Underwater hovering system for unmanned aerial vehicle and unmanned aerial vehicle underwater hovering and releasing method

Abstract

The invention relates to the technical field of underwater hovering systems, and discloses an underwater hovering system for an unmanned aerial vehicle and an underwater hovering and releasing method of the unmanned aerial vehicle. The underwater hovering system comprises a buoyancy bandage, a releaser and an underwater hovering assembly, the underwater hovering assembly is connected to the releaser, the unmanned aerial vehicle is connected to the releaser in a releasable mode through the buoyancy bandage, and the net buoyancy of the buoyancy bandage is a positive number. Due to the fact that the buoyancy bandage has positive net buoyancy and the fixed end of the buoyancy bandage is fixed to the releaser, after the movable end of the buoyancy bandage is separated from the releaser, the unmanned aerial vehicle is separated from the buoyancy bandage and automatically floats upwards, the buoyancy bandage is in a roughly vertical state in water under the action of the buoyancy of the buoyancy bandage, the floating process of the unmanned aerial vehicle is not hindered, and the unmanned aerial vehicle can float upwards. The unmanned aerial vehicle can be effectively prevented from being wound, and barrier-free unhooking of the unmanned aerial vehicle can be achieved. The aerodynamic configuration of the unmanned aerial vehicle is not damaged, the flight performance is not affected, and the method is particularly suitable for hovering and releasing of the unmanned aerial vehicle with the small net buoyancy value and has the engineering practical value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater hovering system, and particularly relates to an underwater hovering system for unmanned aerial vehicle and a method for underwater hovering and releasing of unmanned aerial vehicle. BACKGROUND

[0002] In recent years, unmanned aerial vehicles have attracted more and more attention due to their broad application prospects in the marine field. The unmanned aerial vehicle pre-positioned in the target sea area can take off at any time according to the order, has the outstanding advantages of fast response speed and short task cycle, and can reduce the requirements for the range and time of the unmanned aerial vehicle, and is suitable for performing deep-sea emergency tasks, and provides technical support for human activities in deep-sea.

[0003] During the underwater residence of the unmanned aerial vehicle, one of the main tasks is to make the unmanned aerial vehicle hover underwater and keep the attitude upward. When the underwater hovering system receives a release instruction, the unmanned aerial vehicle is released underwater, and the unmanned aerial vehicle starts to float upward under the action of the net buoyancy of the unmanned aerial vehicle. The best state after the unmanned aerial vehicle floats to the water surface is that the unmanned aerial vehicle body is completely separated from the release device without any obstacle, and the unmanned aerial vehicle body is not attached to any additional component. The additional component will damage the aerodynamic shape of the unmanned aerial vehicle itself and affect the flight performance. In addition, for the underwater unmanned aerial vehicle with small net buoyancy, the existing underwater hovering system cannot release the underwater unmanned aerial vehicle without any obstacle and additional component. SUMMARY

[0004] To solve the above technical problems, the present application provides an underwater hovering system for unmanned aerial vehicle and a method for underwater hovering and releasing of unmanned aerial vehicle.

[0005] In a first aspect, the present application provides an underwater hovering system for unmanned aerial vehicle, and the net buoyancy of the unmanned aerial vehicle is positive. The underwater hovering system comprises a buoyancy binding belt, a release device and an underwater hovering assembly. The net buoyancy of the buoyancy binding belt is positive, which is used to bind the unmanned aerial vehicle and fix it to the release device. The buoyancy binding belt has a fixed end, a movable end and a binding belt body extending between the two ends. The fixed end of the buoyancy binding belt is fixed to the release device, and the release device has a locking part. The movable end of the buoyancy binding belt is releasably connected to the locking part. The underwater hovering assembly comprises an equipped float connected to the release device and an equipped counterweight. The sum of the net buoyancy of the underwater hovering system and the unmanned aerial vehicle excluding the equipped float is negative, and the equipped float is used to provide redundant buoyancy for the unmanned aerial vehicle and the entire underwater hovering system. The release device is configured to open the locking part after receiving a release instruction, and the movable end of the buoyancy binding belt is separated from the locking part under the action of the buoyancy of the buoyancy binding belt, so as to release the unmanned aerial vehicle.

