Underwater Shape Information Acquisition System

Abstract

Provide a system that can measure an unknown shape with high precision without being fixed in a nuclear power plant or decommissioning plant of the Fukushima earthquake disaster that can hardly be fixed in the furnace for measurement. 【Solution means】A shape information measurement unit 3 for measuring the shape information of an object in the stored liquid, and a position detection unit 20 that floats in the stored liquid and detects the position of the shape information measurement unit in the liquid are provided. The shape information measurement unit is suspended from the position detection unit, and the position detection unit rotates around a rotation axis in a direction intersecting the liquid surface of the liquid while irradiating the inner peripheral surface of the tank with laser light, and receives the irradiated laser light. A laser measurement unit 21 that acquires point cloud data indicating the measurement result of the distance to the inner peripheral surface, and a position detection unit that calculates the position of the position detection unit in the XY coordinate system based on the acquired point cloud data.

Description

Technical Field

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

Background Art

[0002] In order to carry out the decommissioning measures plan for plants or the decommissioning plan for nuclear power plants after the Fukushima earthquake, it is necessary to acquire shape information underwater. For this purpose, the shape inside the reactor underwater is measured, and the point cloud data obtained is drawn into a drawing, and based on the information, a decommissioning plan for the nuclear power plant is planned. The methods of underwater shape information acquisition systems for acquiring shape information underwater are roughly classified into an ultrasonic type and a laser type. In nuclear power plants in decommissioning plants or after the earthquake in Fukushima Prefecture, since measurement is to be performed inside a metal container, the ultrasonic type system cannot be used due to reverberation, and a laser type system is used. This laser measurement method includes a TOF method, a triangulation method, etc. In the TOF method, since the time it takes for the laser to hit the subject and return is measured, the accuracy drops or measurement failure occurs in the measurement of shiny metals, curved surfaces, etc. that are not good at lasers. Also, in the triangulation method, the distance measured by the angle between the laser and the light receiving camera is determined, and although the accuracy is high, there is a problem that the distance to the measurement object is limited.

[0003] Conventionally, in an underwater shape information acquisition system, when measuring a measurement object over a wide range, it is crucial that the origin at the start of measurement and the origin at the end of measurement do not shift in order to obtain accurate point cloud data. Therefore, a system that fixes the underwater shape information acquisition system and performs rotational measurement to obtain point cloud data without deviation has become mainstream, but the places where it can be fixedly installed are very limited.

[0004] Therefore, a method has been proposed in which a diver holds a camera and approaches the measurement object to take a picture.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the reactor of a nuclear power plant after the earthquake in Fukushima or at a decommissioning plant, the radiation dose is extremely high, making it impossible for divers to measure. Furthermore, although a handy-type measuring device manually measured by a diver can measure distance and dimensions, there was a problem that the measurement of the area for synthesizing data could not be performed because the origin position could not be fixed.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a system that can measure an unknown shape with high accuracy without fixing a measuring device in a nuclear power plant affected by the Fukushima earthquake or a decommissioning plant where it is almost impossible to fix a measuring device.

Means for Solving the Problems

[0008] In order to solve the above problems, an underwater shape information acquisition system according to an embodiment includes a shape information measurement unit for measuring the 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. The shape information measurement unit is suspended from the position detection unit, and the position detection unit irradiates the inner peripheral surface of the tank with laser light while rotating about a rotation axis in a direction intersecting the liquid surface of the liquid, and acquires point cloud data indicating the measurement result of the distance to the inner peripheral surface by receiving the irradiated laser light. And a position detection unit that calculates the position of the position detection unit in the XY coordinate system based on the acquired point cloud data.

[0009] In one aspect of the above configuration, the position detection unit includes a hull having a self-propelling ability, 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 includes a depth sensor that detects the depth in the liquid, the position on the XY coordinate system of the position detection unit, and the depth sensor S and a display device that displays the position on the Z coordinate system representing the depth, and the display device displays the imaged object as an image on the XYZ coordinate system along the liquid surface.

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

[0012] As one aspect of the above configuration, an ultrasonic output sensor that irradiates the shape information measurement unit with ultrasonic waves and receives the reflected light to detect the depth of the shape information measurement unit and is further provided, and a display device that displays the position on the XY coordinate system of the position detection unit and the position on the Z coordinate system representing the depth of the depth sensor, and the display device displays the imaged object as an image on the XYZ coordinate system along the liquid surface.

