Prism attachment

Abstract

To facilitate measurement of an installation position of a sphere target.SOLUTION: A prism mounting fixture according to one embodiment includes: a mounting part to be mounted to a sphere target; a rail part mounted to the mounting part and including a rail having an arc shape; and a prism part including a prism and moving on the rail. The mounting part includes: a rotation part allowing the rail to rotate around an axis passing through a center of the sphere of the sphere target in an arrangement in which the sphere of the sphere target and the arc shape of the rail have a concentric circle while being mounted to the sphere target.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a prism mounting device. [Background technology]

[0002] In recent years, 3D point cloud data measured by 3D (three-dimensional) laser scanners has come to be used for purposes such as progress confirmation and as-built measurement at construction sites, etc. For example, by overlaying a 3D model such as BIM (Building Information Modeling) created according to the site's blueprints with point cloud data measured by a laser scanner, progress confirmation and as-built measurement can be easily performed.

[0003] In addition, in order to obtain point cloud data for a wider area, multiple point cloud data obtained by scanning from multiple positions with a 3D laser scanner are synthesized.In addition, by placing a target within the measurement range and measuring the point cloud data, the accuracy of synthesizing multiple point cloud data can be improved by using the point cloud of the target as a reference.

[0004] In addition, the position of the target is measured accurately using surveying equipment, and the obtained target position is used to align the position of the measured point cloud data with absolute coordinates. Accurate alignment improves the accuracy of overlay with the design model.

[0005] Also, spherical targets are known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-139891 Summary of the Invention [Problem to be solved by the invention]

[0007] Spherical targets include spheres, and can be measured with the same shape no matter where you look at them. Therefore, spherical targets can be installed in various locations on the site, such as on ceilings and walls, without worrying about orientation. However, when accurately measuring the target's position using surveying equipment, it is necessary to install a prism directly facing the surveying equipment at a position that indicates the target's installation location. However, when installing a spherical target on a wall or ceiling, for example, it can be difficult to install a prism directly facing the surveying equipment at a position that indicates the target's installation location. Therefore, the high degree of freedom in installation location of spherical targets can sometimes be hindered by limitations imposed by surveying using surveying equipment.

[0008] In one aspect, the present invention aims to facilitate surveying of the installation position of a spherical target. [Means for solving the problem]

[0009] A prism mounting device according to one embodiment of the present invention is a prism mounting device comprising: a mounting section to be mounted on a spherical target; a rail section attached to the mounting section, the rail section including an arc-shaped rail; and a prism section having a prism and moving on the rail; wherein the mounting section has a rotating section that rotates the rail around an axis passing through the center of the sphere of the spherical target in an arrangement such that the sphere of the spherical target and the arc-shaped rail are concentric when mounted on the spherical target.

[0010] This makes it easier to survey the installation position of the spherical target. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 illustrates a spherical target. [Figure 2] FIG. 10 is a diagram illustrating an example of surveying the installation position of a target. [Figure 3] 1A and 1B are diagrams illustrating a prism mounting tool according to an embodiment. [Figure 4] 10A to 10C are diagrams illustrating an example of movement of the attachment unit according to the embodiment. [Figure 5] 6A to 6C are diagrams illustrating the movement of a prism portion according to an embodiment. [Figure 6] 10A to 10C are diagrams illustrating the movement of a prism mounting fixture according to an embodiment. [Figure 7] 10 is a diagram illustrating an example of the positional relationship between a prism and the center of a sphere of a spherical target. FIG. [Figure 8] FIG. 10 is a diagram illustrating an example in which a spherical target is installed on an oblique wall or the like. [Figure 9] 10A to 10C are diagrams illustrating the movement of a prism in a prism portion of a prism mounting device according to an embodiment. [Figure 10] 10A and 10B are diagrams illustrating an example of an operation flow of measurement using a prism mounting tool according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described in detail with reference to the drawings. Note that the same reference numerals are used to designate corresponding elements in the various drawings.

