Robot device, robot control method, and program

Abstract

To provide a robot device capable of easily tracking a linear structure installed underwater.SOLUTION: The robot device 20 includes an MBS 23, an image processing unit 42, a position detection unit 43, and a thruster control unit 44. The MBS 23 generates an underwater acoustic image. The image processing unit 42 extracts an image of the mooring line contained in the acoustic image. The position detection unit 43 detects a relative position of the mooring line with respect to the robot body 21 based on the acoustic image and the image of the mooring line. The thruster control unit 44 controls thrusters 22a and 22b based on the detected position of the mooring line obtained by the position detection unit 43.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a robot device, a robot control method, and a program. [Background technology]

[0002] Conventionally, there is an underwater inspection device described in the following Patent Document 1. This underwater inspection device comprises an inspection device main body having a moving means and an imaging means, and a control means for remotely controlling this inspection device main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-94885 Summary of the Invention [Problem to be solved by the invention]

[0004] Mooring lines used to secure floating offshore wind turbines and other equipment are susceptible to deterioration due to corrosion from seawater and biological adhesion, and therefore require regular inspection. When using the underwater inspection device described in Patent Document 1 to inspect such mooring lines, the inspection device itself must be remotely operated by a control means, which reduces work efficiency. For these reasons, there is a demand for a device that can automatically track mooring lines.

[0005] Such problems are not limited to mooring ropes, but can also occur with linear structures such as cables installed underwater.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a robot device, a robot control method, and a program that can easily track linear structures installed underwater. [Means for solving the problem]

[0007] A robot device that solves the above problem is a robot device that navigates underwater and includes an information acquisition unit, an information processing unit, a position detection unit, and a control unit. The information acquisition unit acquires location information of underwater structures. The information processing unit extracts location information of linear structures from the location information of underwater structures. The position detection unit detects the relative position of the linear structures with respect to the robot main body based on the location information of the linear structures. The control unit controls a propulsion unit that propels the robot main body underwater based on the detected position of the linear structures obtained by the position detection unit.

[0008] A robot control method that solves the above problem is a control method for a robot device that submerges underwater, which acquires location information for underwater structures, extracts location information for linear structures from the location information for underwater structures, detects the relative position of the linear structures with respect to the robot body based on the location information for the linear structures, and controls a propulsion unit that propels the robot body underwater based on the detected position of the linear structures.

[0009] The program that solves the above problem is a program for causing a robot device to dive underwater, and causes a computer to function as an information acquisition unit that acquires location information of underwater structures, an information processing unit that extracts location information of linear structures from the location information of underwater structures, a position detection unit that detects the relative position of the linear structure with respect to the robot body based on the location information of the linear structure, and a control unit that controls a propulsion unit that propels the robot body underwater based on the detected position of the linear structure obtained by the position detection unit.

[0010] According to this configuration, the robot body can be submerged so as to follow the detected position of the linear structure, making it possible to easily track the linear structure installed underwater. [Effects of the Invention]

[0011] According to the robot device, the robot control method, and the program of the present invention, it becomes possible to easily track a linear structure installed underwater. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a robot system according to an embodiment. [Figure 2] FIG. 1 is a block diagram showing a schematic configuration of a robot device according to an embodiment. [Figure 3] FIG. 2 is a side view showing a side structure of the robot device according to the embodiment. [Figure 4] FIG. 2 is a diagram schematically illustrating an acoustic beam emitted from the MBS according to the embodiment. [Figure 5] FIG. 2 is a diagram showing an example of an acoustic image acquired by the MBS according to the embodiment. [Figure 6] FIG. 3 is an enlarged view showing an example of an image detection area of ​​an acoustic image according to the embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a positional relationship between the robot device and a mooring rope according to the embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of a positional relationship between the robot device and a mooring rope according to the embodiment. [Figure 9] FIG. 2 is a diagram illustrating an example of a positional relationship between the robot device and a mooring rope according to the embodiment. [Figure 10] 10 is a flowchart illustrating an example of the operation of the robot device according to the embodiment. [Figure 11] 10 is a graph showing the transition of the position of the robot main body in the Xn-Yn plane measured by the ASV of the embodiment. [Figure 12] 10 is a graph showing the transition of the position of the robot main body in the Yn-Zn plane measured by the ASV of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of a robot device, a robot control method, and a program will be described with reference to the drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted.

[0014] Note that the drawings may also show the Xn, Yn, and Zn axes. The Xn, Yn, and Zn axes are coordinate axes fixed to the Earth and form a right-handed, three-dimensional Cartesian coordinate system. The vertical downward direction is the positive direction of the Zn axis. In other words, the Xn and Yn axes are oriented horizontally. Hereinafter, the direction of the Xn axis arrow may be referred to as the Xn axis + direction, and the direction opposite to the arrow may be referred to as the Xn axis - direction. The same applies to the other axes. The Zn axis + direction and the Zn axis - direction may also be referred to as the "downward direction" and "upward direction," respectively. The Zn axis direction may also be referred to as the "depth direction." Furthermore, the planes perpendicular to the Xn, Yn, and Zn axes may be referred to as the Yn-Zn plane, the Zn-Xn plane, and the Xn-Yn plane, respectively. Hereinafter, this three-dimensional Cartesian coordinate system may also be referred to as the "NED (North-East-Down) coordinate system." In this embodiment, the Xn-axis direction and the Yn-axis direction are examples of two directions that are parallel to the horizontal direction and intersect with each other.

[0015] <Embodiment> First, the schematic configuration of the robot system of this embodiment will be described.

