JP2020003290A - Structure displacement measuring system and structure displacement measuring method - Google Patents

Abstract

To measure the displacement of a structure with good accuracy at the time vibration occurs.SOLUTION: A plurality of markers 12 having a prescribed shape are fixed to a lower structure 42. A camera 14, with the plurality of markers 12 included in its imaging range, is installed in an upper structure 40. The image imaged by the camera 14 is copied to a computer 18 by some means, and a displacement amount calculation unit 20 inside of the computer 18 successively calculates a three-dimensional displacement amount between the upper structure 40 and the lower structure 42 on the basis of the images continuously imaged by the camera 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structural displacement measuring system for measuring a structural displacement and a structural displacement measuring method.

2. Description of the Related Art Conventionally, in a structure or the like in which a seismic isolation device is installed, a displacement amount of the structure when an earthquake occurs is measured. The measured displacement is used to estimate the damage to the seismic isolation device and the structure.
As a technique for measuring the displacement of a structure when vibration occurs, a method using an orbiter (a marking device) or image processing has been proposed.
For example, Patent Literature 1 below is an invention relating to an orbiter, and includes a ground supporting a seismic isolation structure, a recording plate fixed to the seismic isolation structure, and the seismic isolation structure, or the seismic isolation thereof. The recording needles are fixedly provided on the ground supporting the structure, and are urged to always contact the recording plate.
Patent Document 2 below is an invention using image processing, in which an imaging member is provided on one of a first structure such as a basic structure and a second structure such as an architectural structure, and the other is provided. And an imaging unit for imaging the member to be imaged. Then, an image captured by the imaging unit is appropriately processed by the image processing unit to detect a relative displacement of the second structure with respect to the first structure.

JP-A-11-142135 JP-A-2006-90474

However, in the above-described conventional technology, there is a problem that although the relative displacement in the horizontal direction between the upper structure and the lower structure can be measured, the relative displacement and the inclination in the vertical direction cannot be measured. Further, Patent Document 1 has a problem that the maximum value of the displacement amount at the time of occurrence of vibration can be measured, but the path, the total amount, and the displacement speed cannot be measured.
The present invention has been made in view of such circumstances, and an object of the present invention is to accurately measure a displacement of a structure when a vibration occurs.

In order to achieve the above object, a structure displacement measuring system according to the invention of claim 1 is a displacement measuring system that measures a relative displacement amount of a structure having an upper structure and a lower structure, A first marker group attached to one of the upper structure or the lower structure and having three or more markers having a predetermined shape, and a first marker group of the upper structure or the lower structure A three-dimensional camera between the upper structure and the lower structure, based on a camera installed in the structure and including the first marker group in a shooting range, and images continuously shot by the camera. A displacement calculating unit for calculating the displacement over time.
In the displacement measurement system for a structure according to the second aspect of the invention, each of the markers is disposed at a tip of a support member erected vertically from a surface of the one structure. .
According to a third aspect of the present invention, there is provided a displacement measuring system for a structure, wherein the wall-shaped member is provided upright from the surface of the one structure and is attached to the wall-shaped member and has a predetermined shape. A second marker group consisting of one or more markers, wherein the camera includes the second marker group in a shooting range together with the first marker group, and the displacement amount calculating section includes: A horizontal relative displacement between the upper structure and the lower structure is calculated based on an image of the marker group, and the upper structure and the lower structure are calculated based on an image of the second marker group. And calculating a vertical relative displacement between the two.
The structure displacement measuring system according to claim 4, wherein a half mirror or a pinhole mirror is arranged in front of the camera lens, and the first marker group and the second marker group are located in an imaging range of the camera. Is included.
In the structure displacement measuring system according to a fifth aspect of the present invention, the plurality of markers are different in at least one of a shape and a color.
The system for measuring displacement of a structure according to the invention of claim 6 further includes a vibration detection unit for detecting vibration, wherein the camera is activated when the vibration detection unit detects the vibration, and the camera starts predetermined photographing of the image. Time is performed.
The displacement measuring system for a structure according to the invention of claim 7 is characterized in that a seismic isolation device is installed between the upper structure and the lower structure.
A displacement measuring method for a structure according to the invention of claim 8 is a displacement measuring method for measuring a relative displacement amount of a structure having an upper structure and a lower structure, wherein the relative displacement of the upper structure or the lower structure is measured. A first marker group consisting of three or more having a predetermined shape is fixed to one of the structures, and the first marker group is fixed by a camera installed on the other of the upper structure and the lower structure. A photographing step of continuously photographing a group of markers; and a displacement amount calculating for successively calculating a three-dimensional displacement amount between the upper structure and the lower structure based on an image photographed by the camera. And a step.
According to a ninth aspect of the present invention, in the method for measuring a displacement of a structure, each of the markers is disposed at a tip of a support member which is vertically erected from a surface of the one structure. .
In the displacement measuring method for a structure according to a tenth aspect of the present invention, in the photographing step, the first marker group and the first marker group are fixed to a wall-like member that is vertically erected from a surface of the one structure. A second marker group consisting of three or more markers having a predetermined shape is photographed, and in the displacement amount calculating step, the upper structure and the lower structure are combined based on an image of the first marker group. Calculating the relative displacement in the horizontal direction between the two, and calculating the relative displacement in the vertical direction between the upper structure and the lower structure based on the image of the second marker group. I do.
12. The method for measuring displacement of a structure according to claim 11, wherein a half mirror or a pinhole mirror is arranged in front of a lens of the camera, and the first marker group and the second marker group are arranged in an imaging range of the camera. Is included.
A structure displacement measuring method according to a twelfth aspect of the present invention is characterized in that the plurality of markers are different in at least one of shape and color.
The method for measuring the displacement of a structure according to the invention of claim 13 further includes a vibration detection step of detecting vibration of the structure, wherein the photographing step is started when vibration is detected by the vibration detection step, The image capturing is performed for a predetermined time.
A structure displacement measuring method according to a fourteenth aspect of the present invention is characterized in that a seismic isolation device is installed between the upper structure and the lower structure.

