Displacement measurement system, displacement measurement program, displacement measurement method, and displacement measurement device

Abstract

To provide a displacement measurement system, a displacement measurement program, a displacement measurement method, and a displacement measurement device, which enable accurate measurement of an amount of displacement of a measurement target in an in-plane direction.SOLUTION: A displacement measurement system disclosed herein comprises a displacement measurement device configured to measure an amount of displacement of a surface of a measurement target in an in-plane direction thereof using a two-dimensional image obtained by capturing a two-dimensional grating pattern provided on the measurement target, and an image capturing device for capturing the two-dimensional grating pattern provided on the measurement target. The displacement measurement device is configured to perform computation processing to compute the amount of displacement of the two-dimensional grating pattern in an analysis area including the two-dimensional grating pattern in the two-dimensional image, and area moving processing to move the analysis area according to the amount of displacement when the amount of displacement satisfies a given condition.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a displacement amount measurement system, a displacement amount measurement program, a displacement amount measurement method, and a displacement amount measurement device. [Background technology]

[0002] In inspection work of measurement objects such as bridges and steel towers, for example, the amount of displacement in the in-plane direction of the measurement object is measured. Patent Document 1 discloses an example of a method for measuring the amount of displacement in the in-plane direction of the measurement object. The displacement measurement method disclosed in Patent Document 1 measures the amount of displacement in the in-plane direction of the surface of the measurement object using a two-dimensional image obtained by capturing a two-dimensional grid pattern placed on the measurement object. The two-dimensional image is captured by, for example, an imaging device. An analysis region including the two-dimensional grid pattern is set within the two-dimensional image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4831703 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described displacement measurement method, the position of the imaging device relative to the object to be measured is fixed. Therefore, if the in-plane displacement of the object to be measured is large, in other words, if the displacement of the two-dimensional grid pattern placed on the object to be measured is large, part of the analysis area may fall outside the two-dimensional grid pattern. If part of the analysis area falls outside the two-dimensional grid pattern, the number of grids in the two-dimensional grid pattern within the analysis area decreases, making it impossible to accurately measure the in-plane displacement of the surface of the object to be measured. Furthermore, the two-dimensional grid pattern must be sized according to the measurement range, and if the installation space is limited, a special mounting jig is required. This also poses additional challenges, such as increased costs.

[0005] An object of the present invention is to provide a displacement amount measurement system, a displacement amount measurement program, a displacement amount measurement method, and a displacement amount measurement device that can accurately measure the amount of displacement in an in-plane direction of a measurement object. [Means for solving the problem]

[0006] A displacement measurement system according to a first aspect of the present invention is a displacement measurement system comprising: a displacement measurement device that measures the in-plane displacement of a surface of a measurement object using a two-dimensional image of a two-dimensional grid pattern placed on the measurement object; and an imaging device that images the two-dimensional grid pattern placed on the measurement object, wherein the displacement measurement device executes a displacement calculation process that calculates the displacement of the two-dimensional grid pattern in an analysis area including the two-dimensional grid pattern in the two-dimensional image; and an area movement process that moves the analysis area based on the displacement amount if the displacement amount satisfies a predetermined condition.

[0007] According to the displacement measurement system, when the displacement of the two-dimensional grid pattern satisfies a predetermined condition, the analysis area moves to follow the displacement of the two-dimensional grid pattern. Even when the displacement of the object to be measured in the in-plane direction is large, it is possible to prevent a part of the analysis area from moving out of the two-dimensional grid pattern. Therefore, the displacement of the object to be measured in the in-plane direction can be measured with high accuracy.

[0008] A displacement measurement system according to a second aspect of the present invention is a displacement measurement system according to the first aspect, wherein the displacement measurement device moves the analysis area when the absolute value of the displacement is greater than or equal to a threshold value during the area movement process.

[0009] According to the displacement measurement system, when the absolute value of the displacement of the two-dimensional grid pattern is equal to or greater than a threshold, in other words, when the displacement of the two-dimensional grid pattern is relatively large, the analysis region moves to follow the displacement of the two-dimensional grid pattern, thereby preventing a part of the analysis region from moving out of the two-dimensional grid pattern.

