Underwater robot system, balance control method, and computer equipment

Abstract

The present invention discloses an underwater robot system and a balance control method, wherein the underwater robot system comprises: at least two docking robots, wherein the at least two docking robots are used to simultaneously dock and capture a target device; a mother body, wherein when docking and capturing the target device, the mother body is located underwater and below the target device; at least two cables, wherein the at least two cables correspond one-to-one to the at least two docking robots, and each of the docking robots is connected to the mother body via one of the cables; a collecting device, wherein the collecting device is located on the mother body and is used to drive the cables to be retracted, thereby driving the target device captured by the docking robot to be recovered; and a balance control device, wherein the balance control device is connected to each of the cables and is used to control the force applied to each of the cables through a PID control algorithm, so that the at least two docking robots maintain posture locking, thereby ensuring the posture balance of the target device.

Description

Technical Field

[0001] The present invention belongs to the field of underwater robots and control technologies, and in particular relates to an underwater robot system, a balance control method, and computer equipment. Background Art

[0002] With the rise of marine engineering, deep-sea underwater operations are becoming increasingly common, and existing underwater object grasping tasks are mostly performed by robotic arms. However, for smaller target devices, robotic arms struggle to reliably grasp them. Furthermore, robotic arms typically utilize rigid contact, which can cause collisions and damage to the target device. To overcome the shortcomings of robotic arms, flexible arm grasping devices have been proposed in the prior art. However, these devices lack sufficient gripping force, and due to the complex underwater environment, the target device is subjected to uneven force, making it impossible to maintain the target device's posture. These devices are therefore not suitable for complex environments with demanding grasping requirements.

[0003] Therefore, it is necessary to improve the existing technology and provide a flexible docking robot and a balance control method for the complex underwater environment, so as to ensure the smooth and reliable recovery of the target equipment. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of the existing technology, the present invention proposes an underwater robot system, a balance control method, and a computer device. The docking robot can achieve flexible docking with the target device, and ensure the posture balance and stability of the target device, and the target device can be recovered reliably without damaging the target device.

[0005] To achieve the above objectives, in some embodiments, an underwater robot system is proposed, comprising:

[0006] At least two docking robots, wherein the at least two docking robots are used to simultaneously dock and capture a target device;

[0007] a mother body, wherein when docking and capturing the target device, the mother body is located underwater and below the target device;

[0008] At least two cables, the at least two cables corresponding to the at least two docking robots one by one, each of the docking robots being connected to the mother body via one of the cables;

[0009] a retrieving device, the retrieving device being located on the mother body and configured to drive the cable to retract, thereby driving the target device captured by the docking robot to be recovered;

[0010] A balance control device is connected to each of the cables and is used to control the force applied to each of the cables so that the at least two docking robots maintain a locked posture, thereby ensuring a balanced posture of the target device.

[0011] In some embodiments, the balance control device includes: a PID controller, which outputs control parameters of the force on the cable through a PID control algorithm according to changes in the posture angle parameters of the docking robot.

[0012] In some embodiments, the cable includes a buoyancy structure, the buoyancy structure includes an inflatable cavity, and the buoyancy structure is used to adjust the force applied to the cable.

[0013] In some embodiments, one end of the cable used to connect to the mother body has an inflation device, the inflation device is connected to the inflation cavity, and the balance control device is connected to the inflation device. By controlling the inflation device to inflate the inflation cavity and adjusting the air pressure in the inflation cavity, the buoyancy of the cable is adjusted.

[0014] In some embodiments, each of the docking robots includes an inertial measurement unit, and each of the inertial measurement units is arranged parallel to a reference direction of the docking robot's posture balance. The inertial measurement unit is used to measure the posture angle of the docking robot, and the posture angle includes a pitch angle, a roll angle, and a heading angle.

[0015] In some embodiments, ensuring the posture balance of the target device includes ensuring that the posture of the target device is in a horizontal state. The balance control device is also connected to the collecting device to control the pulling force of the collecting device on the cable. When the absolute value of the pitch angle of the docking robot increases in a positive or negative direction, the corresponding collecting device is controlled to exert a pulling force on the cable and / or the inflation device is controlled to adjust the buoyancy of the cable to restore the pitch angle to a balanced value.

[0016] In some embodiments, a balance control method for an underwater robot system is further provided. The underwater robot system is the underwater robot system described above. The balance control method includes:

[0017] Before the docking robot completes docking with the target device, the balance control device controls the inflation device to inflate the inflation cavity of the cable and adjusts the buoyancy of the cable so that the buoyancy of the cable is not less than the weight of the cable.

[0018] In some embodiments, the balance control method includes:

[0019] During the docking process between the docking robot and the target device, the balance control device controls the inflation device to adjust the air pressure of the inflation cavity of the cable so that the buoyancy of the cable is equal to the weight of the cable.

[0020] In some embodiments, the balance control method includes:

[0021] After the docking robot completes docking with the target device, the balance control device controls the pulling force of the cable by the collecting device and / or the buoyancy of the cable by the inflation device to balance the posture of the target device.

[0022] In some embodiments, there are two cables, including a first cable and a second cable, and there are two docking robots, including a first docking robot and a second docking robot. The first cable is connected to the first docking robot, and the second cable is connected to the second docking robot. The first docking robot and the second docking robot respectively dock with the front and rear ends of the target device. The balance control method includes:

[0023] When the tension of any one of the first cable and the second cable is zero, and the tension of the other cable is not zero, the balance control device controls the inflation device to adjust the buoyancy of the other cable so that the buoyancy of the other cable is less than the gravity;

[0024] When the tensions of the first cable and the second cable are both 0, the balance control device controls the pulling force of the first cable and the second cable by the collection device to increase the pulling force on the first cable and the second cable.

