JP7660972B2 - Reference sphere installation device and reference sphere system - Google Patents

Description

The present invention relates to an apparatus and a reference sphere system for installing a reference sphere on a support.

In tunnel excavation work using blasting, after removing the debris generated by the blasting, the work of removing protrusions (marks) that will interfere with the subsequent lining work is carried out. The locations where marks need to be removed can be determined by workers' visual inspection, but because the area is wide and time-consuming, a three-dimensional (3D) scanner is used to measure the excavation wall surface and compare it with a reference cross section to identify the locations where marks need to be removed (see, for example, Patent Documents 1 and 2).

The 3D scanner uses laser light to calculate the coordinates of the relative position of the measurement target with respect to the 3D scanner. To compare with the reference cross section, the position coordinates (absolute coordinates) of each measurement point on the excavation wall surface are required, and to calculate the position coordinates of each measurement point, the position coordinates of the 3D scanner are required.

The position coordinates of the 3D scanner can be calculated using a reference sphere having position coordinates measured in advance (see, for example, Patent Document 3). The reference sphere has a spherical surface 10 and a cutout portion 11 with a retroreflective reflecting means inside, as shown in Figure 1 (a), and can be installed at a predetermined position, such as a support or a washer of a rock bolt, using a mounting magnet 12 with a screw, as shown in Figure 1 (b).

Patent No. 5500708 Patent No. 5500709 JP 2019-158637 A

However, with conventional mounting magnets, when removing the reference ball for blasting or other purposes, if the magnet is removed, it is not guaranteed that it can be installed in exactly the same position the next time, so the position coordinates of the reference ball must be measured again.

It is possible to remove only the reference sphere, leaving the mounting magnet in place, but this requires rotating a screw to remove it, which is time-consuming. The same is true for installation. Also, the orientation of the reference sphere needs to be changed when measuring the position coordinates of the reference sphere using an optical rangefinder and when calculating the position coordinates of the 3D scanner, but since the orientation is changed by loosening the screw, the center position of the reference sphere will shift.

The present invention has been made in consideration of the above problems, and provides an apparatus for installing a reference sphere on a support, comprising:
a body having one end fixed to the support and the other end having a groove;
a shaft having one end fixed to the reference sphere and the other end rotatably inserted into the groove;
An installation device is provided that includes anchoring means on the body for contacting the shaft inserted into the groove to inhibit rotation of the shaft.

The present invention makes it easy to install and remove the reference sphere, and makes it possible to change the orientation of the reference sphere without changing its center position.

FIG. 1 is a diagram illustrating a reference sphere and a conventional mounting magnet. A diagram showing an overview of the tunnel construction management system. FIG. 1 shows an example of the configuration of a reference sphere and a conventional mounting magnet. FIG. 2 is a diagram showing a first configuration example of an installation device for installing a reference sphere. FIG. 13 is a diagram showing a second configuration example of the installation device for installing the reference sphere. FIG. 13 is a diagram showing a third configuration example of the installation device for installing the reference sphere.

Before explaining the reference sphere installation device of the present invention, we will explain a tunnel construction management system as an example of a system that uses a reference sphere. Here, we will explain the tunnel construction management system as an example of a system that uses a reference sphere, but the reference sphere is not limited to being used for tunnel construction management.

Figure 2 is a diagram showing an overview of the tunnel construction management system. The tunnel construction management system is used to grasp the tunnel shape, collect information, ensure safety and security during construction, and control the posture of construction vehicles such as heavy machinery, and to identify areas that require marking before the first lining and to measure the displacement of the face and side walls before the second lining. Here, the tunnel construction management system is described as a system that can perform marking.

