Underwater mobile system

Abstract

To provide an underwater mobile system that offers a working area and movement that is not easily restricted. [Solution] An underwater mobile system according to one aspect of the present disclosure comprises a remote control device, a first underwater mobile unit communicatively connected to the remote control device via a communication cable, and a second underwater mobile unit communicatively connected to the first underwater mobile unit via optical wireless communication and performing work underwater, wherein the second underwater mobile unit operates based on a second command signal received from the remote control device via the communication cable, the first underwater mobile unit, and the optical wireless communication.

Description

Technical Field

[0001] The present disclosure relates to an underwater vehicle system.

Background Art

[0002] Patent Document 1 below discloses a composite unmanned underwater vehicle that can be used as a tethered unmanned underwater vehicle by attaching a remote control cable and can also be used as a untethered unmanned underwater vehicle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when transmitting a command signal to an underwater vehicle operating underwater via optical wireless, communication errors are likely to occur due to the influence of sunlight in shallow areas underwater, and it is difficult for the optical rays of optical wireless to reach deep areas underwater. Therefore, the working area of the underwater vehicle when transmitting a command signal via optical wireless is likely to be restricted. On the other hand, when transmitting a command signal to an underwater vehicle operating underwater via a communication cable, there is a risk that the communication cable will interfere with obstacles, so the movement of the underwater vehicle is likely to be restricted.

[0005] Therefore, an object of the present disclosure is to provide an underwater vehicle system in which the working area and movement of the underwater vehicle are less likely to be restricted.

Means for Solving the Problems

[0006] An underwater mobile system according to one aspect of the present disclosure comprises a remote control device, a first underwater mobile unit communicatively connected to the remote control device via a communication cable, and a second underwater mobile unit communicatively connected to the first underwater mobile unit via optical wireless communication and performing work underwater, wherein the second underwater mobile unit operates based on a second command signal received from the remote control device via the communication cable, the first underwater mobile unit, and the optical wireless communication. [Effects of the Invention]

[0007] According to the above configuration, it is possible to provide an underwater mobile system that does not have its working area or movement restricted. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an overall diagram of the underwater mobile system. [Figure 2] Figure 2 is a flowchart of the recovery program. [Modes for carrying out the invention]

[0009] (Overall configuration of the underwater mobile system) The embodiments will be described below. First, the overall configuration of the underwater mobile system 100 will be described. Figure 1 is an overall diagram of the underwater mobile system 100. As shown in Figure 1, the underwater mobile system 100 according to this embodiment comprises a first underwater mobile body 10, a second underwater mobile body 20, and a remote control device 30. These components will be described in order below.

[0010] <First Underwater Mobile Unit> The first underwater mobile body 10 is a mobile body that moves underwater while communicating with a remote control device 30 via a communication cable 40. As shown in Figure 1, the first underwater mobile body 10 of this embodiment includes a first propulsion device 11, a first positioning device 12, a first camera 13, a first optical wireless communication device 14, a first acoustic communication device 15, and a first control device 16.

[0011] The first propulsion device 11 is a device that generates thrust to move the first underwater mobile body 10. In this embodiment, the first propulsion device 11 can move the first underwater mobile body 10 in any orientation and in any direction. The first propulsion device 11 may have a main thruster, a horizontal thruster, and a vertical thruster. The first propulsion device 11 may also have a swivel-type thruster that can change the direction of thrust generation.

[0012] The first positioning device 12 is a device that measures or calculates the position of the first underwater moving object 10. In this embodiment, the first positioning device 12 is an inertial navigation device that calculates the position of the first underwater moving object 10 based on the distance traveled from the starting point. However, the first positioning device 12 may also be an acoustic positioning device that measures the position of the first underwater moving object 10 based on sound waves transmitted from the mother ship 101. The operator (worker) moves the first underwater moving object 10 to the optimal position for the second underwater moving object 20 based on the information obtained from the first positioning device 12.

[0013] The first camera 13 is a camera that images the area around the first underwater moving body 10. The first camera 13 may be a fixed type with a constant imaging direction, or it may be a movable type that can change the imaging direction arbitrarily.

[0014] The first optical wireless communication device 14 is a device that communicates using optical wireless communication with light rays. The first optical wireless communication device 14 can communicate with the second optical wireless communication device 24 of the second underwater mobile body 20, which will be described later. The first optical wireless communication device 14 has a transmitter that transmits light rays to the second optical wireless communication device 24 and a receiver that receives light rays transmitted from the second optical wireless communication device 24. In this embodiment, the first optical wireless communication device 14 communicates with the second optical wireless communication device 24 using visible light rays such as blue light rays and green light rays.

