JP6563723B2 - Long member position measurement method - Google Patents

Description

  The present invention relates to a long member position measuring method capable of efficiently measuring a position when a long member is arranged in the axial direction and comparing it with a planned design arrangement position.

  When constructing a concrete structure, reinforcing bars and tendons are placed in the formwork, and concrete is placed to embed them. The tendon is placed to introduce prestress into the concrete. If it is not placed at the position determined by the design, the amount of prestress introduced into the concrete will be different from the design value. End up. Further, if the reinforcing bars are not arranged at a predetermined position and are embedded at a position close to the surface of the concrete member, corrosion occurs early and the durability of the concrete structure is impaired. For this reason, after arranging a tension material and a reinforcing bar in the assembled formwork, these positions are measured, and after confirming that it has been arranged correctly, concrete is laid.

  As a method of measuring the position of the tendon and the reinforcing bar, it is generally performed to measure the position with respect to the mold by applying a scale. In Patent Document 1, the position of the reinforcing bar is measured using a three-dimensional laser scanner. A method of measuring is proposed.

JP 2010-14669 A

  However, it takes a lot of work time to measure by applying a scale to each of the tendon and rebar. Further, much more work is required for plotting the measured results in comparison with the planned planned arrangement positions. On the other hand, even in the method using a three-dimensional laser scanner as described in Patent Document 1, the measurement time becomes long and the degree of recognition by the laser is limited depending on the situation of the measurement site, and the accuracy is not sufficient.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a long member position measuring method capable of efficiently measuring and plotting the position of a member long in the axial direction. And

In order to solve the above-described problem, the invention according to claim 1 includes a step of installing a plurality of reference points in the vicinity of a position where a long member having a predetermined length is arranged in the central axis direction in substantially the same cross section. Photographing the image from two different positions so as to capture at least three points that are known to be separated from each other as the reference point and the elongated member, and the image captured in the captured image. Identifying a relative positional relationship between each imaging position and the reference point from the position of the reference point on the image, and a relative position between the plurality of positions on the surface of the long member and the imaging position. the positional relationship, a step of calculating from said two images, along the central axis line position of the center axis of the long long members based on the cross-sectional shape of the plurality of positions and the long long member in the calculated said surface Calculating at a plurality of positions Provided is a method for measuring the position of a long member.

  In this method, the relative positional relationship between the reference point and the photographing position is specified from the positional relationship between the image in which the reference point is imprinted and three or more reference points. Then, the relative positional relationship between the surface of the long member arranged and the photographing position is determined from a plurality of positions along the axial direction of the long member and the circumference by a three-dimensional photo measurement method from the two images. It is specified at a number of positions along the direction. If the shape of the long member is known, the position of the central axis can be estimated by calculation based on the position specified for the surface.

  According to a second aspect of the present invention, in the long member position measuring method according to the first aspect, the two different positions where the image is taken are separated in a direction along a straight line connecting both ends of the long member. Shall.

  In this method, it becomes easy to specify the same point from two images for a member that is long in the axial direction, and the position can be specified accurately.

  The invention according to claim 3 is the position measuring method of the long member according to claim 1 or claim 2, wherein the long member is arranged so that the cross section is circular and is long in the horizontal direction. The two different positions for photographing the image are positions where the long member is photographed obliquely from above, and the step of calculating the position of the central axis is performed at a plurality of points along the circumferential direction of the long member. Calculating the position of the apex in the circumferential direction of the elongate member at a plurality of positions from the position information along the axial direction of the elongate member, and calculating the position of the central axis of the elongate member from the position of the apex; To do.

In this method, the circumferential apex of the long member arranged long in the horizontal direction can be photographed from two different positions. Therefore, the position of the apex in the circumferential direction is included in the range in which the position of the surface is specified. Then, by setting the vertical direction in the captured image, the position of the apex in the circumferential direction can be specified at each position along the axial direction, and the position of the central axis is determined from the cross-sectional shape of the long member. Can be identified.
In the present invention, the long member arranged long in the horizontal direction may have a slight gradient between both ends, or the gradient may change.