[0006] Further, the locking part is configured as a release hook which can be opened to the side, and the movable end of the buoyancy binding belt is connected to the release hook. Optionally, the locking part is configured as a clamping piece. Preferably, when the unmanned aerial vehicle is in a hovering state underwater, the release hook is located at the top of the release device.

[0007] Further, the buoyancy harness includes a ring body arranged at the movable end, the ring body is configured as an "O" shape, and the ring body is connected to the release hook.

[0008] Further, the harness body includes a buoyancy bar and a Kevlar fiber rope extending through the buoyancy bar.

[0009] Preferably, the buoyancy harnesses are two, and the two buoyancy harnesses are "crossed" to bind the UAV.

[0010] Further, the releaser includes a releaser body, two releaser float support rods, and two releaser floats, the release hook is arranged at the top of the releaser body, one end of each of the two releaser float support rods is connected to the two sides of the releaser body, and the two releaser floats are respectively connected to the free ends of the two releaser float support rods. Among them, the releaser float is configured such that the net buoyancy of the releaser is positive.

[0011] Further, the releaser includes a releaser lifting ring arranged at the bottom of the releaser body; the underwater hovering assembly further includes a support rod, a first rope, a second rope, and a third rope, one end of the support rod is connected to the releaser lifting ring through the first rope, the other end of the support rod is connected to the equipment float through the second rope, and the equipment counterweight is connected to the support rod through the third rope.

[0012] Further, the underwater hovering system is applied to the sea, and the underwater hovering assembly further includes a Beidou user machine sea surface beacon end arranged at the top of the equipment float, and the Beidou user machine sea surface beacon end is connected to the releaser through a cable.

[0013] In the second aspect, the present application provides a UAV underwater hovering and releasing method, which uses the underwater hovering system of the first aspect to hover and remotely release the UAV. Among them, the underwater hovering step includes fixing the UAV to the releaser by using the buoyancy harness to bind the UAV, so that the UAV is suspended in the water, and the movable end of the buoyancy harness is releasably connected to the release hook of the releaser.

[0014] The remote release step includes that the Beidou user machine ground end transmits a UAV release instruction, the Beidou user machine sea surface end receives the release instruction and then transmits it to the releaser, the releaser receives the release instruction and then opens the release hook, the movable end of the buoyancy harness is separated from the release hook under the action of buoyancy, thereby releasing the UAV, and the UAV floats up under the action of its own buoyancy.

[0015] The characteristics and advantages of the present application include: The underwater hovering system includes a buoyancy strap, a release mechanism, and interconnected underwater hovering components. The drone is releasably connected to the release mechanism via the buoyancy strap, which has a positive net buoyancy. Because the buoyancy strap has positive net buoyancy and one end is fixed to the release mechanism, when the other end separates, the buoyancy strap remains approximately vertical in the water due to its own buoyancy. This does not obstruct the drone's ascent, effectively preventing entanglement and allowing for unobstructed detachment. The buoyancy strap is completely separated from the drone, leaving no residue. No additional components are needed on the drone for connection to the underwater hovering system, thus preserving its aerodynamic shape and flight performance. Furthermore, the separation of the buoyancy strap's movable end from the release mechanism does not require additional buoyancy from the drone, making this underwater hovering system particularly suitable for hovering and releasing drones with low net buoyancy. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an underwater hovering system in an embodiment of the present invention, wherein the release hook of the release device is in the closed state; Figure 2 This is a schematic diagram of the underwater hovering system in an embodiment of the present invention, wherein the release hook of the release device is in the open state; Figure 3 This is a diagram of buoyancy straps; Figure 4 This is a schematic diagram of the cross-section of the buoyancy strap; Figure 5 This is a schematic diagram of the release device and buoyancy straps, where the release hook of the release device is in the closed state; Figure 6 This is a schematic diagram of the initial stage of the release device releasing the buoyancy strap, in which the release hook of the release device is in the open state; Figure 7 This is a schematic diagram of the buoyancy straps being in a vertical position after they have been released. Figure 8 This is a flowchart illustrating the signal transmission process when using the underwater hovering system in this embodiment of the invention.