Tunnels using the NATM method are formed by blasting with explosives or by using excavators such as free-section excavators to excavate the natural ground or underground. The entrance to the tunnel is called the tunnel portal, and the excavation surface in the direction of excavation is called the face 20. Since there is a risk of the tunnel collapsing if left in its excavated state, arch-shaped steel supports 21 are installed at regular intervals, and concrete is sprayed as a primary lining to reinforce the tunnel walls. After the primary lining, rock bolts 22 are driven in, the concrete walls are covered with waterproof sheets, and concrete is poured further inside as a secondary lining. In Figure 2, "S.L" is the Spring Line, which is the line where the upper half arch begins in the tunnel internal cross section.

A primary lining is applied to a tunnel every time it is excavated a certain distance. After a certain distance has been excavated and before the primary lining is applied, the tunnel construction management system determines where re-alignment is required and carries out this re-alignment. A tunnel is formed by repeatedly excavating with blasting or an excavator, re-aligning, and applying the primary lining.

The tunnel construction management system includes a vehicle equipped with an excavation means for determining where marking is required and excavating where excavation is required in order to carry out the marking. This vehicle can be a breaker 23 that continuously strikes with a chisel used in the work of chipping and removing the markings.

In addition to the above vehicles, the tunnel construction management system is equipped with a measuring means for performing three-dimensional measurements inside the tunnel to determine whether or not a mark is required. For example, a three-dimensional (3D) scanner 24 can be used as the measuring means. The 3D scanner 24 irradiates laser light, measures the time it takes for the light to be reflected back from the measurement target, and converts it into distance. The 3D scanner 24 also measures the irradiation angle of the laser light, and calculates the coordinates of the relative position of the measurement target with respect to the 3D scanner 24 based on the converted distance and the measured irradiation angle.

The coordinates of the relative position are the coordinates of the measurement target when the position coordinates of the 3D scanner 24 are (0,0,0). The 3D scanner 24 is installed on the roof of the driver's seat of the breaker 23 via a seismic isolation stand. The seismic isolation stand is a stand equipped with a seismic isolation device, and the seismic isolation device may include laminated rubber, rolling bearings, sliding bearings, or a combination of these with a damper.

The tunnel construction management system includes a calculation means for calculating the position coordinates of one or more locations on the tunnel face 20 based on the results of three-dimensional measurement performed by the 3D scanner 24, comparing the results with design data to determine locations that require excavation, and calculating the amount of construction. The amount of construction is the amount of excavated soil, the amount of sprayed soil, etc. The calculation means may be any device that can calculate the above-mentioned position coordinates, determine the location of excavation based on comparison with design data, and calculate the amount of construction, and may be, for example, a PC (Personal Computer) 25, a tablet terminal, a smartphone, etc.

The PC 25 is communicatively connected to the 3D scanner 24 via a cable, a wireless LAN (Local Area Network), or the like, and is placed in the driver's seat of the breaker 23. Note that the computing means is not limited to a portable computer such as the PC 25, but may also be a computer with a monitor installed in the driver's seat.

The tunnel construction management system includes three or more reference spheres 26 having position coordinates measured in advance within the tunnel in order to calculate the position coordinates of the 3D scanner 24. The reference spheres 26 are positioned closer to the tunnel entrance than the breaker 23.

The reference sphere 26 has a spherical surface and a cutout, and the cutout is provided with a prism as a retroreflective reflecting means. When measuring the position coordinates of the reference spheres 26, the cutout is directed toward an optical range finder, and the optical range finder measures the coordinates of the center of each reference sphere 26. The coordinate values of the position coordinates are, for example, values consisting of latitude, longitude, and altitude, and are absolute coordinates. The optical range finder shines light toward the prism in the cutout, receives the light retroreflected by the prism, and measures the distance and angle to the center of the reference sphere 26. The optical range finder is installed at a point whose position coordinates are known, so the coordinates of the center of the reference sphere 26 are calculated from the position coordinates of the device itself and the measured distance and angle.

When measuring the position coordinates of the 3D scanner 24, the spherical surface is directed toward the 3D scanner 24. Therefore, the 3D scanner 24 scans the spherical surface of the reference sphere 26 and acquires the relative positional relationship between the 3D scanner 24 and the reference sphere 26. This allows the PC 25 to calculate the position coordinates of the 3D scanner 24 as absolute coordinates from the position coordinates of the reference sphere 26 and the acquired relative positional relationship.