[0015] The first acoustic communication device 15 is a device that communicates using acoustic radio with sound waves. The first acoustic communication device 15 can communicate acoustically with the second acoustic communication device 25 of the second underwater mobile body 20, which will be described later. Acoustic radio communication has the advantage of a wider communication angle range compared to optical radio communication, and also has the advantage of being able to communicate even if there are some obstacles between the communication partner and the communication partner.

[0016] The first control device 16 is a device that controls various equipment mounted on the first underwater mobile body 10. The first control device 16 has a processor, volatile memory, non-volatile memory, and an I / O interface, etc. Various programs are stored in the non-volatile memory of the first control device 16, and the processor performs calculations using the volatile memory based on each program.

[0017] The first control device 16 is communicatively connected to the first propulsion device 11, the first positioning device 12, the first camera 13, the first optical wireless communication device 14, and the first acoustic communication device 15. The first control device 16 can control the first propulsion device 11 by transmitting a control signal to the first propulsion device 11, acquire the position of the first underwater mobile body 10 from the first positioning device 12, acquire image data (hereinafter referred to as "first image data") captured by the first camera 13 from the first camera 13, exchange information with the second underwater mobile body 20 via the first optical wireless communication device 14, and exchange information with the second underwater mobile body 20 via the first acoustic communication device 15.

[0018] In addition, a communication cable 40 extending from the remote control facility 30 is attached to the first underwater vehicle 10. The first control device 16 is communicably connected to the remote control facility 30 via this communication cable 40. That is, information can be exchanged between the first control device 16 and the remote control facility 30. Although the communication cable 40 of this embodiment is an optical fiber cable, the communication cable 40 may be an electric cable. Further, the length of the communication cable 40 can be adjusted by winding it around a reel or paying it out from the reel.

[0019] <Second Underwater Vehicle> The second underwater vehicle 20 is a vehicle that moves underwater while communicating with the first underwater vehicle 10 via optical wireless communication. Further, the second underwater vehicle 20 performs operations underwater, such as inspection and photography of underwater structures. The second underwater vehicle 20 of this embodiment includes a second propulsion device 21, a second positioning device 22, a second camera 23, a second optical wireless communication device 24, a second acoustic communication device 25, and a second control device 26. Further, the second underwater vehicle 20 includes a storage battery as a power source. Furthermore, the second underwater vehicle 20 may include equipment for underwater operations, such as an inspection device.

[0020] The second propulsion device 21 is a device that generates a thrust force for moving the second underwater vehicle 20. The second propulsion device 21 of this embodiment can move the second underwater vehicle 20 in an arbitrary direction in an arbitrary posture. The second propulsion device 21 may have a main propulsion thruster, a horizontal thruster, and a vertical thruster. Further, the second propulsion device 21 may have a yawing thruster that can change the direction of thrust generation.

[0021] The second positioning device 22 is a device that measures or calculates the position of the second underwater vehicle 20. The second positioning device 22 of this embodiment is an inertial navigation device that calculates the position of the second underwater vehicle 20 based on the travel distance from the starting point. However, the second positioning device 22 may be an acoustic positioning device that measures the position of the second underwater vehicle 20 based on sound waves transmitted from the mother ship 101.

[0022] The second camera 23 is a camera that images the periphery of the second underwater vehicle 20. The second camera 23 may be a fixed type with a fixed imaging direction, or may be a movable type with an arbitrarily changeable imaging direction.

[0023] The second optical wireless communication device 24 is a device that communicates by optical wireless using light rays. The second optical wireless communication device 24 can communicate with the first optical wireless communication device 14 of the first underwater vehicle 10. The second optical wireless communication device 24 has a transmitter that transmits light rays to the first optical wireless communication device 14 and a receiver that receives the light rays transmitted from the first optical wireless communication device 14.

[0024] The second acoustic communication device 25 is a device that communicates by acoustic wireless using sound waves. The second acoustic communication device 25 can communicate by acoustic wireless with the first acoustic communication device 15 of the first underwater vehicle 10 described above.