  The invention according to claim 4 is the position measurement method for the long member according to claim 1 or 2, wherein the step of calculating the position of the central axis includes a plurality of steps along the circumferential direction of the long member. A step of superimposing the cross-sectional shape of the long member known in advance on the position of the point and extracting the position having the highest correlation is included.

  In this method, an area facing the camera to be photographed is imprinted on the surface of the long member, and the position of this area is specified. In other words, the position is specified for only a part of the long member in the circumferential direction, that is, a part of the cross-section, but the cross-sectional shape of the long member is compared, and the position of the peripheral surface and the cross-sectional outline overlap best. By finding the position, the position of the long member, that is, the position of the central axis can be specified.

  According to a fifth aspect of the present invention, in the long member position measuring method according to any one of the first to fourth aspects, the calculated position of the central axis is compared with the planned arrangement position of the long member. And a step of plotting and displaying.

  In this method, the calculated position of the central axis of the long member is overlapped with a preset planned arrangement position of the long member and compared, and the long member is positioned accurately by plotting this. It can be easily determined whether or not it is arranged. Further, the position where such a long member is arranged can be easily illustrated, and it becomes easy to leave the position where the long member is arranged as a record.

  According to a sixth aspect of the present invention, in the method for measuring the position of the elongated member according to the fifth aspect, the step of comparing the calculated position of the central axis and the planned arrangement position is a line indicating the planned arrangement position. And the point corresponding to the comparison reference position on the central axis calculated from the two images or the point corresponding to the comparison reference position estimated by extending the central axis. It is assumed that both positions are compared over the entire length.

  In this method, the position of the central axis of the long member at the planned arrangement position and the position of the central axis specified from the two images can be easily overlapped with a unified coordinate system. And even when a long member is not image | photographed over the full length of predetermined length, both positional relationship can be compared and illustrated.

  According to a seventh aspect of the present invention, in the method for measuring a position of the long member according to any one of the first to sixth aspects, the step of installing the reference point includes each of three linear bar-shaped scales. It is assumed that a reference frame coupled so as to be at right angles to other bar-shaped scales is disposed, and a plurality of reference points are provided on each of the bar-shaped scales of the reference frame.

  In this method, it is possible to accurately identify the same reference point in both images by photographing the reference frame placed in the vicinity of the long member from two positions. Further, since the bar-shaped scale extends in three directions perpendicular to each other, the relative positional relationship between the reference point and the photographing position can be accurately calculated.

  The invention which concerns on Claim 8 WHEREIN: In the position measuring method of the elongate member of Claim 5, a reference coordinate is set to the position vicinity of the said elongate member, The plan arrangement position of the said elongate member is The step of setting the reference point shall be specified at the position where the coordinate value on the reference coordinate is specified.

  In this method, the position of the reference point is specified on the reference coordinates, and the position of the surface of the long member and the position of the central axis specified from the captured position and the captured image are expressed as coordinate values on the reference coordinates. Can show. Further, the planned arrangement position of the long member is also expressed based on the reference coordinates, and the position of the central axis of the long member obtained from the photographed image and the planned arrangement position can be easily and accurately compared. It becomes possible.

  As described above, in the long member position measuring method according to the present invention, the position of a member long in the axial direction can be efficiently measured and illustrated.

