Optical targeting device and measurement method

Abstract

To eliminate need for installing and removing a retroreflector such as a prism and a mirror for each measurement.SOLUTION: An optical target device 1 includes an actuator 50 disposed inside a mounting hole 97 formed on an inner wall 98 of a tunnel 99, and a retroreflector 40 connected to the actuator 50. The actuator 50 moves the retroreflector 40 out of the mounting hole 97 to inside of the inner wall 98 and moves the retroreflector 40 so as to store the retroreflector 40 inside the mounting hole 97.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an optical targeting device. and Measurement method By law Regarding. [Background technology]

[0002] Patent Documents 1 and 2 disclose methods for measuring the position of the inner wall of a tunnel by collimating targets such as prisms and mirrors installed in the tunnel with a surveying instrument such as a total station and a 3D scanner. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-061417 [Patent Document 2] Patent Publication No. 2021-188994 Summary of the Invention [Problem to be solved by the invention]

[0004] In order to measure the displacement of the tunnel inner wall over time, measurements using surveying equipment and targets must be carried out periodically, for example daily. Setting up and removing targets every time a measurement is required is labor-intensive. If the targets are left installed, they will interfere with tunnel construction and there is a risk that they will be damaged during blasting at the tunnel face. The present invention has been made in view of the above circumstances, and has as its object to eliminate the need to install and remove retroreflectors such as prisms and mirrors every time a measurement is made. [Means for solving the problem]

[0005] According to a first aspect of the present invention for solving the above problems, an optical targeting device includes: An outer cylinder that is fitted into a mounting hole formed in the inner wall of the tunnel, an inner cylinder that is assembled to the outer cylinder so as to be housed in the outer cylinder coaxially with the outer cylinder, and aAn actuator; and a retroreflector coupled to the actuator, wherein the actuator: The inner cylinder The retroreflector is projected from the inside of the inner wall and the retroreflector is The inner cylinder The retroreflector is moved so as to be stored inside the According to a second aspect of the present invention, the optical targeting device comprises a waterproof film sandwiched between the inner tube and the outer tube. According to a third aspect of the present invention, the outer cylinder has a convex portion formed in a convex shape on the outer circumferential surface thereof. According to a fourth aspect of the present invention, the retroreflector retroreflects light rays that are incident on the retroreflector from various directions. According to a fifth aspect of the invention, the optical targeting device comprises a light emitting element provided at an end of the barrel inwardly of the inner wall.

[0006] The present invention 6 According to this aspect, the optical targeting device comprises: Housed in the inner cylinder and a control unit that controls the actuator, and when the control unit receives a deployment command from a remote controller that remotely operates the control unit, the control unit: The inner cylinder and when the control unit receives a storage command from the remote controller, the control unit causes the actuator to project the retroreflector from the inside of the inner wall. The inner cylinder The actuator is caused to store the actuator inside the

[0007] The present invention 7 According to this aspect, the optical targeting device is attached to the retroreflector. , consisting of an insulator Further provided with a cap, the control unit has a receiving antenna for receiving radio waves transmitted by the remote controller and including the deployment command or the storage command, The retroreflector The inner cylinder When the cap is stored in an opening in the barrel at the end of the barrel inward of the inner wall and the retroreflector is The inner cylinder mosquito and others When the cap is positioned inside the inner wall, the end of the outer barrel Away from the opening of the outer cylinder will be released

[0008] The present invention 8 According to the aspect of the present invention, in the measurement method for measuring the inner wall of the tunnel using the optical target device, The inner cylinderAfter the retroreflector is projected from the inside of the inner wall, the three-dimensional position of the retroreflector is measured by using an optical surveying instrument to collimate the retroreflector from inside the inner wall.

