JP2011075414A - System and method for detecting position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of accurately detecting a position of a robot on a skin of a ship body. <P>SOLUTION: A system for detecting a robot position includes two sound sources 31 and 32 attached to different positions on a body skin 80 for generating sound waves to be transmitted in the body skin 80, and a sound wave receiving unit 25 provided on a robot 2A for receiving the sound waves transmitted in the body skin 80. The position detecting system detects the position of the robot 2A based on respective transmission time periods in which the sound waves generated from the respective sound sources 31 and 32 propagate through the body skin 80 and are received by the sound wave receiving unit 25, and position information of the respective sound sources 31 and 32 on the body skin 80. As a result, the position of the robot 2A on the body skin 80 can accurately be detected. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a position detection technique for detecting the position of a robot on a skin of a hull.

  In general, in a ship, if barnacles, mussels, etc. adhere to the outer plate of the hull, foreign species may be carried abroad, which may adversely affect the environment. In addition, the resistance to water increases due to the influence of foreign matter adhering to the hull outer plate, resulting in poor fuel consumption and an increase in fuel cost and CO2 emission. In particular, large vessels such as container ships and tankers consume a large amount of fuel, so even if the fuel efficiency is reduced by several percent, the cost will increase considerably. For this reason, the ship is periodically lifted to the dock at a frequency of once every two and a half years to remove foreign substances adhering to the hull skin and repainting. Necessary costs are also high.

  On the other hand, divers diving underwater in a ship anchored at a port or the like inspects the hull outer plate and removes deposits, but the work efficiency is poor and it is a dangerous and time-consuming work.

  Thus, as a technique for improving the working efficiency of the diver, for example, a technique for inspecting a hull outer plate under water using a submersible robot in a berthed ship has been proposed. In the inspection by the underwater robot, it is important to accurately detect the position in the water.

  Regarding the position detection of the underwater robot, for example, there is a technique disclosed in Patent Document 1. According to this technology, it is possible to detect the position of the underwater robot by receiving the ultrasonic wave transmitted from the underwater robot and transmitted through the underwater with the ultrasonic receiver installed obliquely downward and outward from the ship bottom bilge part. It has become.

JP-A-8-136240

  However, in the technique of the above-mentioned Patent Document 1, since the ultrasonic wave transmitted from the underwater robot propagates through the water and is received by the ultrasonic receiver, the propagation path is affected by the water flow or floating matter. Cause noise. This makes it difficult to accurately detect the position of the underwater robot performing the inspection on the outer plate of the hull.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a position detection technique that can accurately detect the position of the robot on the outer plate of the hull.

  In order to solve the above problems, the invention of claim 1 is a position detection system for detecting the position of a robot on the outer plate of a hull, and is a sound wave that is attached to a different position of the outer plate and propagates to the outer plate. A plurality of sound wave transmitting units that transmit sound waves, a sound wave receiving unit that is provided in the robot and that receives sound waves propagated through the outer plate, and a sound wave transmitted from each of the plurality of sound wave transmitting units propagates through the outer plate. Position detecting means for detecting the position of the robot on the basis of each propagation time until the sound wave receiving means receives and position information of each of the plurality of sound wave transmitting portions on the outer plate.

  According to a second aspect of the present invention, in the position detection system according to the first aspect of the invention, each of the plurality of sound wave transmitting portions is detachable from the outer plate by a magnet.

  According to a third aspect of the present invention, in the position detection system according to the first or second aspect of the present invention, the sound wave receiving means includes a plurality of sound wave receiving units provided at different positions of the robot.

  According to a fourth aspect of the present invention, there is provided a position detection system for detecting a position of a robot on a skin of a hull, a sound wave transmitting means provided on the robot for transmitting a sound wave to be propagated to the skin, and the outside A plurality of sound wave receiving units that are attached to different positions of the plate and receive the sound waves propagated through the outer plate, and a sound wave transmitted from the sound wave transmitting means propagates through the outer plate and is transmitted by each of the plurality of sound wave receiving units. Position detecting means for detecting the position of the robot based on each propagation time until reception and position information of each of the plurality of sound wave receiving units on the outer plate.

  According to a fifth aspect of the present invention, in the position detection system according to the fourth aspect of the invention, each of the plurality of sound wave receiving units is detachable from the outer plate by a magnet.

  According to a sixth aspect of the present invention, in the position detection system according to the fourth or fifth aspect of the present invention, the sound wave transmitting means includes a plurality of sound wave transmitting portions provided at different positions of the robot.

  According to a seventh aspect of the present invention, in the position detection system according to any one of the first to sixth aspects of the present invention, an imaging means provided in the robot for capturing an image by photographing the surface of the outer plate. Further prepare.

  According to an eighth aspect of the present invention, in the position detection system according to the seventh aspect of the present invention, the image pickup means moves the robot on the outer plate and moves the robot by the drive means. Image acquisition means for sequentially acquiring the images is further provided.