[0010] A displacement amount measuring system according to a third aspect of the present invention is the displacement amount measuring system according to the first aspect, wherein the displacement amount measuring device moves the analysis area when the displacement amount is other than 0 in the area moving process.

[0011] According to the displacement measurement system, even if the displacement of the two-dimensional grid pattern is small, the analysis area moves to follow the displacement of the two-dimensional grid pattern, which further prevents part of the analysis area from moving out of the two-dimensional grid pattern.

[0012] A displacement amount measurement program according to a fourth aspect of the present invention is a displacement amount measurement program that measures the amount of displacement in an in-plane direction of the surface of a measurement object using a two-dimensional image of a two-dimensional grid pattern placed on the measurement object, and causes a computer to execute a displacement amount calculation process that calculates the amount of displacement of the two-dimensional grid pattern in an analysis area that includes the two-dimensional grid pattern in the two-dimensional image, and an area movement process that moves the analysis area based on the displacement amount if the displacement amount satisfies a predetermined condition.

[0013] According to the displacement amount measuring program, the same effects as those of the displacement amount measuring system according to the first aspect can be obtained.

[0014] A displacement measurement method according to a fifth aspect of the present invention is a displacement measurement method for measuring an in-plane displacement of a surface of a measurement object using a two-dimensional image of a two-dimensional grid pattern placed on the measurement object, and includes a displacement calculation process for calculating a displacement of the two-dimensional grid pattern in an analysis area including the two-dimensional grid pattern in the two-dimensional image, and an area movement process for moving the analysis area based on the displacement if the displacement satisfies a predetermined condition.

[0015] According to the displacement amount measuring method, the same effects as those of the displacement amount measuring system according to the first aspect can be obtained.

[0016] A displacement measuring device according to a sixth aspect of the present invention is a displacement measuring device that measures the amount of displacement in an in-plane direction on the surface of a measurement object using a two-dimensional image of a two-dimensional grid pattern placed on the measurement object, and executes a displacement amount calculation process that calculates the amount of displacement of the two-dimensional grid pattern in an analysis area that includes the two-dimensional grid pattern in the two-dimensional image, and an area movement process that moves the analysis area based on the amount of displacement if the amount of displacement satisfies a predetermined condition.

[0017] According to the displacement amount measuring device, the same effects as those of the displacement amount measuring system according to the first aspect can be obtained. [Effects of the Invention]

[0018] According to the displacement measurement system, displacement measurement program, displacement measurement method, and displacement measurement device of the present invention, which can accurately measure the in-plane displacement of an object to be measured, the in-plane displacement of an object to be measured can be accurately measured. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic configuration diagram of a displacement amount measuring system according to an embodiment. [Figure 2] Front view of a measurement target on which a two-dimensional grid pattern is placed. [Figure 3] FIG. 10 is a diagram showing an example of a two-dimensional lattice image. [Figure 4] This is a diagram of the two-dimensional grid image in Figure 3, where the two-dimensional grid pattern is displaced in the X-axis direction. [Figure 5] FIG. 2 is a diagram of functional blocks constructed in the control device of FIG. 1. [Figure 6] 10 is a flowchart showing an example of a processing procedure for an in-plane displacement amount calculation process. [Figure 7] FIG. [Figure 8] 10 is a flowchart showing an example of a processing procedure for an in-plane displacement amount calculation process executed by a displacement amount measurement system according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A displacement measurement device according to an embodiment of the present invention and a displacement measurement system including the same will be described below with reference to the drawings.

[0021] <1. Overall configuration of displacement measurement system> FIG. 1 is a schematic diagram of a displacement measurement system 10 (hereinafter referred to as "system 10"). System 10 is a system that measures the amount of displacement in an in-plane direction of measurement object 100 using a two-dimensional image (hereinafter referred to as "two-dimensional lattice image") obtained by capturing a two-dimensional lattice pattern 200 (see FIG. 2) placed on measurement object 100. Measurement object 100 is, for example, an infrastructure structure. Infrastructure structures are, for example, elevated roads, bridges, railway bridges, or tunnels. Displacement measurement system 10 includes a displacement measurement device 20 and an imaging device 30.