[0016] (Outline of the robot system) In the robot system 10 of this embodiment shown in FIG. 1 , the robot device 20 autonomously navigates underwater, for example, along a mooring line 101 installed underwater. The mooring line 101 is used, for example, in a floating wind power generation system 100, and is a chain that moor a float 103 that supports a wind turbine 102. One end of the mooring line 101 is fixed to the float 103. The other end of the mooring line 101 is fixed to the seabed. The mooring line 101 forms a catenary curve (a catenary curve) by being pulled horizontally and hanging down underwater due to its own weight. The mooring force for the float 103 is obtained by the weight and horizontal tension of the mooring line 101 hanging down underwater. This mooring method is called catenary mooring. In this embodiment, the mooring line 101 is an example of a linear structure.

[0017] The robot system 10 includes an ASV (Autonomous Surface Vehicle) 30 in addition to the robot device 20.

[0018] The ASV 30 monitors the position of the robotic device 20. The ASV 30 detects the position of the robotic device 20 at a predetermined interval using, for example, a super short baseline (SSBL) method. That is, the ASV 30 transmits a specific acoustic signal, and then receives a response signal transmitted from a transponder mounted on the robotic device 20 using a receiver array. The ASV 30 measures the angle of arrival of the response signal as a phase difference between the receivers, and calculates the distance to the robotic device 20 from the time difference between the signals received by each receiver. The ASV 30 then detects the relative position of the robotic device 20 with respect to the ASV 30 based on the measured phase difference and the distance to the robotic device 20. The ASV 30 can also detect the position of the robotic device 20 in the NED coordinate system based on the position of the ASV 30 detected by a Global Navigation Satellite System (GNSS) mounted on the ASV 30 and the relative position of the robotic device 20 with respect to the ASV 30.

[0019] (Configuration of the robot device) Next, we will explain the configuration of the robot device 20. The robot device 20 is an AUV (Autonomous Underwater Vehicle) that can autonomously navigate underwater.

[0020] The robot device 20 is configured by mounting various components as shown in Fig. 2 on a robot main body 21 shown in Fig. 1. As shown in Fig. 2, the robot device 20 includes a plurality of thruster devices 22a to 22d, an MBS (Multibeam Imaging Sonar) 23, a swing mechanism 24, a speed sensor 25, a gyro sensor 26, a position sensor 27, a transponder 28, a storage device 29, and a control device 40.

[0021] FIG. 3 is a side view showing the side structure of the robot body 21. Hereinafter, as shown in FIG. 3, coordinate axes fixed to the robot body 21 may be referred to as the Xb-axis, Yb-axis, and Zb-axis. The Xb-axis, Yb-axis, and Zb-axis form a right-handed three-dimensional Cartesian coordinate system fixed to the robot body 21 and having its origin at Ob shown in FIG. 3. The forward direction of the robot body 21 is defined as the + direction of the Xb-axis, and the backward direction of the robot body 21 is defined as the - direction of the Xb-axis. The right direction of the robot body 21 is defined as the + direction of the Yb-axis, and the left direction of the robot body 21 is defined as the - direction of the Yb-axis. The downward direction of the robot body 21 is defined as the + direction of the Zb-axis, and the upward direction of the robot body 21 is defined as the - direction of the Zb-axis. Planes perpendicular to the Xb-axis, Yb-axis, and Zb-axis, respectively, may be referred to as the Yb-Zb plane, the Zb-Xb plane, and the Xb-Yb plane, respectively. Hereinafter, this three-dimensional Cartesian coordinate system will also be referred to as the "robot body coordinate system."

[0022] The thrusters 22a to 22d shown in Fig. 2 are devices for propelling the robot body 21 through water. The thruster 22a applies a propulsive force in the forward / backward direction to the robot body 21, thereby propelling the robot body 21 in the forward / backward direction through water. The thruster 22b applies a propulsive force in the left / right direction to the robot body 21, thereby propelling the robot body 21 in the left / right direction through water. The thruster 22c applies a propulsive force in the up / down direction to the robot body 21, thereby propelling the robot body 21 in the up / down direction through water. The thruster 22d applies a propulsive force in the yaw direction to the robot body 21, thereby propelling the robot body 21 in the yaw direction through water. Therefore, the robot device 20 can be controlled with four degrees of freedom: forward / backward, left / right, up / down, and yaw. In this embodiment, thruster device 22a is an example of a first propulsion unit, thruster device 22b is an example of a second propulsion unit, thruster device 22c is an example of a third propulsion unit, and thruster device 22d is an example of a fourth propulsion unit.

[0023] The MBS 23 emits acoustic beams (sound wave beams) in multiple directions and listens to sound waves from multiple listening directions, including at least some of the multiple directions, to generate an acoustic image, which is time-series data of the listening results. If the mooring line 101 is present within the scanning range of the acoustic beam of the MBS 23, an image of the mooring line 101 will appear in the acoustic image. In this embodiment, the MBS 23 is an example of an information acquisition unit.

[0024] The oscillating mechanism 24 oscillates the MBS 23 relative to the robot main body 21. Specifically, the oscillating mechanism 24 is fixed to the tip of the robot main body 21 as shown in FIG. 3. The oscillating mechanism 24 is equipped with a motor device (not shown). As shown in FIG. 3, the MBS 23 is fixed to a rotation shaft 240 of the motor device. By driving the motor device, the oscillating mechanism 24 can rotate the MBS 23 about the rotation shaft 240 shown in FIG. 3. The oscillating mechanism 24 rotates the rotation shaft 240 at a predetermined angular velocity within a predetermined angular range, thereby causing the MBS 23 to perform continuous oscillating motion.