  The invention according to claim 9 is a position detection method for detecting the position of the robot on the outer plate of the hull, and is propagated to the outer plate from each of a plurality of sound wave transmitting units attached to different positions of the outer plate. A sound wave transmitting step for transmitting a sound wave to be transmitted; a sound wave receiving step for receiving a sound wave propagated through the outer plate by a sound wave receiving means provided in the robot; and a sound wave transmitted from each of the plurality of sound wave transmitting units. A position detection step of detecting the position of the robot based on each propagation time from propagation through the plate until reception by the sound wave receiving means, and position information of each of the plurality of sound wave transmission units on the outer plate. Prepare.

  The invention according to claim 10 is a position detection method for detecting the position of the robot on the outer plate of the hull, wherein the sound wave is transmitted from the sound wave transmitting means provided in the robot to be transmitted to the outer plate. A sound wave receiving step of receiving a sound wave propagated through the outer plate by each of a plurality of sound wave receiving units attached to different positions of the outer plate, and a sound wave transmitted from the sound wave transmitting means propagates through the outer plate. And a position detection step of detecting the position of the robot based on each propagation time until each of the plurality of sound wave receiving units is received and position information of each of the plurality of sound wave receiving units on the outer plate. Prepare.

  The invention according to claim 11 is the position detecting method according to claim 9 or claim 10, wherein the robot is moved on the outer plate by a predetermined driving means, and the imaging means provided in the robot. The method further includes an image acquisition step of sequentially acquiring images by photographing the surface of the outer plate.

  According to the inventions of claims 1 to 3, claims 7 to 9 and claim 11, the sound waves transmitted from each of the plurality of sound wave transmitting portions attached to different positions of the outer plate of the hull are the outer plates. The position of the robot on the outer skin of the hull is detected based on each propagation time until the sound is received by the sound wave receiving means provided on the robot and the position information of each of the plurality of sound wave transmitting parts on the outer skin. Therefore, the position of the robot can be detected with high accuracy.

  In particular, in the second aspect of the invention, each of the plurality of sound wave transmitting portions can be attached to and detached from the outer plate of the hull by a magnet, so that the work of attaching and removing the sound wave transmitting portion can be easily performed.

  In the invention of claim 3, since the plurality of sound wave receiving units are provided at different positions of the robot, the posture of the robot can be detected.

  Further, according to the inventions of claims 4 to 8, 10 and 11, the sound waves transmitted from the sound wave transmitting means provided in the robot propagate through the outer plate of the hull so that the outer plates are different. In order to detect the position of the robot on the outer skin of the hull based on each propagation time until each of the plurality of acoustic wave receiving parts attached to the position is received and the positional information of each of the plurality of acoustic wave receiving parts on the outer skin The position of the robot can be detected with high accuracy.

  In the invention of claim 5, since each of the plurality of sound wave receiving parts is detachable from the outer plate of the hull by a magnet, the work of attaching and removing the sound wave receiving part can be easily performed.

  In the invention of claim 6, since the plurality of sound wave transmitting portions are provided at different positions of the robot, the posture of the robot can be detected.

  In the invention of claim 7, since the robot is provided with an imaging means for photographing the outer plate surface of the hull and obtaining an image, the image of the outer plate surface of the hull can be easily obtained. It can detect abnormalities of the outer plate (adhesion of barnacles, paint peeling, etc.).

  Further, in the inventions of claims 8 and 11, since the image is sequentially acquired by the imaging means provided in the robot while the robot is moved on the outer plate of the hull by the driving means, the image is displayed on the outer plate of the hull. Images in the area that needs to be acquired can be acquired efficiently.

It is a conceptual diagram which shows the principal part structure of the position detection system of the robot which concerns on 1st Embodiment of this invention. It is a perspective view which shows the principal part structure of a robot. It is the figure which looked at the robot from the lower surface. It is a figure for demonstrating the principal part structure of a sound source part. It is a block diagram which shows the mechanism structure of a position detection system. It is a figure which shows an example which carries out mapping display of the area | regions, such as a deposit | attachment detected by the hull outer plate | board. It is a figure for demonstrating the position detection of the robot in a hull outer board. It is a time chart for demonstrating the position detection of a robot. It is a flowchart which shows the basic operation | movement of a position detection system. It is a block diagram which shows the function structure of the position detection system which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the position detection of the robot in a hull outer board.

<First Embodiment>
<Configuration of robot position detection system>
FIG. 1 is a conceptual diagram showing the main configuration of a robot position detection system (hereinafter also abbreviated as “position detection system”) 1A according to a first embodiment of the present invention.

  The position detection system 1A includes a robot 2A that performs work (image acquisition work) on a hull skin (hereinafter also referred to as “hull skin”) 80 in the ship 8, and two hull skins 80 that are attached to the hull skin 80. The sound source units 31 and 32 are provided, and the position of the robot 2A on the hull outer plate 80 is detected. The position detection system 1A is communicably connected to the robot 2A via the cable CBa, and is electrically connected to the sound source units 31 and 32 via the cables CB1 to CB3 in which amplifiers (amplifiers) 33 are inserted. A control device 4 to be connected is provided.