[0025] In some embodiments, a computer device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the balance control method described in any of the above embodiments is implemented.

[0026] Overall, the above embodiments of the present invention offer the following advantages over existing technologies: at least two docking robots are connected to a mother body via two cables, and both docking robots simultaneously capture a target device, enabling flexible docking and smooth control of the target device. Furthermore, a balance control device and PID control method are employed to achieve stable control of the target device's posture, prevent cable entanglement, and achieve reliable recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural block diagram of an underwater robot system according to an embodiment of the present invention.

[0028] Figure 2 The figure is a schematic diagram of the structure of an underwater robot system according to an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the docking status of an underwater device and a docking robot according to an embodiment of the present invention.

[0030] Figure 4 Schematic diagram of the structure of a docking robot according to an embodiment of the present invention.

[0031] Figure 5 The figure is a schematic structural diagram of a docking device for underwater equipment according to an embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram of an embodiment of the present invention when the docking pin is fully inserted into the docking port to complete docking.

[0033] Figure 7 This is a partial cross-sectional schematic diagram of an embodiment of the present invention when the docking pin fully enters the docking port to complete docking.

[0034] Figure 8 for Figure 7 A local enlarged schematic diagram of point A in the middle.

[0035] Figure 9 Schematic diagram of the cross-sectional structure of a zero-gravity cable according to an embodiment of the present invention.

[0036] Figure 10 FIG. 1 is a schematic diagram of the cross-sectional structure of a control valve of a zero-gravity cable according to an embodiment of the present invention.

[0037] Figure 11 for Figure 4 Schematic diagram of the AA section.

[0038] Figure 12 Schematic diagram of a zero-gravity cable having three air-filled cavities according to one embodiment of the present invention.

[0039] Figure 13 Schematic diagram of the composite material layer structure of a zero-gravity cable according to one embodiment of the present invention.

[0040] Figure 14 FIG. 1 is a schematic cross-sectional view of a zero-gravity cable according to an embodiment of the present invention.

[0041] Figure 15 Schematic diagram of the inflatable support structure of a zero-gravity cable according to one embodiment of the present invention.

[0042] Figure 16 Schematic diagram of the force state of the underwater robot system during the target device recovery process of an embodiment of the present invention; (a) is a schematic diagram of the target device in a balanced state, and (b) is a schematic diagram of the target device in a tilted state.

[0043] Figure 17 FIG. 1 is a schematic diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] The following describes embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art will recognize that the described embodiments may be modified in various ways or combinations thereof without departing from the spirit and scope of the present invention. Therefore, the drawings and description are illustrative in nature and are not intended to limit the scope of the claims. Furthermore, throughout this specification, the drawings are not drawn to scale, and like reference numerals represent like parts.

[0045] Figure 1 This is a structural block diagram of an underwater robot system according to an embodiment of the present invention. Figure 2 FIG. 1 is a schematic diagram of an underwater robot system according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the underwater robot system includes:

[0046] At least two docking robots 3000, wherein the at least two docking robots are used to simultaneously dock and capture a target device 2000;

[0047] a mother body 4000, which is located underwater and below the target device when docking and capturing the target device;

[0048] At least two cables 1000, each of the at least two cables corresponding to the at least two docking robots, each of the docking robots being connected to the mother body via one of the cables;

[0049] A retrieving device 5000 is located on the mother body and is used to drive the cable to retract, thereby driving the target device captured by the docking robot to be recovered;

[0050] A balance control device is connected to each of the cables and is used to control the force applied to each of the cables so that the at least two docking robots maintain a locked posture, thereby ensuring a balanced posture of the target device.

[0051] In an embodiment of the present application, the docking robot 3000 is used to dock and capture the target device 2000. The target device 2000 may be a submerged device, and in some embodiments, may be an underwater robot. In some embodiments, the target device is a powered underwater device. When capturing the target device 2000, the mother body 4000 is located underwater, the target device 2000 is located on the water surface or in the water, and the mother body 4000 is located below the target device 2000.

[0052] In some embodiments, the mother body 4000 has a collection device 5000 and a buffer locking mechanism 6000. The collection device 5000 is used to drive the cable 1000 to retract, thereby driving the captured target device 2000 to be recovered. The buffer locking mechanism 6000 is used to buffer the collision when the target device 2000 approaches the mother body 4000 and lock the target device 2000 to the mother body 4000.

[0053] It is understood that target device 2000 is an underwater device, which can be located on the water surface or in the water. Being underwater means that the entire underwater device is completely below the water surface. Being on the water surface means that at least a portion of the underwater device is above the water surface, but the bottom surface of the underwater device is at least in contact with the water surface or is located below the water surface. At least the bottom surface of the underwater device is located below the water surface, and the underwater device may be an underwater robot.

[0054] In some embodiments, the underwater device may have a drive source that can drive the underwater device. In some embodiments, the underwater device may not have a drive source or the drive source may be malfunctioning. The target device 2000 may be a device that performs a target task. Upon completion of the target task or when it needs to be recovered, it needs to be returned to the mother body.

[0055] In some embodiments, the docking robot 3000 is a simple underwater robot having a driving device that can drive the docking robot 3000 to move in water.

[0056] In some embodiments, the cable 1000 comprises an electrical cable. The cable is used to supply power to the docking robot 3000. In some embodiments, the cable 1000 also comprises a signal line for transmitting control signals, etc. Specifically, when recovering the underwater device, the docking robot is released from the mother body. The docking robot's drive unit serves as a power unit, and the cable can supply power to the power unit, which includes a motor and drive propellers. Driven by the power unit, the docking robot approaches the underwater device. Generally, the mother body is located below the underwater device. The underwater device has a docking device on its bottom surface, and the docking robot has a docking structure on its top that mates with the docking device. Once the docking robot approaches the underwater device, the docking structure mates with the docking device to complete docking. The mother body then retracts the cable, driving the underwater device and recovering it back to the mother body. In some embodiments, the mother body is an underwater base station. In some embodiments, the mother body has a power source and can move underwater. In some embodiments, the mother body is a fixed base station and can be located underwater. It is understood that the underwater area can be either seawater or freshwater.

