JP2018072218A - Method and device for displacement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring a displacement which can measure a displacement in a structure easily and accurately.SOLUTION: A target 10 is arranged in different positions of a structure 2, an optical imaging device 30 for imaging the target 10 is arranged in a fixed position, and targets 10 before and after the displacement of the structure 2 are imaged, and the displacement of the structure 2 is measured from the center coordinates of the targets 10 before and after the displacement analyzed based on the concentration distribution of image data of each target 10.SELECTED DRAWING: Figure 3

Description

  The present application relates to a displacement measuring method and a displacement measuring apparatus for measuring a displacement of a structure in which a stress fluctuation occurs.

  In recent years, for example, aging of structures such as bridges has become a problem, and it is necessary to know the degree of aging in order to implement this countermeasure.

  In general, the degree of aging is determined by periodic visual inspection. Although this visual inspection shows material deterioration and external appearance deformation, internal deterioration cannot be known, and safety can be determined appropriately. Have difficulty.

  In visual inspection, hitting a floor slab with a hammer and listening to the sound is used as an indicator of deterioration. In this case, it is necessary to build a scaffold in the lower space of the floor slab.

  In such a method, there are problems that time and cost are required for assembly, disassembly, movement, etc. of the scaffold, and that the judgment is different depending on the skill level.

  Therefore, as a method for determining the degree of aging without assembling a scaffold, a device that measures the displacement of a bridge in a non-contact manner as described in Patent Document 1 is conventionally known.

  This method measures the displacement of a structure with a three-dimensional laser scanner. A measuring device is installed at a position away from the object to be measured, and a laser pulse irradiated toward an arbitrary target is reflected back. By measuring the distance calculated from the time until it comes, the coordinates of an arbitrary point are calculated, and the displacement is measured from the movement of the coordinates.

Japanese Patent No. 4114792

  However, while the method of Patent Document 1 can measure a wide range, the accuracy is low at each point, and it is difficult to accurately specify the measurement position, and the displacement amount of the structure can be accurately measured. It can not be said.

  In addition, as an example of measuring the displacement of a bridge girder, a method using a total station or a method using a digital camera is known, but high measurement accuracy cannot be expected in a total station, and a digital camera performs one measurement with one camera. There is a problem that only a point is measured and a wide range cannot be measured.

  The present application has been made by solving the above-described problems as an example of an object, and is to provide a displacement measuring method and the like that can easily and accurately measure a displacement generated in a structure.

  In order to solve the above-described problem, the displacement measuring method according to claim 1 is an optical imaging device (30) in which a target (10) is arranged in a plurality of different variable portions of the structure (2) and the target is imaged. ) Is placed on a fixed part, the target before and after the displacement of the structure is photographed, and the center coordinates of the target before and after the displacement are analyzed based on the density distribution of the image data of each target. The displacement amount is measured.

  Further, the displacement measuring device (1) according to claim 2 includes a target (10) disposed in a plurality of variable portions of different structures, an optical imaging device (30) disposed in a fixed portion, A processing device (50) for measuring the amount of displacement of the structure from the center coordinates of the target before and after displacement analyzed based on the density distribution of the image data of the target before and after displacement imaged by the optical imaging device; It is characterized by providing.

  The displacement measuring device according to claim 3 is the displacement measuring device according to claim 2, wherein the optical imaging device is arranged so that a plurality of the targets are included within an angle of view. Features.

  The displacement measuring device according to claim 4 is the displacement measuring device according to claim 2 or 3, wherein the central coordinate is an average value of gradation values of pixels in each row or each column of image data. It is calculated from the diagram obtained by graphing.

  Moreover, the displacement measuring apparatus according to claim 5 is the displacement measuring apparatus according to any one of claims 2 to 4, wherein the target is an index in which a surrounding concentration gradually varies with a center as a base point. It is characterized by that.