[0022] <2. Hardware configuration of the displacement measurement system> The displacement amount measuring device 20 has a main body 21, an input device 22, and an output device 23. The main body 21 has a storage device 21A and a control device 21B. The storage device 21A and the control device 21B are connected so as to be able to communicate with each other via a bus 24. The storage device 21A is, for example, a hard disk or a solid state drive. The storage device 21A stores one or more application software programs (hereinafter referred to as "displacement amount calculation software") related to calculating the amount of displacement in the in-plane direction of the measurement object 100.

[0023] The control device 21B includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc., and executes the functions described below. The control device 21B executes in-plane displacement amount calculation software stored in the storage device 21A in response to a request from the input device 22. When the control device 21B executes the in-plane displacement amount calculation software, one or more function blocks described below are constructed in the displacement amount measuring device 20.

[0024] The input device 22 is, for example, a keyboard, and is connected to the main body 21. The output device 23 is, for example, a liquid crystal display, and is connected to the main body 21 so as to be able to receive signals output from the main body 21. Note that the main body 21, the input device 22, and the output device 23 may be integrated into one unit, like a notebook personal computer.

[0025] The imaging device 30 is configured to be able to perform an imaging process for capturing a two-dimensional lattice image. In this embodiment, the imaging device 30 is a camera. In this embodiment, the imaging device 30 is connected to the displacement measuring device 20 so as to be able to communicate wirelessly or via wire. The two-dimensional lattice image captured by the imaging device 30 is transmitted to the displacement measuring device 20 and stored in, for example, a storage device 21A. The imaging device 30 may be a camera mounted on a tablet terminal or a camera mounted on a smartphone.

[0026] <3. 2-dimensional lattice pattern> One or more two-dimensional grating patterns 200 are provided on the measurement object 100 shown in Fig. 2. The specific configuration of the two-dimensional grating pattern 200 can be selected arbitrarily. In this embodiment, the two-dimensional grating pattern 200 is printed on a seal member configured to be attached to the measurement object 100. The two-dimensional grating pattern 200 may be drawn directly on the measurement object 100, or may be printed or engraved on a member such as a plate that is fixed to the measurement object 100.

[0027] 3 is a diagram showing a two-dimensional lattice image 300. In measuring the amount of displacement in the in-plane direction of the measurement object 100, an analysis region 50 is set in the two-dimensional lattice image 300, and the average amount of displacement of the two-dimensional lattice pattern 200 in the analysis region 50 is calculated.

[0028] FIG. 4 is a diagram showing an example of a two-dimensional grid image 300 in a state in which the measurement object 100 is displaced in the positive direction of the X-axis. In the system 10, the position of the imaging device 30 relative to the measurement object 100 is fixed. Therefore, when the amount of displacement of the measurement object 100 in the in-plane direction is large, in other words, when the amount of displacement of the two-dimensional grid pattern 200 placed on the measurement object 100 is large, part of the analysis region 50 may fall outside the two-dimensional grid pattern 200. As a result, the amount of displacement of the measurement object 100 in the in-plane direction cannot be accurately measured. The system 10 of this embodiment is configured to be able to accurately detect the amount of displacement of the measurement object 100 in the in-plane direction, even when the amount of displacement of the measurement object 100 in the in-plane direction is large.

[0029] <4. Software configuration of the displacement measurement system> 5, the functional blocks configured by the control device 21B executing the displacement amount calculation software stored in the storage device 21A (see FIG. 1) include, for example, an analysis area extraction unit 41, a displacement amount calculation unit 42, a total displacement amount calculation unit 43, and an area moving unit 44. By constructing these functional blocks in the displacement amount measuring device 20, an in-plane displacement amount calculation process is executed to calculate the amount of displacement in the in-plane direction of the measurement object 100. Each functional block will be described in detail below.