[0057] In some embodiments, there are two cables 1000, both connected to the same mother body. There are two docking robots 3000, each connected to the mother body 4000 via a cable 1000. Both docking robots 3000 can simultaneously dock with the underwater device 2000. In some embodiments, the cables 1000 are released and retracted via a retraction device 5000. During retraction, the cables 1000 can be wound around the retraction device 5000. When the underwater device is retracted to the mother body, it engages and locks with a buffer locking mechanism to prevent collision damage.

[0058] Figure 3 This is a schematic diagram of the docking status of an underwater device and a docking robot according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of a docking robot according to one embodiment of the present invention. In some embodiments, the bottom surface of the underwater device has a docking device 2100, and the top of the docking robot has a docking structure 3100 that matches the docking device. In some embodiments, the docking device includes a docking port, and the docking structure includes a docking pin. The target device has a docking port below it, and the docking robot has a docking pin that matches the docking port. The docking port and the docking pin function as a locking mechanism when mated.

[0059] Figure 5 Schematic diagram of the structure of the docking device of the underwater equipment according to one embodiment of the present invention. Figure 5 The docking device 2100 includes a docking port 2101 having a tapered structure and a tapered cavity. The lower end of the docking port 2101, near the opening, has a locking groove 2102. The locking groove 2102 may be a groove that surrounds the docking port 2101. The top end of the docking port 2101, away from the opening, has a positioning protrusion 2103. The positioning protrusion 2103 is located at the center of the docking port 2101, protruding downward from the top end of the docking port 2101 and facing into the docking port. In some embodiments, the positioning protrusion 2103 is tapered, with the tip facing downward.

[0060] Specifically, refer to Figure 4 The docking structure 3100 includes a docking pin 3101, which has a tapered structure portion. The docking pin 3101 has a tapered pin structure. The tapered pin structure matches the tapered cavity of the docking port 2101. Specifically, when the docking is completed, the cross-sectional diameter of the tapered pin structure is less than or equal to the cross-sectional diameter of the tapered cavity. The cross-sectional diameter of the top of the tapered pin structure is less than the cross-sectional diameter of the lower end opening of the tapered cavity. The tapered docking port and the docking pin make the docking match smoother and less prone to violent collisions.

[0061] In some embodiments, the docking pin 3101 is a movable pin. Specifically, the docking pin 3101 has a threaded hole 3108 at its center. The docking robot comprises a frame 3102 and a docking motor 3103. The frame includes a stud 3104. One end of the stud 3104 is connected to the output shaft of the docking motor 3103, while the other end extends into the threaded hole of the docking pin 3101, threadedly connected to the docking pin 3101. The docking motor 3103 is fixed to the frame 3102. When the docking motor output shaft rotates, the forward and reverse rotations can thread the docking pin 3101 upward or downward. Before docking, the upper end, or top, of the docking pin 3101 is located within the frame. When docking is required, the docking motor drives the docking pin 3101 upward, extending from the frame and into the docking port 2101 to complete the docking. The provision of a movable pin prevents interference with underwater debris during the docking robot's movement and prevents the extended docking pin from colliding with underwater equipment in the event of misalignment. Only when the docking robot is aligned with the underwater equipment, that is, when the position of the docking pin is aligned with the docking port, does the docking motor drive the docking pin 3101 upward, allowing the docking pin to extend into the docking port 2101. Furthermore, by having the docking pin extend into the docking port, the upper end of the docking robot does not need to be in contact with the underwater equipment, allowing the docking robot's drive paddle to have sufficient drive space, making control more convenient. In some embodiments, the plane on which the drive paddle lies is coplanar with the top plane of the docking robot. The top plane of the docking robot is the top surface of the frame where the docking pin is located when the docking pin is not extending out of the frame.

[0062] In some embodiments, the threaded hole 3108 is a through hole that passes through the docking pin 3101. The top of the threaded hole can dock with the positioning protrusion 2103. The inner diameter of the threaded hole is equal to or slightly smaller than the diameter of the uppermost end of the positioning protrusion.

[0063] Figure 6 This is a diagram showing the docking pin fully entering the docking port to complete docking. Figure 6 The cross-sectional diameter of the tapered pin structure's top is D1, and the cross-sectional diameter of the tapered cavity's top is D2. The inner diameter of the threaded hole is d1, and the diameter of the top end of the positioning protrusion is d2. The taper angle of the tapered pin structure is equal to that of the tapered cavity, meaning the tapered pin structure and the tapered cavity have the same inclination angle, allowing them to fit snugly.

[0064] In some embodiments, D1≥D2, d2≥d1. The cone angle of the tapered pin structure is θ, the cone angle of the tapered positioning protrusion 2103 is β, and the following conditions are satisfied:

[0065]

[0066] In some embodiments,

[0067]

[0068] When the docking pin is completely inserted into the docking port, the center is completely positioned through the top end of the threaded hole and the positioning protrusion.

[0069] Figure 7 This is a partial cross-sectional diagram of the docking pin fully entering the docking interface to complete the docking. Figure 8 for Figure 7 A partial enlarged schematic diagram of point A in the middle. Figure 7 and Figure 8 In some embodiments, the docking pin 3101 has a plurality of transverse holes 3105 at its lower portion. A latch 3106 is disposed in the transverse hole 3105 and is laterally movable. When the latch is extended outward, it can be inserted into the locking groove 2102 at the lower end of the docking port 2101 near the opening.