[0009] The present invention 9 According to the aspect of the present invention, in the measurement method, after measuring the three-dimensional position of the retroreflector, the retroreflector is moved by the actuator. The inner cylinder Store in [Effects of the Invention]

[0011] According to the present invention, it is not necessary to install and remove a retroreflector every time a measurement is performed. [Brief explanation of the drawings]

[0012] [Figure 1] Figure 1 shows the cross section of the tunnel. [Figure 2] FIG. 2 shows the optical targeting device exploded. [Figure 3] FIG. 3 shows a portion of the inner barrel of the optical targeting device and the motorized actuator. [Figure 4] FIG. 4 is an enlarged view of region IV in FIG. [Figure 5] FIG. 5 is an enlarged view of region V in FIG. [Figure 6] FIG. 6 is an enlarged view of region V in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments will be described with reference to the drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. Because the drawings are provided for illustrative purposes only, the scope of the present invention is not limited to the examples shown in the drawings.

[0014] [1. Overview] 1 is a cross-sectional view of a mountain tunnel 99 under construction. The cross section of FIG. 1 is perpendicular to the axial direction of the tunnel 99.

[0015] In the construction work of the tunnel 99, the tunnel 99 is constructed in the mountains by excavating the face of the tunnel 99 by blasting or the like. During the construction work, the movement and displacement of the inner wall 98 of the tunnel 99 are measured periodically, for example, daily, in order to determine the stability of the ground, the safety of the tunnel 99, the effectiveness of the support work, the effectiveness of the lining, etc.

[0016] During measurement, multiple optical target devices 1 and a surveying instrument 85 are used. Multiple optical target devices 1 are arranged circumferentially around the tunnel 99 and installed on the inner wall 98 of the tunnel 99. There are multiple sets, each consisting of multiple optical target devices 1 arranged circumferentially, and the sets are arranged at predetermined intervals in the axial direction of the tunnel 99. As excavation of the tunnel face progresses, additional sets are added. The surveying instrument 85 is an optical collimation device such as a total station, transit, or laser rangefinder. The surveying instrument 85 is set on the floor of the tunnel 99, and the three-dimensional position of the optical target device 1 is measured by using the surveying instrument 85 to collimate the optical target device 1. In other words, the surveying instrument 85 measures the distance, tilt angle, and pan angle from the surveying instrument 85 to the optical target device 1, and the three-dimensional position of the optical target device 1 is calculated and measured using the surveying instrument 85 from the distance, tilt angle, and pan angle. The tilt angle refers to the elevation / depression angle of the collimation direction of the surveying instrument 85 around a horizontal axis perpendicular to the collimation direction. The pan angle refers to the angle (azimuth angle) of the collimation direction around a vertical axis intersecting the collimation direction. The collimation direction refers to the direction along the light beam projected by the surveying instrument 85. The position of the surveying instrument 85 may be shifted in the direction of the axis of the tunnel 99 from a plane passing through the multiple optical target devices 1 arranged circumferentially of the tunnel 99 (this plane is perpendicular to the direction of the axis of the tunnel 99), or may be aligned with that plane.

[0017] If the optical target device 1 protrudes into the inner wall 98 during construction of the tunnel 99, the optical target device 1 will get in the way. Therefore, the optical target device 1 is designed so that it does not get in the way except when measurements are being taken, and almost the entire optical target device 1 retracts toward the outside of the inner wall 98 when measurements are not being taken. The optical target device 1 will be described in detail below with reference to Figures 2 and 3. Figure 2 is an exploded perspective view of the optical target device 1, and Figure 3 is a perspective view of the electric actuator 50 and half body 21 of the optical target device 1. Figure 3 shows a portion of the electric actuator 50 in an exploded state.

[0018] 2. Optical Targeting Devices and Remote Controllers The optical target device 1 is remotely operated by a remote controller 80 (see FIG. 1 ). The optical target device 1 includes an outer tube 10, a waterproof film 18, an inner tube 20, a top tube 28, a light emitting element 29, a holder 30, a battery 32, a retroreflector 40, a cap 45, an electric actuator 50, and a control panel 70.

