A Parallel Mechanism-Based Device and Method for Two-Ship Transshipment and Replenishment Docking at Sea

Abstract

This invention provides a docking device and method for transshipment and resupply between two ships at sea based on a parallel mechanism. The device includes a crane, a quadruped robot, and steel wire ropes. By combining the crane and the quadruped robot, the quadruped robot is firmly fixed to the cargo. The crane lifts the quadruped robot and the cargo to be docked, realizing the overall transfer operation. The crane can transfer the cargo to a high place or any position. After the crane transfers the quadruped robot to the target ship, the quadruped robot first docks with the robot docking platform on the target ship. At this time, the quadruped robot and the target ship remain relatively stationary, and the crane does not need to provide pulling force. The quadruped robot adjusts its body posture, adjusts the posture of the cargo to be docked, and then docks with the cargo docking platform. Utilizing the flexibility and precision of the quadruped robot, precise docking of heavy-load cargo at any position and in any posture can be achieved with high docking accuracy.

Description

Technical Field

[0001] This invention relates to the field of marine replenishment technology, specifically to a device and method for docking and transshipment replenishment between two ships at sea based on a parallel mechanism. Background Technology

[0002] Chinese Patent CN115535155B discloses a bridge-type lateral replenishment system for sea operations. A rigid load-bearing bridge can be deployed between a replenishment vessel and a receiving vessel positioned side-by-side on the sea surface. Compared to the suspension method using flexible overhead ropes, the replenishment passageway supported by the rigid load-bearing bridge has a higher load-bearing capacity, thus supporting heavier single-transport units. Furthermore, the rigid load-bearing bridge has degrees of freedom of extension and contraction, as well as degrees of freedom of rotation relative to the decks of the replenishment and receiving vessels. Therefore, the rigid load-bearing bridge can adapt to the dynamic floating of the replenishment and receiving vessels as the sea surface fluctuates. This allows for the formation of a replenishment passageway on the rigid load-bearing bridge that connects the decks of the replenishment and receiving vessels at both ends, adapting to the sea replenishment operation environment and thus improving the efficiency of sea replenishment.

[0003] However, a bridge-type transverse replenishment system for sea, disclosed in CN115535155B, achieves cargo transportation by deploying a rigid load-bearing bridge between the replenishment vessel and the receiving vessel. Although the system has good load-bearing capacity and can transport heavy cargo, it has poor flexibility and can only transport cargo to the deck of the replenishment vessel, but cannot transport cargo to higher places. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a device and method for docking and resupplying two ships at sea based on a parallel mechanism.

[0005] According to the present invention, a two-ship transshipment and resupply docking device based on a parallel mechanism is provided, comprising: a crane, a quadruped robot and a steel wire rope; The quadruped robot is used for detachable installation and docking of goods; The quadruped robot is mounted on the moving end of the crane by a steel wire rope, and the crane is used to transfer the quadruped robot between the supply ship and the target ship. The target ship is equipped with a robot docking platform and a cargo docking platform. After the quadruped robot is installed on the target ship via the robot docking platform, the quadruped robot adjusts its body posture and adjusts the posture of the cargo to be docked before docking with the cargo docking platform on the target ship.

[0006] Preferably, the quadruped robot includes a lifting point, a body, a depth camera, outriggers, foot ends, and a cargo docking device at the robot end; The lifting point is installed above the machine body and is used to connect to the wire rope; The depth camera is mounted on one side of the fuselage and is used to identify and locate the positions of the robot docking platform and the cargo docking platform on the target ship. One end of each leg is mounted around the lower part of the body, and the legs adjust the body posture of the quadruped robot by self-adjustment. The foot end is mounted on the other end of the support leg, and the foot end is used for docking with the robot platform. The robot-side cargo docking device is installed at the lower center of the robot body and is used to install the docking cargo.

[0007] Preferably, the outrigger includes three Hooke hinges, three telescopic electric cylinders, two ball joints, and an ankle joint; The bases of the three telescopic electric cylinders are respectively connected to the machine body via the three Hooke hinges; The movable parts of the two telescopic electric cylinders are respectively connected to the ankle joint via the two ball joints, and the movable part of the other telescopic electric cylinder is fixedly connected to the ankle joint; The ankle joint is connected to the foot.