When measuring the reference sphere 26 with the 3D scanner 24, the distance measured by the 3D scanner 24 is the distance to the spherical surface. However, since the radius of the reference sphere 26 is known, if the distance to the spherical surface can be measured, the distance to the center of the reference sphere 26 can be obtained by adding the radius to the measured distance. Then, the position coordinates of the center of the reference sphere 26 can be calculated based on that distance.

A special paint is applied to the surface of the spherical surface 30 of the reference sphere 26 to enhance the reflectivity. In particular, it is desirable to apply a retroreflective material that reflects incident light in the direction of the light source, as this increases reflectivity and makes it easier to detect the reference sphere 26. Examples of retroreflective materials include those that contain fine glass beads or glass powder. Increasing the reflectivity in this way can reduce erroneous recognition of the reference sphere 26.

After calculating the position coordinates of the 3D scanner 24, the 3D scanner 24 performs three-dimensional measurement of the face side based on instructions from the PC 25, and transmits the measurement results of the three-dimensional measurement to the PC 25. The PC 25 calculates the position coordinates of multiple points on the face side based on the measurement results and the position coordinates of the 3D scanner 24, and acquires them as point cloud data. The point cloud data is stored in a storage device such as a HDD (Hard Disk Drive) provided in the PC 25.

The PC 25 stores design data including the position coordinates of each point on the designed excavation wall surface (design cross section) of the tunnel in a storage device, compares the acquired point cloud data with the design data, identifies locations that protrude toward the inside of the tunnel by more than a threshold value, and determines that the identified locations are locations that require excavation. The threshold value can be set arbitrarily.

PC25 has a monitor as a display means, and displays the results of the determination on the monitor. Specifically, PC25 displays the areas identified as requiring excavation in a manner that makes them distinct from other areas that do not require excavation, and indicates to the worker the areas where they should perform a marking. Methods for displaying the areas in a distinguishable manner include coloring the areas or changing the color. In addition, the extent to which excavation is required can be displayed using specific numerical values, color coding, etc.

To perform this face-side marking, the breaker 23 equipped with the 3D scanner 24 is positioned close to the face 20. The reference sphere 26 used to calculate the position coordinates of the 3D scanner 24 must be positioned in a position that can be measured by the 3D scanner 24. However, during blasting, flying rock fragments and the like may damage the surface of the reference sphere 26 and break the prism, so the reference sphere 26 is removed and then attached after blasting.

Now, referring to Figure 3, a conventional installation device for installing the reference sphere 26 will be described in detail. The spherical surface 30 of the reference sphere 26 is provided with a screw hole 31 that extends toward the center of the reference sphere 26.

The reference sphere 26 is connected to the mounting magnet 33 by screwing the threaded portion 32 of the mounting magnet 33 into the screw hole 31, and is fixed in a predetermined position, such as the support 21 or the washer of the lock bolt, by the magnetic attraction.

The reference sphere 26 can be removed together with the mounting magnet 33, or the screw can be loosened and only the reference sphere 26 can be removed.

When the reference sphere 26 is removed together with the mounting magnet 33, it is attached to a specified position such as the support 21 or the washer of the rock bolt when it is installed, but it is difficult to install it in exactly the same position before and after removal, so after installation, the position coordinates of the reference sphere 26 must be remeasured using an optical distance meter.

If the mounting magnet 33 is not removed, the notch must be directed toward the optical range finder, and the screws on the mounting magnet 33 must be loosened to rotate the reference sphere 26, or the mounting magnet 33 must be removed, the reference sphere 26 must be rotated, and then the magnet must be attached. In either case, the center position of the reference sphere 26 will shift, making it impossible to measure the exact position coordinates of the 3D scanner 24.