[0019] (1) Outer tube, waterproof film, inner tube, top tube and light emitting element The outer cylinder 10 has two semi-cylindrical half bodies 11. The two half bodies 11 are assembled together to form the cylindrical outer cylinder 10. A seal may be sandwiched between the two half bodies 11 where they butt against each other. The outer cylinder 10 has a hollow 12 inside. The outer cylinder 10 has an opening 13 at one end of the outer cylinder 10 in the axial direction. The outer cylinder 10 has an end plate 14 at the other end of the outer cylinder 10 in the axial direction. The other end of the outer cylinder 10 is closed by the end plate 14. In the following, the "axial direction" refers to the direction along the central axis of the outer cylinder 10. The "circumferential direction" refers to the direction around the central axis of the outer cylinder 10. The "radial direction" refers to the direction perpendicular to the central axis of the outer cylinder 10.

[0020] The outer cylinder 10 has a plurality of first slip stoppers 15 and second slip stoppers 16 on its outer peripheral surface. The first slip stoppers 15 are formed in a convex shape on the outer peripheral surface of the outer cylinder 10. The first slip stoppers 15 are inclined in the axial and radial directions from the radially outward direction toward the opening 13 of the outer cylinder 10. The second slip stoppers 16 are formed in a convex shape on the outer peripheral surface of the outer cylinder 10. The second slip stoppers 16 are inclined in the circumferential and radial directions.

[0021] The outer cylinder 10 has a flange 17 on the outer peripheral surface at the end proximal to the opening 13. The flange 17 is provided over the entire circumferential direction. The flange 17 is a seal having rubber elasticity. The waterproof film 18 is attached to the inner peripheral surface of the outer cylinder 10.

[0022] The inner cylinder 20 has two semi-cylindrical half bodies 21. The two half bodies 21 are assembled together to form the cylindrical inner cylinder 20. A seal may be sandwiched between the two half bodies 21 where they butt against each other. The inner cylinder 20 has a hollow 22 inside. The inner cylinder 20 has an opening 23 at one end of the inner cylinder 20 in the axial direction. The inner cylinder 20 has an end plate 24 at the other end of the inner cylinder 20 in the axial direction. The other end of the inner cylinder 20 is closed by the end plate 24.

[0023] The inner cylinder 20 is housed in the outer cylinder 10, and the inner cylinder 20 and the outer cylinder 10 are coaxial. A waterproof film 18 is sandwiched between the outer peripheral surface of the inner cylinder 20 and the inner peripheral surface of the outer cylinder 10, and the inner cylinder 20 is waterproofed by the waterproof film 18. An opening 23 of the inner cylinder 20 is located further back in the outer cylinder 10 than the opening 13 of the outer cylinder 10.

[0024] The top tube 28 is shaped like a cylinder. The top tube 28 is fitted into the opening 13 of the outer tube 10. The top tube 28 and the inner tube 20 are aligned in series in the axial direction inside the outer tube 10, and the hollows of the top tube 28 and the inner tube 20 are connected to each other.

[0025] The light emitting element 29 is attached to the end of the top tube 28 and is directed toward the opening 13 of the outer tube 10. The light emitting element 29 is, for example, an LED. When power is supplied from the battery 32 via the control panel 70, the light emitting element 29 irradiates light toward the opening 13 of the outer tube 10.

[0026] (2) Holder and battery The holder 30 is housed in the inner cylinder 20 and is fixed to the inner cylinder 20 at a position close to the end plate 24 . The battery 32 is attached to the holder 30 and is housed together with the holder 30 in the inner cylinder 20. The battery 32 is detachable from the holder 30. The battery 32 is a primary battery or a secondary battery.