[0025] In the following, as shown in FIG. 3, the coordinate axes fixed to the MBS 23 may be referred to as the Xs-axis, Ys-axis, and Zs-axis. The Xs-axis, Ys-axis, and Zs-axis are a right-handed, three-dimensional Cartesian coordinate system fixed to the MBS 23 and having the origin Os shown in FIG. 3. The origin Os is located on the Xb-axis of the robot body coordinate system. The forward direction of the MBS 23 is defined as the + direction of the Xs-axis, and the backward direction of the MBS 23 is defined as the - direction of the Xs-axis. The right direction of the MBS 23 is defined as the + direction of the Ys-axis, and the left direction of the MBS 23 is defined as the - direction of the Ys-axis. The downward direction of the MBS 23 is defined as the + direction of the Zs-axis, and the upward direction of the MBS 23 is defined as the - direction of the Zs-axis. The planes perpendicular to the Xs-axis, Ys-axis, and Zs-axis, respectively, may be referred to as the Ys-Zs plane, the Zs-Xs plane, and the Xs-Ys plane, respectively. Hereinafter, this three-dimensional orthogonal coordinate system will also be referred to as the "MBS coordinate system."

[0026] As shown in Fig. 4, in one measurement, the MBS 23 emits acoustic beams 230 in multiple directions on a surface Ss in the Xs-Ys plane and listens to sound waves from the multiple directions. β shown in Fig. 4 indicates the deflection angle of the acoustic beam 230. The direction in which the acoustic beam 230 travels and the direction in which the sound waves are listened to (e.g., sound listening direction Da) are, for example, the same. Hereinafter, the surface Ss will also be referred to as the "sound wave detection surface Ss."

[0027] Based on the detected sound waves, the MBS23 generates an acoustic image IMs, for example, as shown in FIG. 5, corresponding to the acoustic wave detection surface Ss. The MBS23 generates a fan-shaped acoustic image IMs, whose radius and central angle are the elapsed time from the time the acoustic beam 230 was emitted and the deflection angle β, respectively. As shown in FIG. 5, the acoustic image IMs includes an image 110 corresponding to the echo of the acoustic beam 230 from the mooring line 101. The range of the fan-shaped acoustic image IMs is the detection range of the MBS23. The measurement origin of the MBS23 is located at the intersection of two radii passing through both ends of the fan-shaped arc, i.e., the center of the fan.

[0028] As a coordinate representation within the acoustic image IMs, the above intersection point is defined as the origin (0,0), and mutually orthogonal p-axis and q-axis are defined. The p-axis direction is, for example, the direction that bisects the central angle of the sector, and indicates the time-series sound listening results based on the acoustic beam 230 emitted in the Xs-axis direction. Hereinafter, the coordinates of the acoustic image IMs defined by the p-axis and q-axis will also be referred to as acoustic image coordinates.

[0029] When the MBS23 emits an acoustic beam 230 and then listens to sound waves reflected by the mooring line 101, the position of the image 110 in the acoustic image IMs generated by the MBS23 is determined based on the direction of the reflected sound wave and the time elapsed from the time the acoustic beam 230 was emitted until the reflected sound wave was listened to. The shorter the time elapsed until the reflected sound wave was listened to, the closer the image 110 is located to the origin (0,0) of the sector, and the longer the time elapsed, the more outside the sector the image 110 is located. Furthermore, the stronger the intensity of the reflected sound wave, the whiter the image 110 appears. Thus, in this embodiment, the acoustic image IMs is used as an example of location information for underwater structures. Furthermore, the image 110 in the acoustic image IMs is used as an example of location information for linear structures.

[0030] The swing mechanism 24 swings the MBS 23 within the Zb-Xb plane around the Ys axis of the MBS coordinate system. In FIG. 3, the angle formed by the swing of the MBS 23 between the Xs axis of the MBS coordinate system and the Xb axis of the robot coordinate system is indicated by "α." The angle α corresponds to the swing angle of the MBS 23 based on the Xb axis. Therefore, hereinafter, the angle α will be referred to as the "swing angle α of the MBS 23." When the Xs axis coincides with the Xb axis, the swing angle α of the MBS 23 is "0°." Furthermore, the swing angle α of the MBS 23 is indicated by a positive angle in the clockwise direction as shown in FIG. 3, and a negative angle in the counterclockwise direction as shown in FIG. 3, based on the Xb axis. In FIG. 3, the position of the Xs axis when the swing angle α is "-90°" and the position of the Xs axis when the swing angle α is "+30°" are indicated by dashed lines. The oscillating mechanism 24 oscillates the MBS 23 within a range of, for example, "-90°≦α≦+30°." When the oscillating mechanism 24 oscillates the MBS 23, the sound wave detection surface Ss of the MBS 23 also changes within a range of "-90°≦α≦+30°." Therefore, the MBS 23 sequentially generates acoustic images IMs according to the oscillating angle α.

[0031] The speed sensor 25 shown in Fig. 2 detects the speed of the robot main body 21. The speed sensor 25, for example, emits sound waves toward the seabed or underwater while moving, detects the ground speed and water speed based on the waves reflected from the seabed or underwater, and transmits an output signal corresponding to the detected ground speed and water speed to the control device 40. The gyro sensor 26 detects the yaw angular velocity of the robot main body 21 and transmits an output signal corresponding to the detected yaw angular velocity to the control device 40. The gyro sensor 26 also estimates the roll angle and pitch angle of the robot main body 21 and transmits an output signal corresponding to the estimated roll angle and pitch angle to the control device 40. The position sensor 27 detects the position of the robot main body 21 using GNSS or the like while surfacing, and transmits an output signal corresponding to the detected position of the robot main body 21 to the control device 40.