It is a schematic perspective view which shows an example of the condition when implementing the position measuring method of the elongate member which concerns on this invention. FIG. 3 is a front view, a side view, a top view, and a bottom view of a reference frame that can be used to implement the position measuring method for a long member according to the present invention. FIG. 3 is a schematic perspective view of a reference frame shown in FIG. 2. It is the schematic which shows the principle which pinpoints the position of the measuring object imprinted in these images from two images image | photographed in two different positions. It is a figure which shows the outline of operation which pinpoints the same point on two images image | photographed in two different positions. It is the schematic which shows the example of the coordinate system which can be set when pinpointing the state which installed the reference | standard frame shown in FIG. 2, and the position of an elongate member. It is the schematic which shows the example of the method of pinpointing the position of the center axis line of a long member. It is the schematic for demonstrating an example of the method of superimposing the plan arrangement position of a long member, and the position of the center axis line of the long member calculated from two images. It is the schematic which shows an example of the figure which contrasts the plan arrangement position of a long member, and the position of the center axis line of the long member calculated from two images. It is the schematic which shows the example which illustrated the position of the elongate member calculated from two images. It is the schematic which shows the example of arrangement | positioning of a digital camera when the long member to measure is long. It is a schematic perspective view which shows the other example of the condition when implementing the position measuring method of the elongate member which concerns on this invention. It is an elevation view which shows the reference | standard scale and long member which were arrange | positioned. It is a schematic side view which shows a reference | standard scale and the supporting member which supports this. It is a front view which shows an example of arrangement | positioning with a reference | standard scale and a elongate member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view showing an example of a situation when the long member position measuring method according to the present invention is carried out.
In this example, the present invention is applied to measure and plot the position of a tension member 3 embedded in a concrete floor slab 2 of a bridge girder 1 before placing concrete, and a plurality of tension members Two digital cameras 4a and 4b for photographing a range where concrete is placed by placing 3 and reference frames 5 installed at two locations along one tendon for which the position is to be measured are used.

The tendon 3 is arranged on the floor slab portion of the bridge girder 1 having a concrete box-shaped cross section as shown in FIG. Concrete is placed for each construction block divided by a predetermined length in the axial direction of the bridge girder 1. After assembling the form 7 for one construction block, the tension embedded in the concrete in this form A material 3 or a reinforcing bar (not shown) is arranged. And the position of the tension material 3 arrange | positioned before placing concrete is measured.
The tendon 3 is arranged in a direction substantially perpendicular to the axis of the bridge girder 1, arranged in the vertical direction at the highest position on the web, and arranged so as to be bent downward slightly between the webs. The

  It is desirable that the digital cameras 4a and 4b have a small distortion of the lens and a light beam that has passed through the center of the lens is accurately imaged on the light receiving surface of the image sensor, and outputs image data detected by the image sensor to the computer. Use what you can. It is preferable to use a lens in which the focal length of the lens is accurately measured, the optical axis and the light receiving surface are orthogonal, and the position of the optical axis on the light receiving surface is accurately measured.

  As shown in FIGS. 2 and 3, the reference frame 5 is formed by joining three bar-shaped scales 5a, 5b, 5c having a rectangular cross section so as to be perpendicular to each other. , 5b, 5c, that is, a reference point 6 is provided at a corner portion of the cross section of the bar-like scale. The reference points 6 are provided at a plurality of positions in the axial direction of the respective bar-shaped scales 5a, 5b, 5c, and the relative positional relationship between all the reference points 6 is accurately measured. These reference points 6 can be, for example, two triangles drawn on the side of a bar-shaped scale so that the apex is abutted on the ridgeline, and those drawn with paint or printed stickers Attached ones can be used. In addition, other types of reference points may be used as long as they are provided so that they can be easily specified in a captured image.

  Digital data of images taken by the digital cameras 4a and 4b is input to a computer (not shown), and the computer displays an image on a display device (not shown) and a reference on the image displayed on the display device. Specifying the point, the position of the reference point specified by the photogrammetry or three-dimensional photo measurement method, and the distance between the actual reference point and the position taken by the digital camera Specifying the relative positional relationship, specifying the same point from images taken at two different positions, specifying the position of the same point from the position where the same point in the two images is imprinted, etc. It is possible to perform the operation. Also, it is set so that the position of the tendon specified from the two images can be displayed on the display device, the position of the specified tendon can be displayed on the display device in contrast to the planned arrangement position, etc. Yes.