[0027] (3) Retroreflectors and caps The retroreflector 40 is housed in the top tube 28. The retroreflector 40 is driven to move axially by an electric actuator 50 (described later), so that it protrudes from the top tube 28 beyond the opening 13 of the outer tube 10 or is stored inside the top tube 28. The retroreflector 40 retroreflects light rays that enter the retroreflector 40 from various directions using a prism mirror. The retroreflector 40 has, for example, at least one prism.

[0028] The cap 45 is attached to the retroreflector 40. The part where the cap 45 is attached to the retroreflector 40 is the end opposite the inner tube 20 with respect to the retroreflector 40. When the retroreflector 40 is stored in the top tube 28, the outer periphery of the cap 45 contacts the end of the outer tube 10 around the opening 13 of the outer tube 10, and the opening 13 of the outer tube 10 is closed by the cap 45. When the retroreflector 40 extends beyond the opening 13 of the outer tube 10 from the top tube 28, the outer periphery of the cap 45 separates from the end of the outer tube 10, and the opening 13 of the outer tube 10 is open. Note that a notch is formed in the cap 45 at a portion that overlaps with the light-emitting element 29. Therefore, even when the cap 45 is closed, light from the light-emitting element 29 passes through the notch, making the light-emitting element 29 visible from within the tunnel 99.

[0029] The cap 45 is made of an insulating material such as resin so as not to block the radio waves propagating between the control panel 70 and the remote controller 80. The inner cylinder 20 and the outer cylinder 10 may also be made of an insulating material. If the inner cylinder 20 or the outer cylinder 10 is made of a conductor such as metal, the radio waves propagating between the control panel 70 and the remote controller 80 will not leak outside the outer cylinder 10 except through the opening 13 of the outer cylinder 10, resulting in good communication between the control panel 70 and the remote controller 80.

[0030] (4) Electric actuator The electric actuator 50 is housed in the inner cylinder 20 and is fixed to the inner cylinder 20 at a position closer to the opening 13 of the outer cylinder 10 than the holder 30. The electric actuator 50 is powered by the battery 32 and drives the retroreflector 40 to move it in the axial direction.

[0031] The electric actuator 50 includes a linear guide 51 , a motor 52 , a torque limiter 53 , a lead screw 54 , a carriage 55 , a first stopper 56 , a second stopper 57 , and a fixing member 58 .

[0032] The linear guide 51 is fixed to the inner cylinder 20 inside the inner cylinder 20. The linear guide 51 extends in the axial direction. The motor 52 is fixed to the linear guide 51 at a position away from the opening 13 of the outer cylinder 10 towards the end plate 24. The motor 52 is, for example, a DC motor. The torque limiter 53 is connected to the drive shaft of the motor 52. The lead screw 54 extends in the axial direction at a position closer to the opening 23 of the inner cylinder 20 than the motor 52 and the torque limiter 53. By connecting the lead screw 54 to the torque limiter 53, the lead screw 54, the torque limiter 53, and the motor 52 are connected in series in this order. When the load torque acting from the lead screw 54 to the torque limiter 53 is less than a predetermined value, the torque limiter 53 maintains the connection between the lead screw 54 and the motor 52, and when the load torque acting from the lead screw 54 to the torque limiter 53 is less than a predetermined value, the torque limiter 53 disconnects the lead screw 54 from the motor 52.

[0033] The carriage 55 is guided in the axial direction by the linear guide 51, and the load of the carriage 55 in the circumferential direction is received by the linear guide 51. The carriage 55 has a nut into which the lead screw 54 is screwed. This allows the carriage 55 to move in the axial direction by rotation of the lead screw 54. The tip of the carriage 55 is attached to the retroreflector 40, and the retroreflector 40 moves in the axial direction together with the carriage 55. Hereinafter, the rotation of the lead screw 54 and motor 52 that moves the retroreflector 40 and carriage 55 outward from the opening 13 of the outer cylinder 10 will be referred to as forward rotation, and the rotation of the lead screw 54 and motor 52 that moves the retroreflector 40 and carriage 55 inward from the opening 13 of the outer cylinder 10 will be referred to as reverse rotation.