[0013] As one aspect of the above configuration, it further includes an acceleration sensor for checking the level for holding the laser measurement unit horizontally.

[0014] As one aspect of the above configuration, a gyro sensor that corrects the angle of the yaw axis with an optical fiber gyro is mounted on the connection member.

[0015] As one aspect of the above configuration, the shape information measurement unit is a camera.

Brief Description of Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments do not limit the present invention.

[0018] First, with reference to FIGS. 1 to 5, the underwater shape information acquisition system 1 according to the present embodiment will be described. FIG. 1 is a block diagram showing the underwater shape information acquisition system 1 according to the present embodiment. FIG. 2 is a plan view of the underwater shape information acquisition system 1 in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a plan view of the position detection unit 20 in 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 inside a nuclear power plant reactor located in the water 10 stored in the tank 9, which floats in the stored liquid water 10, by a position detection unit 20 that detects the position of the three-dimensional shape measurement device 3 underwater. The three-dimensional shape measurement device 3 suspended from the position detection unit 20 dives and images the inside of the tank 9 to 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 that indicates 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. 3 luminous bodies 4, but the present invention is not limited thereto. For example, the present invention may be configured with one or two luminous bodies, or with five or more luminous bodies. The position detection device 2 of FIG. 1 floats in water 10 stored in a tank 9 and detects the position of the three-dimensional shape measurement device 3 in the water. The position detection device 2 of FIG. 1 is configured with a position detection unit 20, a position detection power supply unit 5, and a position detection PC 6 which is a display device. Here, the position detection CPU 22 which is a position detection section calculates the position of the position detection unit 20 on the XY coordinate system based on the acquired point cloud data, as described later. 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] The position detection unit 20 floating in the 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 Fig. 2, the position detection unit 20 is lowered into the water through a tank manhole 91 that partially penetrates a top plate 90 of the tank 9 and suspended from the upper end of the tank manhole 91.

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

[0023] The position detection PC6 receives, via the cable 11, the detection result of the position of the position detection unit 20 based on the origin described later from the position detection unit 20. Further, the position detection PC6 receives, from the 3D shape measurement device PC8, the detection result of the depth of the 3D shape measurement device 3 by the depth sensor 31 described later. Then, the position detection PC6 calculates (detects) the position of the 3D shape measurement device 3 based on the received detection results with reference to the origin described later. Then, the position detection PC6 displays the calculated position of the 3D shape measurement device 3 as an image and numerical values on the XY coordinate system on the monitor screen.

[0024] The 3D shape measurement device 3 that dives and works in the tank 9 is connected via the cable 12 to the 3D shape measurement device power supply unit 7 and the 3D shape measurement device PC8 arranged on the ground side.

[0025] The 3D shape measurement device power supply unit 7 supplies power to the 3D shape measurement device 3 via the cable 12.

[0026] The 3D shape measurement device PC8 receives, via the cable 12, the captured image of the inside of the tank 9 by the camera 33 described later and the detection result of the depth of the 3D shape measurement device 3 by the depth sensor 31 described later from the 3D shape measurement device 3. The 3D shape measurement device PC8 transmits the received detection result of the depth of the 3D shape measurement device 3 to the position detection PC6.

[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 rotatable 360 degrees about the Z-axis on the 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 thruster 24 for movement which is a moving device, a CPU 25, a thruster activation unit 26, an acceleration sensor 27 for horizontal level confirmation for holding the laser unit 21 horizontally, and a power separation unit 28. Further, as shown in FIGS. 3 and 4, the position detection unit 20 includes a self-propelled hull (frame) 210 having a self-propelling ability, a buoyancy body 211, and a ship control device 26 for controlling the movement of the hull 210. Here, in a coordinate system having X, Y, and Z axes orthogonal to each other, the direction opposite to the gravity direction by is the Z-axis. The laser unit (LIDER) 21 rotates 360 degrees about the Z-axis, measures the distance to the measurement object, determines where the hull (frame) 210 is, and specifies the measurement position.