According to the first and eighth aspects of the present invention, the three-dimensional displacement between the upper structure and the lower structure is continuously calculated based on an image obtained by continuously photographing a plurality of markers. In addition, it is possible to grasp not only the maximum value of the displacement amount when the vibration occurs, but also the temporal change of the displacement. Further, since not only the displacement in the horizontal direction but also the displacement in the vertical direction are calculated, it is advantageous in accurately estimating the influence of the displacement on the structure. Further, it is only necessary to dispose a camera and a marker on the structure, and the displacement of the structure can be measured with a simpler configuration than when an expensive seismometer or the like is installed.
According to the second and ninth aspects of the present invention, since the marker is disposed at the tip of the vertically erected support member, it is advantageous for accurately measuring the vertical displacement.
According to the third and tenth aspects of the invention, the relative displacement in the horizontal direction is determined based on the image of the first marker group, and the relative displacement in the vertical direction is determined based on the image of the second marker group. Since the calculation is performed, the three-dimensional displacement amount between the upper structure and the lower structure can be calculated more accurately.
According to the fourth and eleventh aspects of the present invention, the first and second marker groups can be photographed by one camera, and the cost can be reduced.
According to the fifth and twelfth aspects of the present invention, at least one of the shape and the color of each of the plurality of markers is different from each other, which is advantageous in accurately identifying each marker.
According to the sixth and thirteenth aspects of the present invention, photographing is not performed by the camera except when vibration occurs, which is advantageous in reducing power consumption and processing load of the camera.
According to the seventh and fourteenth aspects of the present invention, it is possible to measure the displacement amount around the seismic isolation device when the vibration occurs, which is advantageous in accurately estimating the damage caused by the vibration to the seismic isolation device. .

