Underwater shape information acquisition system

Abstract

To provide a system with which, in a nuclear power plant or a decommissioning plant after Fukushima earthquake disaster where measurement is hardly feasible by fixation in a reactor, it is possible to measure an unknown shape with high accuracy without fixation.SOLUTION: The system comprises a shape information measurement part 3 for measuring the shape information of an object in a retained liquid, and a position detection unit 20 floating in the retained liquid, for detecting the position of the shape information measuring part in the liquid. The shape information measurement part is suspended in the position detection unit. The position detection unit includes a laser measurement part 21 for irradiating the inner circumferential surface of a tank with laser light while rotating around the axis of rotation in a direction intersecting with the liquid surface of the liquid and acquiring point cloud data indicating the measurement result of the distance to the inner circumferential surface by receiving the irradiated laser light, and a position detection part for calculating the position in XY coordinate system of the position detection unit on the basis of the acquired point cloud data.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an underwater shape information acquisition system. [Background technology]

[0002] It is necessary to obtain underwater shape information in order to plan the dismantling of decommissioning plants and nuclear power plants after the Fukushima earthquake. For this purpose, the shape of the reactor interior is measured underwater, and a drawing is created from the obtained point cloud data, and a dismantling plan for the nuclear power plant is based on that information. Underwater shape information acquisition systems for obtaining shape information underwater can be broadly divided into ultrasonic and laser methods. Measurements are performed inside metal vessels at decommissioning plants and nuclear power plants affected by the Fukushima earthquake, so ultrasonic systems cannot be used due to the reverberation, and laser systems are used instead. Known laser measurement methods include the Time of Flight (TOF) method and triangulation. TOF measures the time it takes for a laser to hit the subject and return, resulting in poor accuracy or measurement failure when measuring shiny metals or curved surfaces, which are difficult for lasers to measure. Furthermore, triangulation determines the measurement distance based on the angle between the laser and the receiving camera, and while it is highly accurate, it has the drawback of limiting the distance to the object being measured.

[0003] Conventionally, when measuring a wide area of ​​an object underwater shape information acquisition system, the key to acquiring accurate point cloud data is to ensure that the origin at the start and end of measurement does not deviate from one another. For this reason, the mainstream system acquires point cloud data without deviation by fixing the underwater shape information acquisition system and performing rotational measurements, but the locations where such a system can be installed are extremely limited.

[0004] Therefore, a method has been proposed in which a diver holds a camera in his / her hand and approaches the object to be measured to take a photograph. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-61513 Summary of the Invention [Problem to be solved by the invention]

[0006] However, high levels of radiation exist in decommissioning plants and inside reactors of nuclear power plants after the Fukushima earthquake, making measurements by divers impossible. Furthermore, while handheld measuring devices that divers use manually can measure distances and dimensions, they have the problem of being unable to measure areas where data can be combined because the origin position cannot be fixed.

[0007] The present invention has been made in light of the above-mentioned circumstances, and its object is to provide a system that can measure unknown shapes with high accuracy without fixing the measuring device, in nuclear power plants affected by the Fukushima earthquake and decommissioning plants, where it is almost impossible to fix the measuring device and perform measurements. [Means for solving the problem]

[0008] In order to solve the above problems, the underwater shape information acquisition system of the embodiment comprises a shape information measurement unit for measuring shape information of an object in a stored liquid, and a position detection unit that floats in the stored liquid and detects the position of the shape information measurement unit in the liquid, wherein the shape information measurement unit is suspended from the position detection unit, and the position detection unit has a laser measurement unit that irradiates a laser beam onto the inner surface of the tank while rotating around a rotation axis that intersects with the liquid surface, and receives the irradiated laser beam to acquire point cloud data that indicates the measurement results of the distance to the inner surface, and a position detection unit that calculates the position of the position detection unit on an XY coordinate system based on the acquired point cloud data.

[0009] In one aspect of the configuration, the position detection unit has a hull capable of self-propelling, and the shape information measurement unit is removably connected to an attachment portion provided at the tip of a connecting member suspended from the hull of the position detection unit.