[0008] Preferably, the foot end includes a foot end shell, a motor, a ball screw, a slider, a tension spring, and a locking component; The motor, ball screw, slider, tension spring, and locking device are respectively installed inside the foot end housing; The foot end shell is provided with a through hole, and the lower end of the locking member extends out or retracts through the through hole; The slider is mounted on the ball screw, and the motor is used to drive the ball screw to move the slider up and down; The locking element is disposed on both sides of the slider, and the middle part of the locking element is mounted on the foot end shell through a rotating shaft. The locking element can rotate around the rotating shaft, and the upper end of the locking element is connected to the tension spring. When the motor drives the ball screw to move the slider upward, the slider pushes the upper half of the locking member outward, the locking member rotates through the shaft, the lower half of the locking member retracts inward, the lower end of the locking member does not protrude from the through hole, and the foot is in the unconnected mode. When the motor drives the ball screw to move the slider downward, the tension spring pulls the upper end of the locking member inward, the locking member rotates through the shaft, the lower end of the locking member expands outward, the lower end of the locking member extends out of the through hole, and the foot is in the docking mode.

[0009] Preferably, the docking cargo is bolted to the cargo docking device at the robot end.

[0010] Preferably, the quadruped robot includes four legs and four foot ends, the robot docking platform includes four foot end docking platforms, and the cargo docking platform is located at the rectangular geometric center of the four foot end docking platforms.

[0011] Preferably, the crane includes a base, a boom, a hoisting mechanism, a winch, and a control system; The boom, hoisting mechanism, winch, and control system are respectively mounted on the base; The boom is used to support the steel wire rope, one end of which is connected to the four groups of robots, and the other end is wound around the winch; The control system is used to control the hoisting mechanism to drive the winch to wind up and unwind the wire rope, and to control the rotation of the boom.

[0012] Preferably, the control system also collects the heave and sag of the supply ship and the target ship, as well as the tension signal of the wire rope, and controls the hoisting mechanism to drive the winch to raise and lower the wire rope, thereby counteracting the interference of the heave and sag of the supply ship and the target ship on the tension of the wire rope.

[0013] According to the present invention, a method for transshipment and resupply docking of two ships at sea based on a parallel mechanism, employing the transshipment and resupply docking device for two ships at sea based on a parallel mechanism as described above, includes: The crane lifted the quadruped robot and transferred it to the supply ship, where the docking cargo was installed onto the quadruped robot. The crane lifted the quadruped robot and transferred it to the target ship; The quadruped robot docks with the robot docking platform of the target ship; The quadruped robot adjusts its body posture and then docks with the cargo docking platform of the target ship after adjusting the posture of the docking cargo. Once the docking cargo is successfully docked with the target ship, the quadruped robot releases the docked cargo.

[0014] Preferably, the initial body posture adjustment of the quadruped robot is performed through manual teaching; The quadruped robot records the docking trajectory, and the docking trajectory used during the initial body posture adjustment is adopted during docking.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention combines a crane with a quadruped robot. The quadruped robot is firmly fixed to the cargo, and the crane lifts the quadruped robot and the docking cargo to achieve overall transfer. The crane can transfer the docking cargo to a high place or any position. After the crane transfers the quadruped robot to the target ship, the quadruped robot first docks with the robot docking platform on the target ship. At this time, the quadruped robot and the target ship remain relatively stationary, and the crane does not need to provide pulling force. The quadruped robot adjusts its body posture and adjusts the posture of the docking cargo before docking with the cargo docking platform. Utilizing the flexibility and precision of the quadruped robot, precise docking of heavy-load cargo in any position and posture can be achieved with high docking accuracy. Attached Figure Description

[0016] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram illustrating the overall structure of the two ships docking for resupply. Figure 2 This is a schematic diagram illustrating the structure of the quadruped robot, which is the main feature of this invention. Figure 3 This is a schematic diagram illustrating the structure of a single leg of a quadruped robot, which is the main feature of this invention. Figure 4 This is a schematic diagram illustrating the structure of the connection between the foot of the quadruped robot and the target ship, which is the main feature of this invention. Figure 5 This is a schematic diagram illustrating the fixing structure of the quadruped robot and the cargo, which is the main feature of this invention. Figure 6 This is a schematic diagram illustrating the structure of the connection between the quadruped robot and the crane, which is the main feature of this invention.