[0013] As mentioned above, point cloud data measured from multiple locations is overlaid to synthesize point cloud data over a wider area. In this case, synthesis can be difficult using only the point cloud information of the measurement target. For example, when measuring the internal shape of a long tunnel, where similar structures continue continuously over a wide area, there are few distinctive points to use for synthesis, and synthesis may not work well using only the point cloud information of the measurement target.

[0014] Therefore, a target is set at the site, point cloud data is measured using a 3D laser scanner so that the target is included, and multiple point cloud data are synthesized using the target point cloud as a clue. In addition, a spherical target 100 is used as an example of a target used for synthesizing multiple point cloud data.

[0015] 1 is a diagram illustrating a spherical target 100. Fig. 1(a) shows a side view of the spherical target 100. The spherical target 100 includes a target portion 101 and an attachment portion 102.

[0016] The target portion 101 is, for example, a sphere. The mounting portion 102 has, for example, a function or structure for mounting the spherical target 100 to an object. For example, in FIG. 1 , the mounting portion 102 includes a magnet 110, and the spherical target 100 can be mounted by the magnet 110 to metal such as rebar used in a building on-site. Note that the mounting portion 102 is not limited to being mounted by a magnet, and an adhesive such as a socket or a seal may also be used.

[0017] FIG. 1(b) also illustrates a spherical target 100 installed on a wall 150. The spherical target 100 can acquire a point cloud of the same spherical shape for the target portion 101, even when measured from different angles using a 3D laser scanner. For example, as shown in FIG. 1(b), even if the spherical target 100 is installed at an angle, the spherical shape of the target portion 101 remains the same as the shape when viewed from the side in FIG. 1(a). Therefore, when combining multiple point cloud data measured from multiple points, the point cloud of the target portion 101 can be used as a reference. In this way, the spherical target 100 can be installed on a ceiling, wall, or the like at a construction site without worrying about orientation. At construction sites, materials are often placed on the floor, and materials must be transported, making it difficult to install the target on the floor or it may interfere with work. Therefore, a spherical target that can be installed on a ceiling, wall, or the like is highly convenient.

[0018] Furthermore, in order to perform coordinate transformation with higher precision, the installation position of the target is also measured accurately using surveying equipment such as a transit and a total station.

[0019] 2 is a diagram illustrating an example of surveying the installation position of a target. For example, as shown in FIG. 2(a), a spherical target 100 is to be installed at a certain position. In this case, a surveying instrument 202 is installed at a position whose position coordinates on a design drawing have been specified in advance, and the installation position of the spherical target 100 from that position is specified by surveying.

[0020] For example, in order to survey the installation position of the spherical target 100 using the surveying instrument 202, the prism surface of the prism 203 is placed at a position indicating the installation position of the spherical target 100 so as to face the surveying instrument 202 approximately directly, as shown in FIG. 2(b). Note that, as an example, facing directly may mean placing the prism surface of the prism 203 approximately parallel to a plane perpendicular to the optical axis of the surveying instrument 202. Furthermore, the position indicating the installation position of the spherical target 100 is, for example, the center position of the target section 101.

[0021] Next, the position of the prism 203 (for example, X, Y, Z position coordinates) is measured using the surveying instrument 202, thereby identifying the installation position of the spherical target 100.

[0022] For example, by using a surveying instrument 202 to survey the position of a reference point 201 or the like whose position coordinates on a design drawing have been specified in advance, the position of the surveying instrument 202 from the reference point 201 can be specified.

[0023] After the survey, the target part 101 is placed at the position of the prism 203, and the area including the spherical target 100 is measured using a 3D laser scanner.

[0024] Similarly, by measuring an area including the spherical target 100 from multiple positions using a 3D laser scanner, it is possible to measure multiple point cloud data including the spherical target 100 whose position is specified in a design drawing or the like. Then, by overlaying the multiple point cloud data based on the position of the spherical target 100, it is possible to synthesize the multiple point cloud data with high accuracy. Furthermore, coordinate transformation can be performed with high accuracy based on the position coordinates of the spherical target 100.