[0010] In one aspect of the above configuration, the shape information measurement unit further includes a depth sensor that detects the depth in the liquid, and a display device that displays the position of the position detection unit on an XY coordinate system and the position on a Z coordinate system that represents the depth relative to the depth sensor, and the display device displays the captured object as an image on an XYZ coordinate system along the liquid surface.

[0011] In one aspect of the above configuration, the depth gauge is a pressure type.

[0012] In one aspect of the configuration, the device further includes an ultrasonic output sensor that detects the depth of the shape information measurement unit by irradiating ultrasonic waves to the shape information measurement unit and receiving the reflected light, and a display device that displays the position of the position detection unit on an XY coordinate system and the position on a Z coordinate system that represents the depth relative to the depth sensor, and the display device displays the imaged object as an image on an XYZ coordinate system along the liquid surface.

[0013] In one aspect of the configuration, the laser measuring device further includes an acceleration sensor for checking horizontality to keep the laser measuring unit horizontal.

[0014] In one aspect of the configuration, the connecting member is equipped with a gyro sensor that corrects the angle of the yaw axis using an optical fiber gyro.

[0015] In one aspect of the above configuration, the shape information measuring unit is a camera. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a block diagram showing an underwater shape information acquisition system 1 according to the present embodiment. [Figure 2] 1 is a plan view showing an underwater shape information acquisition system 1 according to the present embodiment. [Figure 3] 3 is a cross-sectional view taken along line III-III in FIG. 2 showing the underwater shape information acquisition system 1 according to the present embodiment. [Figure 4]1 is a side view showing a position detection unit 20 in an underwater shape information acquisition system 1 according to the present embodiment. [Figure 5] 1 is a plan view showing a position detection unit 20 in an underwater shape information acquisition system 1 according to the present embodiment. [Figure 6] FIG. 10 is a schematic diagram showing a modified example of the underwater shape information acquisition system 1 according to the present embodiment. [Figure 7] FIG. 10 is a schematic diagram showing a modified example of the underwater shape information acquisition system 1 according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments.

[0018] First, an underwater shape information acquisition system 1 according to this embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 1 is a block diagram showing the underwater shape information acquisition system 1 according to this embodiment. Fig. 2 is a plan view of the underwater shape information acquisition system 1 of Fig. 1. Fig. 3 is a cross-sectional view taken along III-III in Fig. 2. Fig. 4 is a plan view of the position detection unit 20 of Fig. 1.

[0019] The underwater shape information acquisition system 1 can be used to detect the position of a three-dimensional shape measurement device (shape information measurement unit) 3 for imaging (measuring) an object such as the inside of a reactor of a nuclear power plant located in water 10 stored in a tank 9, using a position detection unit 20 that floats in the stored liquid water 10 and detects the position of the underwater three-dimensional shape measurement device 3. The three-dimensional shape measurement device 3 suspended from the position detection unit 20 dives underwater to image the interior of the tank 9 and detect deterioration of the metal tank 9.

[0020] As shown in FIG. 1, the underwater shape information acquisition system 1 includes a position detection device 2, a three-dimensional shape measurement device 3, a light source 4 for indicating the direction of movement of the three-dimensional shape measurement device 3, a power supply unit 7 for the three-dimensional shape measurement device, and a PC (personal computer) 8 for the three-dimensional shape measurement device. While the present embodiment uses four light sources 4, the present invention is not limited to this. For example, the present invention may use one, two, or five or more light sources. The position detection device 2 in FIG. 1 floats in water 10 stored in a tank 9 and detects the position of the underwater three-dimensional shape measurement device 3. The position detection device 2 in FIG. 1 includes a position detection unit 20, a position detection power supply unit 5, and a position detection PC 6, which is a display device. Here, a position detection CPU 22, which serves as a position detection unit, calculates the position of the position detection unit 20 on an XY coordinate system based on the acquired point cloud data, as described below. Then, the position detection CPU 22 transmits data on the position of the position detection unit 20 on the XY coordinate system to the position detection PC 6 .