[0034] The carriage 55 has a protrusion 55a on its surface that protrudes radially outward from the surface. The first stopper 56 is fixed to the linear guide 51 via a fixing member 58, closer to the opening 13 of the outer tube 10 than the protrusion 55a. The second stopper 57 is fixed to the linear guide 51 via a fixing member 58, farther from the opening 13 of the outer tube 10 than the protrusion 55a. When the carriage 55 approaches the opening 13 of the outer tube 10 within the inner tube 20, the protrusion 55a abuts against the first stopper 56. Therefore, the first stopper 56 restricts the carriage 55 from moving outward from the opening 13 of the outer tube 10 and increases the load torque acting on the torque limiter 53 to a predetermined value or higher. When the protrusion 55a abuts against the first stopper 56, the retroreflector 40 is not stored inside the top tube 28, and protrudes from the top tube 28 beyond the opening 13 of the outer tube 10. When the carriage 55 moves away from the opening 13 of the outer tube 10 inside the inner tube 20, the protrusion 55a abuts against the second stopper 57. Therefore, the second stopper 57 restricts the carriage 55 from moving toward the end plate 24, and increases the load torque acting on the torque limiter 53 to a predetermined value or higher. When the protrusion 55a abuts against the second stopper 57, the retroreflector 40 is stored inside the top tube 28.

[0035] The protrusion 55a and the stoppers 56, 57 are made of conductors. The voltage level of the protrusion 55a is different from the voltage level of the stoppers 56, 57. For example, the protrusion 55a is grounded so that the voltage level of the protrusion 55a is low, and the stoppers 56, 57 are connected to the positive electrode of the battery 32 via a resistor so that the voltage level of the stoppers 56, 57 is high. When the protrusion 55a comes into contact with the stopper 56 or 57, the voltage level of the stoppers 56, 57 changes to low. The voltage level of the protrusion 55a may be high and the voltage level of the stoppers 56, 57 may be low. In this case, when the protrusion 55a comes into contact with the stopper 56 or 57, the voltage level of the protrusion 55a changes to low.

[0036] (5) Control panel The control panel 70 is attached to the holder 30 and is housed in the inner cylinder 20 .

[0037] The control panel 70 has a circuit board, a receiving antenna, a receiver, and a motor control circuit. The receiving antenna, receiver, and motor control circuit are mounted on the circuit board. The receiving antenna receives radio waves from a remote controller 80 (described below) and generates a current signal by generating a current from the radio waves. The receiver demodulates the current signal supplied from the receiving antenna into a command signal and transfers the command signal to the motor control circuit. The command signal includes commands from the remote controller 80 to the control panel 70. The commands include a storage command and a deployment command.

[0038] The motor control circuit controls the motor 52 in accordance with the command signal transferred from the receiver. Specifically, when the motor control circuit receives a deployment command signal from the receiver, it rotates the motor 52 in the forward direction. When the motor control circuit receives a storage command signal from the receiver, it rotates the motor 52 in the reverse direction.

[0039] The motor control circuit is electrically connected to one or both of the protrusion 55a and the stoppers 56, 57. The motor control circuit detects whether the protrusion 55a and the stoppers 56, 57 are in contact with each other by monitoring the voltage of one or both of the protrusion 55a and the stoppers 56, 57 while the motor 52 is rotating.

[0040] (6) Remote controller The remote controller 80 includes a storage switch, a deployment switch, a transmitter, a transmitting antenna, etc. The storage switch is turned on by an operator pressing or otherwise operating the switch. The deployment switch is turned on by an operator pressing or otherwise operating the switch. When an ON signal is input from the storage switch, the transmitter modulates radio waves in accordance with the command signal of the storage command and transmits the radio waves carrying the command signal of the storage command from the transmitting antenna. When an ON signal is input from the deployment switch, the transmitter modulates radio waves in accordance with the command signal of the deployment command and transmits the radio waves carrying the command signal of the deployment command from the transmitting antenna. The radio waves transmitted by the transmitter and transmitting antenna are received by the receiving antenna of the control panel 70.