[0017] The diagram shows: 1. Supply ship; 2. Crane; 3. Quadruped robot; 4. Wire rope; 5. Cargo docking; 6. Foot docking platform; 7. Target ship; 8. Cargo docking platform; 31. Lifting point; 32. Body; 33. Depth camera; 34. Outrigger; 35. Foot end; 341. Hooke hinge; 342. Telescopic electric cylinder; 343. Ball joint; 344. Ankle joint; 351. Foot end shell; 352. Motor; 353. Ball screw; 354. Slider; 355. Tension spring; 356. Locking element; 361. Cargo docking device at the robot end; 362. Bolt. Detailed Implementation

[0018] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0019] like Figure 1 As shown, a maritime two-ship transshipment and resupply docking device based on a parallel mechanism provided by the present invention includes: a crane 2, a quadruped robot 3, and a steel wire rope 4.

[0020] Crane 2 is installed inside supply ship 1.

[0021] The quadruped robot 3 is used to detachably mount the docking cargo 5. When it is necessary to transfer and dock the cargo 5, the cargo 5 is mounted onto the quadruped robot 3. After the transfer and docking of the cargo 5 is completed, the cargo 5 is detached from the quadruped robot 3.

[0022] The quadruped robot 3 is mounted on the moving end of the crane 2 via steel wire rope 4. The crane 2 is used to transfer the quadruped robot 3 between the supply ship 1 and the target ship 7. The moving end of the crane 2 rotates, causing all four sets of robots 3 to rotate together. The crane 2 extends or shortens the length of the steel wire rope 4 to lower or raise the quadruped robot 3. Both mechanisms work together to transfer the quadruped robot 3 between the supply ship 1 and the target ship 7. The target vessel 7 is equipped with a robot docking platform 6 and a cargo docking platform 8. The robot docking platform 6 is used to install the quadruped robot 3, and the cargo docking platform 8 is used to install the docking cargo 5. After the quadruped robot 3 is installed on the target vessel 7 via the robot docking platform 6, the quadruped robot 3 adjusts its body posture and adjusts the posture of the docking cargo 5 before docking with the cargo docking platform 8 on the target vessel 7.

[0023] When it is necessary to transfer the docking cargo 5 on the supply ship 1, the crane 2 lifts the idle quadruped robot 3 and transfers it to the supply ship 1, and installs the docking cargo 5 on the supply ship 1 onto the quadruped robot 3. The docking cargo 5 and the quadruped robot 3 are fixed together to form a whole.

[0024] Once the quadruped robot 3 is installed with the docking cargo 5 on the supply ship 1, the crane 2 lifts the quadruped robot 3, which is equipped with the docking cargo 5, and transfers it to the target ship 7.

[0025] The quadruped robot 3 docks with the robot docking platform 6 of the target ship 7, and the two are fixed together. At this time, the quadruped robot 3 and the target ship 7 remain relatively stationary.

[0026] The quadruped robot 3 adjusts its body posture and, after adjusting the attitude of the docking cargo 5, docks with the cargo docking platform 8 of the target ship 7. Since the connection between the quadruped robot 3 and the target ship 7 is relatively stationary, the docking cargo 5 will not move with the movement of the target ship 7. The quadruped robot 3 can stably and accurately install the docking cargo 5 under the six-degree-of-freedom ship wave motion.

[0027] Once the docking cargo 5 has docked with the target ship 7, the quadruped robot 3 releases the docking cargo 3.

[0028] Crane 2 can then lift the quadruped robot 3 and transfer it to supply ship 1, thereby enabling the transfer of docked cargo 5 once again.

[0029] The quadruped robot 3 is connected to the crane 2, and then the quadruped robot 3 installs the docking cargo 5. The combination of the crane 2 and the quadruped robot 3 in parallel improves the load-bearing capacity of the docking device, making it suitable for heavy loads. Furthermore, the crane 2 can transport the quadruped robot 3 to any position on the target ship 7, increasing the applicability of the docking device. After installation, the quadruped robot 3 and the target ship 7 remain relatively stationary. The quadruped robot 3 can adjust its body posture, enabling stable and precise installation of the docking cargo 5 under six-degree-of-freedom ship wave motion, achieving high docking accuracy.

[0030] In one feasible implementation, the quadruped robot 3 includes a lifting point 31, a body 32, a depth camera 33, legs 34, foot ends 35, and a robot-end cargo docking device 36.