[0021] A position detection unit 20 floating in water 10 inside the tank 9 is connected to a position detection power supply unit 5 and a position detection PC 6 arranged on the ground side by a cable 11. As shown in Figure 2, the position detection unit 20 is dropped into the water while being suspended from the upper end of a tank manhole 91 that passes through a tank manhole 91 that partially penetrates a top plate 90 of the tank 9.

[0022] The position detection power supply unit 5 supplies power to the position detection unit 20 via a cable 11 .

[0023] The position detection PC 6 receives the detection result of the position of the position detection unit 20 relative to an origin (described later) from the position detection unit 20 via the cable 11. The position detection PC 6 also receives the detection result of the depth of the three-dimensional shape measurement device 3 by a depth sensor 31 (described later) from the three-dimensional shape measurement device PC 8. Then, based on these received detection results, the position detection PC 6 calculates (detects) the position of the three-dimensional shape measurement device 3 relative to an origin (described later). Then, the position detection PC 6 displays the calculated position of the three-dimensional shape measurement device 3 on the monitor screen as an image and numerical values ​​on an XY coordinate system.

[0024] The three-dimensional shape measuring device 3, which works by submerging inside the tank 9, is connected via a cable 12 to a three-dimensional shape measuring device power supply unit 7 and a three-dimensional shape measuring device PC 8, which are located on the ground.

[0025] The power supply unit 7 for the three-dimensional shape measuring device supplies power to the three-dimensional shape measuring device 3 via a cable 12 .

[0026] The PC 8 for three-dimensional shape measuring device receives, via the cable 12, an image of the inside of the tank 9 captured by a camera 33 (described later) and a result of detection of the depth of the three-dimensional shape measuring device 3 by a depth sensor 31 (described later) from the three-dimensional shape measuring device 3. The PC 8 for three-dimensional shape measuring device transmits the received result of detection of the depth of the three-dimensional shape measuring device 3 to the PC 6 for position detection.

[0027] The position detection unit 20 will be described below. As shown in Fig. 1, the position detection unit 20 includes a laser unit (LIDER) 21, which is a laser measurement unit that can rotate 360 ​​degrees around the Z axis on an XY plane, a position detection CPU (Central Processing Unit) 22, which is a position detection unit, a camera 23, which is an imaging device, a movement thruster 24, which is a movement device, a CPU 25, a thruster activation unit 26, a horizontality confirmation acceleration sensor 27 for keeping the laser unit 21 horizontal, and a power supply separation unit 28. Furthermore, as shown in Figs. 3 and 4, the position detection unit 20 includes a self-propelled hull (frame) 210, a buoyant body 211, and a hull control device 26 for controlling the movement of the hull 210. Here, in a coordinate system having mutually orthogonal X-, Y-, and Z-axes, the Z-axis is defined as the direction opposite to the direction of gravity. The laser unit (LIDER) 21 rotates 360 degrees around the Z axis, measures the distance to the object to be measured, determines where the hull (frame) 210 is located, and identifies the measurement position.

[0028] 3, a hull control device 26, a horizontality checking acceleration sensor 27, and a camera 23 are mounted on a hull 210, and a laser unit 21 is mounted on the horizontality checking acceleration sensor 27. A buoyant body 211 is mounted on the bottom of the hull 210, and thrusters 24 for moving the position detection unit 20 are provided below the buoyant body 211.

[0029] The attitude control mechanism may be configured using a reaction wheel as the rotating body. Here, the reaction wheel has a wheel (disk) and a motor connected to the wheel's rotation shaft. When a rotational torque is applied to the wheel, the motor receives a torque in the opposite direction to the rotational torque. Therefore, when the motor is fixed to the aircraft and the wheel is rotated, the aircraft begins to rotate in the opposite direction to the rotational direction of the wheel. In this way, the attitude of the laser unit 21 can be controlled by appropriately controlling the rotation of the wheel. Furthermore, an inertial measurement unit (IMU) may be used as a rotation control mechanism for the hull 210, and a single-axis gyro system may be used to maintain the direction of movement of the hull 210. The three-dimensional shape measuring device 3 is detachably connected to a mounting part (hanging tool) 47 provided at the tip of a single-line hoisting jig (connecting member) 46 suspended from the hull (frame) of the position detection unit 20.