[0032] The transponder 28 is provided to enable the ASV 30 described above to detect the relative position of the robot device 20 .

[0033] The storage device 29 stores various types of information held by the robot device 20. For example, the storage device 29 stores various programs for operating the robot device 20. The storage device 29 also stores an image processing model 290.

[0034] The image processing model 290 is a deep machine learning model that can extract an image of the mooring line 101 from the acoustic image by performing image processing on the acoustic image generated by the MBS 23. For example, YOLO is used as the image processing model 290. In this embodiment, a large number of acoustic images are prepared, and the image processing model 290 is trained on these acoustic images, thereby constructing in advance the image processing model 290 that can detect an image of the mooring line 101 from the acoustic image.

[0035] The control device 40 controls the robot device 20. The control device 40 is configured with a microcomputer, etc. The control device 40 has a swing control unit 41, an image processing unit 42, a position detection unit 43, a thruster control unit 44, etc. as functional components realized by executing a program stored in the storage device 29.

[0036] The swing control unit 41 controls the swing mechanism 24. The swing control unit 41 swings the MBS 23 within a predetermined range, for example. As described above, the predetermined range is set to "-90°≦α≦+30°." The swing control unit 41 also swings the MBS 23 at a constant angular velocity. The constant angular velocity is, for example, 20° / s.

[0037] The image processing unit 42 acquires acoustic images from the MBS 23 at a predetermined cycle. The predetermined cycle is, for example, 2 Hz. The image processing unit 42 performs image processing on the acoustic images IMs acquired from the MBS 23 using the image processing model 290. For example, when the image processing unit 42 acquires an acoustic image IMs as shown in FIG. 5, the image processing unit 42 inputs the acoustic image IMs to the image processing model 290. As a result, the image processing model 290 outputs a rectangular image detection area Ac in which the image 110 of the mooring line 101 is reflected in the acoustic image IMs. The image processing unit 42 sequentially performs the image processing described above on the multiple acoustic images IMs acquired from the MBS 23 at a predetermined cycle, thereby extracting the image detection area Ac of the mooring line 101 for each of the multiple acoustic images IMs. In this embodiment, the image processing unit 42 is an example of an information processing unit.

[0038] The position detection unit 43 detects the relative position of the mooring line 101 with respect to the robot device 20, in other words, the position of the mooring line 101 in the robot coordinate system, based on the image detection area Ac of the mooring line 101 in the acoustic image IMs acquired by the image processing unit 42. For example, as shown in FIG. 6, the position detection unit 43 detects the position Pa at the center of one lower side of the image detection area Ac as the position of the mooring line 101. The position Pa of the mooring line 101 is the position in the image detection area Ac that is estimated to be closest to the robot main body 21. The position detection unit 43 converts this position Pa to a position in the MBS coordinate system using a predetermined calculation formula, thereby determining the position y of the mooring line 101 with respect to the MBS 23. sci s The detected position y of the mooring line 101 is detected. sci s is expressed, for example, as shown in the following formula f1.

[0039]

number

[0040] The position detection unit 43 performs the above-mentioned calculations on the acoustic images IMs sequentially acquired by the image processing unit 42, thereby determining the position y of the mooring rope 101 in the MBS coordinate system according to the swing angle α of the MBS 23. sc1 s ,y sc2 s ,···,y scK s are detected sequentially.

[0041] The position detection unit 43 detects the position y of the mooring rope 101 in the MBS coordinate system.sci s is calculated based on the following equation f2: bci b Convert to.

[0042]

number

[0043]

number

[0044]

number

[0045] In the robot system 10 of this embodiment, the velocity w of the robot body 21 in the Zb axis + direction, in other words, the downward direction, b The target value of w b * is set to a constant value w10. The constant value w10 is, for example, 0.1 m / s. The thruster control unit 44 calculates the actual downward velocity w of the robot body 21. b is the target speed w b * PID control of the thruster device 22c is performed so that

[0046] In the robot system 10 of this embodiment, the yaw angle ψ of the robot body 21 shown in FIG. b The target value of ψb * is set to a constant value ψ10. The thruster control unit 44 controls the actual yaw angle θ of the robot body 21. b is the target angle ψ b * PID control of the thruster device 22d is performed so that

[0047] Furthermore, the thruster control unit 44 detects the detected position y of the mooring line 101 obtained by the position detection unit 43. bci b Based on this, the speed of the robot body 21 in the Xb-axis direction and the Yb-axis direction, in other words, the speed of the robot body 21 in the forward / backward direction and the left / right direction, is controlled, thereby causing the robot body 21 to submerge along the mooring line 101.

[0048] Specifically, the thruster control unit 44 detects the mooring line 101 at a plurality of detection points c i From among these, the horizontal reference point c shown in Figure 9 X and vertical reference point c Z The thruster control unit 44 extracts the swing angle α of the MBS 23 when the mooring line 101 is detected, for example. i Based on the horizontal reference point c X and vertical reference point c Z are set as shown in the following equations f5 and f6, respectively.

[0049]

number

[0050] Next, the thruster control unit 44 determines whether the horizontal reference point c X The detected position y of the mooring line 101 corresponding to bcX b , and vertical reference point c Z The detected position y of the mooring line 101 corresponding to bcZ b Based on this, the deviation e is calculated using the following formula f7. X ,e Y ,e Z Calculate the following.

