-dimensional code 5 is recorded on the recording medium 3 in association with the image data 31 via the recording medium interface unit 25, or recorded in the memory 22 or storage 23, just like other ancillary information 32.

[0070] Figure 10 is a flowchart showing the flow of the two-dimensional code reproduction process performed in the strain analysis apparatus 2B according to the third embodiment of the present invention. The processor 21 of the strain analysis apparatus 2B executes the two-dimensional code reproduction process shown in the flowchart of Figure 10 when there is image data 31 for which related supplementary information 32 could not be obtained by the supplementary information acquisition process described above.

[0071] In step S31, the two-dimensional code reproduction unit 215 calculates the amount of deformation of the two-dimensional code 5, which contains captured image information in the image data 31. Here, multiple reference points are extracted from the image data 31, and the amount of deformation of the two-dimensional code 5 is calculated based on the positional relationship of these multiple reference points. Specifically, first, several element points 51 located at predetermined positions within the two-dimensional code 5 in the image data 31, for example, 3 to 4 element points 51, are extracted as reference points for determining the amount of deformation of the two-dimensional code 5. For example, in the two-dimensional code 5 of Figure 4, each element point 51 located at each of the four corners, and the pattern of characteristic element points 51 located at the three corners (upper right, lower left, and lower right) (hereinafter referred to as "feature patterns"), that is, each element point 51 at a specific position among the three feature patterns consisting of each element point 51 arranged in a rectangular shape and the nine element points 51 enclosed by them, are extracted as reference points. Even if the two-dimensional code 5 is significantly deformed, the positions of these reference points can usually be identified within the captured image. Therefore, by comparing the arrangement of each extracted reference point with the arrangement of each reference point in the original, pre-deformed two-dimensional code 5 that was stored beforehand, and calculating the difference, the amount of deformation of the two-dimensional code 5 can be calculated.

[0072] In step S32, the two-dimensional code reproduction unit 215 performs an inverse transformation of the image data 31 based on the deformation amount calculated in step S31. Here, the entire two-dimensional code 5 is transformed and the positions of each element point 51 are moved so that the deformation amount of the two-dimensional code 5 in the image data 31 becomes 0 and the positions of each element point 51 included in the two-dimensional code 5 return to their original positions. Specifically, for example, if each element point 51 at the four corners is extracted as a reference point as described above, the entire captured image including the unreadable two-dimensional code 5 is transformed so that their arrangement becomes the original square, and if each element point 51 within the three feature patterns is extracted as a reference point, the arrangement becomes the original isosceles triangle. This allows the two-dimensional code 5 to be reproduced in its original state.

[0073] In step S33, the ancillary information acquisition unit 211 reads the two-dimensional code 5 from the image data 31 that underwent the reverse conversion process in step S32. Here, in accordance with well-known two-dimensional code standards, the ancillary information 32 related to the bridge 4 is acquired by reading the character information written in the two-dimensional code 5 from the captured image information of the two-dimensional code 5 contained in the reverse-converted image data 31.

[0074] In step S34, the associated information 32 obtained in step S33 is recorded on the recording medium 3, or on the memory 22 or storage 23, in association with the image data 31 obtained in step S31 from which the deformation amount of the two-dimensional code 5 was obtained.

[0075] After executing the process in step S34, the two-dimensional code reproduction process shown in the flowchart in Figure 10 is terminated.

[0076] According to the third embodiment of the present invention described above, the strain analysis system S includes a two-dimensional code reproduction unit 215 that determines the amount of deformation of the two-dimensional code 5 from the captured image information of the two-dimensional code 5 contained in the image data 31 (step S31), and reproduces the two-dimensional code 5 based on this amount of deformation (step S32). The ancillary information acquisition unit 211 acquires ancillary information 32 based on either the captured image information of the two-dimensional code 5 contained in the image data 31 or the two-dimensional code 5 reproduced by the two-dimensional code reproduction unit 215 (steps S12, S33). In this way, even if the imaging device 1 cannot read the two-dimensional code 5 from the image data 31 for reasons such as the amount of strain of the bridge 4 on which the two-dimensional code 5 is provided being large, and therefore cannot acquire the ancillary information 32, the strain analysis device 2B can reproduce the two-dimensional code 5 from the calculation result of the amount of strain and acquire the ancillary information 32.

[0077] (A variation of a 2D code) Figure 11 shows a modified example of the two-dimensional code 5. The two-dimensional code 5 may be constructed by combining element points 51 and 52 of different sizes and a line 53, as shown in Figure 11. The element points 52 are patterns used to determine the position and orientation of the two-dimensional code 5 when reading it. In the example in Figure 4, multiple element points 51 were combined to form one pattern, but in the example in Figure 11, the pattern is constructed using only element points 52.

[0078] Furthermore, it is possible to describe the supplementary information 32 using a two-dimensional code constructed in any manner, not limited to the two-dimensional code 5 shown in Figures 4 and 11.

[0079] (A modified example of a strain analysis system) In each of the embodiments described above, the strain analysis system S is equipped with an ancillary information acquisition unit 211, and an example was described in which the strain analysis devices 2 and 2B acquire ancillary information 32 from image data 31 using this ancillary information acquisition unit 211. However, the imaging device 1 may acquire the ancillary information 32 and record it together with the image data 31 on the recording medium 3.

[0080] Figure 12 is a block diagram showing the configuration of imaging device 1C according to a modified example of the present invention. In this modified example, the strain analysis system S is equipped with imaging device 1C in place of imaging device 1.