[0028] As shown in FIG. 3, a ship control device 26, an acceleration sensor 27 for horizontal level confirmation, and a camera 23 are attached to the hull 210, and the laser unit 21 is attached to the acceleration sensor 27 for horizontal level confirmation. Further, a buoyancy body 211 is attached to the lower part of the hull 210, and thrusters 24 for the position detection unit 20 to move are respectively provided below the buoyancy body 211.

[0029] Note that a reaction wheel may be used as the rotating body of the attitude control mechanism. Here, the reaction wheel has a wheel (disk) and a motor connected to the rotation axis of the wheel. When the motor applies a rotational torque to the wheel, it receives a torque in the direction opposite to the rotational torque. Therefore, when the motor is fixed to the aircraft body and the wheel is rotated, the aircraft body starts to rotate in the direction opposite to the rotation direction of the wheel. In this way, by appropriately controlling the rotation of the wheel, the attitude of the laser unit 21 can be controlled. Further, an inertial measurement unit (IMU) may be used as a rotation control mechanism of the hull 210, and a uniaxial gyro system may be used to maintain the moving direction of the hull 210. The three-dimensional shape measurement device 3 is detachably connected to a mounting portion (hanging tool) 47 provided at the tip of a single-wire suspension jig (connecting member) 46 suspended from the hull (frame) of the position detection unit 20.

[0030] Alternatively, it may be configured to obtain position information using an IMU. In this case, since roll and pitch are restricted by a single-wire suspension, it is necessary to reduce the deviation of the yaw axis in the rotational direction. Therefore, since the yaw axis affects the traveling direction, in order to control the traveling direction, the position information of the IMU is corrected with an optical fiber gyro to stabilize the angle of the yaw axis for a long time, and the course is measured.

[0031] In FIG. 4, the position detection unit 20 has four bar-shaped frames 210 that intersect in a cross shape, and at the intersection positions of the respective frames 210, a laser unit 21 and the levelness confirmation acceleration sensor 27 are arranged vertically, and a buoyancy body 211 and a thruster 24 for movement are arranged on the opposite sides of the intersection positions of the respective frames 210.

[0032] The laser unit 21 includes a laser distance meter and a control unit that controls the laser distance meter. The laser unit 21 rotates 360 degrees around a rotation axis in a direction substantially perpendicular (i.e., intersecting) to the water surface 10a while floating in water by the buoyancy of the buoyancy body 211, and irradiates the inner peripheral surface 90a with laser light from the irradiation unit of the laser distance meter. The laser unit 21 receives the laser light irradiated on the inner peripheral surface 90a with a light receiving unit (not shown) of the laser distance meter, thereby acquiring point cloud data indicating the measurement result of the distance from the position detection unit 20 (i.e., the position detection device 2) to the inner peripheral surface 90a.

[0033] As shown in FIG. 3, the laser unit 21 is positioned above the water surface 10a without being immersed in the water 10 in a state where the position detection unit 20 is floating in the water 10. Thereby, since the laser unit 21 is positioned above the water surface 10a, the laser unit 21 can irradiate and receive laser light in the air. Thereby, it is possible to obtain point cloud data accurately indicating the distance to the inner peripheral surface 90a of the tank 9.

[0034] As shown in FIG. 3, the camera 23 images the three-dimensional shape measurement device 3 positioned in the water. The camera 23 is arranged on the hull (frame) 210 so that the optical axis faces vertically downward in a state where the position detection unit 20 is floating in the water 10.

[0035] The moving thruster 24 moves the position detection unit 20 on the water surface 10a. Here, the activation and stop of the moving thruster 24 are executed by the thruster activation unit 26. As shown in FIG. 1, the three light emitters 4 mounted on the three-dimensional shape measurement device 3 are , three arranged in a triangular shape so as to indicate the moving direction of the three-dimensional shape measurement device 3. When the position of the image of the light emitter 4 in the captured image of the three-dimensional shape measurement device 3 by the camera 23 described later changes, the thruster activation unit 26 activates the moving thruster 24 so that the position detection unit 20 moves in the moving direction A specified by the image of the light emitter 4. Thereby, the position detection unit 20 can be moved so as to follow the movement of the three-dimensional shape measurement device 3, and the three-dimensional shape measurement device 3 can be continuously captured within the viewing angle of the camera 23. Note that the movement of the position detection unit 20 for continuously capturing the three-dimensional shape measurement device 3 within the viewing angle of the camera 23 may be manually performed by an operator while checking the captured image of the camera 23.