[0070] The locking groove 2102 is embedded with a magnet 2104, and the latch 3106 is made of a magnetic material. When the docking pin 3101 rises to a preset position and the latch 3106 is flush with the locking groove 2102, the latch 3106 is magnetically drawn out by the magnet and inserted into the locking groove 2102, completing the vertical locking. Specifically, multiple latches are arranged in an umbrella shape on the docking pin 3101. The latches are all located in the same plane.

[0071] Specifically, refer to Figure 8 The lower end surface of locking groove 2102 has a rounded corner 2105. The lower end surface of latch pin 3106 has a chamfered corner 3107. The height of locking groove 2102 is greater than the height of latch pin 3106. In the fully locked state, the lower end surface of locking groove 2102 and the lower end surface of latch pin 3106 are flush with each other. The provision of rounded corners 2105 and chamfered corners 3107 ensures smooth insertion of latch pin 3106 into locking groove 2102.

[0072] In some embodiments, reference Figure 4The docking robot has a power unit comprising a motor and drive paddles 3109. There may be multiple drive paddles 3109, for example, four. The docking robot also has a positioning device for determining the location of the target device, and the drive paddles for driving the docking robot to perform active movement. In some embodiments, the positioning device comprises a long-range positioning device and a short-range positioning device. The long-range positioning device is used to locate the target device during the initial phase of the docking robot's separation from the mother body, while the short-range positioning device is used to accurately locate the target device at close range when the docking robot approaches the target device. In some embodiments, the long-range positioning device comprises a sonar positioning device, while the short-range positioning device comprises a camera and an image processing module. The docking robot locates the target device using the long-range positioning device and, driven by the drive paddles, moves toward the target device. When the docking robot approaches the target device, the short-range positioning device accurately locates the target device and docks with the target device. Specifically, the camera and image processing module can perform image recognition to achieve precise positioning, aligning the docking pin with the docking port, and then initiate docking and locking of the docking pin and the docking port.

[0073] In some embodiments, when the docking robot approaches the target device, precise positioning of the target device at close range is achieved using the following method.

[0074] Specifically, the position of the target device is accurately located by a short-range positioning device; at the same time, the position of the target device is monitored in real time.

[0075] The camera includes a first camera and a second camera, and accurately locates the position of the target device through a close-range positioning device, including:

[0076] The first step is to obtain the rough position of the docking port. Specifically, the first camera continuously captures a panoramic view of the target device to obtain at least a first image and a second image comprising a panoramic image of the target device. The image processing module performs image recognition and / or segmentation on the first image and the second image to perform rough positioning, thereby obtaining the rough position of the docking port 2101 of the docking device 2100 on the target device, and obtaining the position difference between the first image and the second image. Based on the shooting time and position difference between the first image and the second image, the rough position change speed and direction of the target device are obtained.

[0077] The second step is to obtain the precise position of the docking interface. Specifically, after obtaining the rough position of the docking interface and its changes, the docking robot is driven to move to the docking interface so that the docking pin 3101 of the docking structure 3100 is basically / roughly aligned with the docking interface. The docking interface is continuously photographed at close range and micro-focus by a second camera to obtain at least a third image and a fourth image including macro images of the docking interface and the positioning protrusion in the docking interface. The third image and the fourth image are subjected to image recognition and / or segmentation by an image processing module, and are precisely positioned to obtain the precise position of the docking interface 2101 and the positioning protrusion 2103 on the target device; at the same time, the position difference between the third image and the fourth image is obtained, and the precise position change speed and direction of the target device are obtained based on the shooting time and position difference of the third image and the fourth image.

[0078] The third step is to accurately track the position of the target device in real time. Specifically, after obtaining the precise position of the docking port, its speed of change, and its direction, the docking robot is driven to precisely align the docking pin 3101 of the docking structure 3100 with the docking port. A second camera continuously captures the docking port at close range with a micro-focus lens. The captured images are processed in real time by an image processing module. Based on the image processing results, the docking robot is driven to track the target device in real time, accurately tracking its position in real time.

[0079] In some embodiments, the buffer locking mechanism includes a buffer mechanism and a locking mechanism, the buffer mechanism includes an elastic device, and the locking mechanism includes a V-shaped structure and a fixing plate. When the underwater device is retracted into the mother body, the underwater device contacts and locks with the buffer locking mechanism to prevent collision damage. Specifically, the V-shaped structure matches the size of the underwater device, the underwater device can be embedded in the V-shaped structure, the fixing plate is rotationally connected or slidingly connected to the V-shaped structure, and after the underwater device is embedded in the V-shaped structure, the fixing plate flips or slides and presses on the upper part of the underwater device, completing the locking.

[0080] In some embodiments, the present application also provides a method for controlling flexible docking and capture of an active underwater robot, wherein the control method utilizes the underwater robot system described in any of the above embodiments to enable the docking robot to flexibly dock and capture the target device.

[0081] In some embodiments, the control method includes:

[0082] The docking robot leaves the mother body;

[0083] The docking robot locates the position of the target device through a remote positioning device and moves toward the target device under the action of a driving paddle;

[0084] When the docking robot approaches the target device, the position of the target device is accurately located by a short-range positioning device, and docking with the target device is achieved;

[0085] The collecting device in the mother body drives the cable to retract, thereby driving the target device captured by the docking robot to be recovered;

[0086] When the target device approaches the mother body, the target device buffers the collision through the buffer locking mechanism, and the buffer locking mechanism locks the target device to the mother body.