[0018] Explanation of reference numerals in the attached figures: 100 - Underwater hovering system, 2 - Sea surface, 4 - Unmanned aerial vehicle (UAV), 6 - Cable; 10-Buoyancy strap, 12-Strap body, 14-Fixed end, 16-Moving end, 18-Ring body; 122-Fiber rope, 124-Buoyancy rod, 126-Fiber tape; 20-Release device, 21-Release device body, 22-Release hook, 24-Release device float support rod, 26-Release device float, 28-Release device shackle; 30-Underwater hovering component, 31-Equipment float, 32-Equipment counterweight, 33-Beidou user terminal sea surface beacon terminal, 34-Support rod, 35-First rope, 36-Second rope, 37-Third rope. Detailed Implementation

[0019] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0020] This invention provides an underwater hovering system for enabling a drone with positive net buoyancy to hover in water. The underwater hovering system includes buoyancy straps and an underwater hovering assembly, with the drone releasably connected to the assembly. Upon receiving a release command, the underwater hovering system releases the drone hovering in the water. Net buoyancy refers to the difference between the buoyancy of an object when it is completely submerged in water and its own weight. Negative net buoyancy means the buoyancy is less than weight; positive net buoyancy means the buoyancy is greater than weight. For a drone, positive net buoyancy means the buoyancy when completely submerged is greater than its own weight. Therefore, after release, the drone can rise from the water to the surface under the influence of buoyancy and then take off to perform its mission. The drone in this invention is a water-to-air amphibious drone. The water in this invention can specifically be ocean, river, lake, etc.; the following explanation uses the ocean as an example.

[0021] See Figure 1 and Figure 2The underwater hovering system 100 includes a buoyancy strap 10, a release device 20, and an underwater hovering assembly 30. The net buoyancy of the buoyancy strap 10 is positive, meaning that the buoyancy of the buoyancy strap 10 when fully submerged in water is greater than its own weight. The buoyancy strap 10 is used to secure the drone 4 to the release device 20. The buoyancy strap 10 has two ends; one end is fixed to the release device 20, which is the fixed end 14; the other end is releasably connected to the release device 20, which is the movable end 16. The underwater hovering assembly 30 is connected to the release device 20. The underwater hovering assembly 30 provides additional sinking force (pull force) for the drone 4, allowing the drone 4 to be submerged in water below sea level 2; it also provides redundant buoyancy for the drone 4 and the entire underwater hovering system 100, enabling the drone 4 to hover in the water. When the release device 20 receives the release command, the movable end 16 of the buoyancy strap 10 separates from the release device 20, thereby releasing the drone 4. Since the buoyancy strap 10 has positive net buoyancy and one end of the buoyancy strap 10 is fixed to the release device 20, when the other end of the buoyancy strap 10 separates from the release device 20, the buoyancy strap 10 is in a roughly vertical state in the water due to its own buoyancy, which does not hinder the upward floating process of the drone 4. It can effectively prevent the drone 4 from getting entangled, realize the drone 4's unhooking without obstacles, and thus achieve complete separation of the buoyancy strap 10 from the drone 4, with no residue of the buoyancy strap 10 on the drone 4.

[0022] Specifically, see Figure 3 , Figure 4 The buoyancy strap 10 includes a fixed end 14, a movable end 16, and a strap body 12 extending between the two ends. The fixed end 14 is fixedly connected to a release device 20 (e.g., a release device float support 24 fixedly connected to the release device 20), and the movable end 16 is releasably connected to the release device 20 (e.g., a release hook 22 releasably connected to the release device 20). The buoyancy strap 10 has characteristics such as soft material, light weight, high buoyancy, and tensile strength, and can remain substantially vertical in water when subjected to a downward pulling force at one end. Specifically, the strap body 12 is formed of a material with a specific gravity less than water, for example, a rope or cable integrated with an air tube filled with gas (such as air), the air tube wrapping around the rope or cable; or buoyancy members are attached to the outside of the rope or cable body at regular intervals. In some embodiments, the strap body 12 includes a rope or cable and a buoyancy member wrapping around the rope or cable. Preferably, see Figure 4The strap body 12 includes a Kevlar fiber rope 122 and a buoyancy bar 124, wherein the Kevlar fiber rope 122 extends through the buoyancy bar 124, and the buoyancy bar 124 provides buoyancy to the Kevlar fiber rope 122, making the net buoyancy of the strap body 12 positive. More preferably, the strap body 12 also includes a fiber adhesive tape 126 wrapped around the buoyancy bar 124. Wrapping the buoyancy bar 124 with fiber adhesive tape 126 helps to enhance the tensile strength of the buoyancy strap 10.