[0025] The second control device 26 is a device that controls various devices mounted on the second underwater vehicle 20. The second control device 26 has a processor, a volatile memory, a non-volatile memory, an I / O interface, etc. Various programs including a return program are stored in the non-volatile memory of the second control device 26, and the processor performs arithmetic processing using the volatile memory based on each program. Note that the above "return program" will be described later.

[0026] The second control device 26 is communicatively connected to the second propulsion device 21, the second positioning device 22, the second camera 23, the second optical wireless communication device 24, and the second acoustic communication device 25. The second control device 26 can control the second propulsion device 21 by transmitting a control signal to the second propulsion device 21, acquire the position of the second underwater mobile body 20 from the second positioning device 22, acquire image data (hereinafter referred to as "second image data") captured by the second camera 23 from the second camera 23, exchange information with the first underwater mobile body 10 via the second optical wireless communication device 24, and exchange information with the first underwater mobile body 10 via the second acoustic communication device 25.

[0027] <Remote control equipment> The remote control equipment 30 is equipment for remotely controlling the first underwater mobile body 10 and the second underwater mobile body 20. In this embodiment, the remote control equipment 30 is installed on the mother ship 101. However, all or part of the remote control equipment 30 may be installed on land, and part of it may consist of portable devices. In this embodiment, the remote control equipment 30 is operated by at least two people: a first operator who remotely controls the first underwater mobile body 10 and a second operator who remotely controls the second underwater mobile body 20. However, the number of operators who operate the remote control equipment 30 is not limited, and the remote control equipment 30 may be operated by one person.

[0028] As shown in Figure 1, the remote control equipment 30 of this embodiment includes a first operating unit 31, a second operating unit 32, a first monitor 33, and a second monitor 34.

[0029] The first operating unit 31 is an operating unit for remotely controlling the first underwater mobile body 10 and is operated by a first operator. Based on the operation by the first operator, the first operating unit 31 generates a first command signal and transmits the first command signal to the first control device 16 of the first underwater mobile body 10 via the communication cable 40. When the first control device 16 receives the first command signal, it controls each of the devices of the first underwater mobile body 10 based on the first command signal and operates the first underwater mobile body 10. However, the first underwater mobile body 10 may be operated not by the operation of the first operator, but by automatic control, such as a program that follows the second underwater mobile body 20.

[0030] The second control unit 32 is an operation unit for remotely controlling the second underwater mobile body 20 and is operated by a second operator. Based on the operation by the second operator, the second control unit 32 generates a second command signal and transmits the second command signal to the first control device 16 of the first underwater mobile body 10 via the communication cable 40. The first control device 16 also transmits the second command signal to the second control device 26 of the second underwater mobile body 20 via optical wireless communication using the first optical wireless communication device 14 and the second optical wireless communication device 24. Furthermore, upon receiving the second command signal, the second control device 26 controls each component of the second underwater mobile body 20 based on the second command signal and operates the second underwater mobile body 20.

[0031] The first monitor 33 is a device that displays images captured by the first camera 13 of the first underwater mobile body 10. The first control device 16 acquires first image data from the first camera 13 and transmits the first image data to the first monitor 33 via the communication cable 40. Upon receiving the first image data, the first monitor 33 displays the images captured by the first camera 13 of the first underwater mobile body 10 based on the first image data.

[0032] The second monitor 34 is a device that displays images captured by the second camera 23 of the second underwater mobile body 20. The second control device 26 acquires second image data from the second camera 23 and transmits the second image data to the first control device 16 of the first underwater mobile body 10 via optical wireless communication using the first optical wireless communication device 14 and the second optical wireless communication device 24. When the first control device 16 acquires the second image data, it transmits it to the second monitor 34 via the communication cable 40. Furthermore, when the second monitor 34 receives the second image data, it displays the images captured by the second camera 23 of the second underwater mobile body 20 based on the second image data.

[0033] The above describes the overall configuration of the underwater mobile system 100 according to this embodiment. As described above, in the underwater mobile system 100 according to this embodiment, a second command signal is transmitted to the second underwater mobile body 20, which performs work underwater, via the communication cable 40. Therefore, the second command signal can be delivered to the second underwater mobile body 20 regardless of the work area of ​​the second underwater mobile body 20, such as shallow or deep areas underwater. In other words, the work area of ​​the second underwater mobile body 20 is not easily restricted. Also, since the communication cable 40 is not attached to the second underwater mobile body 20, the movement of the second underwater mobile body 20 is not easily restricted. In the above embodiment, the first underwater mobile body 10 and the second underwater mobile body 20 communicate wirelessly using optical technology, but since the position of the first underwater mobile body 10 relative to the second underwater mobile body 20 can be adjusted, the influence of sunlight can be suppressed.