[0087] The underwater robot system of the present application completes active capture by docking the docking robot with the target device, and the docking is accurate and reliable. The docking robot and the mother body are connected by cables, and then the docking of the docking robots is used to achieve flexible docking and controllable recovery, thereby avoiding damage to the target device. Two docking robots are connected by two cables, each docking robot is connected to the mother body by a cable, and the two docking robots capture a target device at the same time, thereby achieving stable control of the posture of the target device, avoiding cable entanglement, and achieving reliable recovery. The collection device and the buffer locking mechanism are used to buffer the contact between the target device and the mother body to avoid collision, and the collection device and the locking mechanism cooperate to achieve fixed locking of the target device and complete underwater recovery.

[0088] In some embodiments, the balance control device includes: a PID controller, which outputs control parameters of the force on the cable through a PID control algorithm according to changes in the posture angle parameters of the docking robot.

[0089] In some embodiments, each of the docking robots includes an inertial measurement unit, and each of the inertial measurement units is arranged parallel to a reference direction of the docking robot's posture balance. The inertial measurement unit is used to measure the posture angle of the docking robot, and the posture angle includes a pitch angle, a roll angle, and a heading angle.

[0090] In some embodiments, ensuring the posture balance of the target device includes ensuring that the posture of the target device is in a horizontal state. The balance control device is also connected to the collecting device to control the pulling force of the collecting device on the cable. When the absolute value of the pitch angle of the docking robot increases in a positive or negative direction, the corresponding collecting device is controlled to exert a pulling force on the cable and / or the inflation device is controlled to adjust the buoyancy of the cable to restore the pitch angle to a balanced value.

[0091] In some embodiments, Figure 9 1 is a schematic diagram of a cross-sectional structure of a cable according to an embodiment of the present invention. The cable 1000 can be constructed as a zero-gravity cable. Figure 1 and Figure 2The zero-gravity cable is used in underwater robot systems. Each underwater robot system has two zero-gravity cables. During the recovery process, the buoyancy of the two zero-gravity cables can be controlled to reduce or even avoid the influence of gravity on the zero-gravity cables, making it easier to control the force balance at both ends of the underwater equipment and ensuring stable recovery of the underwater equipment. Figure 9 The cable 1000 is used for underwater equipment recovery, and includes a cable 100. One end of the cable is used to connect to a docking robot, and the other end is used to connect to a mother body. The docking robot is used to capture underwater equipment, thereby recovering the underwater equipment; the cable is used to supply power to the docking robot. In some embodiments, the cable 1000 also includes a buoyancy structure 200. The buoyancy structure includes an inflatable cavity 201. The buoyancy structure is used to make the buoyancy of the cable equal to the gravity when it is in the water, so that it is in a zero-gravity state. It can be understood that the water can be seawater or freshwater. In addition, by providing an inflatable cavity, the cable can be in an expanded state when inflated and subjected to radial outward tension. The overall rigidity of the cable is large and it is not easy to bend, so that the cable is not easy to get entangled during the pulling and recovery process, and motion control is easier.

[0092] In some embodiments, the cable comprises at least two air-filled cavities, the cable being disposed at the center of the cable, and the at least two air-filled cavities extending along the cable. In some embodiments, the cable has two air-filled cavities, the cable being disposed at the center of the cable, the two air-filled cavities extending along the cable, and being symmetrically disposed on either side of the cable.

[0093] Figure 10 This is a schematic diagram of the cross-sectional structure of a cable at a control valve according to an embodiment of the present invention. Figure 11 for Figure 10 Schematic diagram of the AA section. Figure 10 and Figure 11 In some embodiments, a control valve 300 is provided at one end of the cable for connecting to the docking robot. The control valve 300 is connected to the inflatable cavity and is used to control the connection or disconnection of the inflatable cavity. Figure 9 and Figure 10 In the illustrated embodiment, the cable has two air-filled cavities, and the control valve 300 connects the two air-filled cavities to control the connection or disconnection of the two air-filled cavities.

[0094] In some embodiments, the cable has an inflation device 400 at one end for connection to the mother body, which can be mounted on the mother body. In some embodiments, the mother body is provided with an inflation device, and each cable is provided with at least two independent inflation devices, each of which can inflate at least one inflatable cavity. In some embodiments, the cable has two inflatable cavities, and each inflation device inflates one inflatable cavity.

[0095] In an embodiment of the present application, two inflatable cavities and two independent inflatable devices are provided, each independent inflatable device corresponds to an inflatable cavity, and the two inflatable cavities are connected by a control valve to ensure the reliability of inflation and avoid failure to inflate due to failure of a certain inflatable cavity or a certain inflatable device, especially failure to inflate due to damage or blockage of the inflatable cavity. When the inflatable devices are working normally, the control valve is closed, and the two inflatable cavities are independently inflated and the air pressure is controlled to ensure inflation efficiency and stability. When an inflatable device fails, the control valve can be opened, so that the other inflatable device can be used to directly inflate the two inflatable cavities. When an inflatable cavity is damaged and leaks, the control valve can be closed and the air pressure of the other inflatable cavity can be increased to ensure buoyancy.

[0096] In some embodiments of the present application, a balance control method for an underwater robot system is further provided. The underwater robot system is the underwater robot system described above. The balance control method includes:

[0097] Before the docking robot completes docking with the target device, the balance control device controls the inflation device to inflate the inflation cavity of the cable and adjusts the buoyancy of the cable so that the buoyancy of the cable is not less than the weight of the cable.

[0098] In the embodiments of the present application, by independently inflating and controlling the air pressure of the two inflatable cavities, the air pressure of the inflatable cavities can be easily controlled and adjusted, thereby adjusting the buoyancy of the entire cable to adapt to the movement state of the cable, preventing entanglement, and improving efficiency. For example, during the cable release process, that is, during the cable rising process, the docking robot is in an ascending state, and the air pressure of the inflatable cavity can be appropriately increased so that the buoyancy of the cable is greater than the weight of the cable. As a result, the cable itself has an upward driving force under the action of buoyancy, reducing the driving force required for the docking robot, making it easier and faster for the docking robot to approach the underwater equipment that needs to be docked. Of course, the buoyancy of the cable cannot be too greater than the weight of the cable to prevent the cable from moving upward faster than the docking robot, pulling the docking robot, and preventing the docking robot from losing control.