  Further, the displacement measuring device according to claim 6 is the displacement measuring device according to claim 5, wherein the indicator has two triangles arranged point-symmetrically or line-symmetrically so as to have a vertex at the center. One triangle and another area are displayed in different colors.

  A displacement measuring device according to a seventh aspect is the displacement measuring device according to the fifth or sixth aspect, wherein two of the indicators are arranged in a vertical direction.

  Moreover, the displacement measuring device according to claim 8 is the displacement measuring device according to any one of claims 2 to 7, wherein an irradiation body for irradiating the target with light is provided. .

  The displacement measuring device according to claim 9 is the displacement measuring device according to any one of claims 2 to 8, wherein the target can move in a vertical direction and can rotate about a vertical axis. It is characterized by being.

  The displacement measurement device according to claim 10 further includes a support device that supports the optical imaging device in the displacement measurement device according to any one of claims 2 to 9, wherein the support device includes: The optical imaging device includes a base on which a level can be arranged side by side.

Moreover, the displacement measuring device according to claim 11 is the displacement measuring device according to any one of claims 2 to 10, wherein the optical imaging device is an imaging device that captures moving image data.
The image data is a still image cut out in time series from moving image data.

It is a schematic diagram which shows the example of arrangement | positioning of a displacement measuring device, Fig.1 (a) is a schematic diagram of the example of arrangement | positioning in side view, FIG.1 (b) is the schematic diagram of the example of arrangement | positioning in planar view. It is a schematic diagram which shows an example of the parameter | index used as a target. FIG. 3A is a schematic diagram illustrating an example of calculating the center coordinates of an index from image data captured by an imaging device, FIG. 3A is a schematic diagram illustrating a configuration of image data, and FIG. 3B is a diagram for each row of image data. It is a schematic diagram which shows an example which graphed the average value of the gradation value of a pixel. It is a schematic diagram which shows the structural example of a displacement measuring device. It is a perspective view which shows an example of a target. It is a perspective view which shows an example of an imaging device. It is a schematic diagram which shows the example of a displacement of the center coordinate of a parameter | index. It is a schematic diagram which shows the example of a displacement of the parameter | index when the twist arises in the bridge. FIG. 9A is a schematic diagram illustrating an example of an index, FIG. 9B is a schematic diagram illustrating an example of the configuration of the index, and FIG. 9B is a schematic diagram illustrating an example of graphing image data obtained by capturing the index of FIG. 9A. . It is a schematic diagram which shows another example of a parameter | index.

  Hereinafter, embodiments of the present application will be described in detail with reference to FIGS. 1 to 10.

(Outline of displacement detection method)
First, a displacement measuring method will be described with reference to FIGS.

  The displacement measuring method of this embodiment measures the amount of deflection (displacement) during static loading in order to determine the degree of aging of a structure (for example, a bridge) as a measurement object.

  The displacement measuring method of the present embodiment measures the amount of deflection (displacement) generated in the bridge 2 using the target 10, and captures the index 10A displayed on the target 10 shown in FIG. Based on the density distribution of the 10A image data, the center coordinates of the index 10A before and after displacement are calculated, and the amount of displacement generated in the bridge 2 is measured using the center coordinates before and after displacement.

  Note that an optical imaging device (hereinafter referred to as “imaging device 30”) such as a digital camera or a digital video camera capable of recording the captured image as digital data is used for photographing the bridge 2. When an imaging device such as a digital video camera is used, still image data cut out in time series after moving images are used.

  Further, as shown in FIG. 3B, the center coordinates of the index 10A are calculated from a diagram obtained by graphing the average value of the gradation values of the pixels in each row or each column of the image data.

  As an example of an index used in this type of displacement measuring method, for example, as shown in FIG. 9A, a diamond-shaped index obtained by rotating a square by 45 degrees is known. This index has a marker area in which a rectangular portion is filled with black and another area in which the periphery of the marker area is filled with white.