  First, the configuration of the robot 2A will be described with reference to FIGS.

  FIG. 2 is a perspective view showing a main configuration of the robot 2A. FIG. 3 is a view of the robot 2A viewed from the lower surface (back side).

  The robot 2A is configured as an underwater robot capable of underwater work, and each part of the robot 2A is appropriately waterproofed (waterproofing). The robot 2A includes, for example, a robot main body (hereinafter also referred to as “main body”) 20 having a box shape, and four ball casters 21 (FIG. 3) provided on the lower surface of the main body 20. The two wheels 22 provided on both sides of the main body 20, the imaging unit 23 and the illumination unit 24 provided on the front surface (front surface) of the main body 20, and the lower center of the main body 20. And a sound source receiver 25.

  The ball parts of the four ball casters 21 are formed as permanent magnets. Since the ball caster 21 having such a configuration is magnetically attracted to the iron hull outer plate (iron plate) 80, the robot 2A can be sucked and stuck to the hull outer plate 80, and can be moved along the hull outer plate 80. And Each ball caster 21 is preferably provided with a spring mechanism or the like that absorbs vibration generated when the robot 2A moves.

  The two wheels 22 are rotatable around a rotation shaft 22c. By rotating the wheel 22 by an actuator 26 (FIG. 5) such as a motor, it is possible to advance the robot 2A in the direction Da along the Z axis as shown in FIG. The traveling direction of the robot 2 </ b> A can be changed by giving, for example, an unbalanced rotational torque to the wheels 22 or by giving rotations in opposite directions.

  The imaging unit 23 includes a first camera 231 that is used as a main camera and a second camera 232 that is used as a sub camera. As shown in FIG. 2, in the imaging region Es (shaded part) in front of the robot 2A. It is possible to photograph the surface of the hull outer plate 80 and acquire the image. Here, if the robot 2 </ b> A is advanced in the direction Da by the rotation of the wheel 22, the image of the next imaging region Et ahead of the imaging region Es can be acquired by the imaging unit 23. As for the forward movement of the robot 2A for photographing the next photographing region Et, for example, the rotation angle of the wheel 22 is detected by an encoder so that the robot 2A moves a distance of about several tens of centimeters. Thus, if the image of the imaging region Es is sequentially acquired by the imaging unit 23 while moving the robot 2A on the hull outer plate 80 by a predetermined distance, for example, the entire hull outer plate 80 below the waterline is imaged without any problem. It becomes possible.

  In the imaging unit 23, a two-dimensional image of the imaging region Es can be acquired by the first camera 231, but if the imaging region Es is also captured by the second camera 232, the hull outer plate 80 relating to the imaging region Es is captured. Three-dimensional shape information can be acquired. Thereby, since protrusions such as barnacles attached to the hull outer plate 80 can be easily detected, it is possible to control the robot 2A to move so as to avoid the protrusions. In the robot 2A that moves by attracting to the hull outer plate 80 by the magnetic attraction force of the ball caster 21 by the avoiding operation of the robot 2A, the ball caster 21 rides on the protrusion, and the robot 2A moves to the hull outer plate 80. It is possible to prevent falling away from the camera.

  The illumination unit 24 illuminates the vicinity of the imaging region Es in front of the robot 2A, and is used, for example, at the time of imaging in water where illumination light is insufficient.

  The sound wave receiving unit 25 is configured as a concrete microphone, for example, and functions as a sound wave sensor that receives sound waves propagated through the hull outer plate 80. In the sound wave receiving unit 25, the lower surface portion 25f is brought into contact with the surface of the hull outer plate 80 to detect sound waves. However, when the robot 2A moves, the lower surface portion 25f needs to be separated from the hull outer plate 80. There is. Therefore, the sound wave receiver 25 can be moved up and down in the vertical direction Db using a drive mechanism (not shown). Accordingly, the sound wave receiving unit 25 can be raised while the robot 2A is moving, and the sound wave receiving unit 25 can be lowered when the sound wave is received by the stationary robot 2A. The lower surface portion 25f of the portion 25 can be protected, and sound waves can be received appropriately.

  Next, the configuration of the sound source units 31 and 32 will be described with reference to FIG.

  FIG. 4 is a diagram for explaining a main configuration of the sound source unit 31. In FIG. 4, a longitudinal section of the sound source unit 31 is mainly shown.

  The sound source unit (hereinafter also referred to as “first sound source unit”) 31 includes a sound source main body 310 and a housing 311 formed so as to cover the sound source main body 310.

  The sound source main body 310 is configured as a speaker (for example, a bone conduction speaker) including a magnet and a moving coil, and a sound wave propagated to the hull outer plate 80 by bringing the lower surface 310f into contact with the hull outer plate 80. It is possible to make a call.