[0099] In some embodiments, the balance control method includes: during the docking process between the docking robot and the target device, the balance control device controls the inflation device to adjust the air pressure of the inflation cavity of the cable so that the buoyancy of the cable is equal to the gravity of the cable.

[0100] In the embodiments of the present application, the docking process between the docking robot and the target device involves the precise positioning of the target device at close range when the docking robot approaches the target device, and the completion of the docking and locking process, i.e., the docking pin and the docking port are docked and locked. During this process, the buoyancy of the cable is equal to the weight of the cable, which effectively prevents entanglement and facilitates the motion control of the docking robot, thereby enabling the docking pin and the docking port to accurately complete the docking and locking process and reduce docking shock and collision.

[0101] In some embodiments, the balance control method includes: after the docking robot completes docking with the target device, the balance control device controls the pulling force of the cable by the collecting device and / or the inflation device adjusts the buoyancy of the cable to balance the posture of the target device.

[0102] During the cable descent and recovery process, the docking robot also descends with the underwater equipment. The air pressure in the inflatable cavity can be appropriately reduced to make the cable's buoyancy less than or equal to the cable's weight. As a result, the cable itself has a downward driving force or a floating state under the action of gravity. Under the action of the collection device on the mother body, the cable can easily recover the underwater equipment. Of course, the cable's buoyancy cannot be too less than the cable's weight to prevent the cable from moving downward too quickly under the action of gravity, pulling on the docking robot and preventing the docking robot from losing control. It is also necessary to prevent the cable's downward movement speed from being greater than the collection speed of the collection device, which will cause the cable to pile up and tangle, hindering recovery.

[0103] Figure 16 Schematic diagram of the force state of the underwater robot system during the target device recovery process. (a) is a schematic diagram of the target device in a balanced state, and (b) is a schematic diagram of the target device in a tilted state.

[0104] In some embodiments, there are two cables, including a first cable and a second cable, and there are two docking robots, including a first docking robot and a second docking robot. The first cable is connected to the first docking robot, and the second cable is connected to the second docking robot. The first docking robot and the second docking robot respectively dock with the front and rear ends of the target device. The balance control method includes:

[0105] When the tension of any one of the first cable and the second cable is zero, and the tension of the other cable is not zero, the balance control device controls the inflation device to adjust the buoyancy of the other cable so that the buoyancy of the other cable is less than the gravity;

[0106] When the tensions of the first cable and the second cable are both 0, the balance control device controls the pulling force of the first cable and the second cable by the collection device to increase the pulling force on the first cable and the second cable.

[0107] Specifically, such as Figure 16 As shown, after the docking robot completes docking with the target device, the docking robot stops self-driving, and the driving force of the docking robot on the target device comes from the tension of the cable. The force on the target device includes its own buoyancy F 浮 , gravity G and the driving force F of the first docking robot on the target device 1驱动 , the driving force F of the second docking robot on the target device 2驱动 The driving force F of the first docking robot on the target device 1驱动 The driving force F of the second docking robot on the target device is downward. 2驱动 Direction downward.

[0108] Among them, the driving force F of the first docking robot on the target device 1驱动 , the pulling force F of the first cable by the collecting device 1拉力 , the gravity F of the first cable 1g , the buoyancy of the first cable F 1f The relationship is:

[0109] F 1驱动 =F 1拉力 +F 1g -F 1f

[0110] The driving force F of the second docking robot on the target device 2驱动 , the pulling force F of the collecting device on the second cable 2拉力 , the gravity of the second cable F 2g , the buoyancy of the second cable F 2f The relationship is:

[0111] F 2驱动 =F 2拉力 +F 2g -F 2f

[0112] In the equilibrium state, the target device is horizontal and the pitch angle is 0 degrees. When disturbed by the underwater environment or other unbalanced forces, the target device is in a tilted state and the pitch angle changes. It is necessary to control the buoyancy and tension of the cable and adjust the driving force of the first docking robot on the target device to F 1驱动’ The driving force of the second docking robot on the target device is F 2驱动’ , providing a restoring torque M for the target device 恢复 , so that the pitch angle returns to a balanced value.

[0113] In an embodiment of the present application, by jointly controlling the tension and buoyancy of the two cables, the target device can be set to always be kept in a tensioned state as much as possible during the recovery process, regardless of the gravity and buoyancy of the target device itself, thereby controlling its horizontal posture.

[0114] In some embodiments, the cable has multiple inflatable cavities, with the number of cavities being three or more, for example, three, four, or five. In some embodiments, the number of inflatable cavities is no greater than five. Providing two or more inflatable cavities ensures inflation reliability and avoids failure to inflate due to damage or blockage of a cavity. Furthermore, a number of no more than five inflatable cavities simplifies the structure, reduces manufacturing difficulties, and avoids blockage caused by the small cross-sectional dimensions of a single inflatable cavity. In some embodiments, the number of inflatable cavities is 2-5, with each cavity corresponding to an independent inflatable device. Providing multiple independent inflatable devices ensures inflation pressure and improves inflation efficiency. In some embodiments, two or more inflatable cavities share a single independent inflatable device. Of course, each cable has at least two independent inflatable devices. The corresponding inflatable cavities of the two independent inflatable devices are connected by a control valve. The control valve connects or disconnects the two inflatable cavities. When the two inflatable cavities are connected, each independent inflatable device can inflate the two inflatable cavities, and the air pressure in the two inflatable cavities is the same. When the two inflatable cavities are disconnected, each independent inflatable device can only inflate the corresponding inflatable cavity, and the air pressure in the two inflatable cavities can be different.