Next, steps when the long member position measuring method according to the present invention is implemented using the digital cameras 4a and 4b, the reference frame 5, and the like will be described.
The digital cameras 4a and 4b are arranged so that the floor slab portion on which the tension material is arranged can be photographed obliquely from above. For example, as shown in FIG. 1, when placing concrete sequentially for each construction block, it can be installed on a portion 1a where concrete has been previously placed. It is desirable that the two digital cameras 4a and 4b are set at substantially the same height, and are arranged side by side along the substantially axial direction of the disposed tendon 3. And it is good to set a mutual space | interval to about 0.5m-1.5m.

  As shown in FIG. 1, a plurality of reference point frames 5 are installed in a range where the tendon 3 is placed and concrete is placed. The reference point frame 5 can be installed at an arbitrary position within a range that can be photographed with a digital camera. However, two reference point frames 5 are installed at a position along one tension material 3a. desirable. Three or more reference point frames may be installed. Each reference point frame 5 is preferably installed such that the two bar-like scales 5a and 5b coupled so as to be perpendicular to each other are substantially horizontal and the one 5c is substantially vertical. After installing a plurality of reference point frames 5, the distance between the reference points of different reference point frames can be measured by a scale or the like. By measuring the distance between the reference point frames as described above, it is possible to specify the shooting position by the digital cameras 4a and 4b and to improve the accuracy when the position of the tendon 3 is specified. In addition to installing the reference point frame 5, it is possible to increase the accuracy by arranging a scale, a scale, etc., whose dimensions can be clearly read so that they can be captured by a digital camera.

  When the installation of the reference frame 5 is completed, the range in which the tendon material is disposed is photographed by the two digital cameras 4a and 4b. The photographed image data is input to a computer, and the relative positional relationship between the photographing position by the digital cameras 4a and 4b and the reference point is calculated from the position of the reference point 6 imprinted in the image, and further, two images are obtained. About the tension material 3 imprinted, the position in a three-dimensional space is calculated about several points on the surface.

These calculation methods use a method known as photogrammetry or photo measurement. From an image in which a reference point 6 whose distance between them is known is imprinted, the reference point 6 is displayed on the image. Specify the imprinted position. The photographing positions by the digital cameras 4a and 4b are specified from the angle formed with the optical axis when these reference points 6 are photographed. Then, the same point on the two images is specified, and as shown in FIG. 4, the position in the three-dimensional space is specified from the position where this point is imprinted on each image.
At this time, the shooting position by the digital cameras 4a and 4b and the position of the reference point 6 can specify a three-dimensional coordinate in a coordinate system set based on the shooting position as shown in FIG. Further, as will be described later, it is also possible to display with three-dimensional coordinates converted into a coordinate system set based on the measurement object.

The step of identifying the same point on the two captured images can be performed as follows, for example.
A partial range is extracted from one of the two images with a low resolution, and this is used as a template T ₁ to scan the other image P as shown in FIG. Then, the correlation between the images is calculated while sequentially moving the positions, and the position where the correlation value reaches a peak is set as the same point between the two images. Next, the resolution of the image is increased, and a part is further extracted from the range previously extracted as the template T ₁ to be the template T _2, and within the range t ₁ where the correlation value is peaked with the resolution being low, The other image is scanned as shown in FIG. Then, the correlation between the images is calculated while sequentially moving the positions, and the position where the correlation value reaches a peak is set as the same point between the two images. By repeating such an operation, the same point on the two images is specified for each block of a predetermined size at a large number of axial and circumferential positions on the surface of the tendon 3.

The template T is desirably corrected according to the angle at which the image is taken, as shown in FIG. Images taken from two different positions are taken with the shape distorted even in the same part due to the difference in the angle of photography. For this reason, if a part is taken out from the image as it is photographed and used as the template T ₀ , the correlation value becomes small. Therefore, correction according to the angle at which the image was taken is performed.
Moreover, in order to make it easy to specify the same point from two images by the above scanning, a pattern or a mark that is a characteristic of each part may be attached to the surface of the tendon material 3. Thereby, the characteristic of each position on the surface of the tendon 3 becomes clear, and the identification of the same point becomes easy.