[0030] <4-1.Analysis area extraction part> The analysis region extraction unit 41 executes an analysis region extraction process to extract an area including the two-dimensional grid pattern 200 from the two-dimensional grid image 300 (see FIG. 3 ) as the analysis region 50. The analysis region 50 may be the entire area of ​​the two-dimensional grid image 300 in which the two-dimensional grid pattern 200 appears, or may be a part of the area. In this embodiment, the analysis region extraction unit 41 extracts a part of the area of ​​the two-dimensional grid image 300 in which the two-dimensional grid pattern 200 appears as the analysis region 50 in the analysis region extraction process. The shape of the analysis region 50 can be selected arbitrarily. In this embodiment, the shape of the analysis region 50 is a square. The shape of the analysis region 50 may also be a rectangle, a rhombus, a triangle, a polygon with pentagons or more sides, a circle, or an ellipse.

[0031] <4-2. Displacement calculation section> The displacement amount calculation unit 42 executes a displacement amount calculation process to calculate an average displacement amount of the two-dimensional grid pattern 200 in the analysis region 50. For example, if the images captured by the imaging device 30 are consecutive still images, the displacement amount calculation unit 42 calculates an average displacement amount of the two-dimensional grid pattern 200 in the analysis region 50 for each still image in the displacement amount calculation process. For example, if the images captured by the imaging device 30 are a video, the displacement amount calculation unit 42 calculates an average displacement amount of the two-dimensional grid pattern 200 in the analysis region 50 for each frame in the displacement amount calculation process. In the displacement amount calculation process, the displacement amount is calculated for each pixel in the analysis region 50 in one still image or one frame of the video, and the average value of the displacement amounts of all pixels is calculated as the average displacement amount. In the displacement amount calculation process, the displacement amount calculation unit 42 calculates an average displacement amount dAx in the X-axis direction and an average displacement amount dAy in the Y-axis direction of the two-dimensional grid pattern 200 in the analysis region 50. The average displacements dAx and dAy can be calculated using a known method such as that described in Patent Document 1.

[0032] <4-3. Total displacement calculation section> The total displacement amount calculation unit 43 executes a total displacement amount calculation process to calculate the total displacement amount of the two-dimensional grid pattern 200. In the total displacement amount calculation process, the total displacement amount calculation unit 43 calculates the total displacement amount of the two-dimensional grid pattern 200 by adding the average displacement amounts dAx and dAy calculated by the displacement amount calculation process to the cumulative displacement amount of the two-dimensional grid pattern 200.

[0033] <4-4. Area movement section> The region moving unit 44 executes a region moving process to move the analysis region 50 based on the average displacement amounts dAx and dAy when the average displacement amounts dAx and dAy calculated by the displacement amount calculation process satisfy a predetermined condition. In this embodiment, when the average displacement amount dAx is equal to or greater than a predetermined threshold value XA in the region moving process, the region moving unit 44 moves the analysis region 50 in the X-axis direction by the average displacement amount dAx so that the analysis region 50 follows the two-dimensional grid pattern 200. In this embodiment, when the average displacement amount dAy is equal to or greater than a predetermined threshold value XB in the region moving process, the region moving unit 44 moves the analysis region 50 in the Y-axis direction by the average displacement amount dAy so that the analysis region 50 follows the two-dimensional grid pattern 200. Note that the region moving unit 44 may execute a region moving process to move the analysis region 50 based on the displacement amount when the displacement amount of an arbitrary pixel in the analysis region 50 calculated by the displacement amount calculation process satisfies a predetermined condition.