Therefore, in order to make it easy to install and remove the reference sphere 26 and to change the orientation of the reference sphere 26 without changing the center position of the reference sphere 26, an installation device configured as shown in FIG. 4 is used. The reference sphere 26 has a screw hole 31 that extends from the spherical surface 30 toward the center.

The installation device includes a main body 41 having one end fixed to a support such as the shoring 21 or a washer of a rock bolt and a groove 40 at the other end, a shaft 42 having one end fixed to the reference sphere 26 and the other end rotatably inserted into the groove 40, and a fixing means 43 provided on the main body 41 and contacting the shaft 42 inserted into the groove 40 to prevent the shaft 42 from rotating.

The main body 41 is cylindrical, and at one end of the circle, there are tripod screw holes 44, 45 for fixing to the support 21, a lock bolt washer, a tripod, etc., and a disk-shaped neodymium magnet 46. The tripod screw hole 44 is a screw hole for a camera tripod, and the tripod screw hole 45 is a screw hole for a surveying tripod. In this example, two screw holes are provided, but there may be one screw hole or three or more screw holes. The neodymium magnet 46 is a permanent magnet whose main components are neodymium, iron, and boron, and has the strongest magnetic force. When using the tripod screw holes 44, 45, the neodymium magnet 46 is removed, and the tripod screws are directly screwed into these tripod screw holes 44, 45. Here, a neodymium magnet is used as the magnet, but this is not limited to this, and an alloy magnet whose main component is iron, a ferrite magnet whose main component is iron oxide, etc. may also be used.

In addition, to make it easier to attach and remove the main body 41, it is fixed using a magnet, but it may also be fixed using bolts and nuts, etc.

At the other circular end of the main body 41, a cylindrical groove 40 is provided that extends toward one end. In addition, a hole 47 is provided on the side of the main body 41 that penetrates the side of the groove 40, and a screw hole 48 is provided continuous with the hole 47. A fastening screw 43a that constitutes the fixing means 43 is inserted into the hole 47 and the screw hole 48, and the screw part at the tip is screwed into the screw hole 48. A fastening piece 43b, which is an insert piece that is tapered in a direction perpendicular to the insertion direction of the shaft body 42 into the groove 40, is attached to the center part of the fastening screw 43a. Therefore, as the screw part at the tip of the fastening screw 43a is screwed into the screw hole 48, it moves in the vertical direction, and the surface exposed in the groove 40 facing the side of the shaft body 42 of the fastening piece 43b is pressed against the side of the shaft body 42 to suppress the rotation of the shaft body 42. That is, when viewed from the reference sphere 26 side, the tightening piece 43b is tapered and has an inclination on the shaft 42 side, so that as it is inserted, the inclined surface comes into contact with the side of the shaft 42, and as it is inserted further, it comes into pressure contact.

One end of the shaft body 42 has a threaded portion 49 that screws into the screw hole 31 of the reference sphere 26, and the other end has a cylindrical insertion portion 50 that is inserted into the groove 40 of the main body 41. The shaft body 42 is fixed to the reference sphere 26 and is free to rotate within the groove 40 of the main body 41 until the tightening top 43b is pressed against it. Therefore, the tightening top 43b is pressed against the shaft body 42 by the tightening screw 43a, thereby fixing the reference sphere 26, and the reference sphere 26 is free to rotate when the tightening top 43b is released from its pressure on the shaft body 42.

When removing the reference sphere 26, loosen the tightening screw 43a, release the tightening block 43b from the shaft 42, and pull out the shaft 42 from the main body 41 while it is still attached to the reference sphere 26. When installing the reference sphere 26, loosen the tightening screw 43a and insert the shaft 42 attached to the reference sphere 26 into the groove 40 of the main body 41. After inserting the shaft 42, tighten the tightening screw 43a and press the tightening block 43b against the side of the shaft 42 to fix it in place.