[0051]

number

[0052]

number

[0053] Also, in formula f7, "x * " is the horizontal reference point c of the mooring line 101 from the robot body 21 in the forward direction of the robot body 21. X This indicates the target distance to be maintained until the * " is the distance from the robot body 21 to the right of the robot body 21. cX b +y cZ b ) / 2 position. * " is the vertical reference point c of the mooring rope 101 from the robot body 21 downward of the robot body 21. Z Indicates the target distance to be maintained until the

[0054] In this embodiment, the deviation e shown in formula f7 X is an example of the first deviation, and the deviation e Y is an example of the second deviation, and the deviation e Z is an example of the third deviation. Also, the target distance x * is an example of the first target position, and the target distance y * is an example of the second target position, and the target distance z * is an example of the third target position.

[0055] In the robot system 10 of this embodiment, the target distance y * is set to "0". Therefore, in the following, the target distance y * This explanation is based on the assumption that is set to "0".

[0056] The thruster control unit 44 calculates the deviation e calculated by the formula f7. X ,e Z Based on this, the target forward velocity u of the robot body 21 is b * is calculated based on the following formula f10. In this embodiment, the target speed u b* is an example of the first target speed.

[0057]

number

[0058] The thruster control unit 44 controls the actual forward velocity u of the robot body 21. b is the target speed u calculated based on the above formula f10 b * The thruster 22a is subjected to PID control so that the forward velocity u b When is a positive value, the robot body 21 is moving forward, i.e., in the + direction of the Xb axis. b When is a negative value, the robot body 21 is propelled backward, that is, in the Xb-axis direction.

[0059] For example, the deviation e X is the deviation e Z smaller than and deviation e X "0 <e X ≦e u " is satisfied, that is, in the front-rear direction, the horizontal reference point c of the mooring line 101 from the robot body 21 X Distance to is target distance x * If it exceeds the target forward speed u b * is set to a positive value. Therefore, the robot body 21 moves relative to the horizontal reference point c of the mooring line 101. X In order to propel the robot forward so as to approach the horizontal reference point c of the mooring line 101 from the robot body 21, XDistance to target distance x * can be approached.

[0060] On the other hand, for example, deviation e X is the deviation e Z smaller than and deviation e X "-e u ≦e X <0" is satisfied, that is, in the front-rear direction, the horizontal reference point c X Distance to is target distance x * If it is less than the target forward velocity u b * is set to a negative value. Therefore, the robot body 21 moves relative to the horizontal reference point c of the mooring line 101. X In order to propel the robot backward so as to move away from the horizontal reference point c of the mooring line 101 from the robot body 21, X Distance to target distance x * can be approached.

[0061] In this way, in the robot device 20 of this embodiment, the horizontal reference point c of the mooring rope 101 from the robot body 21 X Distance to target distance x * As a result, the robot body 21 can follow the target distance x from the mooring line 101 in the front-rear direction. * It is possible to dive while maintaining this.

[0062] Also, the deviation e Z is the deviation e X , the forward / backward speed of the robot body 21 is controlled in the same way. * It is possible to dive while maintaining this.

[0063] On the other hand, the thruster control unit 44 calculates the deviation e calculated by the formula f7. Y Based on this, the target velocity v of the robot body 21 in the right direction is b * is calculated based on the following formula f11. In this embodiment, the target speed v b* is an example of the second target speed.

[0064]

number

[0065] The thruster control unit 44 controls the actual rightward velocity v of the robot body 21. b is the target speed v calculated based on the above formula f11. b * The thruster 22b is subjected to PID control so that the velocity v in the right direction is b is a positive value, the robot body 21 is moving to the right, i.e., in the + direction of the Yb axis. b When is a negative value, the robot body 21 is propelled to the left, that is, in the −Yb axis direction.

[0066] For example, the deviation e Y "-e v ≦e Y <0”, that is, when the position of the robot body 21 is “(y cX b +y cZ b If the position is shifted in the positive direction of the Yb axis relative to the position of " ) / 2", the target velocity v b * is set to a negative value. Therefore, the robot body 21 cX b +y cZ b In order to propel the robot body 21 in the Yb-axis direction so as to approach "(y ) / 2", cX b +ycZ b ) / 2".

[0067] On the other hand, for example, deviation e Y "0 <e Y ≦e v ", that is, when the position of the robot body 21 satisfies "(y cX b +y cZ b ) / 2" position, the target velocity v b * is set to a positive value. Therefore, the robot body 21 cX b +y cZ b In order to propel the robot body 21 in the positive direction of the Yb axis so as to approach "(y cX b +y cZ b ) / 2".

[0068] In this way, in the robot device 20 of this embodiment, the position of the robot body 21 in the left-right direction is calculated as "(y cX b +y cZ b ) / 2".

[0069] The thruster control unit 44 determines whether the robot body 21 has submerged to a predetermined depth, and when it determines that the robot body 21 has submerged to the predetermined depth, executes control to cause the robot body 21 to surface. The predetermined depth is set to, for example, 40 m. The depth of the robot body 21 may be detected by a sensor mounted on the robot body 21, or may be detected by the ASV 30. When the ASV 30 detects the depth of the robot body 21, the ASV 30 may determine whether the robot body 21 has submerged to the predetermined depth, and when the ASV 30 determines that the robot body 21 has submerged to the predetermined depth, the ASV 30 may cause the robot body 21 to surface by transmitting a surface command to the robot body 21.

[0070] (Example of robot device operation) Next, an example of the operation of the robot device 20 of this embodiment will be described.

[0071] As shown in FIG. 10, in the robot device 20 of this embodiment, first, the thruster control unit 44 adjusts the yaw angle ψ of the robot body 21. b Control of vertical speed w b Specifically, the thruster control unit 44 starts the control of the yaw angle ψ of the robot body 21 (step S10). b is the target angle ψ b * Also, the downward velocity of the robot body 21 is b is the target speed w b * PID control is performed on each of the thrusters 22c and 22d so that the target angle ψ b * and target speed w b * are set to constant values.