[0036] The CPU 22 for position detection 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 CPU 22 for position detection determines a specific position within the region 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 region surrounded by the point cloud data, that is, the center of the tank 9. Then, the CPU 22 for position detection executes a process for detecting the position of the three-dimensional shape measurement device 3 based on the determined origin.

[0037] Specifically, the CPU 22 for position detection 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 thruster 24 for movement. More specifically, the CPU 22 for position detection compares the position of the position detection unit 20 within the region surrounded by the point cloud data acquired by the laser unit 21 after the movement by the thruster 24 for movement with the origin, thereby detecting the position of the position detection unit 20 with respect to the origin. With this configuration, it becomes possible to freely collect data by registering the origin and to create a three-dimensional model by synthesizing the data.

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

[0039] The CPU 22 for position detection transmits the detection result of the position detection unit 20 with respect to the origin and the detection result of the position of the three-dimensional shape measurement device 3 with respect to the origin to the PC 6 for position detection via the cable 11.

[0040] The position detection PC6 displays the position of the position detection unit 20 based on the origin transmitted from the position detection CPU22 as the position of the three-dimensional shape measurement device 3.

[0041] The leveling acceleration sensor 27 checks whether the position detection unit 20 is parallel, i.e., horizontal, to the water surface 10a when the position detection unit 20 is immersed in water. If the position detection unit 20 is not parallel to the water surface 10a, the suspension device positions are adjusts the inclination of the position detection unit 20 until it is confirmed by the leveling acceleration sensor 27 that it is parallel.

[0042] The CPU25 comprehensively controls the operations of the components 21 to 24, 26, and 27 of the position detection unit 20. The power separation unit 28 distributes the power supplied from the position detection power unit 5 to the components 21 to 27 of the position detection unit 20.

[0043] Hereinafter, the three-dimensional shape measurement device 3 will be described in detail. As shown in FIG. 1, the three-dimensional shape measurement device 3 includes a depth sensor 31 which is a depth gauge, a marker control unit 32, a camera 33 which is a shape information measurement unit for measuring the shape information of an object in the stored liquid, a CPU34, and a power 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 in water. The depth sensor 31 is a pressure-type depth sensor. By adopting 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 the reflection of the metal tank 9.

[0045] In the present invention, the distance (depth) of the three-dimensional shape measurement device 3 from the water surface is configured 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-type depth sensor instead of the pressure-type depth sensor. As shown in FIG. 6, ultrasonic waves are transmitted inside the wire, a reflector 51 is installed above the three-dimensional shape measurement device 3, and the reflection speed of the ultrasonic waves is measured to measure the depth. That is, the ultrasonic-type 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. According to this configuration, it is not affected by ultrasonic noise, which is a problem in a metal environment. Furthermore, the accuracy does not decrease due to the influence in an environment with salt or temperature changes.

[0046] The depth sensor 31 transmits the detection result of the depth of the three-dimensional shape measurement device 3 to the PC 8 for the three-dimensional shape measurement device via the cable 12. The PC 8 for the three-dimensional shape measurement device transfers the transmitted detection result of the depth 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 images the inside of the tank 9. The camera 33 transmits the captured image inside the tank 9 to the PC 8 for the three-dimensional shape measurement device via the cable 12.

[0049] The CPU 25 comprehensively controls the operations of the respective components 31 to 33 of the three-dimensional shape measurement device 3.

[0050] The power supply separation unit 35 distributes the power supplied from the power supply unit 7 for the three-dimensional shape measurement device to the respective components 31 to 34 of the three-dimensional shape measurement device 3.

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

[0052] First, as shown in FIG. 3, the suspension device at the positionTherefore, the position detection unit 20 is suspended inside the tank 9 from the tank manhole 91 and then dropped into the water. At this time, the horizontality checking acceleration sensor 27 checks whether the position detection unit 20 is horizontal with respect to the water surface 10a. If the position detection unit 20 is not horizontal, the suspended unit is lowered into the water. at the position Then, the inclination of the position detection unit 20 is adjusted so that it is horizontal.