  Such an index is photographed by the photographing device 30, and the barycentric coordinates of the photographed image data are, for example, the average of the gradation values of the pixels in each row or each column of the image data, as shown in FIG. 9B. It is calculated from a linear diagram obtained by graphing the values. When calculating the barycentric coordinates of the above-described square index from a linear diagram, it is necessary to analyze a higher-order function in order to obtain linear vertex coordinates as shown in FIG.

  In addition, the longer the distance between the image capturing apparatus 30 and the index, the smaller the number of pixels obtained from the image data captured by the image capturing apparatus 30, and the lower the analysis accuracy. On the other hand, when the index is increased, in general, a plurality of targets are arranged at arbitrary points, and shooting is performed so that a plurality of targets are reflected in the angle of view of the imaging device 30. Therefore, it is necessary to change the arrangement of the targets. Workability is poor.

  In addition, when obtaining the center-of-gravity (center) coordinates using other conventional general indices, it is difficult to set a threshold value for determining the black-and-white boundary. In particular, the threshold value must be changed when the ambient brightness changes. Prone to errors.

(About indicators)
Therefore, the index 10A used in the displacement measurement method of the present embodiment is displayed so that the surrounding density gradually changes with the center X as a base point, as shown in FIGS. The same two triangles are arranged point-symmetrically or line-symmetrically so as to have a vertex at the center X, and the two triangles and the area of the other part are displayed in different colors.

  According to this index, when calculating the barycentric coordinates by graphing the index, the barycentric coordinates can be obtained by analyzing the linear function because the intersection coordinates of the linear diagram as shown in FIG. 3 are obtained. Therefore, errors are less likely to occur than when the barycentric coordinates are obtained by analysis of a higher order function, and the barycentric coordinates can be calculated with high accuracy by an easy calculation formula.

  In addition, the index 10A of the present embodiment is set to a shooting range according to the distance between the imaging device 30 and the target 10. Specifically, when the distance between the imaging device 30 and the target 10 is short, the frame 10b shown in FIG. 2 is set as a range to be analyzed, and when the distance between the imaging device 30 and the target 10 is far, FIG. The frame 10c shown is set as a range to be analyzed.

  Therefore, it is possible to secure a predetermined number of pixels even when the distance between the imaging device 30 and the index 10A is increased as in the conventional case, and it is possible to use one index without changing the size of the target 10 (index). The barycentric coordinates can be calculated with high accuracy.

  In addition, since the index of the present embodiment is calculated by graphing the average value of gradation values, it is not necessary to set a threshold value for determining a black and white boundary.

(About indicator accuracy)
Table 1 shows the results of accuracy measurement when the index 10A used in the present embodiment is displaced indoors while changing the shooting distance.

  The measurement in Table 1 shows that when the shooting distance is 5 m and 10 m indoors, the target 10 is displaced in the range of 1 to 10 mm, and the displacement is measured from the captured image by photographing with the imaging device 30 for each displacement. Went. From Table 1, the average measurement error of the index of the present invention was 0.019 (mm) when the shooting distance was 5 m, and -0.007 (mm) when the shooting distance was 10 m. From this result, it can be seen that the error can be reduced to about 1/50 or less by using the index of the present invention.

  Table 2 shows the results of accuracy measurement when the index 10A used in the present embodiment was displaced outdoors while changing the shooting distance.

  The measurement in Table 2 shows that when the shooting distance is changed in the range of 5 to 30 m outdoors, the target is displaced in the range of 1 to 10 mm, and the image is taken by the imaging device 30 for each displacement. The error of the displacement amount was measured, and the minimum value, maximum value, and average value were measured. According to Table 2, the average measurement error of the index of the present invention was within approximately 1/50. From this result, it can be seen that an error tends to occur usually when the ambient brightness is dark or the shooting distance is long, but in the present invention, it is difficult to be influenced by the ambient brightness and the shooting distance.