[0081] The imaging device 1C has the same configuration as the imaging device 1 described in the first embodiment. The processor 11 in the imaging device 1C works in cooperation with the memory 12 to execute a predetermined program, thereby realizing the functions of the imaging control unit 111 and the recording control unit 112, as well as the additional functions of the ancillary information acquisition unit 113.

[0082] The ancillary information acquisition unit 113 acquires ancillary information 32 related to the bridge 4 by reading the two-dimensional code 5 contained in the image data 31, similar to the ancillary information acquisition unit 211 of the strain analysis device 2 described in the first embodiment. The recording control unit 112 associates the ancillary information 32 acquired by the ancillary information acquisition unit 113 with the image data 31 and records it on the recording medium 3 via the recording medium interface unit 15. As a result, the ancillary information 32 is acquired together with the image data 31 by the imaging device 1C and recorded on the recording medium 3. In this modified example, since the ancillary information 32 is acquired by the imaging device 1C, the strain analysis device 2 does not need to be equipped with an ancillary information acquisition unit 211.

[0083] According to this modified example, the imaging device 1C includes an imaging unit 14 that photographs the bridge 4, which is a structure, and acquires image data 31; an ancillary information acquisition unit 113 that acquires ancillary information 32 related to the bridge 4 from the image data 31; and a recording control unit 112 that associates the image data 31 and the ancillary information 32 with each other and records them on a recording medium 3. The bridge 4 is provided with a two-dimensional code 5, and the ancillary information acquisition unit 113 acquires the ancillary information 32 based on the image data 31 containing the two-dimensional code 5. In this way, a strain analysis system S capable of acquiring ancillary information 32 can be realized without providing an ancillary information acquisition unit 211 in the strain analysis device 2.

[0084] The present invention is not limited to the embodiments described above, and can be implemented using any components without departing from the spirit of the invention.

[0085] The embodiments and modifications described above are merely examples, and the present invention is not limited to these, as long as the features of the invention are not impaired. Furthermore, although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of Symbols]

[0086] S: Strain analysis system, 1,1C: Imaging device, 2,2B: Strain analysis device, 3: Recording medium, 4: Bridge, 5: Two-dimensional code, 6: Gauge, 11: Processor, 12: Memory, 13: Optical unit, 14: Imaging unit, 15: Recording medium interface unit, 16: Operation unit, 21: Processor, 22: Memory, 23: Storage, 24: Recording medium interface unit, 26: Input / Output unit, 31: Image data, 32: Ancillary information, 111: Imaging control unit, 112: Recording control unit, 113: Ancillary information acquisition unit, 211: Ancillary information acquisition unit, 212: Image data selection unit, 213: Strain amount calculation unit, 214: Degradation diagnosis unit, 215: Two-dimensional code reproduction unit

Claims

1. An ancillary information acquisition unit acquires ancillary information related to the structure from image data obtained by photographing the structure for analyzing the strain of the structure, A strain calculation unit that calculates the amount of strain of the structure based on the image data, The system includes an image data selection unit that selects any of the multiple image data based on the aforementioned supplementary information, The aforementioned structure is provided with a two-dimensional code. The aforementioned ancillary information acquisition unit acquires the ancillary information based on the captured image information of the two-dimensional code included in the image data. The strain amount calculation unit is, From the image data selection unit, a plurality of measurement points pre-set within the two-dimensional code are extracted from the captured image information of the two-dimensional code contained in the image data. Calculate the distance between each extracted measurement point. A strain analysis system that calculates the amount of strain based on the calculated distance between each measurement point.

2. In the strain analysis system according to claim 1, A strain analysis system in which the aforementioned supplementary information includes at least one of the following pieces of information: a unique ID pre-assigned to the structure, the type, material, installation location or construction date of the structure, and the location of the two-dimensional code on the structure.

3. In the strain analysis system according to claim 1 or 2, The strain amount calculation unit measures the change in distance between each measurement point over time and calculates the strain amount based on the measurement results of the change over time, and is a strain analysis system.

4. In the strain analysis system according to any one of claims 1 to 3, A strain analysis system comprising a deterioration diagnosis unit that diagnoses the deterioration state of the structure based on the aforementioned strain amount.

5. In the strain analysis system according to any one of claims 1 to 4, The image data includes the image information of the two-dimensional code and the image information of a gauge having multiple scale lines drawn at predetermined intervals. The strain amount calculation unit is a strain analysis system that calculates the distance between each measurement point based on the captured image information of the gauge.

6. In the strain analysis system according to any one of claims 1 to 5, The system includes a two-dimensional code reproduction unit that determines the amount of deformation of the two-dimensional code from the captured image information of the two-dimensional code contained in the image data, and reproduces the two-dimensional code based on the amount of deformation. The strain analysis system includes an ancillary information acquisition unit which acquires the ancillary information based on either the captured image information of the two-dimensional code included in the image data or the two-dimensional code reproduced by the two-dimensional code reproduction unit.

7. By photographing a structure equipped with a QR code, multiple image data points are obtained. Based on the captured image information of the two-dimensional code contained in each of the multiple image data, ancillary information relating to the structure is obtained. Based on the aforementioned supplementary information, select one of the image data from the multiple image data, From the captured image information of the two-dimensional code contained in the selected image data, a plurality of measurement points pre-set within the two-dimensional code are extracted. Calculate the distance between each extracted measurement point. A strain analysis method that calculates the amount of strain in the structure based on the calculated distances between each measurement point.

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