[0030] It may also be configured to use an IMU to obtain position information. In this case, since roll and pitch are limited by the single-line suspension, it is necessary to reduce the deviation of the yaw axis in the rotational direction. Therefore, since the yaw axis affects the direction of travel, the IMU position information is corrected using an optical fiber gyro to control the direction of travel, and the course is measured by stabilizing the angle of the yaw axis for a long period of time.

[0031] In Figure 4, the position detection unit 20 has four rod-shaped frames 210 that intersect in a crisscross pattern, and at the intersection of each frame 210, a laser unit 21 and a camera 23 are arranged above and below, and on the opposite side of the intersection of each frame 210, a buoyant body 211 and a movement thruster 24 are arranged.

[0032] The laser unit 21 includes a laser rangefinder and a control unit that controls the laser rangefinder. The laser unit 21 irradiates the inner circumferential surface 90a with laser light from an irradiating unit of the laser rangefinder while rotating 360 degrees around a rotation axis that is approximately perpendicular (i.e., intersects) with the water surface 10a while floating in the water due to the buoyancy of the buoyant body 211. The laser unit 21 receives the laser light irradiated to the inner circumferential surface 90a with a light-receiving unit (not shown) of the laser rangefinder, thereby acquiring point cloud data that indicates the measurement results of the distance from the position detection unit 20 (i.e., the position detection device 2) to the inner circumferential surface 90a.

[0033] 3, when the position detection unit 20 is floating on the water 10, the laser unit 21 is positioned above the water surface 10a without being immersed in the water 10. As a result, the laser unit 21 is positioned above the water surface 10a, and the laser unit 21 can emit and receive laser light in the air. This makes it possible to obtain point cloud data that accurately indicates the distance to the inner circumferential surface 90a of the tank 9.

[0034] 3, the camera 23 captures an image of the three-dimensional shape measuring device 3 located underwater. The camera 23 is disposed on the hull (frame) 210 so that the optical axis faces vertically downward when the position detection unit 20 is floating on the water 10.

[0035] The movement thrusters 24 move the position detection unit 20 above the water surface 10a. The movement thrusters 24 are activated and stopped by a thruster activation unit 26. As shown in FIG. 1, the three light-emitting bodies 4 mounted on the three-dimensional shape measurement device 3 are arranged in a triangular shape to indicate the movement direction of the three-dimensional shape measurement device 3, as indicated by the arrow A in FIG. 2. When the position of the image of the light-emitting body 4 in the image captured by the camera 23 (described later) of the three-dimensional shape measurement device 3 changes, the thruster activation unit 26 activates the movement thrusters 24 so that the position detection unit 20 moves toward the movement direction A identified by the image of the light-emitting body 4. This allows the position detection unit 20 to move to follow the movement of the three-dimensional shape measurement device 3, thereby enabling the three-dimensional shape measurement device 3 to be continuously captured within the field of view of the camera 23. The movement of the position detection unit 20 to continuously capture the three-dimensional shape measurement device 3 within the field of view of the camera 23 may be manually performed by an operator while checking the image captured by the camera 23.

[0036] The position detection CPU 22 determines the origin of the position detection unit 20 (i.e., the position detection device 2) based on the point cloud data acquired by the laser unit 21. More specifically, the position detection CPU 22 determines a specific position within the area surrounded by the point cloud data acquired by the laser unit 21 as the origin of the coordinates (position) of the position detection unit 20. For example, the origin may be the center point of the area surrounded by the point cloud data, i.e., the center of the tank 9. Then, the position detection CPU 22 executes processing to detect the position of the three-dimensional shape measuring device 3 based on the determined origin.