(Configuration of displacement measuring device)
Next, a displacement measuring device (hereinafter referred to as “measuring device 1”) for carrying out the displacement measuring method will be described with reference to FIGS.

  As an example, the measurement apparatus 1 of the present embodiment shows an embodiment in which a bridge 2 as shown in FIG. 1 is applied as a measurement object, but is not limited to this embodiment. It can be applied to large structures such as highways. In the following description, as shown in FIG. 1, the bridge 2 has an abutment 5 in which the upper end is flush with the road surface 4 as an example, and the bridge girder 7 is placed via the support body 6. It shall be. Further, in the present embodiment, the road surface 4 and the support body 6 are described as positions where the displacement hardly occurs (does not displace) (fixed portions), and positions where the bridge girder 7 is displaced (variable portions).

  As shown in FIGS. 1 and 4, the measurement apparatus 1 of the present embodiment includes a target 10 disposed on a bridge girder 7 of a bridge 2, an imaging device 30 that captures the target 10, and captured image data. And a processing device 50 for analyzing the amount of deflection (displacement) generated in the bridge (bridge girder) during static loading.

  As shown in FIG. 1, a plurality of targets 10 are installed in the variable part, and the imaging device 30 is installed in the fixed part. In the illustrated example, a plurality of targets 10 are arranged on a straight line with an appropriate interval. However, as shown in FIG. 1B, the targets 10 are arranged so as to be included in the angle of view of the imaging device 30. In particular, it is not limited to this embodiment. Specifically, in the present embodiment, as shown in FIG. 1B, the imaging device 30 is shifted laterally and the target 10 is photographed from an oblique direction. However, the imaging device 30 is arranged on a straight line in which the targets 10 are arranged. Then, each target 10 may be shifted in the height direction or the left and right (lateral) direction so that each target 10 is included within the angle of view of the imaging device 30.

  Since a plurality of targets 10 can be photographed by one imaging device 30 by including a plurality of targets 10 within the angle of view of the imaging device 30 in this way, equipment and equipment for measurement are used. Can be installed easily, and work efficiency can be improved and costs can be reduced.

  As shown in FIG. 5, the target 10 includes a display device 11 on which an index 10 </ b> A serving as a mark is displayed, and an irradiation device 17 that irradiates the index 10 </ b> A with light, and the display device 11 and the irradiation device 17 are integrated. Configured.

  The display device 11 includes a base 12 that is fixed to the ground, two standing bodies 13 that are mounted on the base 12 and are erected in parallel, and are stretched over the two standing bodies 13 in the vertical direction. A bracket 14 slidably attached to the frame 14 and a display body 16 attached to a frame 15 erected from the bracket 14. The frame 15 is attached to the bracket 14 so as to be rotatable about the vertical axis, and the display body 16 can be appropriately rotated and adjusted about the vertical axis.

  Thus, the display device 11 can be adjusted to face the imaging device 30 because the display body 16 can be adjusted in the vertical direction and can be rotated about the vertical axis.

  Although not shown, the base 12 has a plurality of holes, and a fixture such as an anchor is inserted into the holes and installed on the ground such as asphalt or concrete. In addition, screws with a head and a shaft are attached to the four corners of the base 12, and the level of the base is adjusted by adjusting the amount of protrusion from the base bottom of the shaft of the left and right screws. Is done.

  The display body 16 has, for example, an index 10A displayed on the surface of the light shielding plate 16a formed of an impermeable material. The index 10A is a peripheral point around the center X as shown in FIG. The density is displayed so as to change gradually.

  Specifically, for example, as shown in FIG. 2, the index 10A is arranged such that two triangles are arranged point-symmetrically or in a line object with a vertex at the center X, the two triangles are displayed as black, The part is displayed in white.

  Note that the display form of the index is not limited to the above-described embodiment. For example, an area is divided by oblique lines of 45 ° and −45 ° so as to pass through an arbitrary center X, and two opposing two The area and the other two opposing areas may be displayed in different colors.