[0031] The lifting point 31 is installed above the machine body 32 and is used to connect to the wire rope 4.

[0032] A depth camera 33 is installed on one side of the fuselage 32. Specifically, the depth camera 33 is installed at the hip joint of the fuselage 32. The depth camera 33 is used to identify and locate the positions of the robot docking platform 6 and the cargo docking platform 8 on the target ship 7. This solves the problem of docking cargo 5 in different installation positions. It can automatically identify and locate the installation positions of the robot docking platform 6 and the cargo docking platform 8, and realize the unmanned docking and installation process of cargo 5.

[0033] One end of the support leg 34 is installed around the bottom of the body 32. The support leg 34 adjusts the body posture of the quadruped robot 3 by its own adjustment.

[0034] The foot end 35 is installed at the other end of the support leg 34, and the foot end 35 is used to dock with the robot platform 6.

[0035] The robot-side cargo docking device 36 is installed at the center of the lower part of the robot body 32 and is used to install and dock cargo 5.

[0036] When the quadruped robot 3 and the docking cargo 5 are transferred by the crane 2 to the docking part of the target ship 7, the depth camera 33 guides the feet of the quadruped robot 3 to dock with the foot docking point in the robot docking platform 6. After docking is completed, the quadruped robot 3 remains relatively stationary with respect to the target ship 7.

[0037] After the quadruped robot 3 docks with the target ship 7, it is manually taught to adjust its body posture and position, aligning the cargo 5 with the target ship 7 to complete the docking process. The docking trajectory is then recorded, allowing for direct use of the first docking trajectory in subsequent docking attempts.

[0038] Cargo docking platform 8 is used for docking cargo 5, and robot docking platform 6 is used for docking quadruped robot 3.

[0039] In one feasible implementation, the legs 34 are in a UP&2UPS configuration, where U represents a Hooke's joint, P represents a prismatic joint, and S represents a ball joint. Each leg of the quadruped robot 3 consists of three branches. The first branch is connected to the base via a Hooke's joint and is fixed to the ankle joint, hence the UP configuration. The second and third branches are connected to the base via Hooke's joints and to the ankle joint via ball joints, hence the UPS configuration. Therefore, each leg is in a UP&2UPS configuration. The legs 34 include three Hooke's joints (U) 441, three telescopic electric cylinders (P) 442, two ball joints (S) 443, and an ankle joint 444.

[0040] The bases of the three telescopic electric cylinders 442 are connected to the machine body 32 via three Hooke hinges 441.

[0041] The movable parts of the two telescopic electric cylinders 442 are connected to the ankle joint 444 respectively through two ball joints 443, and the movable part of the other telescopic electric cylinder 442 is fixedly connected to the ankle joint 444.

[0042] The ankle joint 444 is connected to the foot end 35 via a separate ball joint.

[0043] By designing the leg configuration of quadruped robot 3 and adopting the UP&2UPS configuration, the load-bearing capacity of quadruped robot 3 can be significantly improved, overcoming the shortcoming of low load-bearing capacity in traditional quadruped robots 3. This enables the device to dock with larger masses of goods and improves the accuracy of docking installation, achieving the effect of precise docking of large goods.

[0044] In one possible implementation, the foot end 35 includes a foot end housing 451, a motor 452, a ball screw 453, a slider 454, a tension spring 455, and a locking element 456.

[0045] The motor 452, ball screw 453, slider 454, tension spring 455 and locking element 456 are respectively installed in the foot end housing 451.

[0046] The foot end housing 451 is provided with a through hole, and the lower end of the locking member 456 extends or retracts through the through hole.

[0047] The slider 454 is mounted on the ball screw 453, and the motor 452 is used to drive the ball screw 453 to move the slider 454 up and down.

[0048] Locking member 456 is disposed on both sides of slider 454. The middle part of locking member 456 is mounted on foot end housing 451 via a pivot. Locking member 456 can rotate around pivot. The upper end of locking member 456 is connected to tension spring 455.

[0049] When the motor 452 drives the ball screw 453 to move the slider 454 upward, the slider 454 pushes the upper half of the locking member 456 outward, the locking member 456 rotates through the shaft, the lower half of the locking member 456 retracts inward, the lower end of the locking member 456 does not protrude from the through hole, and the foot end 35 is in the unconnected mode.