[0023] In some embodiments, the buoyancy strap 10 further includes a loop 18 connected to the strap body 12 and located at the movable end 16. The buoyancy strap 10 is connected to the release device 20 via the loop 18. Preferably, the loop 18 is configured as an "O" ring. Specifically, the loop 18 is formed by folding the Kevlar fiber rope 122 at the movable end 16 into an "O" ring. The folded portion of the Kevlar fiber rope 122 can be kept in the "O" ring by applying or soaking in a curing material. Preferably, a plastic air tube is looped around the outside of the folded portion of the Kevlar fiber rope 122 and wrapped with waterproof tape to increase the buoyancy, hardness, and smoothness of the "O" ring, thereby enhancing the smoothness of the "O" ring's release and preventing it from tangling with the release hook 22 after release. Alternatively, the loop 18 can also be integrally formed from a material with a density less than water and then fixed to the end of the Kevlar fiber rope 122 by binding, bonding, or other methods.

[0024] The release device 20 includes a release device body 21 and a locking portion movably connected to the release device body 21. The movable end 16 of the buoyancy strap 10 is connected to the locking portion. When the locking portion is closed, it restricts the movement of the buoyancy strap 10. When the locking portion is open, the movable end 16 of the buoyancy strap 10 separates from the locking portion under buoyancy. In some embodiments, the locking portion is configured as a clamping member. When the clamping member clamps the movable end 16 of the buoyancy strap 10, it restricts the movement of the movable end 16 of the buoyancy strap 10; when the clamping member does not clamp the movable end 16 of the buoyancy strap 10 (i.e., when open), the movable end 16 of the buoyancy strap 10 separates from the clamping member under buoyancy.

[0025] In some embodiments, the locking part is configured as a release hook 22. The movable end 16 of the buoyancy strap 10 is connected to the release hook 22; specifically, the loop 18 of the buoyancy strap 10 is connected to the release hook 22. See also Figure 5 , Figure 6The release hook 22 has an arcuate hook portion, a portion of which extends through the ring 18 and restricts the movement of the ring 18, thereby securing the buoyancy strap 10. When the release device 20 receives a release command, the arcuate hook portion of the release hook 22 rotates laterally to open, causing the ring 18 to disengage from the release hook 22. Preferably, in some embodiments, the release hook 22 includes a protrusion connected to the arcuate hook portion, which rotates synchronously when the arcuate hook portion of the release hook 22 opens, pushing the ring 18 out of the release device 20. In some embodiments, the release hook 22 is disposed on top of the release device body 21, and the release device 20 keeps the release hook 22 facing upwards in the water (the release hook 22 is closer to the water surface than the release device body 21). See also Figure 6 When the release device 20 receives a release command, the release hook 22 opens to the side, which facilitates the disengagement of the loop 18 of the buoyancy strap 10 from the release hook 22. In some embodiments, the release device 20 has two release hooks 22, which can open to opposite sides.

[0026] In some embodiments, the release device 20 includes a release device float support 24 and a release device float 26 connected to the release device float support 24. Specifically, the release device 20 includes two release device float support 24s and two release device floats 26s. The two release device float support 24s are respectively disposed on both sides of the release device body 21, and the two release device floats 26 are respectively connected to the suspended ends of the release device float support 24s. Preferably, the release device float 26 is constructed as a sphere, and the release device float 26 is used to provide buoyancy for the components of the release device 20. Specifically, the release device float 26 makes the buoyancy of the release device 20 greater than or equal to its weight, that is, the net buoyancy of the release device 20 is positive or zero. The release device floats 26 are respectively disposed on both sides of the release device body 21, which helps to maintain the vertical attitude of the release device 20 in the water (keeping the release hook 22 facing upwards).