  As described above, the index 10A is displayed so that the surrounding density gradually changes with the center X as a base point, whereby the center coordinates can be easily and accurately calculated from the image data photographed by the imaging device 30.

  A diagonal member 21 extending obliquely downward is rotatably attached to the back surface of the display body 16 via a pivot, and the diagonal member 21 is disposed between the two standing bodies 13 and 13 of the display device 11. It is attached to the rear of the guide 23 to be rotatable through a pivot. Further, an irradiation device 17 is detachably attached to the front of the guide 23 via a bracket (not shown) and is rotatable in the vertical direction, and its direction is adjusted to irradiate the surface of the display body 16 with light. Is possible.

  The movement of the guide 23 in the left-right direction is restricted by the two standing bodies 13, 13 and is movable in the front-rear direction, and moves by adjusting the height of the display body 16. In addition, it is possible to stabilize the display body 16 by moving the guide 23 backward to reduce the tilt angle of the diagonal member 21.

  In this way, the display body 16 is supported by the truss structure formed by the standing body 13, the diagonal member 21, and the guide 23, so that the display body 16 is stabilized, and the rollover of the display body due to wind is prevented.

  Further, two indicators 10A and 10B are displayed on the display body 16 in the vertical direction. The two indicators 10A and 10B may be the same indicator, but as shown in the indicator 10B of the present embodiment, the indicator 10A may have a shape inverted by 90 degrees. And the measuring device 1 of this embodiment can measure the torsion of the abutment 7 by measuring the deviation of the centers of the two indexes 10A and 10B.

  The imaging device 30 uses an optical imaging device such as a digital camera, for example, and photographs and records the indicators 10A and 10B displayed on the target 10 as digital data. Note that the imaging device 30 is not limited to the digital camera, and may be a digital video camera or the like as long as it can record a still image as image data.

  The imaging device 30 includes an optical imaging device 35, a level 36, and a support device 38 that stably supports the optical imaging device 35 and the level 36. As shown in FIG. 6, the support device 38 includes a support body 32 provided with legs 31, 31, 31 extending in at least three directions, and a base 33 placed on the support body 32.

  The base 33 includes a base portion 33a on which the optical imaging device is placed, and an extension portion 33b that is provided at the rear end portion of the base portion 33a and on which a level is placed. It extends and is formed in a substantially T shape in plan view. In addition, in this embodiment, although the extension part 33b is provided integrally with the base part 33a, you may be comprised so that attachment or detachment is possible as needed. The extension 33b has a frame 33c for positioning the level 36, and the level is placed on the frame 33c. On the base, although not shown, the optical imaging device and the level 36 are arranged side by side.

  A leg 34 in contact with the ground is attached to the front end of the base 33, and the optical imaging device and the level are stably supported by the leg 34 and the three legs 31 of the support body 32.

  Moreover, although not shown, the leg 34 is fixed to the ground by a fixing tool such as a P-less anchor, for example, via a fixing bracket.

  The processing device 50 is a device generally called a computer. For example, the processing device 50 acquires image data captured by the imaging device, calculates the center coordinates of the index based on the image data, and images of the abutment before and after the displacement. An analysis processing unit 50a that compares the center coordinates of the data and analyzes the displacement amount and the displacement direction is provided. This computer includes a CPU (Central Processing Unit) having a calculation function, a working RAM (Random Access Memory), a nonvolatile memory, and a ROM (Read Only Memory) for storing various processing programs and data. Each unit is controlled centrally by reading and executing various programs stored in.

  Specifically, for example, the analysis processing unit 50a first acquires the image data of the abutment before and after the displacement photographed by the imaging device, and, as shown in FIG. After obtaining the two linear expressions from the linear diagram obtained by calculating the average value of the gradation values and connecting the points of the values, the intersection of the two linear expressions is calculated, and the calculated intersection is Calculated as the center coordinates of the index.