[0050] When motor 452 drives ball screw 453 to move slider 454 downward, tension spring 455 pulls the upper end of locking member 456 inward, locking member 456 rotates via shaft, and the lower end of locking member 456 expands outward, extending out of the through hole, and foot 35 is in docking mode. The lower end of locking member 456 extending out of the through hole engages with the groove of the foot docking platform in robot docking platform 6, thereby fixing the quadruped robot 3 to the target ship 7.

[0051] In one feasible implementation, the docking cargo 5 is connected to the robot-end cargo docking device 36 by bolts 462.

[0052] In one feasible implementation, the quadruped robot 3 includes four legs 34 and four foot ends 35, the robot docking platform 6 includes four foot end docking platforms, and the cargo docking platform 8 is located at the rectangular geometric center of the four foot end docking platforms.

[0053] In one possible implementation, the crane 2 includes a base, a boom, a lifting mechanism, a winch, and a control system.

[0054] The boom, hoisting mechanism, winch, and control system are each mounted on the base.

[0055] The boom is used to support the wire rope 4, one end of which is connected to four sets of robots 3, and the other end is wound around the winch.

[0056] The control system is used to control the hoisting mechanism to drive the winch to wind up and unwind the wire rope 4, and to control the rotation of the boom.

[0057] The control modes of crane 2 include position control, which switches between working and non-working states by controlling the on / off state of the hydraulic circuit. In the working state, the crane provides tension, and in the non-working state, the crane does not provide tension.

[0058] Specifically, when the quadruped robot 3 needs to be lifted, the crane 2 provides tension, and the control system controls the lifting mechanism to drive the winch to retract the wire rope 4. The length of the wire rope 4 becomes shorter, and the quadruped robot 3 is lifted.

[0059] After the quadruped robot 3 is lifted, the boat corresponding to the quadruped robot 3 needs to be changed. The control system controls the boom to rotate and change the boat corresponding to the bottom of the quadruped robot 3.

[0060] When it is necessary to lower the quadruped robot 3, the control system controls the lifting mechanism to drive the winch to release the wire rope 4. The length of the wire rope 4 increases, and the quadruped robot 3 is lowered. After all four sets of robots 3 have been lowered, the crane 2 no longer provides tension.

[0061] In one feasible implementation, the control mode of the crane 2 also includes constant tension control. The control system also collects the heave and sag of the supply ship 1 and the target ship 7, as well as the tension signal of the wire rope 4, and controls the hoisting mechanism to drive the winch to raise and lower the wire rope 4, thereby counteracting the interference of the heave and sag of the supply ship 1 and the target ship 7 on the tension of the wire rope 4, so that the load remains relatively stable under sea conditions.

[0062] In one feasible implementation, the body posture adjustment of the four sets of robots 3 is carried out for the first time by manual teaching; the quadruped robot 3 records the docking trajectory, and the docking trajectory during the first body posture adjustment is used during docking.

[0063] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0064] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A maritime two-ship transshipment and resupply docking device based on a parallel mechanism, characterized in that, include: Crane (2), quadruped robot (3) and wire rope (4); The quadruped robot (3) is used to detachably install docking cargo (5); The quadruped robot (3) is mounted on the moving end of the crane (2) by a steel wire rope (4), and the crane (2) is used to transfer the quadruped robot (3) between the supply ship (1) and the target ship (7); The target ship (7) is equipped with a robot docking platform (6) and a cargo docking platform (8). After the quadruped robot (3) is installed on the target ship (7) through the robot docking platform (6), the quadruped robot (3) adjusts its body posture and adjusts the posture of the docking cargo (5) before docking with the cargo docking platform (8) on the target ship (7).

2. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 1, characterized in that, The quadruped robot (3) includes a lifting point (31), a body (32), a depth camera (33), legs (34), foot ends (35), and a robot end cargo docking device (36). The lifting point (31) is installed above the body (32) for connection with the wire rope (4); The depth camera (33) is installed on one side of the fuselage (32) and is used to identify and locate the positions of the robot docking platform (6) and the cargo docking platform (8) on the target ship (7); One end of the support leg (34) is installed around the lower part of the body (32), and the support leg (34) adjusts the body posture of the quadruped robot (3) by self-adjustment; The foot end (35) is mounted on the other end of the support leg (34), and the foot end (35) is used to be installed with the robot docking platform (6); The robot-end cargo docking device (36) is installed at the lower center of the body (32) for installing the docking cargo (5).

3. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 2, characterized in that, The outrigger (34) includes three Hooke hinges (441), three telescopic electric cylinders (442), two ball joints (443), and an ankle joint (444). The bases of the three telescopic electric cylinders (442) are connected to the body (32) via the three Hooke hinges (441); The movable parts of the two telescopic electric cylinders (442) are connected to the ankle joint (444) respectively through the two ball joints (443), and the movable part of the other telescopic electric cylinder (442) is fixedly connected to the ankle joint (444); The ankle joint (444) is connected to the foot end (35).

4. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 2, characterized in that, The foot end (35) includes a foot end shell (451), a motor (452), a ball screw (453), a slider (454), a tension spring (455), and a locking element (456). The motor (452), ball screw (453), slider (454), tension spring (455) and locking member (456) are respectively installed inside the foot end housing (451); The foot end shell (451) is provided with a through hole, and the lower end of the locking member (456) extends out or retracts through the through hole; The slider (454) is mounted on the ball screw (453), and the motor (452) is used to drive the ball screw (453) to move the slider (454) up and down. The locking member (456) is disposed on both sides of the slider (454). The middle part of the locking member (456) is mounted on the foot end shell (451) through a rotating shaft. The locking member (456) can rotate around the rotating shaft. The upper end of the locking member (456) is connected to the tension spring (455). When the motor (452) drives the ball screw (453) to move the slider (454) upward, the slider (454) pushes the upper half of the locking member (456) outward, the locking member (456) rotates through the shaft, the lower half of the locking member (456) retracts inward, the lower end of the locking member (456) does not protrude from the through hole, and the foot end (35) is in the unconnected mode; When the motor (452) drives the ball screw (453) to move the slider (454) downward, the tension spring (455) pulls the upper end of the locking member (456) inward, the locking member (456) rotates through the shaft, the lower end of the locking member (456) expands outward, the lower end of the locking member (456) extends out of the through hole, and the foot end (35) is in the docking mode.

5. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 2, characterized in that, The docking cargo (5) is connected to the cargo docking device (36) on the robot end by bolts (462).

6. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 1, characterized in that, The quadruped robot (3) includes four legs (34) and four foot ends (35). The robot docking platform (6) includes four foot end docking platforms. The cargo docking platform (8) is located at the rectangular geometric center of the four foot end docking platforms.

7. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 1, characterized in that, The crane (2) includes a base, boom, lifting mechanism, winch and control system; The boom, hoisting mechanism, winch, and control system are respectively mounted on the base; The boom is used to support the wire rope (4), one end of which is connected to the four sets of robots (3), and the other end is wound around the winch; The control system is used to control the hoisting mechanism to drive the winch to wind up and unwind the wire rope (4), and to control the rotation of the boom.

8. The maritime two-ship transshipment and resupply docking device based on a parallel mechanism as described in claim 1, characterized in that, The control system also collects the heave and sag of the supply ship (1) and the target ship (7) and the tension signal of the wire rope (4), and controls the hoisting mechanism to drive the winch to raise and lower the wire rope (4) to counteract the interference of the heave and sag of the supply ship (1) and the target ship (7) on the tension of the wire rope (4).

9. A method for transshipment replenishment docking between two ships at sea based on a parallel mechanism, characterized in that, The maritime two-ship transshipment and resupply docking device based on a parallel mechanism, as described in any one of claims 1 to 8, comprises: The crane (2) lifts the quadruped robot (3) and transfers it to the supply ship (1), and installs the docking cargo (5) on the supply ship (1) onto the quadruped robot (3); The crane (2) lifts the quadruped robot (3) and transfers it to the target ship (7); The quadruped robot (3) docks with the robot docking platform (6) of the target ship (7); The quadruped robot (3) adjusts its body posture and adjusts the posture of the docking cargo (5) to dock with the cargo docking platform (8) of the target ship (7); Once the docking cargo (5) has docked with the target ship (7), the quadruped robot (3) releases the docking cargo (3).

10. The method for transshipment and resupply docking of two ships at sea based on a parallel mechanism as described in claim 9, characterized in that, The body posture of the quadruped robot (3) was adjusted for the first time through manual teaching; The quadruped robot (3) records the docking trajectory, and the docking trajectory during the first body posture adjustment is used during docking.

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