[0027] In some embodiments, the releaser 20 further includes a releaser ring 28, through which the releaser 20 is connected to the underwater hovering assembly 30. Specifically, the releaser ring 28 is disposed at the bottom of the releaser body 21. More specifically, the releaser ring 28 is disposed opposite to the release hook 22. Preferably, the releaser float 26 provides a net buoyancy greater than zero for the entire releaser 20, that is, the buoyancy provided is greater than the weight of the entire releaser 20, allowing the releaser 20 to float on its own in the water, keeping the release hook 22 vertically upward and the releaser ring 28 vertically downward. The greater the overall net buoyancy of the releaser 20, the more stable the releaser 20's attitude in the water.

[0028] See also Figure 1Preferably, the underwater hovering system 100 is provided with two buoyancy straps 10, and the drone 4 is connected to the release device 20 through the two buoyancy straps 10. More preferably, the two buoyancy straps 10 are used to fix the drone 4 to the release device 20 in a "cross" arrangement. Specifically, one end (fixed end 14) of the two buoyancy straps 10 is fixed to the same release device float support 24, and the other end of each of the two buoyancy straps 10 is connected to the release hook 22 through a ring 18. The wings of the drone 4 are placed parallel to the release device float support 24, and the two buoyancy straps 10 extend from the fixed end 14 of the buoyancy straps 10 around the leading and trailing edges of the wing root on the same side of the drone, respectively, cross on the back of the drone 4, and then extend around the trailing and leading edges of the wing root on the other side of the drone. The "cross" binding of the drone 4 not only reliably secures the drone 4, ensuring its underwater attitude is stable and preventing it from flipping, but also prevents it from separating from the buoyancy strap 10 due to water flow impact. Furthermore, it facilitates the rapid and effective separation of the buoyancy strap 10 and the drone 4 during the release process.

[0029] The underwater hovering assembly 30 includes at least a float 31 and a counterweight 32, which are connected to the release device 20 via ropes or the like. The counterweight 32 provides additional downward pull for the drone 4, while the float 31 provides redundant buoyancy for the drone 4 and the entire underwater hovering system 100. Specifically, the underwater hovering assembly 30 also includes a support rod 34, a first rope 35, a second rope 36, and a third rope 37. One end of the support rod 34 is connected to the release device 20 via the first rope 35, and the other end is connected to the float 31 via the second rope 36. The counterweight 32 is connected to the support rod 34 via the third rope 37. Specifically, one end of the first rope 35 is connected to the release device's swivel 28, and the other end is connected to one end of the support rod 34. One end of the second rope 36 is connected to the float 31, and the other end is connected to the other end of the support rod 34.

[0030] Under the weight of the equipment counterweight 32, the sum of the net buoyancy of the entire underwater hovering system 100 and the UAV 4 (excluding the equipment float 31) is negative. The equipment float 31 provides redundant buoyancy for the UAV 4 and the entire underwater hovering system 100. The support rod 34 helps maintain a certain distance between the UAV 4 and other components, especially flexible components in the underwater hovering system 100, such as ropes, preventing the UAV 4 from becoming entangled during underwater hovering and ensuring rapid and successful release of the UAV 4 in case of emergency missions. The support rod 34 is also flexible, maintaining a certain distance between the UAV 4 and the ropes in the system while also withstanding the impact of waves and ocean currents. Specifically, the support rod 34 is a metal rod. Alternatively, the support rod 34 can also be made of flexible materials such as plastic or rubber.

[0031] Specifically, the specifications of the equipment counterweight 32 can be selected according to the net buoyancy of the UAV 4 and the release device 20, with additional weight reserved so that the sum of the net buoyancy of the entire underwater hovering system 100 (excluding the equipment float 31) and the UAV 4 is negative, increasing the underwater hovering system 100's resistance to impact interference in water and improving system stability. Furthermore, the pulling force of the equipment counterweight 32 further stabilizes the underwater attitude of the release device 20, ensuring that the release hook 22 is in a vertically upward position in the water.