FIG. 1 is a block diagram illustrating a configuration of a displacement measurement system 10 according to an embodiment. FIG. 3 is an explanatory diagram schematically showing the installation state of a marker and a camera. FIG. 3 is an enlarged perspective view of a marker 12. 5 is a flowchart illustrating a process of the displacement measurement system 10. FIG. 9 is an explanatory diagram illustrating another configuration example of the displacement measurement system 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a structure displacement measuring system and a structure displacement measuring method according to the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating a configuration of a structure displacement measurement system 10 according to the embodiment. FIG. 2 is an explanatory diagram schematically showing the installation state of the marker 12 and the camera 14. FIG. 3 is an enlarged perspective view of the marker 12.
In the present embodiment, the displacement measurement system 10 measures the amount of displacement of a structure having the upper structure 40 and the lower structure 42.
As shown in FIG. 2, a seismic isolation device 30 is installed in a space S between the upper structure 40 and the lower structure 42. The upper structure 40 is, for example, a building, and the lower structure 42 is, for example, a foundation of a building. Although not shown in FIG. 1, a plurality of seismic isolation devices 30 are installed in the space S at intervals.
The seismic isolation device 30 includes a steel upper flange 32 attached to the upper structure 40, a steel lower flange 34 attached to the lower structure 42, and a laminated rubber 36 sandwiched between the upper flange 32 and the lower flange 34. And
The laminated rubber 36 supports vertical load from the upper structure 40 while allowing horizontal displacement of the upper structure 40 on the lower structure 42, and includes a plurality of rubber sheets and a plurality of steel plates. Are alternately laminated, and the outside thereof is covered with rubber. The upper flange 32 is joined to the upper surface of the laminated rubber 36, and the lower flange 34 is joined to the lower surface of the laminated rubber 36. In some cases, a lead plug is disposed at the center of the laminated rubber 36 as energy absorbing means. In addition, the structure of the seismic isolation device 30 is not limited to the above-described one, and various conventionally known structures can be applied. The seismic isolation device is a general term for rolling bearings, sliding bearings, lead-containing laminated rubber, laminated rubber, curved spring structural types, and the like.
For example, when an earthquake occurs, relative displacement in the horizontal direction between the lower structure 42 and the upper structure 40 is allowed due to the deformation of the laminated rubber 36, and the vibration energy is Is absorbed.
On the other hand, the seismic isolation device 30 may be damaged by the load applied during the deformation. By measuring the amount of displacement of the structure during vibration, the load applied to the seismic isolation device 30 can be estimated, and the degree of damage to the seismic isolation device 30 can be estimated. You can also know the status of the aftershocks.

As shown in FIG. 1, a structure displacement measurement system 10 includes a marker group 11 (first marker group) including three or more markers 12, a camera 14, a communication unit 16, a computer 18, and a displacement amount calculation. Unit 20 and an acceleration sensor 24 (vibration detecting unit). The minimum system of the structural displacement measurement system 10 may be a configuration of the marker group 11 and the camera 14.
The marker group 11 is fixed to one of the upper structure 40 and the lower structure 42 and includes three or more markers 12 having a predetermined shape.
In the present embodiment, a marker group 11 is constituted by three circular (regular) markers 12. Each marker 12 is fixed to the lower structure 42 at a position where the marker 12 becomes a triangle when viewed from above. Note that “fixed to the structure” means that the position relative to the structure does not change even when subjected to vibration such as an earthquake.
In the present embodiment, as shown in FIGS. 2 and 3, the marker 12 is arranged at the tip of the support member 13 that stands vertically from the surface of the lower structure 42. The support member 13 is installed with a strength that maintains a position and an angle with respect to the lower structure 42 even when subjected to vibration such as an earthquake. By providing the marker 12 at a position away from the surface of the structure (on the space S between the structures), it is easy to measure not only the displacement in the horizontal direction but also the displacement in the vertical direction (vertical direction). In addition, the marker 12 can be protected from flooding and dust accumulation.
Further, since the distance between the marker 12 and the camera 14 becomes shorter, all the markers 12 can be included in the photographing range A even if the angle of view of the camera 14 is small.
Other methods of fixing the marker 12 to the structure (the upper structure 40 or the lower structure 42) include, for example, drawing the shape of the marker 12 on the surface of the structure, attaching a seal or the like having the shape of the marker 12, and the like. A method can be adopted. In particular, when the distance between the upper structure 40 and the lower structure 42 is short, the marker 12 may be installed on the lower structure 42 to eliminate the need for the support member 13.

As described above, in the present embodiment, the marker 12 is formed in a circular shape (a perfect circle). However, the present invention is not limited to this. It may be. Note that "having a predetermined shape" indicates that the marker 12 has a fixed area, not a point-like area having almost no area. Accordingly, when a displacement including a vertical component such as a twist occurs, the shape of the marker 12 changes and is visually recognized.
Further, in the present embodiment, three markers 12 are installed, but if the shape and dimensions of the markers 12 are known, only one marker 12 is in principle required, and the one marker is a circle, It may be an elliptical or polygonal plate, or a three-dimensional object such as a sphere or a polyhedron.
On the other hand, it is preferable to install a plurality of markers 12 in order to improve the accuracy of displacement measurement.