[0041] 2. Optical Targeting Device Installation Method As shown in Figures 1 and 4, as tunnel excavation progresses, a plurality of mounting holes 97 are drilled into the inner wall of the tunnel 99 at intervals around the circumference of the tunnel 99. The mounting holes 97 are located near but away from the tunnel face. Figure 4 is an enlarged view of region IV shown in Figure 1.

[0042] Thereafter, the end plates 14 of the outer tube 10 are directed toward the back of the mounting holes 97, and the optical target devices 1 are fitted into the mounting holes 97, and the flange 17 of the outer tube 10 is brought into contact with the inner wall of the tunnel 99 around the mounting hole 97. As a result, almost the entire optical target device 1, that is, the outer tube 10 (excluding the flange 17), waterproof film 18, inner tube 20, top tube 28, holder 30, battery 32, retroreflector 40, electric actuator 50, and control panel 70, are inserted into the mounting hole 97. In addition, the cap 45 of the optical target device 1 is provided along the inner wall 98 of the tunnel 99 and is exposed inside the tunnel 99.

[0043] When the optical target device 1 is fitted into the mounting hole 97, the outer surface of the outer tube 10 is in contact with the inner surface of the mounting hole 97, and the first anti-slip surface 15 and the second anti-slip surface 16 are slightly compressed. The first anti-slip surface 15 prevents the outer tube 10 from sliding axially relative to the mounting hole 97, and the second anti-slip surface 16 prevents the outer tube 10 from sliding circumferentially relative to the mounting hole 97.

[0044] 3. How to use the optical targeting device when not measuring Times other than when measurements are being taken include, for example, when excavating Tunnel 99, when materials are being brought in, when materials are being removed, when shoring is being constructed, when shoring is being removed, when lining is being constructed, and when spraying work is being carried out.

[0045] When the operator presses or otherwise operates the storage switch on the remote controller 80, a storage command signal is sent from the remote controller 80 to the control panel 70 of the optical target device 1. This causes the motor control circuit of the control panel 70 to drive the motor 52 of the electric actuator 50 in the reverse direction, which causes the retroreflector 40 to be retracted into the top tube 28 as shown in FIG. 5, and the opening 13 of the outer tube 10 to be closed by the cap 45. When the outer periphery of the cap 45 hits the end of the outer tube 10, the protrusion 55a of the carriage 55 hits the second stopper 57. As a result, the load torque acting on the torque limiter 53 exceeds a predetermined value, and the lead screw 54 is disconnected from the motor 52 by the torque limiter 53. Furthermore, when the protrusion 55a of the carriage 55 hits the second stopper 57, the voltage level of the protrusion 55a or the second stopper 57 drops from a high level to a low level, and the motor control circuit of the control panel 70 uses this voltage drop as a trigger to stop the motor 52.

[0046] Although only the cap 45 is exposed inside the tunnel 99, most of the optical targeting device 1, especially the retroreflector 40, fits inside the mounting hole 97. Therefore, the optical targeting device 1 does not interfere with the construction work of the tunnel 99. In particular, the retroreflector 40 is protected from debris generated by blasting at the tunnel face, so that the retroreflector 40 is not hit.

[0047] Even when the cap 45 is closed, the operator can visually recognize the light from the light emitting element 29 and thus grasp the position of the optical target device 1. This is particularly effective when the inside of the tunnel 99 is dark.

[0048] Furthermore, even if the operator operates the storage switch when the retroreflector 40 is retracted into the top tube 28, the motor control circuit of the control panel 70 ignores the storage command and does not operate the motor 52.