[0032] Specifically, the equipment float 31 provides buoyancy to components connected to the metal support rod, particularly to the equipment counterweight 32, thereby balancing the forces acting on the metal support rod. This allows the drone 4, release device 20, and equipment counterweight 32, directly or indirectly connected to the metal support rod, to suspend in the water and maintain the stability of the drone 4 and release device 20. Specifically, the specifications of the equipment float 31 can be selected based on the sum of the net buoyancy of the equipment counterweight 32, drone 4, and release device 20 in the water, with additional redundant buoyancy to increase the underwater hovering system 100's resistance to impact and interference in the water, improving system stability. Specifically, the equipment float 31 can be a cylindrical or spherical float.

[0033] Specifically, the third rope 37 is constructed in a Y-shape and has three connecting ends. Two ends of the third rope 37 are connected to the two ends of the metal support rod, and the third end is connected to the equipment counterweight 32. The equipment counterweight 32 is connected to the metal support rod via the Y-shaped third rope 37, so that the tension on both ends of the metal support rod is ultimately concentrated at the equipment counterweight 32, which is beneficial to the force balance at both ends of the metal support rod.

[0034] In some embodiments, a BeiDou user terminal sea surface beacon terminal 33 is provided on the top of the equipment float 31, and the release device 20 can receive release commands through the BeiDou user terminal sea surface beacon terminal 33. Specifically, the underwater hovering system 100 also includes a cable 6, which extends along the metal support rod and the second rope 36. One end of the cable 6 is connected to the release device 20, and the other end is connected to the BeiDou user terminal sea surface beacon terminal 33. The release device 20 and the BeiDou user terminal sea surface beacon terminal 33 transmit signals through the cable 6. Preferably, the cable 6 is a waterproof cable.

[0035] Optionally, the underwater hovering system 100 may further include a stationary component, with the underwater hovering component 30 connected to the stationary component. The stationary component includes an anchoring float, an anchoring counterweight, an anchor, and a stationary rope. The anchoring float and the anchoring counterweight are connected via the stationary rope, and the anchor is connected to the anchoring counterweight. The underwater hovering component 30 is connected to the stationary component via a connecting rope, and the stationary component provides stationary positioning for the underwater hovering system 100 and the unmanned aerial vehicle (UAV) 4.

[0036] This invention provides a method for underwater hovering and release of a drone. The method uses the aforementioned underwater hovering system 100 to hover the drone 4 underwater and release it remotely. The underwater hovering step includes using a buoyancy strap 10 to secure the drone 4 and fix it to a release device 20 to suspend the drone 4 in the water. The movable end 16 of the buoyancy strap 10 is releasably connected to the release hook 22 of the release device 20.

[0037] In some embodiments, the underwater hovering system 100 is assembled and then transported to the target docking point. In other embodiments, the underwater hovering system 100 is not assembled or only partially assembled, and the assembly is completed at the target docking point. The drone 4 is connected to the release hook 22 of the release device 20 via the buoyancy strap 10, and the drone 4, buoyancy strap 10, release device 20, and assembled underwater hovering assembly 30 are placed in the water.

[0038] See Figure 1 The drone 4 is arranged parallel to the release device's float support 24. Two buoyancy straps 10 extend from the leading and trailing edges of the wing root on one side of the drone, respectively, cross over the back of the drone 4, and then extend around the trailing and leading edges of the wing root on the other side of the drone. The fixed ends 14 of both buoyancy straps 10 are fixed to the release device's float support 24, and the movable ends 16 are connected to the release hooks 22 of the release device 20. When the underwater hovering system 100 and the drone 4 are in the water, the drone 4 has a tendency to float upwards due to its positive net buoyancy, but it remains suspended in the water due to the constraint of the buoyancy straps 10. The suspension depth of the drone 4 in the water is mainly affected by the first rope 35 and the second rope 36. The shorter the first rope 35 and the longer the second rope 36, the deeper the suspension depth of the drone 4.