In general, the space S between the structures is not an area where a person resides, and therefore, there is a case where there is no lighting, or even if there is a lighting, a minimum number is installed. Further, since the marker 12 is installed for a long period of time, visibility may decrease due to dirt such as dust.
For this reason, for example, even if the marker 12 is formed by attaching a reflective tape to the surface of a thin plate made of a resin or the like formed in a circular shape, and the camera 14 side irradiates light such as an infrared ray or a laser to improve the visibility. Good. For example, the marker 12 may be formed by applying a fluorescent paint (or a fluorescent tape) to the surface of a thin plate. Further, a power source may be provided on the marker 12 side to cause the marker 12 itself to emit light, or illumination may be provided near the marker 12.

  Further, in FIGS. 2 and 3, the plurality of markers 12 have the same shape, but the invention is not limited thereto, and at least one of the shape and the color of the plurality of markers 12 may be different from each other. This makes it easier to identify the plurality of markers 12 in the displacement amount calculation unit 20 described later, and can improve the accuracy of displacement measurement.

The camera 14 is installed on the other of the upper structure 40 and the lower structure 42 in which the marker 12 is not installed. In the present embodiment, the camera 14 is installed on the upper structure 40 as shown in FIG. The camera 14 includes a plurality of markers 12 installed in the imaging range A so as to face each other in the optical axis direction.
The camera 14 has a photographing function and an image recording function. For example, it is a CCD camera for shooting moving images. The camera 14 is connected to a power source (not shown) (a DC power source and a regular power source), and operates by receiving power from these power sources. Even if the power supply from the regular power supply is cut off due to a power failure such as an earthquake, it is assumed that the DC power supply has the necessary power supply for the required shooting time. In the present embodiment, the recorded image is transmitted to the computer 18 via the communication unit 16 connected to the camera 14. However, the computer 18 may directly copy the image from a storage device in the camera 14 and download it. .

The photographing with the camera 14 may be performed at all times. For example, the camera 14 is set to a sleep state in a normal state, and the acceleration sensor 24 (vibration detecting unit) detects an acceleration equal to or more than a predetermined value, that is, mainly detects vibration due to an earthquake. In such a case, the camera 14 may be activated to take an image for a predetermined time, and then return to the sleep state again. Thereby, the power consumption of the camera 14 can be reduced.
Hereinafter, in the present embodiment, the camera 14 starts photographing when vibration is detected by the acceleration sensor 24.
Note that, for example, an image may be constantly captured by the camera 14, and the image may be overwritten in order from the oldest image while storing the image of the storage capacity of the camera 14. Further, for example, the image may be always captured by the camera 14 but not stored, and the storage of the image may be started when the acceleration sensor 24 detects vibration.

  A plurality of pairs of the marker 12 and the camera 14 as shown in FIG. 2 may be provided in the space S between the upper structure 40 and the lower structure 42.

The communication unit 16 transmits an image captured by the camera 14 to the computer 18. The transmission of the image may be performed sequentially during the photographing by the camera 14, or may be performed after a predetermined time has elapsed after the photographing of the image, such as after the vibration stops. When data is directly downloaded from the camera 14, the communication unit 16 may be omitted.
Communication with the computer 18 by the communication unit 16 may be performed by wire or wireless.

The computer 18 is provided at a location away from the space S where the camera 14 and the like are installed. The computer 18 includes a CPU, a ROM for storing and storing a control program and the like, a RAM as an operation area of the control program, an EEPROM for rewritably retaining various data, an interface unit for interfacing with peripheral circuits, a monitor, a keyboard, and the like. It is comprised including. Note that the computer 18 does not need to be permanently installed, and need not be in a building. For example, the computer 18 may be brought near the camera 14 when downloading image data.
The computer 18 functions as the displacement amount calculation unit 20 when the CPU executes the control program.

The displacement calculator 20 calculates a three-dimensional displacement between the upper structure 40 and the lower structure 42 based on the image captured by the camera 14.
More specifically, the displacement amount calculation unit 20 calculates the center positions of the three markers 12 and the vertices of the triangular pyramid formed by the lens center of the camera 14 by image analysis, and performs trigonometric function analysis and simultaneous ternary quadratic equations. Non-linear analysis is performed to calculate three-dimensional six-values (position and orientation = X, Y, Z, pitching, rolling, yawing) at each time (each continuously shot image).
Further, based on the position and orientation at each time, it is also possible to calculate parameters including speed components such as gal, cain, and acceleration direction.
That is, by calculating various parameters by the displacement amount calculation unit 20, it is possible to temporally evaluate the relative displacement (horizontal direction and vertical direction) between the building and the ground.