  When the same point on the surface of the tendon 3 is specified on the two images as described above, the position in the three-dimensional space is specified from the position where this point is imprinted on the two images. Then, the position of the central axis of the tendon 3 is calculated from the coordinates of many positions specified on the surface of the tendon 3. In this calculation, it is desirable to set a coordinate system based on the direction in which the tendon is arranged. For example, as shown in FIG. 6, a line connecting the reference points 6a provided on the bar-like scale 5c that is substantially vertical of the two reference point frames 5 arranged along one tension member 3a is set on the X axis. The direction of the bar-like scale 5c arranged almost vertically is taken as the Y axis. Then, the Z axis is set in a direction perpendicular to these. In the coordinate system set in this way, the position of the central axis of the tendon 3 can be calculated as follows.

  Since each tendon is photographed obliquely from above by the two digital cameras 4a and 4b, the top of the tendon having a circular cross section is photographed as shown in FIG. When coordinate values are calculated at a plurality of positions in the circumferential direction, as shown in FIG. 7B, the values in the Y direction are compared for a plurality of points D having substantially the same coordinate value in the X direction. Let the point which becomes the maximum be the position of the apex A of the tendon material in the said X value. The cross-sectional shape of the tendon is known in advance and has a circular shape with a radius of r. Therefore, the position of the central axis is a point Q at which the coordinate value in the Y direction is lower than the vertex A by r, that is, the coordinate value in the Y direction is smaller by r. Thus, the position of the central axis of the tendon 3 can be calculated by sequentially calculating the position of the central axis at a number of positions with different X coordinates and connecting these points.

  Also, the calculation of the position of the central axis can be performed as follows. As shown in FIG. 7C, a plurality of points D having the same coordinate value in the X direction are extracted, and a circle C having a radius r corresponding to the cross section of the tendon 3 is superimposed. Then, scanning the circle C to calculate the amount that the plurality of points D deviate from the circle C, and estimating the position Q of the central axis with the position where the amount is minimized as the position of the tendon 3 it can.

When the position of the central axis of the tendon 3 is thus calculated, this is compared with the planned arrangement position of the tendon 3. This comparison can be performed as follows.
The tendon 3 is often difficult to shoot over the entire length with the two digital cameras 4a and 4b. In particular, at both ends, when the fixing tool 8 is attached to the tendon 3 and the fixing tool 8 is fixed to the mold 7, the ends of the tendon cannot be photographed, and both ends of the tendon are photographed. It is difficult to specify from the image. In such a case, the positions of both ends of the tendon 3 are estimated by complementing from the range in which the position of the central axis is calculated based on the two captured images. FIG. 8A is an elevational view showing the planned placement position of the tendon 3, and for the tendon 3 to be placed in this way, the position of the central axis identified by calculation from two images is FIG. As shown in b), the position data at both ends are missing. With respect to the calculated data, the positions E of both ends of the tendon 3 are estimated so as to coincide with the designed length L, that is, the total length becomes L shown in FIG. For example, a point where the same length L ″ is extended on both sides of the central axis from the range L ′ where the position of the central axis is calculated and the total length is L can be estimated as both ends E.

  Also, as shown in FIG. 8 (a), a mark was attached to a position M at a distance Lm measured from one end of the placed tendon, and the photograph was taken as shown in FIG. 8 (c). It is also possible to specify the position M with the mark from the image and extend the length Lm from this position to estimate the position of the end E of the tendon.

When the coordinates of both ends E are specified as described above, the measured position of the tendon is overlapped with the planned arrangement position and compared. The comparison can be performed by unifying the coordinate system and superposing both ends of the tendon as the comparison reference positions. When the tendon 3 is arranged, the formwork 7 is accurately measured and assembled at the design position, and the portion for fixing the end of the arranged tendon 3 is also accurately measured and set. Yes. For this reason, it can be considered that the both ends of the arranged tendon 3 are arrange | positioned correctly.
In addition, when attaching a mark to the tendon 3, it is also possible to superimpose the marked position as a comparison reference position.