[0025] However, in this case, if the installation position of the spherical target 100 and the surveying position of the prism 203 are not aligned with high precision, the accuracy of the coordinate transformation of the point cloud data will decrease. Therefore, to achieve high-precision alignment, the spherical target 100 is precisely installed on a flat surface such as a floor using a spirit level. Furthermore, depending on the installation location of the spherical target 100, such as when the spherical target 100 is installed in the air, it may be difficult to install the prism 203 directly facing the surveying instrument 202 at a position corresponding to the installation position of the spherical target 100. Therefore, although the spherical target 100 has a high degree of freedom in its installation position as a target for a 3D laser scanner, when performing high-precision coordinate transformation such as determining the installation position of the target by surveying, the installation position may be limited by the surveying. As a result, the advantage of the spherical target, which can be installed anywhere, may not be fully utilized.

[0026] Therefore, it is desired to provide a prism that makes it easy to measure the installation position of the spherical target 100 regardless of the installation position of the spherical target 100. In the embodiment described below, a prism mounting fixture 300 for a spherical target is provided.

[0027] FIG. 3 is a diagram illustrating a prism mounting device 300 according to an embodiment. In FIG. 3(a), the prism mounting device 300 includes, for example, a rail portion 301, a prism portion 302, and a mounting portion 303. The rail portion 301 is attached to the mounting portion 303 and includes an arc-shaped rail. The mounting portion 303 has a function or structure for mounting the prism mounting device 300 to the spherical target 100. The mounting portion 303 has a function or structure for attaching and detaching the rail portion 301, and the rail portion 301 may be detachable. The prism portion 302 includes a prism 310. The prism portion 302 can fit (ride) on the rail portion 301 and move along the rail portion 301. The prism portion 302 may be detachable from the rail portion 301.

[0028] FIG. 3(b) shows the rail portion 301, the prism portion 302, and the mounting portion 303 in a separated state.

[0029] FIG. 4 illustrates the movement of the mounting portion 303. FIG. 4(a) shows the rotation of the rail by the mounting portion 303. As shown in FIG. 4(a), the mounting portion 303 includes a first portion 401 and a second portion 402. FIG. 4(b) illustrates a cross section of the second portion 402 of the mounting portion 303, illustrating the rotating structure of the mounting portion 303. As shown in FIG. 4(b), the first portion 401 and the second portion 402 of the mounting portion 102 include an opening 403. The size and shape of the opening 403 may be made to match the shape and size of the mounting portion 102 of the spherical target 100. As shown in FIG. 4(a), the mounting portion 102 can be inserted through the opening 403. Then, by tightening a fixing screw 404, the first portion 401 of the mounting portion 303 can be fixed to the mounting portion 102.

[0030] 4(b), the second portion 402 of the mounting portion 102 includes an opening 405. An end of the rail portion 301 can be inserted into the opening 405, and the inserted rail portion 301 can be fixed by tightening a fixing screw 406, or the rail portion 301 can be removed by loosening the fixing screw 406. Note that the fixing using the opening and screw illustrated in FIG. 4 is merely an example, and fixing may be performed using other configurations.

[0031] As shown in FIG. 4( b), the second member 402 may be, for example, a bearing, and includes an inner member 411 and an outer member 412 to which multiple balls 420 are attached. The outer member 412 is sometimes referred to as a rotating unit. The inner member 411 is connected to, for example, the first member 401 and is fixed to the mounting unit 102 together with the first member 401. The multiple balls 420 smoothly rotate on the inner member 411, allowing the outer member 412 to rotate around the inner member 411 as indicated by arrow 430. As a result, when the mounting unit 303 is attached to the spherical target 100, the rail unit 301 can rotate around the spherical target 100 with the longitudinal axial direction of the mounting unit 102 as the rotation axis as indicated by arrow 450. When the prism mounting device 300 is attached to the spherical target 100, the arc-shaped rail of the rail unit 301 is arranged around the sphere of the spherical target 100. Furthermore, when the prism mounting device 300 is mounted on the spherical target 100, the center of the target portion 101 of the spherical target 100 and the center of the arc-shaped rail of the rail portion 301 may coincide. When the prism mounting device 300 is mounted on the spherical target 100, the arc-shaped rail of the rail portion 301 is arranged concentrically with the sphere of the target portion 101. Therefore, when mounted on the spherical target 100, the mounting portion 303 can rotate the rail around an axis passing through the center of the sphere of the spherical target 100, with the sphere of the spherical target and the arc-shaped rail arranged concentrically.