  Next, a method for measuring the amount of displacement (amount of deflection) generated in the bridge 2 using the measuring device 1 will be described.

  First, preparation is required, and as shown in FIG. 1A, the target 10 is installed at a plurality of positions of the variable portion set by the user, and as shown in FIG. The imaging device 30 is installed on the fixed portion so that the plurality of targets 10 are within the angle of view.

  In addition, the target 10 does not need to be installed in multiple numbers, For example, you may install only in the center position of the bridge 2 estimated that the displacement amount becomes the maximum.

(About target installation)
First, a work space is set on the bridge 2. The work space is preferably a sidewalk part adjacent to the road part as shown in FIG.

  And as shown in FIG. 1, the some target 10 is suitably installed in the upper surface (variation part) of the abutment 7. As shown in FIG. In addition, as illustrated in FIG. 1B, the imaging device 30 is installed on the road upper surface (fixed portion) deviated from the abutment 7 so that the plurality of targets 10 are within the angle of view.

  In addition, the height of the display body 16 is preferably adjusted so that the target is positioned at substantially the same height as the lens surface of the imaging device 30, and the target 10 is positioned relative to the lens surface of the imaging device 30. The orientation of the display body 16 is adjusted so as to face each other. Further, the direction of the irradiation device 17 is adjusted so that the light irradiated from the irradiation device 17 is irradiated onto the index 10A. Further, when the wind is strong, adjustment is performed by moving the guide 23 rearward so that the tilt angle of the diagonal member 21 provided on the back surface of the display body 16 is reduced, thereby stabilizing the display body 16. .

  When the display body 16 is tilted in the left-right direction, the base 12 is adjusted to be horizontal by a horizontal adjustment screw.

(About measurement method)
Next, the index 10A of each target 10 is photographed by the imaging device 30 in the no-load (before displacement) state, and the index 10A of each target 10 is captured by the imaging device 30 in the static loading (after displacement) state. Is filmed. The captured image data is transmitted (output) to the processing device 50 with a predetermined resolution. In addition, as shown in FIG. 3A, these image data are image data expressed by pixels of arbitrary gradations arranged in a lattice shape, and are generally recorded when taken with a digital camera. Is a digital image.

  Next, the processing device 50 calculates the center coordinates of the index 10A from the image data before and after the displacement, and calculates the displacement amount based on the coordinate information.

(About the calculation method of center coordinates)
First, image data before and after displacement is read, and an image of a certain region including the center X of each index 10A is cut out.

  At this time, as shown in FIG. 2, the target 10 close to the imaging device 50 sets a narrow range as the cutout range Y, and the target 10 far from the imaging device 30 sets the wide range as the cutout range Z, By analyzing the image data, the coordinates can be calculated efficiently and accurately.

  Next, as shown in FIG. 3, the intersection coordinates of two linear expressions obtained from the distribution of the average values of the gradation values of the columns or rows of each pixel of the displayed image data are calculated in units of subpixels. This coordinate is used as the center coordinate of the index.

  Specifically, for example, an average of gradation values of sub-pixel columns of image data is graphed as an X-axis value, and a row side of the sub-pixel is graphed as a Y-axis value of each sub-pixel column.

  At this time, the distribution of gradation values is V-shaped as shown in FIG. 3B, and two linear expressions are calculated from this graph, and the intersection coordinates of the two linear expressions are calculated. Is the center coordinate of the index.

(Calculation of displacement (bending amount))
Next, since the center X of the index 10A before and after the displacement moves downward as shown in FIG. 7, the value of the Y-axis of the intersection coordinates of each target before and after the displacement is read, the difference is calculated, and the value Is a displacement amount (amount of deflection).