The tightening screw 43a is provided with a lever 43c, and the tightening screw 43a can be tightened by rotating the lever 43c in a specified direction, and loosened by rotating the lever 43c in the opposite direction.

In this configuration, the reference sphere 26 can be easily installed by simply inserting it, and can be easily removed by simply pulling out the reference sphere 26. In addition, by simply loosening the fastening screw 43a, the tip of the shaft 42 can be rotated around the shaft 42 while in contact with the bottom of the groove 40, so the coordinates of the center of the reference sphere 26 do not change, and there is no need to remeasure using an optical rangefinder.

As shown in FIG. 5, it is also possible to press the tip of the tightening screw 43a directly against the side of the shaft 42, or to press it against the side via a pressing member made of plastic, rubber, or the like, without using the tightening top 43b. FIG. 5 is a diagram showing a second configuration example of the installation device. FIG. 5(a) shows an example in which the tip of the tightening screw 43a is pressed directly against the side of the shaft 42, and FIG. 5(b) shows an example in which it is pressed against the side via a pressing member 51.

However, when the reference ball 26 is fixed by pressing, the area of the tip of the tightening screw 43a pressed against the side of the shaft body 42 is small, and the ball is fixed at a point. This makes it difficult to fix the reference ball 26 so that it does not rotate. Therefore, as shown in the example in FIG. 4, it is desirable to press the tightening block 43b against the side of the shaft body 42 to increase the area of the pressing and fix the ball by a line. It is also possible to make the pressing member 51 have a curved surface adjacent to the side of the shaft body 42, move the pressing member 51 toward the shaft body 42 by the tightening screw 43a, and bring the curved surface into close contact with the side of the shaft body 42, thereby fixing the ball by a surface. In terms of fixing the reference ball 26 so that it does not move, it is more desirable to fix the ball by a surface in this way. In addition, when the pressing member 51 is adjacent to the side of the shaft body 42, it is desirable to use a material with high friction resistance, and it is desirable to use a material made of plastic or rubber.

Figure 6 shows a third example of the configuration of the installation device. As with the example shown in Figure 4, the example shown in Figure 6 has a screw hole 31 provided in the reference sphere 26, and is composed of a main body 41, a shaft body 42, and a fixing means. The main body 41 has screw holes 44, 45 for a tripod and a neodymium magnet 46 at one end. The main body 41 also has a groove 40 at the other end.

The shaft 42 has one end threaded and an extension 52 that functions as a washer and is expanded compared to the other end, and has a cylindrical insertion portion 53 at the other end. The insertion portion 53 is inserted into the groove 40 of the main body 41.

In the example shown in FIG. 6, the fixing means is a neodymium magnet 54 that is fixed to the main body 41 and arranged so as to be exposed at the bottom of the groove 40. In this example, a neodymium magnet is used, but other magnets such as alloy magnets and ferrite magnets may also be used as long as they are magnets.

In the example shown in FIG. 6, the iron shaft 42 can be removed by lifting it while still attached to the reference sphere 26, and moving it away from the neodymium magnet 54. On the other hand, the reference sphere 26 can be installed by inserting the shaft 42 into the groove 40 of the main body 41, bringing the shaft 42 close to the neodymium magnet 54, and magnetically attracting the end of the shaft 42. Since the reference sphere 26 is fixed by magnetic attraction, it can be easily rotated by applying a force that exceeds the attraction force.

The insertion portion 53 has a larger diameter and a shorter length than the insertion portion 50 shown in FIG. 4. The larger diameter is to increase the area of the surface that is attracted to the neodymium magnet 54 disposed at the bottom of the groove 40, and to fix the reference sphere 26 so that it does not rotate. The shorter length is to make it easier to insert the shaft body 42 into the groove 40.

However, if the length of the insertion portion 53 of the shaft body 42 is too short, stability will decrease when the reference sphere 26 is attached, so it is desirable to provide a certain length and an extended extension portion 52.