  When the measured position of the tendon is plotted against the planned arrangement position, it is as shown in FIG. 9, and the relationship between the amount of the measured tendon position deviating from the planned arrangement position and the management value is shown. It can be displayed over the entire length of the tendon. That is, when the error of the allowable arrangement position is 5 mm, it can be clearly displayed whether or not the arrangement position of the tendon measured with respect to the management value is within the allowable range.

  Moreover, the position where the tendon 3 is actually arranged can be illustrated and displayed. FIG. 10A shows an arrangement position in the axial direction for each of the arranged tendons 3 and can be displayed as a height from the formwork. When the mold 7 is assembled, the position and height are accurately measured and set, and the positions of both ends of the tendon 3 estimated by the calculation are superimposed on predetermined positions of the mold 7 in the design. Thus, the position of the tendon 3 relative to the mold 7 can be specified over the entire length of the tendon 3 and displayed as shown in FIG. Moreover, as shown in FIG.10 (b), the position of the tendon measured by the predetermined position of the axial direction about the some tendon 3 can also be displayed.

In the embodiment described above, the tension material 3 to be subjected to position measurement is photographed by the two digital cameras 4a and 4b. However, the tension material 3 is long and the two installed digital cameras 4a and 4b are used. When the full length cannot be photographed, as shown in FIG. 11, an image over the full length can be photographed by using a plurality of digital cameras 4 and 4 ′ as a set of two digital cameras. At this time, the relative positional relationship between a plurality of sets of digital cameras 4 and 4 ′ is specified by photographing a common reference point frame 5-1 by two adjacent sets of digital cameras 4 and 4 ′. Measurement data over the entire length of the tendon 3 can be obtained.
Note that the plurality of sets of digital cameras 4 and 4 ′ may sequentially convert one set of digital cameras 4.

FIG. 12 is a schematic perspective view showing another example of the situation when the long member position measuring method according to the present invention is carried out.
In this example, the position of the tension material 3 embedded in the concrete floor slab 2 of the bridge girder 1 is measured before placing concrete as in the example shown in FIG. 1, and similarly, the two digital cameras 4a and 4b are measured. Use to capture the measurement object. At this time, in this example, the reference point to be copied together with the measurement object is different from the example shown in FIG.

  In this example, the reference point is set based on reference coordinates set in advance at the site. That is, the reference coordinates are set at the site where the measurement object is arranged, and the coordinate values of the reference points are known on the reference coordinates. The reference points are set by installing a plurality of reference scales 11 with reference point indications as shown in FIG. These reference scales 11 are installed in the vicinity of both ends and the center point in the axial direction of the tension material 3 to be measured so that the reference points are at predetermined positions on the reference coordinates.

  For example, as shown in FIG. 12 and FIG. 13, the reference coordinates are set in the direction along the upper surface of the bridge girder 1 in the direction perpendicular to the axis of the bridge girder 1 with the side edge on the upper surface of the bridge girder where concrete is newly placed as the origin O. The X axis can be set. The Y axis can be set in the vertical direction so as to be perpendicular to the X axis, and the Z axis can be set in the axial direction of the bridge girder 1. In addition, it is desirable that the origin O coincides with the arrangement position of one tendon 3 in the Z-axis direction.

  As shown in FIG. 13, two reference points 12 are provided on a single plate-like reference measure 11 at a predetermined interval. The two reference points 12 are vertically moved by supporting the reference measure 11 in the vertical direction. Shall be arranged. The reference point 12 is obtained by dividing the square into four parts by a vertical line and a horizontal line, and blacking two small squares with which the apex angle is abutted, and setting the position of the apex angle abutted as the reference point 12. Such a reference scale 11 can be set at a predetermined position on preset reference coordinates, for example, by a support member 13 using a magnet as shown in FIG.