[0034] Furthermore, although the underwater mobile system 100 according to this embodiment comprises two underwater mobile bodies, a first underwater mobile body 10 and a second underwater mobile body 20, the underwater mobile system 100 may comprise three or more underwater mobile bodies. For example, the underwater mobile system 100 may further comprise a third underwater mobile body that is communicably connected to the first underwater mobile body 10 and the second underwater mobile body 20 via optical wireless communication. In this case, the third underwater mobile body can be positioned between the first underwater mobile body 10 and the second underwater mobile body 20 and function as a relay. In other words, the remote control equipment 30 can transmit a second command signal to the second underwater mobile body 20 via the communication cable 40, the first underwater mobile body 10, the optical wireless communication between the first underwater mobile body 10 and the third underwater mobile body, the third underwater mobile body, and the optical wireless communication between the third underwater mobile body and the second underwater mobile body. With this configuration, the second underwater mobile body 20, which is located in a work area where the optical wireless beam from the first underwater mobile body 10 cannot reach, can be remotely controlled.

[0035] (Recovery Program) Next, the recovery program executed by the second control device 26 of the second underwater mobile body 20 will be described. The recovery program is a program that moves the second underwater mobile body 20 to the recovery position when optical wireless communication between the second underwater mobile body 20 and the first underwater mobile body 10 is not possible, for example, when the optical wireless light beam transmitted from the first underwater mobile body 10 is blocked by an obstacle 102.

[0036] Figure 2 is a flowchart of the recovery program. As shown in Figure 2, when the recovery program is started, the second control device 26 determines whether or not optical wireless communication between the second underwater mobile body 20 and the first underwater mobile body 10 is impossible for a predetermined time (e.g., 5 seconds) (step S1).

[0037] In step S1, if it is determined that optical wireless communication between the second underwater mobile body 20 and the first underwater mobile body 10 is not impossible, or if it is impossible, the state of being unable to communicate is less than a predetermined time (NO in step S1), the second control device 26 repeats step S1.

[0038] On the other hand, in step S1, if it is determined that optical wireless communication between the second underwater mobile body 20 and the first underwater mobile body 10 is impossible for a predetermined time, that is, if it is determined that the state of communication being impossible has continued for a predetermined time or longer (YES in step S1), the second control device 26 sets a recovery position (step S2). The recovery position is the position of the second underwater mobile body 20 where optical wireless communication becomes possible between the second underwater mobile body 20 and the first underwater mobile body 10. In this embodiment, the recovery position is set to the point where the second underwater mobile body 20 was located immediately before optical wireless communication between the second underwater mobile body 20 and the first underwater mobile body 10 became impossible.

[0039] After step S2, the second control device 26 moves the second underwater mobile body 20 toward the return position set in step S2 (step S3). Based on the position of the second underwater mobile body 20 obtained from the second positioning device 22, the second control device 26 moves the second underwater mobile body 20 toward the return position.

[0040] After step S3, the second control device 26 determines whether the second underwater moving body 20 has reached its return position (step S4). If it determines that the second underwater moving body 20 has not reached its return position (NO in step S4), it returns to step S3 and repeats steps S3 onward. On the other hand, if it determines that the second underwater moving body 20 has reached its return position (YES in step S4), it returns to step S1 and repeats steps S1 onward.

[0041] The above is a description of the recovery program. By executing the above recovery program, the second underwater mobile unit 20 can quickly recover to a state where it can communicate via optical wireless even if optical wireless communication with the first underwater mobile unit 10 becomes impossible, such as when the optical wireless light beam is blocked.

[0042] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0043] (summary) The first item disclosed herein is an underwater mobile system comprising: a remote control device; a first underwater mobile body communicatively connected to the remote control device via a communication cable; and a second underwater mobile body communicatively connected to the first underwater mobile body via optical wireless and performing work underwater, wherein the second underwater mobile body operates based on a second command signal received from the remote control device via the communication cable, the first underwater mobile body, and the optical wireless.