Even with this configuration, the reference sphere 26 can be easily installed by simply inserting it, and can be easily removed by simply pulling it out. In addition, the reference sphere 26 can be rotated around the shaft 42 by simply applying a force that exceeds the adhesive force of the neodymium magnet 54, so the coordinates of the center of the reference sphere 26 do not change, and there is no need to remeasure using an optical range finder.

In the example shown in FIG. 6, the neodymium magnet 54 is disposed at the bottom of the groove 40, but this is not limited to the bottom of the groove 40. For example, the insertion portion 53 of the shaft 42 may be made nonmagnetic, and the neodymium magnet 54 may be disposed at the top of the main body 41 with which the extension portion 52 comes into contact, so that the extension portion 52 is attracted and fixed in place.

So far, the installation device for the reference sphere 26 of the present invention has been described in detail with reference to the embodiment shown in the drawings, but the present invention is not limited to the above-mentioned embodiment, and can be modified within the scope of what a person skilled in the art can imagine, such as other embodiments, additions, modifications, deletions, etc., and as long as the function and effect of the present invention are achieved in any aspect, it is included in the scope of the present invention. Therefore, the present invention can also provide a reference sphere system that includes an installation device such as the one illustrated in Figures 4 to 6 and a reference sphere.

10, 30... spherical surface 11... cutout portion 12, 33... mounting magnet 20... face 21... shoring 22... rock bolt 23... breaker 24... 3D scanner 25... PC
26...reference sphere 31, 44, 45, 48...screw hole 32, 49...threaded portion 40...groove 41...main body 42...shaft body 43...fixing means 43a...tightening screw 43b...tightening block 43c...lever 46, 54...neodymium magnet 47...hole 50, 53...insertion portion 51...pressing member 52...extension portion

Claims (7)

A device for mounting a reference sphere on a support, comprising:
a body having one end fixed to the support and the other end having a groove;
a shaft having one end fixed to the reference sphere and the other end rotatably inserted into the groove;
a fixing means provided on the body and contacting the shaft inserted into the groove to prevent rotation of the shaft ,
the main body extends from a side surface of the main body in a direction perpendicular to a direction in which the shaft body is inserted into the groove, and has a hole penetrating a side portion of the groove and a screw hole continuous with the hole;
The fixing means is an installation device that includes a clamping screw that is inserted into the hole and has a threaded portion at one end that is screwed into the screw hole, an insertion piece attached to the longitudinal center of the clamping screw, tapered toward the vertical direction, and whose surface exposed in the groove as the threaded portion is screwed into the screw hole is pressed against the side of the shaft, and a lever provided at the other end of the clamping screw for rotating the clamping screw . A device for mounting a reference sphere on a support, comprising:
a body having one end fixed to the support and the other end having a groove;
a shaft having one end fixed to the reference sphere and the other end rotatably inserted into the groove;
a fixing means provided on the body and contacting the shaft inserted into the groove to prevent rotation of the shaft ,
the shaft body includes an insertion portion that is inserted into the groove, and an expansion portion that contacts a top of the body when the insertion portion is inserted into the groove and that expands in diameter compared to the insertion portion,
The fixing means is disposed on the main body so that a portion of the fixing means is exposed at the bottom of the groove, and includes a magnet that attracts the tip of the insertion portion inserted into the groove . The insertion portion is non-magnetic and the extension portion is magnetic;
3. The installation device according to claim 2, wherein the magnet is disposed so as to attract the extension to a top portion of the body with which the extension comes into contact, instead of to a bottom portion of the groove. The installation device according to any one of claims 1 to 3, wherein the main body includes a fixing magnet provided at the one end and attracted to the support part. The installation device according to any one of claims 1 to 4, wherein the shaft body has a threaded portion that screws into the reference sphere having a threaded hole. The installation device according to any one of claims 1 to 5, wherein the main body has a screw hole at one end into which a screw portion provided on the support portion is screwed. A reference sphere system comprising a reference sphere and an installation device according to any one of claims 1 to 6.