[0049] 4. How to use the optical targeting device during measurement When the operator presses or otherwise operates the deployment switch on the remote controller 80, a deployment command signal is sent from the remote controller 80 to the control panel 70 of the optical target device 1. This causes the motor control circuit of the control panel 70 to drive the motor 52 of the electric actuator 50 to rotate in the forward direction, which causes the retroreflector 40 to be extended from the mounting hole 97 to the inside of the inner wall 98 as shown in FIG. 6, and the cap 45 to release the closure of the opening 13 of the outer tube 10 and the mounting hole 97. Then, the protrusion 55a of the carriage 55 hits the first stopper 56, causing the load torque acting on the torque limiter 53 to exceed a predetermined value. As a result, the lead screw 54 is disconnected from the motor 52 by the torque limiter 53. Furthermore, when the protrusion 55a of the carriage 55 hits the first stopper 56, the voltage level of the protrusion 55a or the first stopper 56 drops from high to low, and the motor control circuit of the control panel 70 uses this voltage drop as a trigger to stop the motor 52. Even if the operator operates the storage switch when the retroreflector 40 is extended from the top tube 28 beyond the opening 13 of the outer tube 10, the motor control circuit of the control panel 70 ignores the deployment command and does not operate the motor 52.

[0050] Thereafter, the surveying instrument 85 is set inside the tunnel 99. When a light beam is projected from the surveying instrument 85 onto the retroreflector 40 of the optical target device 1, the light beam is retroreflected by the retroreflector 40 back to the surveying instrument 85, and the reflected light beam is received by the surveying instrument 85. The surveying instrument 85 then measures the distance from the surveying instrument 85 to the retroreflector 40, as well as the tilt angle and pan angle, and the three-dimensional position of the retroreflector 40 is calculated by the surveying instrument 85 based on the distance, tilt angle, and pan angle.

[0051] After the measurement is completed, when the operator operates the storage switch, the control unit 70 activates the electric actuator 50 , and the retroreflector 40 is stored inside the top tube 28 by the electric actuator 50 .

[0052] The above measurements are carried out periodically, for example, every day.

[0053] 5. Summary When not taking measurements, the retroreflector 40 is stored inside the mounting hole 97, so the retroreflector 40 does not get in the way of tunnel construction work. In addition, debris and equipment from blasting at the tunnel face, etc., do not hit the retroreflector 40. Therefore, there is no need to remove the retroreflector 40 and the optical target device 1 from the inner wall 98 of the tunnel 99. Furthermore, there is no need to install and remove the retroreflector 40 and the optical target device 1 every time a measurement is taken. Therefore, the effort and labor required for measurement can be minimized. In addition, there is no need to work at height every time a measurement is taken, and measurements of the inner wall 98 of the tunnel 99 can be taken safely.

[0054] When the retroreflector 40 is stored inside the mounting hole 97 and the outer cylinder 10, the mounting hole 97 is covered with the cap 45. Thus, the retroreflector 40 is protected.

[0055] The cap 45 is made of an insulating material. Therefore, even if the opening 13 and the mounting hole 97 of the outer cylinder 10 are covered with the cap 45, the radio waves emitted from the remote controller 80 are not blocked by the cap 45 and can propagate to the control panel 70.

[0056] The light emitting element 29 is provided at the end of the optical target device 1, and the light emitting element 29 is not hidden by the cap 45. The operator can recognize the position of the optical target device 1 through the light from the light emitting element 29.

[0057] A torque limiter 53 is attached between the lead screw 54 and the motor 52. This prevents the motor 52 from being overloaded.

[0058] When the protrusion 55a of the carriage 55 hits the first stopper 56 or the second stopper 57, the motor 52 is stopped by the motor control circuit. This prevents the motor 52 from being overloaded. Furthermore, the retroreflector 40 can be stopped at a predetermined position without employing a complex position control mechanism such as a servo mechanism. The predetermined position refers to the position where the retroreflector 40 protrudes from the outer tube 10 and the mounting hole 97, and the position where the retroreflector 40 is stored inside the outer tube 10 and the mounting hole 97.