The support member 13 includes a base 14 having a built-in magnet and an arm 15 that is supported by the base 14 and has a rating that allows a plurality of rotations.
When the steel mold is used, the base portion 14 can be fixed to the steel mold by a magnet. When the wooden mold 17 is used, a member made of a magnetic material such as an iron plate 16 is used as a base member on the mold. And can be fixed to this. Moreover, the said base member may be mounted on the arrange | positioned reinforcing bar (not shown), and you may adhere to this.
The arm 15 has a first rod-like member 21 whose elevation angle can be changed with respect to the base portion 14 and is joined so as to be able to turn, and a first rotation shaft 22 around the first rod-like member 21. A second rod-like member 23 connected to the second rod-like member 23 and a third rod-like member 25 connected to the second rod-like member 23 so as to be rotatable around the second turning shaft 24. And have. Thereby, the position and angle of the reference | standard scale 11 fixed to the 3rd rod-shaped member 25 can be set arbitrarily. Moreover, in order to set the reference | standard scale 11 vertically, the level 18 is being fixed to the attaching part of the reference | standard scale.

For example, as shown in FIGS. 13 and 15, the reference scale 11 is provided at three distances L1, L2, and L3 in the X direction from the origin so that the lower side of the reference scale 11 coincides with the X axis. Install. Thereby, the reference point 12 is set in a state where the X coordinate and the Y coordinates L4 and L5 are specified. Further, if the origin O coincides with the position of one tendon in the Z-axis direction, the reference point is placed immediately above one tendon 3 as shown in FIG.
The above three places where the reference scale 11 is installed are set near the both ends of the tendon 3 so that the tendon can be clearly captured when the digital camera 4 is photographed, and near the center of the tendon 3 To do.
In this way, when the reference scale 11 is arranged according to the reference coordinates, a lightweight thread, so-called water thread, is stretched from the set origin O along the position of the upper surface of the bridge girder 1 and installed according to the position of this thread. be able to.

  When photographing the reference scale 11 thus arranged and the arranged tension material 3 with the digital camera 4 before placing concrete, the reference scale installed near one end of the tension material 3 as shown in FIG. The first photographing range 31 is photographed by the two digital cameras 4a and 4b so as to photograph 11a and the reference scale 11b disposed at the center in the length direction of the tendon. Then, the second measuring range 32 is displayed on the two digital cameras 4a by copying the reference measure 11c installed near the end on the opposite side and the reference measure 11b arranged at the center in the length direction of the tendon. , 4b.

  Images taken as described above are input to a computer, and the shooting position of the digital camera 4 is specified from the position of the reference point 12 imprinted in each image. Four reference points are imprinted on each photographed image, and each reference point 12 has a specified position on the reference coordinates, and each shooting position is also specified on the reference coordinates. Can do.

  When the shooting positions of the two digital cameras are specified, the same point on the image shot by the two digital cameras 4a and 4b is specified, thereby specifying the position of the same point on the reference coordinates. Can do. Such identification of the same point can be performed in the same manner as in the embodiment described with reference to FIGS. 4 and 5, and the center position of the tension member 3 whose cross-sectional shape is known in advance is also illustrated in FIG. 7. This can be performed in the same manner as the embodiment described based on the above. And in this Embodiment, it can carry out on the reference | standard coordinate which set the specification and plotting of the position of the tendon 3. Further, the position information specified from the image of the first shooting range 31 and the position information specified from the image of the second shooting range 32 are also obtained based on the unified reference coordinates. The position of a series of tendons can be specified over the entire length by being integrated into the figure and plotted.

  The long member position measuring method according to the present invention is not limited to the embodiment described above, and can be implemented with appropriate modifications within the scope of the present invention. For example, the long member to be measured is not limited to the tension material, and can be applied when measuring the position of a member that is long in the axial direction, such as a reinforcing bar or piping. In addition, the shape and dimensions of the reference point frame or the reference scale, and the positions and number of installation can be changed as appropriate.