[0032] FIG. 5 is a diagram illustrating the movement of the prism portion 302. FIG. 5(a) shows the prism portion 302 attached to the rail portion 301. FIG. 5(b) is a diagram illustrating a cross section of the portion where the prism portion 302 is attached to the rail portion 301. In the example of FIG. 5, the rail portion 301 includes a groove 501 having a hollow structure. The groove 501 may be, for example, a groove that opens on the side opposite the target portion 101. As shown in FIG. 5(b), the prism portion 302 includes, for example, a prism 310, a support 502 to which the prism 310 is attached, and a disk member 503 attached to the tip of the support 502. A plurality of balls 504 are attached to the disk member 503, and the smooth rotation of the balls 504 allows the prism portion 302 to move along the groove 501 of the rail of the rail portion 301, as indicated by arrow 520 in FIG. 5(a). As the prism portion 302 moves on the rail, for example, the prism 310 moves on a circle concentric with the arc shape of the rail.

[0033] Prism unit 302 also includes a second rotating unit that rotates the prism surface of prism 310 around an axial direction extending from the center of the arc-shaped rail toward prism 310. For example, ball 504 may function as the second rotating unit, and smooth rotation of ball 504 allows prism 310 within rail unit 301 to rotate around support 502 as the rotation axis, as indicated by arrow 530. Note that while the example in FIG. 5 describes an example in which the entire prism unit 302 rotates as indicated by arrow 530, the embodiment is not limited thereto. For example, in another example, prism 310 may be rotatable around support 502 as indicated by arrow 530.

[0034] As described above, the prism mounting device 300 according to the embodiment can change the position of the prism portion 302 by rotating the mounting portion 303 around its axis (arrow 601) and moving the prism portion 302 along the rails of the rail portion 301 (arrow 602) as shown in Fig. 6(a). As a result, for example, even if the spherical target 100 is attached to a wall, ceiling, or the like in various orientations as shown in Fig. 6(b), when the prism portion 302 is suspended, these two movements allow the prism 310 of the prism portion 302 to be suspended at a position vertically below the center of the sphere of the spherical target 100.

[0035] Furthermore, for example, prism portion 302 rotates the prism surface of prism 310 around the axial direction extending from the center of the arc shape of the rail toward prism 310. For example, prism portion 302 can be rotated as shown by arrow 603 while suspended vertically below the center of the sphere of spherical target 100. Therefore, prism portion 302 can be rotated to match the installation position of surveying instrument 202, so that prism 310 faces directly toward surveying instrument 202.

[0036] Furthermore, since the prism 310 of the prism section 302 hangs vertically below the center of the sphere of the spherical target 100, the positional relationship between the prism 310 and the center of the sphere of the spherical target 100 is kept constant.