[0037] Specifically, the position detection CPU 22 detects the position of the position detection unit 20 on the XY coordinate system with respect to the origin in accordance with the movement of the position detection unit 20 by the movement thrusters 24. More specifically, the position detection CPU 22 detects the position of the position detection unit 20 with respect to the origin by comparing the position of the position detection unit 20 in the area surrounded by the point cloud data acquired by the laser unit 21 after movement by the movement thrusters 24 with the origin. With this configuration, it becomes possible to freely collect data by registering the origin and to synthesize the data to create a three-dimensional image.

[0038] Furthermore, the position detection CPU 22 captures the image of the three-dimensional shape measurement device 3 captured by the camera 23 via the CPU 25, and detects the position of the position detection unit 20 as the position of the three-dimensional shape measurement device 3 based on the captured image of the three-dimensional shape measurement device 3. More specifically, the position detection CPU 22 recognizes the blinking of the light-emitting body 4 via the image of the three-dimensional shape measurement device 3 captured by the camera 23, and detects the position of the position detection unit 20 as the position of the three-dimensional shape measurement device 3 by performing image processing on the image of the three-dimensional shape measurement device 3 captured via the CPU 25.

[0039] The position detection CPU 22 transmits the detection results of the position detection unit 20 based on the origin and the detection results of the position of the three-dimensional shape measuring device 3 based on the origin to the position detection PC 6 via the cable 11.

[0040] The position detection PC 6 displays the position of the position detection unit 20 relative to the origin transmitted from the position detection CPU 22 as the position of the three-dimensional shape measuring device 3 .

[0041] When the position detection unit 20 is immersed in water, the acceleration sensor 27 for checking horizontality checks whether the position detection unit 20 is parallel, i.e., horizontal, to the water surface 10a. If the position detection unit 20 is not parallel to the water surface 10a, the suspension device 92 adjusts the inclination of the position detection unit 20 until the acceleration sensor 27 for checking horizontality checks that the position detection unit 20 is parallel.

[0042] The CPU 25 controls the overall operation of the components 21-24, 26, and 27 of the position detection unit 20. The power supply separation unit 28 distributes the power supplied from the position detection power supply unit 5 to the components 21-27 of the position detection unit 20.

[0043] The following provides a detailed description of the three-dimensional shape measuring device 3. As shown in Fig. 1, the three-dimensional shape measuring device 3 includes a depth sensor 31, which is a depth meter, a marker control unit 32, a camera 33, which is a shape information measuring unit for measuring shape information of an object in stored liquid, a CPU 34, and a power supply separation unit 35.

[0044] The depth sensor 31 is mounted on the three-dimensional shape measurement device 3 and detects the depth of the three-dimensional shape measurement device 3 underwater. The depth sensor 31 is a pressure-type depth sensor. By using the pressure-type depth sensor 31 instead of a magnetic-type depth sensor, the depth of the three-dimensional shape measurement device 3 can be accurately detected without being affected by echoes from the metal tank 9.

[0045] In the present invention, the distance (depth) from the water surface of the three-dimensional shape measurement device 3 is measured using a pressure-type depth sensor. However, the present invention is not limited to this. For example, the present invention may be configured using an ultrasonic depth sensor instead of a pressure-type depth sensor. As shown in Figure 6, ultrasonic waves are emitted inside the wire, and a reflector 51 is installed on top of the three-dimensional shape measurement device 3 to measure the reflection speed of the ultrasonic waves and measure the depth. In other words, an ultrasonic depth sensor can detect the depth of the three-dimensional shape measurement device 3 by irradiating the three-dimensional shape measurement device 3 with ultrasonic waves and receiving the reflected light. This configuration is not affected by ultrasonic noise, which is a problem in metallic environments. Furthermore, accuracy is not reduced by the effects of environments with salt or temperature changes.

[0046] The depth sensor 31 transmits the depth detection result of the three-dimensional shape measuring device 3 to the PC 8 for three-dimensional shape measuring device via the cable 12. The PC 8 for three-dimensional shape measuring device transfers the transmitted depth detection result to the PC 6 for position detection.