1: bridge girder, 2: concrete floor slab, 3: tension material, 4: a set of digital cameras, 4a, 4b: respective digital cameras, 5: reference frame, 5a, 5b, 5c: bar scale of the reference frame, 6 : Reference point, 7: Formwork, 8: Fixing tool,
11: Reference scale, 12: Reference point, 13: Support member, 14: Base of support member, 15: Arm of support member, 16: Iron plate, 17: Wooden formwork, 18: Level
21: First rod-shaped member of the arm, 22: Second pivot shaft of the arm, 23: Second rod-shaped member, 24: Second pivot shaft, 25: Third rod-shaped member,
31: First shooting range, 31: Second shooting range,
A: Apex in the cross section of the tendon arranged long in the horizontal direction, C: Circle corresponding to the cross section of the tendon, D: Point on the surface of the tendon where the three-dimensional coordinates are specified, E: Estimated tension The position of the end of the material, P: Image of scanning the template, T: Template, O: The position of the estimated central axis of the tension material, L: Total length of the tension material (design value), L ': Tensile material Length whose position is measured from the image, L ", Lm: Length complemented with tendon, O: Origin of reference coordinates

Claims (8)

A step of installing a plurality of reference points in the vicinity of a position where a long member having a predetermined length is arranged in the central axis direction in substantially the same cross section;
Capturing images from two different positions so as to capture at least three points that are known from each other as the reference point and the elongated member;
Identifying a relative positional relationship between each shooting position and the reference point from a position on the image of the reference point captured in the captured image;
Calculating a relative positional relationship between a plurality of positions on the surface of the elongated member and the photographing position from the two images;
A step of calculating the position of the central axis of the long member at a plurality of positions along the central axis based on the calculated plurality of positions on the surface and the cross-sectional shape of the long member;
A method for measuring the position of a long member.   2. The long member position measuring method according to claim 1, wherein the two different positions at which the image is taken are separated in a direction along a straight line connecting both ends of the long member. The elongate member is arranged so that the cross section is circular and is long in the horizontal direction,
Two different positions for photographing the image are positions where the long member is photographed obliquely from above,
In the step of calculating the position of the central axis, the position of the vertex in the circumferential direction of the long member is determined along the axial direction of the long member from the position information of a plurality of points along the circumferential direction of the long member. 3. The long member position measuring method according to claim 1, wherein calculation is performed at a plurality of positions, and the position of the central axis of the long member is calculated from the position of the apex.   In the step of calculating the position of the central axis, the cross-sectional shape of the long member that is known in advance is superimposed on the positions of a plurality of points along the circumferential direction of the long member, and the position having the highest correlation is obtained. The method for measuring the position of a long member according to claim 1 or 2, further comprising a step of extracting the position.   The long position according to any one of claims 1 to 4, further comprising a step of comparing the calculated position of the central axis line with the planned arrangement position of the long member and displaying it in a diagrammatic manner. Member position measurement method.   The step of comparing the calculated position of the central axis line with the planned arrangement position includes the two comparison reference positions set on the line indicating the planned arrangement position and the central axis line calculated from two images. 6. The point corresponding to the reference position for comparison or the point corresponding to the reference position estimated by extending the central axis is overlapped to compare both positions over the entire length. The method for measuring the position of the long member according to claim 1.   The step of setting the reference point is to dispose a reference frame in which each of the three linear bar-shaped scales is coupled to the other bar-shaped scales at right angles to each other. The position measuring method for a long member according to any one of claims 1 to 6, wherein a plurality of reference points are provided on each. Set reference coordinates near the position where the long member is arranged,
The planned arrangement position of the long member is specified by the reference coordinates,
6. The long member position measuring method according to claim 5, wherein the step of installing the reference point is installed at a position where a coordinate value on the reference coordinate is specified.

Images