  The casing 311 has a cylindrical outer shape, and a magnet portion 31m (parallel oblique line portion) configured as, for example, an annular (ring-shaped) permanent magnet is attached to the lower portion thereof. The sound source unit 31 is detachably attached to the hull outer plate 80 by the magnetic attraction force to the hull outer plate 80 by the magnet portion 31m. With such a configuration, it is possible to facilitate the attaching / detaching operation of the sound source unit 31 with respect to the hull outer plate 80.

  Note that the sound source unit (hereinafter also referred to as “second sound source unit”) 32 has the same configuration as the first sound source unit 31 shown in FIG. 4.

  Returning to FIG. 1, the configuration of the control device 4 will be described.

  The control device 4 is configured as, for example, a personal computer, and includes an input unit 41 including a keyboard and a mouse (not shown), and a display unit 42 configured as, for example, a liquid crystal display.

  Next, the functional configuration of the position detection system 1A will be described with reference to FIG.

  FIG. 5 is a block diagram showing a mechanism configuration of the position detection system 1A.

  The robot 2 </ b> A includes the imaging unit 23, the illumination unit 24, the sound wave receiving unit 25, and the actuator 26 described above, a control unit 27 that is electrically connected to each of these parts, and an interface unit for communicating with the control device 4. 28.

  The actuator 26 functions as a drive unit that drives the wheels 22 to move the robot 2A on the hull outer plate 80.

  The control unit 27 includes, for example, a CPU and a memory, and is a part for comprehensively controlling each unit of the robot 2A.

  Further, the first sound source unit 31 and the second sound source unit 32 described above are attached to different positions of the hull outer plate 80, for example, at positions above the bow and near the stern as shown in FIG. The sound wave transmission part 3 which transmits the sound wave propagated to 80 is configured.

  The control device 4 includes a storage unit 43 in addition to the input unit 41 and the display unit 42 described above. The control unit 44 is connected to these units so as to be able to transmit data, and communicates with the robot 2A via the amplifier 33. And an interface unit 45 for controlling the sound source transmission unit 3.

  The storage unit 43 is configured as a hard disk, for example, and stores an application program for detecting the position of the robot 2A described later.

  The control unit 44 has, for example, a CPU and a memory that function as a computer, and is a part that controls the control device 4 in an integrated manner. In the control unit 44, for example, various functions can be realized in software by reading an application program stored in the storage unit 43 and executing the program by the CPU.

  The control unit 44 includes a position detection unit 441 and an image analysis unit 442 that are implemented as software.

  In the position detection unit 441, the time taken for the sound waves transmitted from the sound source units 31 and 32 to propagate through the hull outer plate 80 and reach the sound wave receiving unit 25 of the robot 2A, and the sound source units 31 and 32 Based on the position, the position of the robot 2A on the hull outer plate 80 is detected. The position detection of the robot 2A will be described in detail later.

  The image analysis unit 442 performs control to sequentially acquire images of the imaging region Es (FIG. 2) in front of the robot 2 </ b> A with the imaging unit 23 while moving the robot 2 </ b> A using the actuator 26, and an image group acquired thereby. Is analyzed. In this image analysis, for example, the adhering material or paint is peeled off due to a difference in color or texture from the hull outer plate 80, and rust is detected, and the detected adhering material is further characterized by the feature amount (color, Classify barnacles, mussels, etc. based on texture, geometric shape, etc.). For example, barnacles can be distinguished from other deposits based on the feature that the color is gray and there are many edges. As for the results obtained by the image analysis, for example, as shown in FIG. 6, a region Ea where barnacles are attached, a region Eb where mussels are attached, or paint peeling occurs on a simplified stereoscopic image Gs of a hull. The displayed area Ec is displayed by mapping. If such an analysis result is displayed, the kind and position (attachment range) of the attached matter on the hull outer plate 80 can be easily grasped, and therefore, for example, the removal work of the attached matter by a diver can be performed efficiently. Note that it is not essential to display a simplified three-dimensional image Gs of the hull shown in FIG. 6, and the three-dimensional data of the hull may be displayed in detail. Further, if the position of the robot 2A detected in real time by the position detection unit 441 is displayed on the three-dimensional image Gs of the hull shown in FIG. 6, the current position of the moving robot 2A can be grasped, which is convenient. Will improve. In addition, when a diver who visually recognizes the display of the analysis result as shown in FIG. 6 divides and performs the removal work of the attached matter, it becomes a mark indicating the position (location) of the actual attached matter (for example, a flag equipped with a magnet). If the robot 2A is equipped with the robot 2A and the robot 2A is attached to the position of the deposit detected by the image analysis unit 442 during the operation (moving) of the robot 2A, Efficient removal work can be achieved.