[0047] The marker control unit 32 controls the driving of the light emitter 4 so that the light emitter 4 blinks.

[0048] The camera 33 captures an image of the inside of the tank 9. The camera 33 transmits the captured image of the inside of the tank 9 to the PC 8 for three-dimensional shape measuring device via the cable 12.

[0049] The CPU 25 controls the operations of the components 31 to 33 of the three-dimensional shape measuring device 3 in an integrated manner.

[0050] The power supply separation unit 35 distributes the power supplied from the three-dimensional shape measuring apparatus power supply unit 7 to each of the components 31 to 34 of the three-dimensional shape measuring apparatus 3.

[0051] Next, a method for capturing an image of an object such as the inside of a reactor of a nuclear power plant will be described.

[0052] 3, the position detection unit 20 is suspended from the tank manhole 91 into the tank 9 by the suspension device 92, and then the position detection unit 20 is dropped into the water. At this time, the horizontality confirmation acceleration sensor 27 checks whether the position detection unit 20 is horizontal with respect to the water surface 10a, and if it is not horizontal, the suspension device 92 adjusts the inclination of the position detection unit 20 so that it is horizontal.

[0053] Then, at the position where the position detection unit 20 is placed in the water, i.e., directly below the tank manhole 91, the laser unit 21 irradiates the inner circumferential surface 90a of the tank 9 with laser light along the circumferential direction while rotating 360 degrees in a rotational direction around a rotation axis (Z-axis) approximately perpendicular to the water surface 10a, as shown in Fig. 7. The laser unit 21 then receives the laser light irradiated onto the inner circumferential surface 90a, and measures the distance from the position detection unit 20 to the inner circumferential surface 90a based on the time from when the laser light is emitted to when it is received. The laser unit 21 then acquires point cloud data indicating the distance measurement results, as shown in Fig. 6.

[0054] After acquiring the point cloud data, the position detection CPU 22 calculates the center position of the tank 9 within the area surrounded by the acquired point cloud data d0, and determines the calculated center position of the tank 9 as the origin (0,0) of the position detection unit 20.

[0055] Furthermore, the movement thruster 24 automatically or manually moves the position detection unit 20 to a position where the light emitting body 4 mounted on the three-dimensional shape measurement device 3 is captured within the viewing angle of the camera 23 .

[0056] After determining the origin, the camera 23 of the position detection unit 20 captures an image of the light-emitting body 4 of the three-dimensional shape measurement device 3. The image of the light-emitting body 4 is captured after the position detection unit 20 is moved to a position where the light-emitting body 4 is captured.

[0057] After capturing an image of the light-emitting body 4, the position detection CPU 22 compares the position of the position detection unit 20 in the area surrounded by the point cloud data acquired by the laser unit 21 after movement with the origin, thereby calculating the position of the position detection unit 20 based on the origin (0,0).

[0058] Next, the PC 8 for three-dimensional shape measuring device receives depth data detected by the depth sensor 31 and transmits it to the PC 6 for position detection. The PC 6 for position detection receives the detection results of the position of the position detection unit 20 relative to the origin. Then, based on these received detection results, the PC 6 for position detection calculates (detects) the position of the three-dimensional shape measuring device 3 relative to the origin. At this calculated timing, the camera 33 captures an image of the interior of the tank 9, and the captured image data is transmitted to the PC 6 for position detection via the PC 8 for three-dimensional shape measuring device. The PC 6 for position detection then displays the calculated position of the three-dimensional shape measuring device 3 on the monitor screen as an image and numerical values ​​on an XY coordinate system. By combining the images at each coordinate, a three-dimensional image of the object is displayed on the PC 6 for position detection.

[0059] The underwater shape information acquisition system 1 according to this embodiment makes it possible to measure unknown shapes with high precision without fixing a measuring device, even in places covered with thick metal and concrete, such as decommissioning plants and nuclear power plants affected by the Fukushima earthquake, where it is almost impossible to fix a measuring device inside the reactor for measurements.