[0072] Next, the swing control unit 41 starts the swing operation of the MBS 23 (step S11), and the image processing unit 42 starts acquiring acoustic images IMs from the MBS 23 (step S12). The image processing unit 42 also performs image processing on the acoustic images IMs sequentially acquired from the MBS 23 using the image processing model 290, thereby extracting an image detection area Ac of the mooring line 101 in the acoustic images IMs (step S13). Furthermore, the position detection unit 43 calculates the position y of the mooring line 101 in the robot coordinate system based on the image detection area Ac of the mooring line 101 in the acoustic images IMs. bci b Furthermore, the thruster control unit 44 detects a plurality of detected positions y of the mooring line 101 obtained by the position detection unit 43 (step S14). bci b From the horizontal reference position y bcX b and vertical reference position y bcZ b (step S15), and the extracted horizontal reference position ybcX b and vertical reference position y bcZ b Based on the deviation e X ,e Y ,e Z (Step S16). Then, the thruster control unit 44 calculates the deviation e X ,e Y ,e Z Based on this, the target forward velocity u of the robot body 21 is calculated. b * and the target velocity v to the right b * (Step S17). The thruster control unit 44 also calculates the calculated forward target velocity u b * and the target velocity v to the right b * Based on this, the forward velocity u of the robot body 21 b and rightward velocity v b Specifically, the thruster control unit 44 controls the forward velocity u of the robot body 21. b is the target speed u b * Also, the rightward velocity v of the robot body 21 is b is the target speed v b * PID control of the thrusters 22a and 22b is performed so that

[0073] Next, the thruster control unit 44 determines whether the actual depth of the robot body 21 has reached a predetermined depth (step S19). If the actual depth of the robot body 21 has not reached the predetermined depth (step S19: NO), the thruster control unit 44 returns to the processing of step S11. Therefore, the thruster control unit 44 repeatedly executes the processing of steps S11 to S19 until the actual depth of the robot body 21 reaches the predetermined depth. Since the robot body 21 descends at a constant speed, the relative positional relationship between the robot body 21 and the mooring line 101 changes over time. Therefore, the horizontal reference position y detected by the position detection unit 43 changes depending on the relative positional relationship between the robot body 21 and the mooring line 101 at each time. bcXb and vertical reference position y bcZ b changes, and the target speed u is calculated based on these changes. b * ,v b * changes.

[0074] Thereafter, when the thruster control unit 44 determines that the actual depth of the robot body 21 has reached a predetermined depth (step S19: YES), it controls the thrusters 22a to 22d so that the robot body 21 rises (step S20).

[0075] (Experimental results) The inventors experimentally measured the position of the robotic device 20, having the above-described configuration, using the ASV 30 when the robotic device 20 was submerged along the mooring line 101. Next, the results of the experiment conducted by the inventors will be described.

[0076] Fig. 11 shows the change in position of the robot body 21 in the Xn-Yn plane measured by the ASV 30, in other words, the change in position of the robot body 21 in the horizontal direction. Fig. 12 shows the change in position of the robot body 21 in the Zn-Yn plane measured by the ASV 30, in other words, the change in position of the robot body 21 in the vertical direction.

[0077] 11 and 12 indicate the actual position of the mooring line 101. The multiple circular dots shown in FIGS. 11 and 12 indicate the detection points c of the mooring line 101 detected by the robot device 20. i 11 and 12 indicates the transition of the position of the robot main body 21. Point Pc shown in Fig. 11 and 12 indicates one end of the mooring line 101 that is fixed to the floating body 103. Furthermore, the triangular point shown in Fig. 11 indicates the position of the robot device 20 detected by the position sensor 27 when the robot device 20 is located on the sea surface.

[0078] As shown in Figs. 11 and 12, multiple detection points c i is arranged so as to be substantially aligned with the dashed line Lm, the robot device 20 can appropriately detect the actual position of the mooring line 101.

[0079] 11, the solid line La moves along the dashed line Lm. That is, the robot body 21 moves along the mooring line 101 in the Xn direction and the Yn direction. Furthermore, even if the robot body 21 moves away from the mooring line 101, it is controlled to return toward the mooring line 101.

[0080] 12, the solid line La moves along the broken line Lm at a constant distance. That is, the robot body 21 moves along the mooring line 101 at a predetermined distance from the mooring line 101 in the Zn and Xn directions. When the depth of the robot body 21 reaches a predetermined depth (40 m), the robot body 21 rises to the water surface.

[0081] As shown in FIGS. 11 and 12, in an experiment conducted by the inventors, it was confirmed that the robot body 21 moves along the mooring rope 101.

[0082] (Actions and Effects of the Robot Device of the Present Embodiment) As described above, the robot device 20 of this embodiment includes the MBS 23 (information processing unit), the image processing unit 42, the position detection unit 43, and the thruster control unit 44. The MBS 23 generates underwater acoustic images IMs by scanning the water with sound waves. The image processing unit 42 performs image processing on the acoustic images IMs to extract an image 110 of the mooring line 101 (linear structure) contained in the acoustic images IMs. The position detection unit 43 calculates the relative position y of the mooring line 101 with respect to the robot main body 21 based on the acoustic images IMs and the image 110 of the mooring line 101. bci b The thruster control unit 44 detects the detected position y of the mooring line 101 obtained by the position detection unit 43. bci bThe thrusters 22a to 22d are controlled based on the above.

[0083] According to this configuration, the detected position y bci b Since the robot body 21 can be made to submerge along the mooring line 101, it is possible to easily track the mooring line 101 provided underwater.