[0037] FIG. 7 is a diagram illustrating the positional relationship between the prism 310 and the center of the spherical target 100. In FIG. 7(a), the spherical target 100 is attached in a horizontal orientation, while in FIG. 7(b), the spherical target 100 is attached in an oblique orientation. However, because the prism portion 302 hangs vertically below the center of the spherical target 100, even if the spherical target 100 is attached in various orientations, the horizontal positions (positions in the X and Y directions) of the center of the spherical target 100 and the prism 310 coincide as shown in FIG. 7. Furthermore, the vertical distance between the center of the spherical target 100 and the prism 310 is a predetermined value A. In other words, when the prism mounting device 300 is attached to the spherical target 100, the prism 310 moves on a circle concentric with the sphere of the target portion 101, so the vertical distance between the center of the sphere of the spherical target 100 and the prism 310 is a predetermined value A. Therefore, when the position coordinates of the prism 310 are identified by the surveying instrument 202, the coordinates of the center of the sphere of the spherical target 100 can be identified by shifting the coordinates by adding A to the Z component of the coordinates, for example.

[0038] 8, even if the spherical target 100 is installed on an inclined wall 150, the position can be identified by placing the prism 310 directly opposite the surveying instrument 202. Then, by shifting the Z component of the identified prism 310 by A, the center position of the spherical target 100 can be identified.

[0039] As described above, according to the embodiment, it is possible to easily identify the installation position even when using the spherical target 100. Furthermore, according to the embodiment, it is possible to easily identify the installation position even when the spherical target 100 is installed in various orientations.

[0040] The prism portion 302 of the prism mounting device 300 may be provided with a movable portion that enables movement of the prism 310 along the axial direction from the center of the arc of the rail portion 301 toward the prism 310. For example, as shown in Fig. 8, even when the spherical target 100 is installed on a wall or ceiling higher than the floor, the presence of an obstacle may cause the prism 310 to be in a blind spot when viewed from the position of the surveying instrument 202. Even in such a case, if the position of the prism 310 is movable, it can be moved to a position where the prism 310 is visible.

[0041] FIG. 9 is a diagram illustrating movement of the prism 310 in the prism unit 302 according to the embodiment. As shown in FIG. 9, in the prism unit 302, the prism 310 can slide and move in a direction along the central axis of the support 502. In one example, the prism 310 may be fixed to the support 502 using fasteners such as a bolt and a nut. In this case, for example, the support 502 may have a groove through which the threads of the bolt pass, and the prism 310 may be fixed to the support 502 by turning a bolt attached to the prism 310 to tighten the support 502 between the bolt head and the nut. In this case, the prism 310 may be movable along the support 502 by loosening the bolt. This allows the prism 310 to move along the axial direction from the center of the arc of the rail unit 301 toward the prism 310.

[0042] Furthermore, in order to make it possible to identify the position of prism 310 when it is moved, prism portion 302 may have a scale 901 that indicates the position of prism 310. In the example of Fig. 9, support column 502 includes a scale along the axial direction of support column 502, and it is possible to identify the position of prism 310 along the axial direction from the center of the arc of rail portion 301 toward prism 310 when the position of prism 310 is moved.

[0043] 9, prism portion 302 includes weight 902. As described above, prism portion 302 may hang vertically by its own weight, and including weight 902 in this manner makes the hanging in the vertical direction more stable. Furthermore, no manual labor is required to fix the prism.

[0044] FIG. 10 is a diagram illustrating an example of an operational flow of measurement using the prism mounting fixture 300 according to the embodiment.

[0045] In S1001, a reference point 201 whose position on a design drawing is known is surveyed with a surveying instrument 202 such as a transit or total station, and the position of the surveying instrument 202 is identified.

[0046] In S1002, the spherical target 100 is installed. The spherical target 100 may be installed in various locations, such as on a wall or ceiling.

[0047] The prism mounting device 300 is attached to the spherical target 100 installed in S1003. When the prism mounting device 300 is attached to the spherical target 100, for example, the prism portion 302 hangs down vertically by its own weight. Furthermore, the prism surface of the prism in the prism portion 302 can be rotated, and the prism surface can be oriented to face the surveying instrument 202.

[0048] In S1004, the surveying instrument 202 measures the prism 310 of the prism mounting fixture 300, and identifies the position coordinates of the prism 310.

[0049] Then, in S1005, the position coordinates (X, Y, Z coordinates) of the spherical target 100 are determined by adding a predetermined value A to the position coordinates of the prism 310, for example.