[0060] [Other embodiments] The three-dimensional shape measuring device 3 may be configured with a gyro sensor. In this case, by detecting the angle and controlling the rotation of the attitude control flywheel, it becomes possible to stabilize the attitude by the rotational force. Furthermore, a gyro sensor 50 (see FIG. 6) may be mounted on the single-line hoisting jig (connecting member) 46, and configured to control the three-dimensional shape measuring device 3 so that it is always level. Therefore, even if the hull (frame) 210 tilts when it moves, it is possible to keep the three-dimensional shape measuring device 3 level (the three-dimensional shape measuring device 3 tilts after the hull 210 moves, which causes a time lag, but this time lag can be prevented).

[0061] In the above embodiment, a self-propelled hull is used and the three-dimensional shape measurement device 3 is suspended from the hull. However, the present invention is not limited to this. For example, the three-dimensional shape measurement device 3 may be moved by a single suspension using a crane or the like, without using a self-propelled hull. In this case, as shown in Figure 7, a measuring device 48 is attached below the three-dimensional shape measurement device 3, which has a cylindrical tube with three propellers spaced 120 degrees apart. The speed of movement is determined by the rotation of the propellers, and the movement distance is calculated by integration. The direction is first determined with the measuring unit facing forward, and the device is inserted, and the angle (orientation) is obtained with a single-axis sensor, and the position is determined by combining this with the movement distance. Note that although the figure shows three propellers, three or more is sufficient, and the more propellers there are, the more accurate the measurement.

[0062] 7, the position detection unit 20A differs from the position detection unit 20 according to the above-described embodiment in that it includes two laser units 21. The position detection unit 20A uses two distance measurement laser units (LIDER) 21 to measure 270 degrees, and by overlapping the measurement angle to eliminate and correct blind spots, it is possible to perform 360-degree measurement.

[0063] As shown in FIG. 7, the position detection unit 20A may be configured to be connected later to the three-dimensional shape measurement device 3, which is suspended by a single stainless steel wire, using a clamp mechanism. In this case, a mechanical clamping mechanism may be used. Furthermore, a clamping mechanism 55 (see FIG. 7), such as a non-contact eddy current magnetic sensor or photoelectric sensor, may be used to remotely attach the wire. In this case, the clamping mechanism 55 is used to detect the wire at a position of 8 mm when the wire is aligned with the center of the U-shaped hull, and the position detection unit identifies the position of the three-dimensional shape measurement device 3 while maintaining a gap by controlling the thruster in a certain direction. With this configuration, compared to using a mechanical clamping mechanism, tension is applied to the wire due to the gripping force or angle, and this does not affect the posture of the three-dimensional shape measurement device 3 in the water.

[0064] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims. [Explanation of symbols]

[0065] 1. Underwater shape information acquisition system 2. Position detection device 3. Three-dimensional shape measurement device (shape information measurement unit) 4. Luminous Object 5 Position detection power supply unit 6 PC for position detection 7. Power supply unit for 3D shape measurement device 8 PC for 3D shape measurement device 9. Tank 10 water 20 Position detection unit 21 Laser unit 22 Position detection CPU 23,33 Camera 24 Movement thrusters 25,34 CPU 26 Thruster Launch Unit 27 Acceleration sensor for checking horizontality 28,35 Power Separation Unit 31 Depth sensor 32 Marker Control Unit

Claims

1. a shape information measuring unit for measuring shape information of an object in the stored liquid; a position detection unit that floats in the stored liquid and detects the position of the shape information measurement unit in the liquid, the shape information measurement unit is suspended from the position detection unit, The position detection unit a laser measurement unit that irradiates the inner circumferential surface of the tank with laser light while rotating around a rotation axis that intersects with the liquid surface, and receives the irradiated laser light to acquire point cloud data that indicates measurement results of the distance to the inner circumferential surface; and a position detection unit that calculates the position of the position detection unit on an XY coordinate system based on the acquired point cloud data.

2. the position detection unit comprises a self-propelled vessel; 2. The underwater shape information acquisition system according to claim 1, wherein the shape information measurement unit is detachably connected to a mounting part provided at a tip of a connecting member suspended from the hull of the position detection unit.