In FIG. 1, only the marker group 11 (first marker group) arranged in the horizontal direction is provided. However, the present invention is not limited to this. For example, the marker group 51 (second marker group) arranged in the vertical direction as shown in FIG. May be provided.
The marker group 51 shown in FIG. 5 is attached to a wall-like member 50 that is erected upward (in the vertical direction) from the surface of the lower structure 42 (the structure on the side where the camera 14 is not provided), and It is composed of three or more markers 52 having a shape. The restrictions on the shape and arrangement of the marker 52 are the same as those of the marker 12. For example, in FIG. 5, the marker 52 is arranged at the tip of the support member 53, but the marker 52 may be arranged directly on the surface of the wall-like member 50.
The camera 14 includes the marker group 51 arranged in the vertical direction together with the marker group 11 arranged in the horizontal direction in the shooting range. In the example of FIG. 5, the first camera 14A that captures the marker group 11 and the second camera 14B that captures the marker group 51 are provided.
In addition, instead of providing two cameras as shown in FIG. 5, for example, only one camera 14 is arranged as shown in FIG. 1, and a half mirror or a pinhole mirror is provided in front of the lens of the camera 14, The marker group 11 and the marker group 51 may be photographed simultaneously.
When the marker group 51 is also arranged in the vertical direction as shown in FIG. 5, the displacement amount calculation unit 20 determines the relative displacement in the horizontal direction between the upper structure 40 and the lower structure 42 based on the image of the marker group 11. The amount is calculated, and the vertical relative displacement between the upper structure 40 and the lower structure 42 is calculated based on the image of the marker group 51.
As described above, the three-dimensional displacement amount between the upper structure 40 and the lower structure 42 can be calculated using only one of the marker group 11 and the marker group 51. However, by arranging the marker groups in the horizontal direction and the vertical direction, it is possible to calculate a more accurate three-dimensional displacement amount.

FIG. 4 is a flowchart showing the processing of the displacement measurement system 10.
In the initial state, the displacement measurement system 10 is in a sleep state (Step S400). Until vibration is detected by the acceleration sensor 24 (step S401: No loop), the displacement measurement system 10 continues the sleep state.
When the vibration is detected by the acceleration sensor 24 (Step S401: Yes, vibration detection step), the camera 14 is started (Step S402), the photographing of the marker 12 is started (Step S404, photographing step), and the photographed image is stored in the internal memory. (Step S406).
Until a predetermined time elapses after the vibration is detected or until the predetermined time elapses after the stop of the vibration is detected (step S408: No loop), the process returns to step S404, and the image capturing / recording by the camera 14 is performed. continue.
When the predetermined time has elapsed (step S408: Yes), the camera 14 stops capturing an image and shifts to a sleep state (step S410).
The image recorded in the camera 14 is transmitted to the computer 18 by the communication unit 16 (Step S411). Note that the computer 18 may directly download image data from the camera 14 without using the communication unit 16.
The displacement calculating unit 20 of the computer 18 calculates a three-dimensional displacement between the upper structure 40 and the lower structure 42 based on the image transmitted from the camera 14 (step S412, a displacement calculating step).

As described above, the displacement measurement system 10 according to the embodiment calculates a three-dimensional displacement amount between the upper structure 40 and the lower structure 42 based on an image obtained by continuously photographing a plurality of markers 12. Since the calculation is performed successively, not only the maximum value of the displacement amount at the time of occurrence of vibration, but also the path, the total amount, and the temporal change of the displacement can be grasped. Further, since not only the displacement in the horizontal direction but also the displacement in the vertical direction and the displacement in the rotational direction are calculated, it is advantageous in accurately estimating the influence of the displacement on the structure. In addition, it is only necessary to dispose the camera 14 and the marker 12 on the structure, and the displacement of the structure can be measured with a simpler configuration than when an expensive seismometer or the like is installed.
In the displacement measuring system 10, if the marker 12 is arranged at the tip of the support member 13 erected in the vertical direction, it is advantageous in accurately measuring the displacement in the vertical direction.
Further, in the displacement measurement system 10, if at least one of the shape and the color of the plurality of markers 12 is different from each other, it is advantageous in identifying each marker 12 with high accuracy.
In addition, in the displacement measurement system 10, if the imaging with the camera 14 is not performed except when the vibration occurs, it is advantageous in reducing the power consumption and the processing load of the camera 14.
In addition, by using the displacement measurement system 10, the amount of displacement around the seismic isolation device 30 when vibration occurs can be measured, which is advantageous in accurately estimating the damage caused to the seismic isolation device 30 by vibration. .