<Robot 2A position detection>
FIG. 7 is a view for explaining position detection of the robot 2A on the hull outer plate 80. As shown in FIG. In FIG. 7, the arc-shaped broken line represents the propagation of sound waves in the hull outer plate 80. FIG. 8 is a time chart for explaining position detection of the robot 2A. In FIG. 8, the horizontal axis indicates time t, and the sound waves J1 and J2 transmitted from the first sound source unit 31 and the second sound source unit 32 are transmitted by the sound wave receiving unit 25 with time delays T1 and T2. Indicates that it is received.

  A method for detecting the position of the robot 2A on the hull outer plate 80 in the position detection system 1A of the present embodiment will be described below.

  First, for example, a sound wave is emitted from each of the sound source units 31 and 32 attached to a reference position (known position) on the hull outer plate 80, for example, by shifting the time to propagate to the hull outer plate 80. Specifically, the control device 4 controls the transmission timing of sound waves at the sound source units 31 and 32, and after transmitting the sound wave J1 from the first sound source unit 31 as shown in FIG. The sound wave J2 is transmitted.

  Thus, the sound waves transmitted from the sound source units 31 and 32 to the hull outer plate 80 reach the sound wave receiving unit 25 of the robot 2A along the propagation paths P1 and P2 of the hull outer plate 80 shown in FIG. Therefore, as shown in FIG. 8, the sound waves J1 and J2 transmitted from the sound source units 31 and 32 propagate through the hull outer plate 80, and the sound waves K1 and K2 are received (catch) by the sound wave receiving unit 25. By measuring the propagation times T1 and T2, the distances of the sound wave propagation paths P1 and P2 shown in FIG. 7 can be derived. Here, for example, information on the timing (time) at which sound waves are received by the sound wave receiving unit 25 from the robot 2A is sent via the cable CBa to the control device 4 that controls the transmission timing of sound waves at the sound source units 31 and 32. Then, the control device 4 obtains the difference between the transmission timing and the reception timing of the sound wave to obtain the propagation times T1 and T2. The propagation times T1 and T2 [s] obtained in this way are multiplied by the speed (sound speed) Vo [m / s] (the speed of the steel plate is about Vo = 5000 m / s) when the sound wave propagates through the hull outer plate 80. Then, the distance between the propagation paths P1 and P2, that is, the distance from the sound source units 31 and 32 to the sound wave receiving unit 25 can be calculated. If the distances from the sound source units 31 and 32 to the sound wave receiving unit 25 are known, the positions of the sound source units 31 and 32 on the hull outer plate 80 are known, and therefore the position of the robot 2A on the hull outer plate 80 is specified. Is possible. In the arrangement of the two sound source units 31 and 32 and the robot 2A shown in FIG. 7, the position of the robot 2A can be detected on one side of the hull outer plate 80 (the upper side of the paper surface in FIG. 7). When the position of the robot 2A is detected on the opposite surface (the lower side of the paper surface in FIG. 7), the sound source units 31 and 32 and the robot 2A are arranged on the opposite surface as shown in FIG. Just do it.

  Note that the sound speed at the hull outer plate 80 changes due to the influence of the material of the hull outer plate 80 and the like, so it is preferable to measure the sound speed in advance and perform calibration. For example, before starting the work of the robot 2A, the robot 2A is set at a known position on the hull outer plate 80, that is, at a position where the distance from the sound source 31 (32) is known, and from the sound source 31 (32). If the sound wave propagation time T1 (T2) is measured, the speed of sound at the hull outer plate 80 can be obtained with high accuracy.

  The position detection method as described above can appropriately detect the position of the robot 2A that works while sticking to the hull outer plate 80 under the water surface Lw as shown in FIG. 7, for example. The operation will be described.

<Operation of Position Detection System 1A>
FIG. 9 is a flowchart showing the basic operation of the position detection system 1A. About this operation | movement, it is performed by the control part 44 of the control apparatus 4, for example.

  As shown in FIG. 1, when the sound source units 31 and 32 are attached to the ship outer plate 80 and the robot 2A is set at a known position, and the application program in the storage unit 43 is executed by the control device 4, the position of the robot 2A Calibration relating to the detection operation is executed (step S1). By this calibration, the sound velocity Vo at the ship outer plate 80 is accurately obtained as described above, and is used for position detection of the robot 2A.

  In step S <b> 2, sound waves are transmitted from the sound source units 31 and 32 to the hull outer plate 80. Here, as shown in FIG. 8, the transmission timing of the sound wave J <b> 1 from the first sound source unit 31 and the transmission timing of the sound wave J <b> 2 from the second sound source unit 32 are shifted so as to be transmitted from the sound source units 31 and 32. The sound waves J1 and J2 can be distinguished by the sound wave receiving unit 25.

  In step S3, the sound wave transmitted in step S2 and propagating through the hull outer plate 80 is received by the sound wave receiving unit 25 of the robot 2A and the propagation times T1 and T2 (FIG. 8) are measured.

  In step S4, the position detector 441 detects the position of the robot 2A on the hull outer plate 80 from the propagation times T1 and T2 measured in step S3. Here, as described above, the position of the robot 2A is specified by multiplying the propagation times T1 and T2 by the speed of sound Vo at the hull outer plate 80, and this speed of sound Vo is obtained by the calibration operation of step S1. If is used, the position detection accuracy of the robot 2A is improved.