[0084] The robot device 20 further includes a swing mechanism 24. The swing mechanism 24 causes the MBS 23 to swing.

[0085] According to this configuration, acoustic images IMs can be acquired over a wider range, so that the position y bci b Therefore, it becomes possible to control the robot body 21 more appropriately.

[0086] The position detection unit 43 detects a plurality of relative positions y of the mooring line 101 with respect to the MBS 23 based on the acoustic images IMs and the image 110 of the mooring line 101. sci s Furthermore, the position detection unit 43 detects the relative position y of the mooring rope 101 with respect to the MBS 23 based on the swing angle α of the MBS 23. sci s is the relative position y of the mooring line 101 with respect to the robot body 21. bci b The position detection unit 43 converts the mooring rope 101 into a plurality of detected positions y bci b The thrusters 22a and 22b are controlled based on the above.

[0087] According to this configuration, the position y of the mooring line 101 relative to the robot body 21 is bci b In addition, it is possible to easily detect the plurality of detection positions y bci b By controlling the thruster devices 22a and 22b based on the above, it becomes possible to control the robot body 21 with higher accuracy.

[0088] The position detection unit 43 detects a plurality of positions y bci b From these, the horizontal reference position y bcX b and the vertical reference position y bcZ b The thruster control unit 44 sets the horizontal reference position y bcX b and vertical reference position y bcZ b Specifically, the thruster control unit 44 controls the thruster devices 22a and 22b based on the deviation e X , deviation e Z , and deviation e Y Based on these, the target forward velocity u of the robot body 21 is calculated. b * and the target velocity v to the right b * Then, the thruster control unit 44 sets the forward velocity u of the robot body 21. b is the target speed u b * and the rightward velocity of the robot body 21 is v b is the target speed v b * Furthermore, the vertical speed of the robot body 21 is b The thruster control unit 44 controls the thrusters 22a to 22c so that the yaw angle ψ of the robot body 21 is constant. b The thruster device 22d is controlled so that the angle is constant.

[0089] According to this configuration, it is possible to make the robot body 21 submerge along the mooring line 101 as shown in FIGS.

[0090] As shown in the above equations f10 and f11, the forward velocity u of the robot body 21 b and rightward velocity v bEach has an upper and lower speed limit.

[0091] This configuration makes it possible to prevent the speed of the robot body 21 in the forward and backward directions and the left and right directions from becoming extremely high.

[0092] The image processing unit 42 extracts the image 110 of the mooring line 101 from the acoustic image IMs using the image processing model 290 .

[0093] This configuration makes it possible to easily extract the image 110 of the mooring rope 101 from the acoustic image IMs.

[0094] <Other embodiments> The present disclosure is not limited to the above specific examples.

[0095] For example, the position detection unit 43 may detect the detected position y of the mooring rope 101 based on the center position Cc of the image detection area Ac instead of the position Pa shown in FIG. sci s may be determined.

[0096] The thruster control unit 44 determines the horizontal reference point c of the mooring line 101 as a parameter for controlling the thruster devices 22a and 22b. X and vertical reference point c Z The horizontal reference point c of the mooring line 101 was used. X In this case, for example, the time-series data of the horizontal reference points sequentially acquired by the position detection unit 43 may be used. X (0),c X (1),···,c X (k), the thruster control unit 44 calculates the time-series data c of the horizontal reference point. X (0),c X (1),···,c X The thrusters 22a and 22b may be controlled based on (k), where "k" is a natural number of 1 or more.

[0097] In addition to the thrusters 22a to 22d, the robot device 20 may be equipped with a thruster for propelling the robot body 21 in a roll direction, which is a rotation direction about the Xb axis, and a thruster for propelling the robot body 21 in a pitch direction about the Yb axis.

[0098] The thruster control unit 44 controls the downward velocity w of the robot body 21. b The target value of w b * For example, deviation e Z In this case, the thruster control unit 44 may set the forward velocity u of the robot body 21 based on the b The target value u b * As shown in equation f10, the deviation e X ,e Z Instead of setting it based on the deviation e X It may be set based only on the

[0099] The thruster control unit 44 may calculate the deviation between the robot body 21 and the mooring line 101 in the roll direction relative to the robot body 21, and then control the attitude of the robot body 21 in the roll direction based on the deviation. The same applies to the pitch and yaw directions relative to the robot body 21. In this way, the robot device 20 only needs to control at least one of the forward / backward direction, left / right direction, up / down direction, roll direction, pitch direction, and yaw direction of the robot body 21 in order to make the robot body 21 submerge along the mooring line 101.

[0100] The thruster control unit 44 adjusts the yaw angle ψ of the robot body 21 so that the mooring line 101 is positioned within a range where sound waves can be effectively input and output in the MBS 23. b may be controlled.

[0101] The thruster control unit 44 may control the robot body 21 so that it is positioned at the center of the sound waves of the MBS 23, in other words, on the Xs axis of the sound wave detection surface Ss shown in FIG.

[0102] The thruster control unit 44 adjusts the direction of the robot body 21 so that it coincides with the direction of the mooring rope 101, in other words, so that the direction of the Xb axis of the robot body 21 is aligned with the horizontal reference point c X and vertical reference point c Z Alternatively, the robot body 21 may be controlled so that it coincides with the line connecting

[0103] The robot device 20 may use, instead of the image processing unit 42, any information processing unit capable of extracting location information of a linear structure from information on reflected waves acquired by the MBS 23. For example, if the time elapsed between the emission of a sound wave from the MBS 23 and the return of the reflected wave, generated by the sound wave being reflected by the linear structure, to the MBS 23 is measured, the distance from the MBS 23 to the linear structure can be calculated by using the elapsed time and the speed of the sound wave in water. Utilizing this, the information processing unit may, for example, emit one or more sound waves from the MBS 23 in multiple directions, calculate the distance from the MBS 23 to the linear structure for each of the multiple directions, and extract location information of the linear structure based on the calculated multiple distance information.