[0115] In the embodiments of the present application, by providing multiple inflatable cavities and multiple independent inflating devices, the reliability and efficiency of inflation are further guaranteed, and the anti-entanglement effect is improved. In addition, the air pressure in the multiple inflatable cavities can be controlled to achieve different air pressures in different inflatable cavities, thereby adapting to the influence of water flow direction.

[0116] refer to Figure 12The cable has three inflatable cavities: a first inflatable cavity 2011, a second inflatable cavity 2012, and a third inflatable cavity 2013. Each inflatable cavity is provided with an independent inflatable device, resulting in three independent inflatable devices. Every two adjacent inflatable cavities are connected by a control valve 300. Specifically, a first control valve 301 is provided between the first inflatable cavity 2011 and the second inflatable cavity 2012, a second control valve 302 is provided between the second inflatable cavity 2012 and the third inflatable cavity 2013, and a third control valve 303 is provided between the third inflatable cavity 2013 and the first inflatable cavity 2011.

[0117] Figure 13 Schematic diagram of the composite material layer structure of a cable according to an embodiment of the present invention. Figure 9 and Figure 13 The cable is wrapped with a composite material layer 500 made of a high-strength material. The composite material layer is made of a flexible, flex-resistant material. The composite material layer ensures that the cable can be wound without bending, thereby preventing damage to the air-filled cavity and cable, while also facilitating recovery. In some embodiments, the composite material layer includes a tensile layer 501, a bending-resistant layer 502, and a protective layer 503. The protective layer is disposed around the tensile layer, and the tensile layer is disposed around the bending-resistant layer. The tensile layer 501 has high strength to prevent the cable from breaking due to excessive tension. The tensile layer 501 can be composed of metal wires forming a mesh structure. The metal wires can be stainless steel. The bending-resistant layer 502 has high rigidity to prevent the cable from bending due to excessive bending moments. The bending-resistant layer 502 can be a flexible plastic. The protective layer 503 has good wear and corrosion resistance to prevent wear and corrosion of the cable in seawater environments and during recovery. The protective layer 503 can be made of rubber. By arranging the anti-bending layer, anti-tensile layer and protective layer in sequence, with the anti-bending layer on the innermost side and the protective layer on the outermost side, wear, tear and bending can be effectively prevented.

[0118] refer to Figure 9 In some embodiments, the outer periphery of the cable has an insulating layer 600, which is disposed between the cable and the air-filled cavity. The insulating layer 600 is disposed closely to the cable to insulate and protect the cable.

[0119] In some embodiments, the inflatable cavity has a cavity skin 202. The cavity skin 202 can be made of an elastic material. The cavity skin has good flexibility and elasticity and can adapt to different inflation pressures. The cavity skin 202 also has good airtightness. In some embodiments, the cavity skin 202 can be a rubber material. In some embodiments, between the composite material layer 500 and the insulating layer 600, the space other than the inflatable cavity has a filling material 700, and the filling material 700 can be a porous flexible material, such as a foam material. The filling material 700 has shaping and protective effects, and can also increase buoyancy. Figure 9 As shown, the filling material 700 has a certain shape, with an air-filled cavity in the middle. When the air-filled cavity is inflated, the cavity skin 202 is tightly attached to the filling material 700 and fills the space containing the filling material 700 .

[0120] Figure 14 Schematic diagram of the cross section of a cable according to an embodiment of the present invention. Figure 14 As shown, the inflatable cavity 201 has an inflatable support structure. Figure 15 Schematic diagram of the inflatable support structure of a cable according to an embodiment of the present invention. Figure 14 and Figure 15In some embodiments, the inflatable support structure includes an inflatable column 203, an inflatable hole 204, and a connecting rod 205. Each inflatable cavity 201 has two inflatable columns 203, and the two inflatable columns 203 are connected by a connecting rod 205. There are multiple connecting rods 205. They are arranged at intervals between the two inflatable columns 203. The inflatable column 203 extends along the longitudinal direction of the inflatable cavity 201, that is, the length direction of the cable. The inflatable column 203 is annular, and the center of the inflatable column 203 is a hollow structure. The inflatable column 203 has multiple inflatable holes 204. The multiple inflatable holes 204 can be arranged at intervals on the inflatable column 203. The multiple inflatable holes 204 can be staggered to prevent blockage. The inflatable device is connected to the inflatable column 203. During inflation, the inflatable device transmits gas through the hollow structure in the center of the inflatable column 203 and enters the inflatable cavity through the inflatable holes 204. In some embodiments, the inflatable support structure can be wound together with the cable. In this embodiment, the composite material layer 500 can be a compressible and deformable structure. When the cable is recycled, the inflatable cavity 201 that has been recycled into the mother body can be completely flattened, and the entire cable can be flattened and then wound, thereby reducing the recycling space. In this embodiment, there are two inflatable cavities 201 arranged symmetrically. After the inflatable cavities are flattened, the cable as a whole is flat. Specifically, the connecting rod 205 is tangentially connected to the outer side of the inflatable column 203. After the inflatable cavity 201 is flattened, the cavity skin 202 can be close to the connecting rod 205 and the inflatable column 203. In this embodiment, filling material may not be provided or a softer filling material may be provided. The inflatable support structure as a whole can itself serve as a supporting structure. The cavity skin 202 is wrapped around the outside of the inflatable support structure and will not shift. The shape and position of the inflated and flattened states are controllable.