  In step S5, the surface of the hull outer plate 80 is imaged by the imaging unit 23 of the robot 2A to acquire an image. Specifically, as shown in FIG. 2, the imaging region Es in front of the robot 2A is imaged by the imaging unit 23, and an image of the upper surface of the hull outer plate 80 is acquired. The image data acquired by the imaging unit 23 is sent to the control device 4 via the cable CBa (FIG. 1).

  In step S6, it is determined whether or not the image of the area of the hull skin 80 that requires image acquisition (for example, the area below the water surface Lw (FIG. 7) in the hull skin 80) is incomplete. If shooting has not been completed, the process proceeds to step S7. If shooting of a necessary area has been completed, the process proceeds to step S8.

  In step S7, the actuator 26 is driven to move the robot 2A. As a result, for example, as shown in FIG. 2, an image of the imaging region Et in front of the imaging region Es captured before the movement can be acquired by the imaging unit 23. As described above, by moving the robot 2A on the hull skin 80 by the actuator 26 and photographing the surface of the hull skin 80 with the imaging unit 23 provided on the robot 2A and sequentially acquiring images, the outside of the hull is obtained. It is possible to efficiently acquire an image of an area where image acquisition is necessary with the plate 80. As described above, when receiving the sound wave propagating through the hull outer plate 80 in step S3, the sound wave receiving unit 25 is lowered in the robot 2A, but when moving the robot 2A in step S7, the sound wave receiving unit. 25 is raised so that the lower surface portion 25f is protected.

  In step S8, an adhering substance or the like is detected from the image acquired by the imaging unit 3 in step ST5 and displayed on the display unit 42. That is, the image analysis unit 442 analyzes each image of the imaging region Es (FIG. 2) sequentially acquired by the imaging unit 23 while moving the robot 2A in the region where the image acquisition is necessary on the hull outer plate 80, and appends it. Kimono, paint peeling, rust and the like are detected, and the detection result is superimposed on the three-dimensional image Gs of the hull and displayed on the display unit 42 as shown in FIG. If the operation (inspection) for analyzing the image acquired using the robot 2A and displaying the deposits and the like on the hull outer plate 80 is periodically performed, the state of the deposits and the like on the hull outer plate 80 will be described. Can be grasped in chronological order and can be used for determining the maintenance time of the hull.

  In the position detection system 1A described above, the sound waves transmitted from the two sound source units 31 and 32 attached at different positions propagate through the hull outer plate 80 and are received by the sound wave receiving unit 25. Based on the propagation times T1 and T2 (FIG. 8) and the position information of the sound source units 31 and 32 on the hull outer plate 80, the position of the robot 2A is detected. As a result, the propagation paths P1 and P2 (FIG. 7) of the sound waves transmitted from the sound source units 31 and 32 are paths along the hull outer plate 80. The position of the robot 2A on the hull outer plate 80 can be detected with high accuracy without receiving.

  If the position of the robot 2A can be detected with high accuracy in this way, it is possible to analyze the image acquired by the robot 2A and appropriately map and display the detected region of the adhered matter as shown in FIG. Then, a diver who knows in advance the position (attachment status) of the deposits and the like by visually recognizing the mapping display can efficiently remove the deposits and the like on the hull outer plate 80 below the water surface.

Second Embodiment
<Configuration of position detection system>
FIG. 10 is a block diagram showing a functional configuration of a position detection system 1B according to the second embodiment of the present invention. FIG. 10 corresponds to FIG. 5, and parts having the same functions as those in the first embodiment are denoted by the same reference numerals.

  The position detection system 1B has a configuration similar to that of the position detection system 1A of the first embodiment, but the configuration of the robot is different, and the two sound source units 31 and 32 of the first embodiment are replaced with the outside of the hull. The difference is that the two sound wave receivers 51 and 52 are attached to different positions of the plate 80.

  That is, the robot 2B of the second embodiment has a configuration similar to that of the first embodiment, but instead of the sound wave receiving unit 25 of the first embodiment, the sound source unit 31 (32) of the first embodiment and The difference is that a sound source unit 29 having the same function is provided.

  The two sound wave receivers (hereinafter also referred to as “first sound wave receiver” and “second sound wave receiver”) 51 and 52 of the second embodiment have the same functions as the sound wave receiver 25 of the first embodiment. Have. In each of the sound source receiving units 51 and 52, the same configuration as that of the sound source unit 31 in which the magnet unit 31m is attached to the lower part of the housing 311 as shown in FIG. 4 is adopted. As a result, the sound wave receiving portions 51 and 52 can be freely attached to and detached from the hull outer plate 80 by the attractive force of the magnet to the hull outer plate 80, and the attachment and removal of the sound wave receiving portions 51 and 52 to the hull outer plate 80 are easy. Can be

  The position detection of the robot 2B in the position detection system 1B having the above configuration will be described below.