[0104] The robot device 20 is not limited to the mooring line 101, and may be any linear structure that can be submerged to follow along the cable 104 of a wind power generation plant 100 that is placed underwater as shown in Fig. 1. The cable 104 shown in Fig. 1 is for transmitting the power generated by the wind power generation plant 100 to the outside.

[0105] Design modifications made by a person skilled in the art to the above specific examples as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of each of the above specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of each of the above specific examples can be combined as appropriate as long as no technical contradictions arise. [Explanation of symbols]

[0106] 20: Robot device, 22a: Thruster device (first propulsion unit), 22b: Thruster device (second propulsion unit), 22c: Thruster device (third propulsion unit), 22d: Thruster device (fourth propulsion unit), 23: MBS (information acquisition unit), 24: Swing mechanism, 40: Control device (computer), 42: Image processing unit (information processing unit), 43: Position detection unit, 44: Thruster control unit, 101: Mooring rope (linear structure).

Claims

1. A robotic device that can navigate underwater, an information acquisition unit that acquires information about the location of underwater structures; an information processing unit that extracts the location information of linear structures from the location information of the underwater structures; a position detection unit that detects a relative position of the linear structure with respect to the robot body based on the arrangement information of the linear structure; a control unit that controls a propulsion unit that propels the robot body in water based on the detected position of the linear structure obtained by the position detection unit. Robotic device.

2. The information acquisition unit acquires the location information of the underwater structure by scanning the underwater environment with sound waves. The robotic device according to claim 1 .

3. the information acquisition unit scans underwater with sound waves to acquire an underwater acoustic image as location information of the underwater structure, the information processing unit performs image processing on the acoustic image to extract, from the acoustic image, an image of the linear structural object included in the acoustic image as location information of the linear structural object; The position detection unit detects the relative position of the linear structure with respect to the robot body based on the acoustic image and the image of the linear structure. The robotic device according to claim 1 .

4. The robot further includes a swing mechanism for swinging the information acquisition unit relative to the robot body. The robot device according to claim 2 or 3.

5. The position detection unit Detecting a relative position of the linear structure based on the information acquisition unit from the acoustic image and the image of the linear structure; Based on the swing angle of the information acquisition unit, the position of the linear structure with respect to the information acquisition unit is converted into a relative position of the linear structure with respect to the robot body. The robot device according to claim 4.

6. the position detection unit detects a plurality of positions of the linear structure relative to the robot body based on the arrangement information of the underwater structure; The control unit controls the propulsion unit based on a plurality of detected positions of the linear structure. The robot device according to claim 2 or 3.

7. the position detection unit sets a first reference position, which is a reference position of the linear structure in a front-to-rear direction of the robot body, and a second reference position, which is a reference position of the linear structure in a top-to-bottom direction of the robot body, from among a plurality of detected positions of the linear structure; The control unit controls the propulsion unit based on the first reference position and the second reference position of the linear structure. The robotic device according to claim 6.

8. The control unit further setting a third reference position, which is a reference position of the linear structure in a left-right direction of the robot main body, based on the first reference position and the second reference position of the linear structure; The propulsion unit is controlled based on a first deviation between the first reference position and a first target position in a front-rear direction of the robot body, a second deviation between the second reference position and a second target position in a left-right direction of the robot body, and a third deviation between the third reference position and a third target position in a up-down direction of the robot body. The robotic device according to claim 7.

9. The control unit setting a first target speed, which is a target speed in a forward / backward direction of the robot body, and a second target speed, which is a target speed in a left / right direction of the robot body, based on the first deviation, the second deviation, and the third deviation; The propulsion unit is controlled so that the speed of the robot body in the forward and backward directions becomes the first target speed, the speed of the robot body in the left and right directions becomes the second target speed, and the speed of the robot body in the up and down directions becomes a constant speed. The robotic device according to claim 8.

10. The first target speed and the second target speed are provided with at least one of an upper limit speed and a lower limit speed. The robotic device according to claim 9.

11. The control unit controls the propulsion unit so that the yaw angle of the robot body is a constant angle. The robotic device according to claim 9.

12. The propulsion unit includes a first propulsion unit that propels the robot body in a forward / backward direction, a second propulsion unit that propels the robot body in a left / right direction, a third propulsion unit that propels the robot body in an up / down direction, and a fourth propulsion unit that propels the robot body in a yaw direction. The robotic device according to claim 9.

13. The information processing unit extracts an image of the linear structural object from the acoustic image using an image processing model. The robot device according to claim 3 .

14. A method for controlling a robotic device that navigates underwater, comprising: Obtaining information on the location of underwater structures, extracting location information of linear structures from the location information of underwater structures; detecting a relative position of the linear structure with respect to the robot body based on the arrangement information of the linear structure; A propulsion unit that propels the robot body through water is controlled based on the detected position of the linear structure. How to control a robot.

15. A program for causing a robotic device to submerge underwater, Computer, an information acquisition unit that acquires information about the location of underwater structures; an information processing unit that extracts the location information of linear structures from the location information of the underwater structures; a position detection unit that detects a relative position of the linear structure with respect to the robot body based on the arrangement information of the linear structure; a control unit that controls a propulsion unit that propels the robot body through water based on the detected position of the linear structure obtained by the position detection unit. program.

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