[0121] In some embodiments of the present application, after the docking pin and the docking port are docked and locked, the docking robot is controlled to lock its posture, and the tension of the two cables is precisely controlled to ensure the posture balance of the target device (mainly maintaining horizontality in the embodiments of the present application). The posture balance control method of the present application takes into account the influence of cable tension, the force applied to the docking robot, the motion changes of the target device, water flow, etc., and also combines the coordinated balance of the two docking robots and the cables to maintain the horizontal position of the target device. The entire control process is achieved through PID algorithm control, and cable entanglement can also be avoided.

[0122] Figure 17 Schematic diagram of an electronic device according to an embodiment of the present invention. Figure 17 In some embodiments, an electronic device is further provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above methods when executing the program. In some embodiments, the electronic device is a computer device.

[0123] At the hardware level, the electronic device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and of course may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the above method. Of course, in addition to software implementation, this specification does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices. It can be understood that it is only necessary to program the method flow slightly in a hardware description language and program it into an integrated circuit to obtain a hardware circuit that implements the logical method flow.

[0124] The above method can be implemented by a controller in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, microcontrollers. The memory controller can also be implemented as part of the control logic of the memory. It is understood that in addition to implementing the controller in a purely computer-readable program code manner, it is entirely possible to implement the same function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules that implement the method and structures within the hardware component.

[0125] The systems, devices, modules, or units in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0126] For the convenience of description, the above devices are described as being divided into various modules according to their functions. Of course, when implementing this specification, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0127] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, this specification can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0128] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0129] In some embodiments, a computer-readable storage medium is further provided, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, any of the above methods is implemented.

[0130] In some embodiments, these computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0131] In some embodiments, these computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process described in the flow. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0132] In some embodiments, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0133] In some embodiments, memory may include non-permanent storage in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0134] In some embodiments, computer-readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

[0135] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An underwater robot system, characterized in that: The underwater robot system includes: At least two docking robots, the at least two docking robots being used to simultaneously dock and capture a target device, the target device being a powered underwater device, the underwater device having a docking device on its bottom surface, and the docking robots having a docking structure on their top surfaces that matches the docking device, the docking robots having a power unit comprising a motor and a plurality of drive paddles, the docking robots further having a positioning device for obtaining a position of the target device, and the drive paddles for driving the docking robots to perform active movement; a mother body, wherein when docking and capturing the target device, the mother body is located underwater and below the target device; At least two cables, the at least two cables corresponding to the at least two docking robots one by one, each of the docking robots being connected to the mother body via one of the cables; a retrieving device, the retrieving device being located on the mother body and configured to drive the cable to retract, thereby driving the target device captured by the docking robot to be recovered; A balance control device is connected to each of the cables and is used to control the force applied to each of the cables so that the at least two docking robots maintain a locked posture, thereby ensuring a balanced posture of the target device.

2. The underwater robot system according to claim 1, characterized in that: The balance control device includes a PID controller, which outputs control parameters of the force on the cable through a PID control algorithm according to changes in the posture angle parameters of the docking robot.

3. The underwater robot system according to claim 2, characterized in that: The cable includes a buoyancy structure, which includes an inflatable cavity. The buoyancy structure is used to adjust the force applied to the cable. One end of the cable used for connecting to the mother body has an inflatable device, which is connected to the inflatable cavity. The balance control device is connected to the inflatable device. The inflatable cavity is inflated by controlling the inflatable device, and the air pressure in the inflatable cavity is adjusted, thereby adjusting the buoyancy of the cable.

4. The underwater robot system according to claim 3, characterized in that: Each of the docking robots includes an inertial measurement unit, which is arranged parallel to a reference direction of the docking robot's posture balance. The inertial measurement unit is used to measure the posture angle of the docking robot, which includes a pitch angle, a roll angle, and a heading angle.

5. The underwater robot system according to claim 4, characterized in that: Ensuring the posture balance of the target device includes ensuring that the posture of the target device is in a horizontal state. The balance control device is also connected to the collecting device to control the pulling force of the collecting device on the cable. When the absolute value of the pitch angle of the docking robot increases in the positive or negative direction, the corresponding collecting device is controlled to exert a pulling force on the cable and / or the inflation device is controlled to adjust the buoyancy of the cable to restore the pitch angle to a balanced value.

6. A balance control method for an underwater robot system, characterized in that: The underwater robot system is the underwater robot system according to claim 5, and the balance control method includes: Before the docking robot completes docking with the target device, the balance control device controls the inflation device to inflate the inflation cavity of the cable and adjusts the buoyancy of the cable so that the buoyancy of the cable is not less than the weight of the cable.

7. The balance control method of the underwater robot system according to claim 6, characterized in that: The balance control method comprises: During the docking process between the docking robot and the target device, the balance control device controls the inflation device to adjust the air pressure of the inflation cavity of the cable so that the buoyancy of the cable is equal to the weight of the cable.

8. The balance control method of the underwater robot system according to claim 6, characterized in that: The balance control method comprises: After the docking robot completes docking with the target device, the balance control device controls the pulling force of the cable by the collecting device and / or the buoyancy of the cable by the inflation device to balance the posture of the target device.

9. The balance control method of the underwater robot system according to claim 8, characterized in that: There are two cables, including a first cable and a second cable; there are two docking robots, including a first docking robot and a second docking robot; the first cable is connected to the first docking robot, and the second cable is connected to the second docking robot; the first docking robot and the second docking robot are docked with the front and rear ends of the target device respectively; the balance control method includes: When the tension of any one of the first cable and the second cable is zero, and the tension of the other cable is not zero, the balance control device controls the inflation device to adjust the buoyancy of the other cable so that the buoyancy of the other cable is less than the gravity; When the tensions of the first cable and the second cable are both 0, the balance control device controls the pulling force of the first cable and the second cable by the collection device to increase the pulling force on the first cable and the second cable.

10. A computer device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the balance control method according to any one of claims 6 to 9 is implemented.

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