[0034] When it is expected that the amount of displacement of the measurement object 100 in the in-plane direction may be large and that part of the analysis region 50 may deviate from the two-dimensional grid pattern 200, it is preferable that the thresholds XA and XB be determined based on the size of the two-dimensional grid pattern 200. However, the thresholds XA and XB must be set to values ​​that will not cause the analysis region 50 to deviate from the two-dimensional grid pattern 200. For example, when the difference between the area of ​​the two-dimensional grid pattern 200 and the area of ​​the analysis region 50 is large, in other words, when the two-dimensional grid pattern 200 is sufficiently large relative to the analysis region 50, even if the amount of displacement of the measurement object 100 in the in-plane direction is large, it is unlikely that part of the analysis region 50 will deviate from the two-dimensional grid pattern 200. On the other hand, when the difference between the area of ​​the two-dimensional grid pattern 200 and the area of ​​the analysis region 50 is small, it is highly likely that part of the analysis region 50 will deviate from the two-dimensional grid pattern 200 even if the amount of displacement of the measurement object 100 in the in-plane direction is small. For this reason, it is preferable that the threshold values ​​XA and XB be set to higher values ​​as the area of ​​the two-dimensional grating pattern 200 used increases. In other words, it is preferable that the threshold values ​​XA and XB be set to lower values ​​as the area of ​​the two-dimensional grating pattern 200 used decreases.

[0035] <5. In-plane displacement calculation process> An example of a processing procedure for the in-plane displacement amount calculation processing will be described with reference to FIG. The control device 21B starts the in-plane displacement amount calculation process, for example, when an arbitrary two-dimensional lattice image 300 is stored in the storage device 21A and a request is made by the user.

[0036] In step S11, the control device 21B sets the reference displacement of the first two-dimensional grid image 300 or the two-dimensional grid pattern 200 from the first frame of the two-dimensional grid image 300.

[0037] In step S12, the control device 21B calculates the average displacement amounts dAx and dAy of the two-dimensional grid pattern 200.

[0038] In step S13, the control device 21B determines whether the absolute value of the average displacement amount dAx is equal to or greater than a threshold value XA and whether the absolute value of the average displacement amount dAy is equal to or greater than a threshold value XB. If the determination in step S13 is positive, that is, if at least one of the conditions that the absolute value of the average displacement amount dAx is equal to or greater than the threshold value XA and the absolute value of the average displacement amount dAy is equal to or greater than the threshold value XB is satisfied, the control device 21B executes the process of step S14.

[0039] In step S14, the control device 21B moves the analysis region 50 based on the average displacement amount dAx and the average displacement amount dAy so that the analysis region 50 follows the two-dimensional grid pattern 200. If the absolute value of the average displacement amount dAx is equal to or greater than the threshold value XA, the control device 21B moves the analysis region 50 in the X-axis direction by the average displacement amount dAx. If the absolute value of the average displacement amount dAy is equal to or greater than the threshold value XB, the control device 21B moves the analysis region 50 in the Y-axis direction by the average displacement amount dAy. In step S14, the control device 21B moves the analysis region 50 only in the X-axis direction, only in the Y-axis direction, or in both the X-axis and Y-axis directions, depending on the calculation results of the average displacement amount dAx and the average displacement amount dAy. For example, when the absolute value of the average displacement amount dAx is equal to or greater than the threshold value XA, the absolute value of the average displacement amount dAy is less than the threshold value XB, and the average displacement amount dAx is a positive number, the two-dimensional grid pattern 200 is significantly displaced in the positive direction of the X-axis, as shown in Fig. 7. Therefore, as shown by the arrow in Fig. 7, the control device 21B moves the analysis region 50 by the average displacement amount dAx in the positive direction of the X-axis.

[0040] In step S15, the control device 21B changes the reference displacement of the two-dimensional lattice pattern 200 to the displacement within the analysis region 50 in the two-dimensional lattice image 300 in a state in which the analysis region 50 has been moved.

[0041] In step S16, the control device 21B adds the average displacement amount dAx and the average displacement amount dAy to the cumulative displacement amount to calculate the total displacement amount of the two-dimensional grid pattern 200.

[0042] In step S17, the control device 21B sets the average displacement amount dAx and the average displacement amount dAy to zero.

[0043] On the other hand, if the determination in step S13 is negative, that is, if the absolute value of the average displacement amount dAx is less than the threshold value XA and the absolute value of the average displacement amount dAy is less than the threshold value XB, the control device 21B executes the process of step S18. In step S18, the control device 21B maintains the position of the analysis region 50 in the two-dimensional lattice image 300.