[0053] Then, at the position where the position detection unit 20 was dropped into the water, i.e., directly below the tank manhole 91, the laser unit 21 irradiates the inner peripheral surface 90a of the tank 9 with laser light along the circumferential direction while rotating 360 degrees in a rotational direction centered on a rotation axis (Z-axis) that is approximately perpendicular to the water surface 10a. The laser unit 21 then receives the laser light irradiated to the inner peripheral surface 90a, and measures the distance from the position detection unit 20 to the inner peripheral surface 90a based on the time from when the laser light was irradiated to when it was received. The laser unit 21 then , distance The point cloud data showing the distance measurement results is obtained.

[0054] After acquiring the point cloud data, the position detection CPU 22 processes the acquired point cloud data. with The center position of the tank 9 within the enclosed area is calculated, and the calculated center position of the tank 9 is determined as the origin (0,0) of the position detection unit 20.

[0055] Further, 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 measuring 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 imaging the light emitter 4, the position detection CPU 22 calculates the position of the position detection unit 20 with respect to the origin (0, 0) by comparing the position of the position detection unit 20 within the area surrounded by the point cloud data acquired by the laser unit 21 after movement with the origin.

[0058] Next, the PC 8 for the three-dimensional shape measurement device receives the 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 result of the position of the position detection unit 20 with respect 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 measurement device 3 with respect to the origin. At this calculated timing, the inside of the tank 9 is imaged by the camera 33, and the captured image data is transmitted to the PC 6 for position detection via the PC 8 for the three-dimensional shape measurement device. Then, the PC 6 for position detection displays the calculated position of the three-dimensional shape measurement device 3 as an image and numerical values on the XY coordinate system on the monitor screen. By synthesizing the images at each coordinate, a three-dimensional image of the object is displayed on the PC 6 for position detection.

[0059] According to the underwater shape information acquisition system 1 according to this embodiment, even in a place covered with thick metal or concrete such as a decommissioning plant where it is almost impossible to fix a measuring device in the furnace or a nuclear power plant in the Fukushima earthquake, it is possible to accurately measure an unknown shape without fixing the measuring device.

[0060] [Other Embodiments] The three-dimensional shape measurement device 3 may be configured to include a gyro sensor. In this case, by detecting the angle and controlling the rotation of the attitude control flywheel, it is possible to stabilize the attitude by the rotational force. Also, a gyro sensor 50 (see FIG. 6) may be mounted on a single-point suspension jig (connecting member) 46 and configured to always control the three-dimensional shape measurement device 3 to be horizontal. Therefore, even when the hull (frame) 210 tilts when the hull (frame) 210 moves, it is possible to keep the three-dimensional shape measurement device 3 horizontal. .

[0061] In the above-described embodiment, the three-dimensional shape measuring device 3 is suspended from the hull of a self-propelled hull. The present invention is not limited to this. For example, it may be configured to move the three-dimensional shape measuring device 3 by single-point suspension using a crane or the like without using a self-propelled hull. In this case, as shown in FIG. 7, a measuring instrument 48 having three propellers provided at 120-degree intervals is attached to a cylindrical cylinder under the three-dimensional shape measuring device 3. The moving speed is obtained by the rotation of the propellers, and the moving distance is calculated by integration. The azimuth is determined first with the front of the measuring unit as the reference, and the angle (azimuth) is obtained by a uniaxial sensor and combined with the moving distance to specify the position. Although three propellers are shown in the figure, three or more propellers may be used, and the measurement accuracy improves as the number of propellers increases.

[0062] As shown in FIG. 7, when the position detection unit 20A is compared with the position detection unit 20 according to the above-described embodiment, the difference is that the position detection unit 20A includes two laser units 21. The position detection unit 20A can perform 360-degree measurement by using two distance-measuring laser units (LIDARs) 21 for 270-degree measurement, wrapping the measurement angle, eliminating dead angles, and performing correction.