[0050] In S1006, the prism mounting fixture 300 is removed from the spherical target 100.

[0051] In S1007, the spherical target 100 is measured from multiple positions using a 3D laser scanner to obtain multiple point cloud data.

[0052] In S1008, a plurality of point cloud data are synthesized using the position coordinates of the spherical target 100.

[0053] As described above, the position of the spherical target 100 can be identified by the prism mounting fixture 300, which allows accurate coordinate alignment and improves the efficiency of post-processing related to point cloud synthesis and coordinate transformation.

[0054] Furthermore, the prism mounting device 300 according to the embodiment makes it possible to easily measure the spherical target 100 installed in various places such as on a wall surface or a ceiling.

[0055] Therefore, it is not necessary to install the spherical target 100 in a location that is easy to survey, such as the floor, for the purpose of measurement, and the spherical target 100 can be installed anywhere.

[0056] For example, when the position of the spherical target 100 is to be determined by surveying, the spherical target 100 can be installed not on the floor but on a wall or ceiling, etc., where it will not interfere with traffic or construction. This makes it possible to leave the spherical target 100 installed for a long period of time. This eliminates the need to install the spherical target 100 every time a measurement is made. For example, when performing fixed-point observation of the completed state of a construction site using a 3D laser scanner, measurements can be made with the spherical target 100 installed, which is highly convenient.

[0057] Several embodiments have been described above. However, the embodiments are not limited to the above embodiments and should be understood to include various modifications and alternative forms of the above embodiments. For example, it will be understood that the various embodiments can be realized by modifying the components without departing from the spirit and scope of the embodiments. It will also be understood that various embodiments can be implemented by appropriately combining multiple components disclosed in the above-described embodiments. Furthermore, it will be understood by those skilled in the art that various embodiments can be implemented by deleting some components from all the components shown in the embodiments or by adding some components to the components shown in the embodiments. [Explanation of symbols]

[0058] 100: Spherical target 101: Target section 102: Mounting part 110: Magnet 150: Wall 201 :Reference point 202: Surveying equipment 203: Prism 300: Prism attachment 301: Rail section 302: Prism part 303: Mounting part 310: Prism 401: Part 1 402:Second part 403: Opening 404: Fixing screw 405: Opening 406: Fixing screw 411: Inner member 412:Outer member 420: Ball 501: Groove 502: Post 503: Disk member 504: Ball 901: Scale 902: Weight

Claims

1. a mounting portion that is mounted on the spherical target; a rail portion attached to the mounting portion, the rail portion including an arc-shaped rail; a prism unit having a prism and moving on the rail; A prism mounting device comprising: the mounting unit includes a rotation unit that rotates the rail around an axis passing through the center of the sphere of the spherical target in an arrangement in which the sphere of the spherical target and the arc shape of the rail are concentric when the mounting unit is mounted on the spherical target; Prism mounting device.

2. When the prism portion moves on the rail, the prism moves on a circle concentric with the arc shape of the rail.

2. The prism mounting device according to claim 1, wherein the prism mounting device is a prism mounting device.

3. the rotating portion is rotatable by the weight of the prism portion, the rail portion holds the prism portion so that the prism portion can slide on the rail due to its own weight; 3. The prism mounting device according to claim 1, wherein when the mounting portion is mounted on the spherical target, the prism portion hangs from the rail by its own weight so that the prism is positioned vertically below the center of the sphere of the spherical target.

4. 4. The prism mounting device according to claim 1, wherein the prism portion includes a second rotating portion that rotates the prism surface of the prism around an axis extending from the center of the arc shape of the rail toward the prism.

5. the prism portion includes a movable portion that enables movement of the prism in an axial direction from the center of the arc shape of the rail toward the prism; and a scale for identifying the position of the prism from the center of the arc shape. The prism mounting device according to any one of claims 1 to 4.

6. The prism mounting device according to claim 1 , wherein the rail portion is detachable from the mounting portion.

Images