  Further, when the abutment 7 is twisted, the position of the center X of the indices 10A and 10B before and after the displacement is shifted as shown in FIG. 8, so the intersection (center) coordinates of the indices 10A and 10B are calculated and the displacement is calculated. It is also possible to calculate the amount of twist by reading the values of the X and Y axes of the front and rear intersection coordinates and calculating the difference between the coordinates.

  As described above, the measuring device 1 according to the present embodiment includes the targets 10 arranged at different positions of the bridge 2, the imaging device 30 arranged at the fixed portion, and the displacement photographed by the imaging device 30. And a processing device 50 that measures the displacement amount of the bridge 2 from the center coordinates of the index 10A before and after displacement analyzed based on the density distribution of the image data of the index 10A displayed on the front and rear targets 10. Further, the center coordinates of the index 10A are calculated from a diagram obtained by graphing the average value of the gradation values of the pixels in each row or each column of the image data. Further, the index 10A displayed on the target 10 is one in which the surrounding density gradually changes with the center X as a base point. Specifically, the index 10A has a vertex at the center X. Two triangles are arranged point-symmetrically or line-symmetrically, and the two triangles and other regions are displayed in different colors.

  According to the measuring apparatus 1 configured as described above, since the center coordinates can be accurately measured, the displacement amount can be accurately measured. Further, even if the illuminance changes, the measurement accuracy is not greatly affected. In addition, it can be adapted to low temperature and high temperature environments without being affected by outside air temperature. Further, since the displacement of the structure can be measured in a non-contact manner, a scaffold is unnecessary, and work efficiency can be improved and costs can be reduced.

  The imaging device 30 is arranged so that a plurality of targets 10 are included within the angle of view. Therefore, since a plurality of targets 10 can be photographed with one imaging device 30, it is excellent in economic efficiency.

  In addition, two indicators 10A and 10B are arranged side by side in the vertical direction, and the twist of the bridge 2 can be measured by measuring the deviation of the centers of the two indicators 10A and 10B.

  Moreover, the irradiation apparatus 17 which irradiates light to the parameter | index 10A is provided, and it is possible to measure the displacement in the bridge 2 at night.

  Further, the display body 16 is movable in the vertical direction and can be rotated around the vertical axis, and the index 10A can be arranged so as to face the imaging device 30. Can be taken.

(Other examples)
Next, another embodiment of the displacement measuring method will be described.

  The displacement measurement method described above is a method for measuring the displacement of a bridge, but it is possible to measure the displacement of a building other than a bridge, for example, an arbitrary portion of a structure other than a bridge. .

  Specifically, the displacement of the building can be easily measured by placing the target 10 having the index 10A on the pillars provided on the left and right of the building and comparing the barycentric coordinates of the respective indexes 10A. . Specifically, the amount of strain in the horizontal direction can be measured by the displacement of the X coordinate of the center of gravity coordinate of the left and right index 10A, and the amount of strain due to torsion can be measured by the displacement of the Y coordinate of the center of gravity coordinate of the left and right index 10A. is there.

  Moreover, when measuring the deformation | transformation of arbitrary places, the displacement, rotation, a twist, etc. of various directions can be measured especially by arrange | positioning the parameter | index 10A continuously in the same direction (vertical or horizontal direction). Is possible.

  Further, regarding the installation of the target, in the above-described embodiment, as shown in FIG. 1, the target 10 is appropriately installed only on the upper surface (variable portion) of the abutment 7, but the road upper surface (fixed portion) that is out of the abutment 7. Although a plurality of targets 10 are arranged, a target (hereinafter referred to as “fixed target”) is installed at a position (fixed portion) where the road surface 4 and the support body 6 are less likely to be displaced (not displaced) (hereinafter referred to as “fixed target”). By arranging this fixed target so as to be included in the angle of view of the imaging device 30 together with the other target 10, when the imaging device 30 is removed and re-installed, the coordinates of the fixed target installed in the fixing unit are also obtained. In addition, it is possible to correct the coordinates of the image data.