3. the shape information measurement unit includes a depth sensor that detects a depth in the liquid; a display device that displays the position of the position detection unit on an XY coordinate system and the position of the position detection unit on a Z coordinate system that represents the depth relative to the depth sensor; The underwater shape information acquisition system according to claim 1 , wherein the display device displays the image of the captured object as an image on an XYZ coordinate system along the liquid surface.

4. The underwater shape information acquisition system according to claim 3 , wherein the depth sensor is a pressure sensor.

5. an ultrasonic output sensor that detects the depth of the three-dimensional shape measurement device by irradiating ultrasonic waves to the shape information measurement unit and receiving reflected light thereof; a display device that displays the position of the position detection unit on an XY coordinate system and the position of the position detection unit on a Z coordinate system that represents the depth relative to the depth sensor; 3. The underwater shape information acquisition system according to claim 1, wherein the display device displays the captured image of the object as an image on an XYZ coordinate system along the liquid surface.

6. 3. The underwater shape information acquisition system according to claim 1, further comprising an acceleration sensor for checking horizontality to keep the laser measurement unit horizontal.

7. 3. The underwater shape information acquisition system according to claim 2, wherein the connecting member is equipped with a gyro sensor that corrects the angle of the yaw axis using an optical fiber gyro.

8. The underwater shape information acquisition system according to claim 1 , wherein the shape information measurement unit is a camera.

9. An underwater shape information acquisition method for an underwater shape information acquisition system including a shape information measurement unit for measuring shape information of an object in stored liquid, and a position detection unit that floats in the stored liquid and detects the position of the shape information measurement unit in the liquid, comprising: The position detection unit irradiating a laser beam onto the inner peripheral surface of the tank while rotating the tank about a rotation axis in a direction intersecting the liquid surface, and receiving the irradiated laser beam to acquire point cloud data indicating a measurement result of the distance to the inner peripheral surface; and calculating the position of the position detection unit on an XY coordinate system based on the acquired point cloud data.

10. The underwater shape information acquiring method according to claim 9 , wherein the shape information measuring unit is suspended from the position detecting unit.

11. the position detection unit comprises a self-propelled vessel; The underwater shape information acquisition method according to claim 10 , wherein the shape information measurement unit is detachably connected to a mounting part provided at a tip of a connecting member suspended from the hull of the position detection unit.

12. The underwater shape information acquiring method according to claim 11 , wherein the shape information measuring unit is configured to be connected to the mounting unit using a mechanical clamping mechanism.

13. The underwater shape information acquisition method according to claim 11 , wherein the shape information measurement unit is remotely attached to a wire by using a clamping mechanism of a non-contact eddy current magnetic sensor or a photoelectric sensor on the attachment unit.

14. detecting a depth of the shape information measuring unit in the liquid; and displaying a position of the position detection unit on an XY coordinate system and a position of the position detection unit on a Z coordinate system representing a depth relative to the depth sensor; The underwater shape information acquisition method according to claim 10 , wherein the displaying step includes displaying the image of the captured object as an image on an XYZ coordinate system along the liquid surface.

15. a step of detecting a depth of the three-dimensional shape measuring device by irradiating the shape information measuring unit with ultrasonic waves and receiving reflected light thereof; and displaying a position of the position detection unit on an XY coordinate system and a position on a Z coordinate system representing the detected depth, The underwater shape information acquisition method according to claim 10 , wherein the displaying step includes displaying the image of the captured object as an image on an XYZ coordinate system along the liquid surface.

16. The underwater shape information acquisition method according to claim 10 , wherein the shape information measurement unit is a camera.

17. The underwater shape information acquisition method according to claim 10 , wherein the position detection unit comprises a self-propelled hull, and the shape measurement unit is hung from the hull.

18. The underwater shape information acquisition method according to claim 10 , wherein the shape information measurement unit is provided with a propeller, and the movement speed is obtained by rotation of the propeller, and the movement distance is calculated by integrating the speed.

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