[0044] In step S19, the control device 21B adds the average displacement amount dAx and the average displacement amount dAy to the cumulative displacement amount to calculate the total displacement amount of the two-dimensional grid pattern 200.

[0045] In step S20, the control device 21B determines whether or not a signal requesting termination of the in-plane displacement amount calculation process has been input from the user. If the determination in step S20 is affirmative, the control device 21B terminates the in-plane displacement amount calculation process. If the determination in step S21 is negative, the control device 21B repeatedly executes the processes from step S12 onwards. Note that in step S20, the control device 21B may also determine whether or not a predetermined time has elapsed. If the determination in step S20 is affirmative, i.e., if the predetermined time has elapsed, the control device 21B terminates the in-plane displacement amount calculation process. If the determination in step S21 is negative, i.e., if the predetermined time has not elapsed, the control device 21B repeatedly executes the processes from step S12 onwards.

[0046] <6. Effects of the embodiment> According to the system 10 configured as above, the following effects can be obtained.

[0047] <6-1> If the average displacement amounts dAx and dAy of the two-dimensional lattice pattern 200 satisfy predetermined conditions, the analysis region 50 moves in the region movement process of step S14 so as to follow the displacement of the two-dimensional lattice pattern 200. Even if the displacement amount in the in-plane direction of the measurement object 100 is large, it is possible to prevent a part of the analysis region 50 from moving out of the two-dimensional lattice pattern 200. Therefore, the displacement amount in the in-plane direction of the measurement object 100 can be measured with high accuracy.

[0048] <6-2> Conventionally, a two-dimensional grid pattern needs to be sized according to the measurement range, and if the installation space is limited, a special mounting jig is required. This increases costs. In this embodiment, the analysis region 50 moves to follow the displacement of the two-dimensional grid pattern 200, allowing a small-sized two-dimensional grid pattern 200 to be used. This reduces the cost of the two-dimensional grid pattern 200. Furthermore, even if the installation space for the two-dimensional grid pattern 200 is limited, the two-dimensional grid pattern 200 can be easily positioned without using a special mounting jig. Furthermore, even if the measurement object 100 is installed outdoors, external factors such as wind acting on the two-dimensional grid pattern 200 can be reduced.

[0049] <7. Variations> The above-described embodiments are examples of possible forms of the displacement measurement system, displacement measurement program, displacement measurement method, and displacement measurement device according to the present invention, and are not intended to limit the forms. The displacement measurement system, displacement measurement program, displacement measurement method, and displacement measurement device according to the present invention may take forms different from those illustrated in the embodiments. Examples of such forms include forms in which part of the configuration of the embodiments is replaced, modified, or omitted, or forms in which new configurations are added to each embodiment. Some examples of modified forms of the embodiments are shown below. Note that the following modified forms can be combined with each other to the extent that they are not technically inconsistent.

[0050] <7-1> In the above embodiment, the specific method of the in-plane displacement amount calculation process can be changed. Fig. 8 is a flowchart showing an example of the in-plane displacement amount calculation process executed by the displacement amount measurement system 10 of a modified example. The in-plane displacement amount calculation process shown in Fig. 8 differs from the in-plane displacement amount calculation process shown in Fig. 6 in that it includes the process of step S21 instead of the process of step S13.

[0051] In step S21, the control device 21B determines whether the average displacement amount dAx is other than 0 and whether the average displacement amount dAy is other than 0. If the determination in step S21 is affirmative, that is, if at least one of the average displacement amount dAx being other than 0 and the average displacement amount dAy being other than 0 is satisfied, the control device 21B executes the processing of step S14. According to the displacement amount measurement system of this modified example, even if the average displacement amounts dAx and dAy of the two-dimensional lattice pattern 200 are small, the analysis region 50 moves so as to follow the displacement of the two-dimensional lattice pattern 200. Therefore, it is further prevented that a part of the analysis region 50 deviates from the two-dimensional lattice pattern 200.