[0044] With this configuration, the second command signal is transmitted to the second underwater mobile unit performing work underwater via a communication cable, so the second command signal can be delivered to the second underwater mobile unit regardless of its work area. Therefore, the work area of ​​the second underwater mobile unit is not easily restricted. Also, since the second underwater mobile unit does not have a communication cable attached, its movement is not easily restricted. Thus, with the above configuration, it is possible to provide an underwater mobile unit system in which the work area and movement of the underwater mobile unit are not easily restricted.

[0045] A second item disclosed herein is the underwater mobile system described in the first item, wherein the first underwater mobile operates based on a first command signal received from the remote control equipment via the communication cable.

[0046] With this configuration, the first underwater mobile unit can be operated by a worker, allowing for appropriate operation depending on the situation.

[0047] A third item disclosed herein is the underwater mobile system according to the second item, wherein the remote control equipment includes a first operating unit that generates the first command signal based on an operation by a first operator, and a second operating unit, separate from the first operating unit, that generates the second command signal based on an operation by a second operator.

[0048] With this configuration, a first operator, distinct from the second operator who controls the second underwater mobile unit, can control the first underwater mobile unit. Therefore, while the second operator controls the second underwater mobile unit, the first operator can move the first underwater mobile unit to a range where the optical radio beam can reach the second underwater mobile unit, while avoiding collisions with obstacles.

[0049] The fourth item disclosed herein is an underwater mobile system according to any one of the first to third items, wherein the first underwater mobile includes a first camera and transmits first image data captured by the first camera to the remote control equipment via the communication cable, and the second underwater mobile includes a second camera and transmits second image data captured by the second camera to the remote control equipment via the optical wireless, the first underwater mobile, and the communication cable.

[0050] With this configuration, the operator can control the first and second underwater mobile units while checking the surrounding conditions of the first and second underwater mobile units.

[0051] A fifth item disclosed herein is an underwater mobile system according to any one of the first to fourth items, wherein the second underwater mobile includes a second acoustic positioning device for measuring the position of the second underwater mobile relative to the first underwater mobile, and when communication with the first underwater mobile via optical radio is impossible for a predetermined time, the second underwater mobile moves toward a predetermined return position based on the measurement result of the second acoustic positioning device.

[0052] With this configuration, even if the optical radio beam is blocked or other circumstances prevent the second underwater mobile unit from communicating with the first underwater mobile unit via optical radio, it can return to a state where communication is possible. [Explanation of symbols]

[0053] 10. First underwater mobile unit 11 First propulsion device 12. First positioning device 13. Camera 1 14. First Optical Wireless Communication Device 15. First Acoustic Communication Device 16. First control device 20. Second Underwater Mobile Unit 21 2nd propulsion device 22. Second positioning device 23. Second camera 24. Second Optical Wireless Communication Device 25. Second Acoustic Communication Device 26 Second Control Device 30 Remote control equipment 31 1st operation section 32 2nd operation section 33. First Monitor 34 Second Monitor 40 Communication Cables 100 Underwater Mobile Systems 101 Mothership 102 Obstacles

Claims

1. Remote control equipment, A first underwater mobile body is connected to the remote control equipment via a communication cable in a manner that allows communication, A second underwater mobile body is connected to the first underwater mobile body via optical wireless communication and performs work underwater, The second underwater mobile unit is an underwater mobile unit system that operates based on a second command signal received from the remote control equipment via the communication cable, the first underwater mobile unit, and the optical wireless communication.

2. The underwater mobile system according to claim 1, wherein the first underwater mobile unit operates based on a first command signal received from the remote control equipment via the communication cable.

3. The aforementioned remote control equipment is A first operation unit that generates the first command signal based on an operation by a first operator, The underwater mobile body system according to claim 2, further comprising a second operating unit, separate from the first operating unit, which generates the second command signal based on an operation by a second operator.

4. The first underwater mobile body includes a first camera, and transmits the first image data captured by the first camera to the remote control equipment via the communication cable. The underwater mobile system according to claim 1, wherein the second underwater mobile body includes a second camera, and transmits the second image data captured by the second camera to the remote control equipment via the optical wireless, the first underwater mobile body, and the communication cable.

5. The underwater mobile system according to claim 1, wherein the second underwater mobile includes a second acoustic positioning device for measuring the position of the second underwater mobile relative to the first underwater mobile, and when communication between the second underwater mobile and the first underwater mobile is impossible via optical wireless for a predetermined time, the second underwater mobile moves toward a predetermined return position based on the measurement result of the second acoustic positioning device.

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