  In the present embodiment, the case where the upper structure 40 and the lower structure 42 are connected by the seismic isolation device 30 has been described, but the connection between the upper structure 40 and the lower structure 42 to which the present invention can be applied. The embodiment is not limited to this, and can be applied to conventionally known various embodiments.

Reference Signs List 10 displacement measurement system 11, 51 marker group 12, 52 marker 14 camera 16 communication unit 18 computer 20 displacement amount calculation unit 24 acceleration sensor 30 seismic isolation device 40 upper structure 42 lower structure A imaging range S space

Claims (14)

A displacement measurement system that measures a relative displacement amount of a structure having an upper structure and a lower structure,
A first marker group attached to one of the upper structure and the lower structure, the first marker group including three or more markers having a predetermined shape;
A camera that is installed on the other of the upper structure and the lower structure and includes the first marker group in a shooting range;
A displacement amount calculating unit that successively calculates a three-dimensional displacement amount between the upper structure and the lower structure based on images continuously captured by the camera;
A displacement measuring system for a structure, comprising: Each of the markers is disposed at a tip of a support member that stands vertically from the surface of the one structure,
The structure displacement measurement system according to claim 1, wherein: A wall-shaped member that stands vertically from the surface of the one structure,
A second marker group attached to the wall-shaped member and including three or more markers having a predetermined shape,
The camera includes the second marker group in an imaging range together with the first marker group,
The displacement amount calculation unit calculates a horizontal relative displacement amount between the upper structure and the lower structure based on the image of the first marker group, and calculates the relative displacement amount in the image of the second marker group. Calculating a vertical relative displacement between the upper structure and the lower structure based on the
3. The displacement measurement system for a structure according to claim 1, wherein: A half mirror or a pinhole mirror is arranged in front of the lens of the camera, and the first marker group and the second marker group are included in an imaging range of the camera.
4. The displacement measuring system for a structure according to claim 3, wherein: The markers are different in at least one of shape and color,
The displacement measurement system for a structure according to claim 1, wherein: It further includes a vibration detection unit that detects vibration,
The camera is activated when vibration is detected by the vibration detection unit, and performs photographing of the image for a predetermined time,
The structural displacement measurement system according to any one of claims 1 to 5, wherein: A seismic isolation device is installed between the upper structure and the lower structure,
The structural displacement measuring system according to any one of claims 1 to 6, wherein: A displacement measurement method for measuring a relative displacement amount of a structure having an upper structure and a lower structure,
A first marker group having three or more having a predetermined shape is fixed to one of the upper structure and the lower structure, and the other of the upper structure and the lower structure is fixed to the first structure. A photographing step of continuously photographing the first marker group with a camera installed in
A displacement amount calculating step of sequentially calculating a three-dimensional displacement amount between the upper structure and the lower structure based on an image captured by the camera;
A method for measuring the displacement of a structure, comprising: Each of the markers is disposed at a tip of a support member that stands vertically from the surface of the one structure,
The method for measuring the displacement of a structure according to claim 8, wherein: In the photographing step, a second marker including, with the first marker group, three or more markers having a predetermined shape fixed to a wall-like member vertically provided from the surface of the one structure. Shoot the marker group,
In the displacement amount calculating step, a relative displacement amount in the horizontal direction between the upper structure and the lower structure is calculated based on the image of the first marker group, and an image of the second marker group is calculated. Calculating a vertical relative displacement between the upper structure and the lower structure based on the
The method for measuring the displacement of a structure according to claim 8 or 9, wherein: A half mirror or a pinhole mirror is arranged in front of the lens of the camera, and the first marker group and the second marker group are included in an imaging range of the camera.
The method for measuring a displacement of a structure according to claim 10, wherein: The markers are different in at least one of shape and color,
The method for measuring a displacement of a structure according to any one of claims 8 to 11, wherein: The method further includes a vibration detection step of detecting vibration of the structure,
The photographing step is started when vibration is detected by the vibration detecting step, and performs photographing of the image for a predetermined time.
The method for measuring the displacement of a structure according to any one of claims 8 to 12, wherein: A seismic isolation device is installed between the upper structure and the lower structure,
The method for measuring the displacement of a structure according to any one of claims 8 to 13, wherein:

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