[0052] <7-2> In the above embodiment, the control device 21B moves the analysis region 50 in the X-axis direction by the average displacement amount dAx when the absolute value of the average displacement amount dAx is equal to or greater than the threshold value XA. However, the control device 21B may move the analysis region 50 in the X-axis direction by a displacement amount smaller than the average displacement amount dAx or a displacement amount larger than the average displacement amount dAx. Similarly, the control device 21B moves the analysis region 50 in the Y-axis direction by the average displacement amount dAy when the absolute value of the average displacement amount dAy is equal to or greater than the threshold value XB. However, the control device 21B may move the analysis region 50 in the Y-axis direction by a displacement amount smaller than the average displacement amount dAy or a displacement amount larger than the average displacement amount dAy. In other words, when the average displacement amounts dAx and dAy satisfy a predetermined condition, the control device 21B may move the analysis region 50 so that the analysis region 50 follows the two-dimensional grid pattern 200.

[0053] <7-3> In the above embodiment, the analytical region 50 is set by the analytical region extraction unit 41, but the analytical region 50 may also be set by the user.

[0054] <7-4> In the above embodiment, the displacement measuring device 20 is connected to the imaging device 30 so as to be able to communicate with them wirelessly or via a wire, but the displacement measuring device 20 and the imaging device 30 do not have to be connected so as to be able to communicate with each other. In this case, the two-dimensional lattice image 300 captured by the imaging device 30 is stored in an auxiliary storage device such as a USB flash memory or an SD memory card. The displacement measuring device 20 executes the in-plane displacement calculation process by acquiring the two-dimensional lattice image 300 from the auxiliary storage device. [Explanation of symbols]

[0055] 10: Displacement measurement system 20: Displacement measuring device 30: Imaging device 50:Analysis area 60: Sub-area 100: Measurement object 200: 2D grid pattern

Claims

1. a displacement amount measuring device that measures a displacement amount in an in-plane direction of a surface of a measurement object by using a two-dimensional image obtained by capturing a two-dimensional grid pattern placed on the measurement object; an imaging device that captures the two-dimensional grid pattern installed on the measurement object, The displacement amount measuring device is a displacement amount calculation process for calculating a displacement amount of the two-dimensional grid pattern in an analysis region including the two-dimensional grid pattern in the two-dimensional image; If the displacement amount satisfies a predetermined condition, a region moving process is executed to move the analysis region based on the displacement amount. Displacement measurement system.

2. The displacement amount measuring device is In the region moving process, the analysis region is moved when the absolute value of the displacement amount is equal to or greater than a threshold value. The displacement measurement system according to claim 1 .

3. The displacement amount measuring device is In the region moving process, the analysis region is moved when the displacement amount is other than 0. The displacement measurement system according to claim 1 .

4. A displacement amount measurement program for measuring an amount of displacement in an in-plane direction of a surface of a measurement object by using a two-dimensional image obtained by capturing a two-dimensional grid pattern placed on the measurement object, a displacement amount calculation process for calculating a displacement amount of the two-dimensional grid pattern in an analysis region including the two-dimensional grid pattern in the two-dimensional image; a region moving process for moving the analysis region based on the amount of displacement when the amount of displacement satisfies a predetermined condition; Displacement measurement program.

5. A displacement amount measuring method for measuring an amount of displacement in an in-plane direction of a surface of a measurement object using a two-dimensional image obtained by capturing a two-dimensional grid pattern placed on the measurement object, comprising: a displacement amount calculation process for calculating a displacement amount of the two-dimensional grid pattern in an analysis region including the two-dimensional grid pattern in the two-dimensional image; and a region moving process for moving the analysis region based on the amount of displacement when the amount of displacement satisfies a predetermined condition. Displacement measurement method.

6. A displacement amount measuring device that measures an amount of displacement in an in-plane direction of a surface of a measurement object by using a two-dimensional image obtained by capturing a two-dimensional grid pattern placed on the measurement object, a displacement amount calculation process for calculating a displacement amount of the two-dimensional grid pattern in an analysis region including the two-dimensional grid pattern in the two-dimensional image; If the displacement amount satisfies a predetermined condition, a region moving process is executed to move the analysis region based on the displacement amount. Displacement measuring device.

Images