[0063] As shown in FIG. 7, the position detection unit 20A may be Move it in the direction of arrow A configured to be connected to the three-dimensional shape measuring device 3 that is later single-point suspended using a stainless steel wire by using a clamping mechanism. In this case, it may be configured using a mechanical clamping mechanism. Further, it may be configured to be remotely attached to the wire using a clamping mechanism 55 (see FIG. 7) such as a non-contact eddy current type magnetic sensor or a photoelectric sensor. In this case, when the clamping mechanism 55 is used and the wire is aligned with the center of the U-shaped hull, the wire is detected at a position of 8 millimeters (mm), and the position of the three-dimensional shape measuring device 3 is specified by the position detection unit while maintaining the gap by controlling the thruster in a certain direction. According to this configuration, compared with using a mechanical clamping mechanism, the tension on the wire due to the gripping force or angle does not affect the posture of the three-dimensional shape measuring device 3 in water.

[0064] Although some embodiments of the present invention have been described, each of the above embodiments is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0065] 1 Underwater shape information acquisition system 2 Position detection device 3 Three-dimensional shape measuring device (shape information measuring unit) 4 Light emitter 5 Power supply unit for position detection 6 PC for position detection 7 Power supply unit for three-dimensional shape measuring device 8 PC for three-dimensional shape measuring device 9 Tank 10 Water 20 Position detection unit 21 Laser unit 22 CPU for position detection 23, 33 Camera 24 Thruster for movement 25, 34 CPU 26 Thruster activation unit 27 Acceleration sensor for horizontal level confirmation 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 immersed in the liquid stored in the tank; a position detection unit that floats in the stored liquid and detects a position of the shape information measurement unit in the liquid, the shape information measuring unit is suspended from the position detection unit, The position detection unit includes: a laser measurement unit that irradiates a laser beam onto an inner peripheral surface of the tank while rotating about a rotation axis that intersects with a liquid level of the liquid, and receives the irradiated laser beam to obtain point cloud data indicating a measurement result of a distance to the inner peripheral surface; and a position detection unit that determines a specific position within an area surrounded by the acquired point cloud data as the origin of the position detection unit, and calculates the position of the position detection unit on an XY coordinate system in accordance with the movement of the position detection unit using the origin as a reference.

2. The position detection unit includes 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 portion provided at a tip of a connecting member suspended from a hull of the position detection unit.

3. the shape information measuring unit includes a depth sensor for detecting a depth in the liquid; a display device that displays a position of the position detection unit on an XY coordinate system and a position of the depth sensor on a Z coordinate system that represents a depth, The underwater shape information acquisition system according to claim 1 , wherein the display device displays 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 shape information measuring unit by irradiating ultrasonic waves to the shape information measuring unit and receiving reflected light; a display device that displays a position of the position detection unit on an XY coordinate system and a position of the shape information measurement unit on a Z coordinate system that represents a depth, 3. The underwater shape information acquisition system according to claim 1, wherein the display device displays the captured 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 performs angle correction 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. 1. 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 a liquid stored in a tank, and a position detection unit that floats in the stored liquid and detects a position of the shape information measurement unit in the liquid, comprising: The position detection unit includes: irradiating a laser beam onto an inner peripheral surface of the tank while rotating about a rotation axis in a direction intersecting with the liquid level of the liquid, and receiving the irradiated laser beam to obtain point cloud data indicating a measurement result of a distance to the inner peripheral surface; determining a specific position within an area surrounded by the acquired point cloud data as the origin of the position detection unit, and calculating a position on an XY coordinate system of the position detection unit in accordance with the movement of the position detection unit based on the origin.

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

11. The position detection unit includes a self-propelled vessel. The underwater shape information acquiring method according to claim 10 , wherein the shape information measuring section is detachably connected to a mounting section provided at a tip of a connecting member suspended from a hull of the position detecting 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 clamp mechanism.

13. The underwater shape information acquiring method according to claim 11 , wherein the shape information measuring unit is remotely attached to a wire by using a clamp mechanism of a non-contact eddy current type magnetic sensor or a photoelectric type 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 acquiring 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. detecting a depth of the shape information measuring unit by irradiating the shape information measuring unit with an ultrasonic wave and receiving a reflected light; 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 acquiring 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 acquiring method according to claim 10 , wherein the shape information measuring unit is a camera.

17. The underwater shape information acquiring method according to claim 10 , wherein the position detection unit comprises a hull capable of self-propelling, and the shape information measuring section 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 a moving speed is obtained by rotation of the propeller, and is integrated to calculate a moving distance.

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