  In addition, when measuring displacement from image data captured by an imaging device, the coordinates are first measured in units of pixels, and then multiplied by the pixel size to convert to actual units (mm), so it is necessary to calculate the pixel size. is there. The pixel size calculation method will be described below.

  First, for the index 10A, as shown in FIG. 10 (a), the pixel size can be calculated easily and accurately by displaying parallel lines 70 indicating the reference positions A and B representing the range of the triangle in the vertical direction. It becomes possible. Specifically, the distance between A and B is previously stored in the storage unit of the processing device 50, and the number of pixels between A and B of the image data captured by the imaging device 30 is calculated by the processing device 50. The pixel size is calculated based on the distance between A and B and the number of pixels.

  As another pixel size calculation method, as shown in FIG. 10 (b), the index 10A is arranged in the vertical direction, and the center coordinates C and D of the two indices 10A are connected to each other. The distance between them is stored in the storage unit of the processing device 50 in advance. Next, based on the image data photographed by the imaging device 30, the center coordinates of the two indices 10A are calculated from the linear diagram, the number of pixels between C and D is calculated by the processing device 50, and between these CDs. Calculate pixel size based on distance and number of pixels.

  In addition, this embodiment is one form and is not limited to this form. For example, in this embodiment, the average value of the gradation values of the pixels in each row of the image data is obtained and graphed. However, the average value of the gradation values of the pixels in each column of the image data may be obtained and graphed. I do not care. Further, an average value of gradation values of pixels in each row and each column of image data may be obtained and graphed.

  In addition, the target 10 of the present embodiment integrally configures the display device 11 and the irradiation device 17, but may be separate, and the irradiation device 17 is not an essential component.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Bridge 10 Target 10A Index 30 Imaging apparatus 50 Processing apparatus

Claims (11)

  A target is arranged in a plurality of variable parts having different structures, an optical imaging device for photographing the target is arranged in a fixed part, the target before and after the displacement of the structure is photographed, and image data of each target is captured. A displacement measurement method characterized in that the displacement amount of the structure is measured from the center coordinates of the target before and after displacement analyzed based on the concentration distribution. A target arranged in a plurality of variable parts of different structures;
An optical imaging device disposed in the fixed portion;
A processing device that measures the amount of displacement of the structure from the center coordinates of the target before and after displacement analyzed based on the density distribution of the image data of the target before and after displacement imaged by the optical imaging device;
Displacement measuring device characterized by comprising.   The displacement measuring device according to claim 2, wherein the optical imaging device is arranged so that a plurality of the targets are included within an angle of view.   The said processing apparatus calculates the said center coordinate from the diagram obtained by graphing the average value of the gradation value of the pixel of each row or each column of the said image data, or Claim 2 characterized by the above-mentioned. Item 4. The displacement measuring device according to Item 3.   5. The displacement measuring apparatus according to claim 2, wherein the target is an index in which a surrounding density gradually changes with a center as a base point. 6.   The index is characterized in that two triangles are arranged point-symmetrically or line-symmetrically so as to have a vertex at the center, and the two triangles and areas of other parts are displayed in different colors. 5. The displacement measuring device according to 5.   The displacement measuring device according to claim 5 or 6, wherein two of the indexes are arranged side by side in the vertical direction.   The displacement measuring apparatus according to claim 2, wherein an irradiation body that irradiates the target with light is provided.   The displacement measuring apparatus according to claim 2, wherein the target is movable in a vertical direction and is rotatable about a vertical axis. A support device for supporting the optical imaging device;
The displacement measuring device according to any one of claims 2 to 9, wherein the support device includes a base on which a level can be arranged side by side with the optical imaging device. The optical imaging device is:
An imaging device for capturing video data,
The displacement measurement apparatus according to any one of claims 2 to 10, wherein the image data is a still image cut out in time series from moving image data.

Images