<Robot 2B position detection>
FIG. 11 is a view for explaining position detection of the robot 2B on the hull outer plate 80. As shown in FIG. In FIG. 11, the arc-shaped broken line represents the propagation of sound waves on the hull outer plate 80.

  In the position detection system 1A according to the first embodiment, the sound waves transmitted from the two sound source units 31 and 32 attached to different positions on the hull outer plate 80 propagate through the hull outer plate 80 as described above, and the robot 2A. The position of the robot 2A is detected by measuring the propagation times T1 and T2 (FIG. 8) until they are received by the sound wave receiver 25. On the other hand, in the position detection system 1B of the second embodiment, as shown in FIG. 11, the sound wave transmitted from the sound source unit 29 of the robot 2B propagates through the hull outer plate 80 and reaches different positions on the hull outer plate 80. The position of the robot 2B is detected by measuring each propagation time until it is received by the two attached sound wave receivers 51 and 52. A method for detecting the position of the robot 2B will be specifically described below.

  First, sound waves are transmitted from the sound source unit 29 of the robot 2B and propagated to the hull skin 80. The sound waves emitted from the sound source unit 29 toward the hull outer plate 80 are attached to the reference position (known position) on the hull outer plate 80 along the propagation paths Q1 and Q2 shown in FIG. The sound wave receiving units 51 and 52 are reached. Therefore, if each propagation time until the sound wave transmitted from the sound source unit 29 propagates through the hull outer plate 80 and is received (caught) by each of the two sound wave receiving units 51 and 52 is measured, the first embodiment described above. Similarly, the distance between the sound wave propagation paths Q1 and Q2 shown in FIG. 11, that is, the distance from the sound source unit 29 to each of the sound wave receiving units 51 and 52 can be derived.

  Thus, if the distance from the sound source unit 29 to each of the sound wave receiving units 51 and 52 is known, the position of each of the sound wave receiving units 51 and 52 on the hull outer plate 80 is known, so the position of the robot 2B on the hull outer plate 80 Can be specified.

  By the position detection method as described above, for example, as shown in FIG. 11, the position of the robot 2B that works while sticking to the hull outer plate 80 under the water surface Lw can be detected appropriately.

  The basic operation of the position detection system 1B is similar to that of the first embodiment shown in the flowchart of FIG. 9, but the operations of steps S2 to S3 of FIG. 9 are slightly different.

  That is, in the position detection system 1B of the present embodiment, sound waves are transmitted from the sound source unit 29 of the robot 2B to the hull skin 80 in step S2 of FIG. 9, and the sound waves propagated through the hull skin 80 in step S3 of FIG. Is received by each of the sound wave receiving units 51 and 52, and each propagation time is measured.

  In the position detection system 1B described above, each propagation time until the sound wave transmitted from the sound source unit 29 of the robot 2B propagates through the hull outer plate 80 and is received by each of the two sound wave reception units 51 and 52, and The position of the robot 2B is detected based on the position information of the sound wave receiving units 51 and 52 on the hull outer plate 80. As a result, as in the first embodiment, the position of the robot 2B on the hull outer plate 80 can be detected with high accuracy.

<Modification>
In each of the above embodiments, the robot 2A (2B) may be provided with a cleaning mechanism for cleaning foreign matter or the like on the hull outer plate 80 with a rotating brush or a water jet. By such a cleaning mechanism, things that can be removed relatively easily, such as barnacle larvae detected during the movement of the robot 2A (2B), can be removed from the hull outer plate 80 each time. In particular, the above-described cleaning mechanism provided on the robot is applied to the hull outer plate 80 that has been subjected to a special coating (adhesion prevention coating) that makes it possible to easily remove the foreign matters that are difficult to adhere. It is effective to remove deposits and the like.

  In each of the above embodiments, instead of the ball caster 21 in which the ball portion is configured as a magnet, the outer peripheral portion of the wheel 22 that contacts the hull outer plate 80 is configured as a magnet, and the robot is magnetized against the hull outer plate 80. Alternatively, it may be adsorbed.

  In each of the above-described embodiments, it is not essential to attach the sound source units 31 and 32 and the sound wave receiving units 51 and 52 to the hull outer plate 80 using a magnet, and attach to the hull outer plate 80 using a double-sided adhesive sheet or the like. You may do it.

  In each of the above embodiments, the sound wave propagated to the hull outer plate 80 may be any sound that can be received by the sound wave receiving unit with vibrations that propagate around it. For example, ultrasonic waves or audible sounds can be used. It is.

  In the first embodiment, it is not essential to provide one sound wave transmission unit 25 in the robot 2A, and two or more sound wave transmission units 25 may be provided at different positions of the robot 2A. As a result, two or more different positions on the robot 2A can be detected, so that the posture (tilt) of the robot 2A can be detected. Similarly, if two or more sound source units 29 are provided at different positions of the robot 2B in the second embodiment, two or more different positions on the robot 2B can be detected, and thus the posture of the robot 2B is detected. It becomes possible.