[0059] 6. Variations Although the embodiments have been described above, the scope of the present invention is not limited to the above-described embodiments and illustrated examples. In the above embodiment, communication between the remote controller 80 and the control panel 70 of the optical target device 1 is wireless, but it may also be wired.

[0060] In the above-described embodiment, the linear transmission mechanism consisting of the carriage 55 and the lead screw 54 converts the rotational motion of the motor 52 into linear motion of the retroreflector 40. Instead of the linear transmission mechanism consisting of the carriage 55 and the lead screw 54, other linear transmission mechanisms, such as a pinion-rack mechanism or a wrap-around transmission mechanism, may be used.

[0061] In the above-described embodiment, the tunnel 99 is under construction. However, after the construction of the tunnel 99 is completed, the interior wall 98 of the tunnel 99 can be measured using the surveying instrument 85 and the optical targeting device 1. In addition, by drilling a mounting hole in the inner wall of an existing tunnel and fitting the optical target device 1 into the mounting hole, the inner wall of the existing tunnel can be measured using the surveying instrument 85 and the optical target device 1. [Explanation of symbols]

[0062] 1 Optical targeting device 40 Retroreflector 45 Cap 50 Electric Actuator 52 Motor 70 Control panel (control section) 97 Mounting hole 98 Inner wall 99 Tunnel

Claims

1. An outer cylinder that is fitted into a mounting hole formed in the inner wall of a tunnel; an inner cylinder that is assembled to the outer cylinder so as to be housed in the outer cylinder coaxially; an actuator housed in the inner cylinder; a retroreflector coupled to the actuator; The optical targeting device, wherein the actuator moves the retroreflector to project it from the inner cylinder to inside the inner wall and to retract it inside the inner cylinder.

2. A waterproof film sandwiched between the inner tube and the outer tube.

10. The optical targeting device of claim 1, comprising:

3. The outer cylinder has a convex portion formed in a convex shape on its outer circumferential surface.

3. An optical targeting device according to claim 1 or 2.

4. The retroreflector retroreflects light rays incident on the retroreflector from various directions.

3. An optical targeting device according to claim 1 or 2.

5. A light emitting element provided at an end of said outer cylinder on the inside of said inner wall.

3. The optical targeting device of claim 1 or 2, further comprising:

6. Further comprising a control unit housed in the inner cylinder and controlling the actuator; When the control unit receives a deployment command from a remote controller that remotely operates the control unit, the control unit causes the actuator to project the retroreflector from the inner tube to the inside of the inner wall, The optical targeting device of claim 1 or 2, wherein when the control unit receives a retraction command from the remote controller, the control unit causes the actuator to retract the retroreflector inside the inner tube.

7. A cap attached to the retroreflector and made of an insulating material is further provided. the control unit has a receiving antenna for receiving radio waves transmitted by the remote controller and including the deployment command or the storage command, When the retroreflector is stored in the inner cylinder, the cap closes the opening of the outer cylinder at the end of the outer cylinder on the inside of the inner wall, and when the retroreflector is extended from the inner cylinder to the inside of the inner wall, the cap moves away from the end of the outer cylinder, opening the opening of the outer cylinder.

7. The optical targeting device of claim 6.

8. 3. A measurement method for measuring the inner wall of the tunnel using the optical targeting device according to claim 1 or 2, comprising: After the retroreflector is projected from the inner cylinder to the inside of the inner wall by the actuator, the three-dimensional position of the retroreflector is measured by the optical surveying instrument by collimating the retroreflector from the inside of the inner wall using the optical surveying instrument. Measurement method.

9. After measuring the three-dimensional position of the retroreflector, the actuator stores the retroreflector in the inner cylinder. The measurement method according to claim 8.

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