  In the first embodiment, it is not essential to attach the two sound source parts 31 and 32 to the hull outer plate 80, and three or more sound source parts may be attached. As a result, information on three or more distances from each sound source unit to the robot can be obtained, so that the position of the robot can be detected with higher accuracy. Similarly, if three or more sound wave receiving units are attached to the hull outer plate 80 in the second embodiment described above, information on three or more distances from each sound wave receiving unit to the robot can be obtained, and therefore more accurate. The robot position can be detected.

  In the first embodiment, it is not essential to distinguish the sound wave from each sound source unit by changing the transmission timing of the sound wave, and the sound wave from each sound source unit by changing the frequency and pulse width of the sound wave. You may make it distinguish.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

1A, 1B Robot position detection system 2A, 2B Robot 3 Sound wave receiving unit 4 Control device 23 Imaging unit 25 Sound wave receiving unit 29 Sound source unit 31 Sound source unit (first sound source unit)
31m Magnet part 32 Sound source part (second sound source part)
42 display unit 44 control unit 51 sound wave receiving unit (first sound wave receiving unit)
52 Sound wave receiver (second sound wave receiver)
80 Hull skin (hull skin)
441 Position detection unit 442 Image analysis unit T1, T2 Propagation time of sound wave

Claims (11)

A position detection system for detecting the position of a robot on the outer skin of a hull,
A plurality of sound wave transmitting parts that are attached to different positions of the outer plate and transmit sound waves that propagate to the outer plate;
A sound wave receiving means provided in the robot for receiving a sound wave propagated through the outer plate;
Each propagation time until the sound wave transmitted from each of the plurality of sound wave transmitting parts propagates through the outer plate and is received by the sound wave receiving means, and position information of each of the plurality of sound wave transmitting units on the outer plate, Based on the position detection means for detecting the position of the robot,
A position detection system comprising: The position detection system according to claim 1,
Each of the plurality of sound wave transmission units is detachably attached to the outer plate by a magnet. In the position detection system according to claim 1 or 2,
The sound wave receiving means
A plurality of sound wave receiving units provided at different positions of the robot;
A position detection system comprising: A position detection system for detecting the position of a robot on the outer skin of a hull,
A sound wave transmitting means that is provided in the robot and transmits a sound wave propagated to the outer plate;
A plurality of sound wave receivers that are attached to different positions of the outer plate and receive the sound waves propagated through the outer plate;
Each propagation time until a sound wave transmitted from the sound wave transmitting means propagates through the outer plate and is received by each of the plurality of sound wave receiving units, and position information of each of the plurality of sound wave receiving units on the outer plate, Based on the position detection means for detecting the position of the robot,
A position detection system comprising: The position detection system according to claim 4,
Each of the plurality of sound wave receiving units is detachably attached to the outer plate by a magnet. In the position detection system according to claim 4 or 5,
The sound wave transmitting means includes
A plurality of sound wave transmission units provided at different positions of the robot;
A position detection system comprising: The position detection system according to any one of claims 1 to 6,
An imaging means provided in the robot for capturing an image of the surface of the outer plate;
A position detection system further comprising: The position detection system according to claim 7,
Driving means for moving the robot on the outer plate;
Image acquisition means for sequentially acquiring the images by the imaging means while moving the robot by the driving means;
A position detection system further comprising: A position detection method for detecting the position of a robot on the outer skin of a hull,
From each of a plurality of sound wave transmitting units attached to different positions of the outer plate, a sound wave transmitting step for transmitting a sound wave to be propagated to the outer plate,
A sound wave receiving step of receiving sound waves propagated through the outer plate by sound wave receiving means provided in the robot;
Each propagation time until the sound wave transmitted from each of the plurality of sound wave transmitting parts propagates through the outer plate and is received by the sound wave receiving means, and position information of each of the plurality of sound wave transmitting units on the outer plate, Based on the position detection step of detecting the position of the robot,
A position detection method comprising: A position detection method for detecting the position of a robot on the outer skin of a hull,
A sound wave transmitting step for transmitting a sound wave to be propagated to the outer plate from a sound wave transmitting means provided in the robot;
A sound wave receiving step of receiving sound waves propagated through the outer plate at each of a plurality of sound wave receiving units attached to different positions of the outer plate;
Each propagation time until a sound wave transmitted from the sound wave transmitting means propagates through the outer plate and is received by each of the plurality of sound wave receiving units, and position information of each of the plurality of sound wave receiving units on the outer plate, Based on the position detection step of detecting the position of the robot,
A position detection method comprising: In the position detection method according to claim 9 or 10,
An image acquisition step of sequentially acquiring images by photographing the surface of the outer plate with an imaging unit provided in the robot while moving the robot on the outer plate by a predetermined driving unit;
A position detection method further comprising:

Images