[0039] The release device 20 is affected not only by the buoyancy of the release device float 26, the drone 4, and the buoyancy strap 10, but also by the equipment counterweight 32. The release device 20 remains suspended in the water, maintaining an attitude with the top (release hook 22) above and the bottom (release device ring 28) below. During suspension, the release hook 22 of the release device 20 is in a vertically upward attitude in the water.

[0040] See Figure 8 and Figure 2The remote release process includes the BeiDou user terminal ground unit transmitting a release command for the UAV 4. The BeiDou user terminal sea surface beacon terminal 33 receives the release command and forwards it to the release device 20. Upon receiving the release command, the release device 20 opens the release hook 22, and the movable end 16 of the buoyancy strap 10 separates from the release hook 22 under buoyancy, thus releasing the UAV 4. The UAV 4 then floats upwards under its own buoyancy. Specifically, the operating terminal first sends the UAV 4 release command to the BeiDou user terminal ground unit via cable 6. The BeiDou user terminal ground unit then transmits the command to the BeiDou user terminal sea surface beacon terminal 33 via BeiDou satellite. In some embodiments, each intermediate node, upon successfully receiving the command, sends a message indicating successful command reception to the operating terminal. Specifically, after receiving the release command, the BeiDou user terminal ground unit, the BeiDou user terminal sea surface beacon terminal 33, and the release device 20 all send a message indicating successful command reception to the operating terminal.

[0041] Under the buoyancy of the release floats 26 on both sides and the tension at the release ring 28, the release device 20 can maintain the release hook 22 in an upward orientation in the water (when the release hook 22 is open, the opening faces upward). When the release hook 22 opens to the side, the loops 18 of the two buoyancy straps 10 can move upward under the buoyancy of the buoyancy straps 10, thus separating from the release hook 22 without obstruction. The loops 18 do not require additional buoyancy from the UAV 4 during the process of detaching from the release hook 22, so the underwater hovering system 100 is particularly suitable for hovering and releasing UAVs 4 with a small net buoyancy value.

[0042] See Figure 6 , Figure 7 After the loops 18 of the two buoyancy straps 10 detach from the release hook 22, the movable ends 16 are unrestricted. The fixed ends 14 of the two buoyancy straps 10 are connected to the release device float support 24 and are restricted by the release device 20. Since the buoyancy straps 10 have positive net buoyancy, the movable ends 16 gradually move upwards, causing the buoyancy straps 10 to... Figure 7 The vertical position is shown. During the ascent of the drone 4, the buoyancy strap 10 does not obstruct the ascent of the drone 4, effectively preventing it from becoming entangled, thus achieving complete separation between the buoyancy strap 10 and the drone 4. Furthermore, no additional components are needed on the drone 4 for connection to the underwater hovering system 100. Therefore, this invention provides a method for underwater hovering and releasing of a drone that does not damage the aerodynamic shape of the drone 4 or affect its flight performance.

[0043] The above descriptions are merely a few embodiments of this disclosure. Those skilled in the art can make various modifications or variations to the embodiments of this disclosure based on the content disclosed in the application documents without departing from the spirit and scope of this disclosure.

Claims

1. An underwater hovering system for an unmanned aerial vehicle (UAV), wherein the net buoyancy of the UAV is positive, characterized in that, Includes buoyancy straps, release mechanism, and underwater hovering assembly: The buoyancy strap has a positive net buoyancy and is used to bind the drone and fix it to the release device. The buoyancy strap has a fixed end, a movable end, and a strap body extending between the two ends. The fixed end of the buoyancy strap is fixed to the release device, which has a locking part. The movable end of the buoyancy strap is releasably connected to the locking part. The underwater hovering assembly includes: The equipment float and equipment counterweight are connected to the release device; under the gravity of the equipment counterweight, the sum of the net buoyancy of the underwater hovering system and the UAV after deducting the equipment float is negative, and the equipment float provides redundant buoyancy for the UAV and the underwater hovering system. The release device is configured to open the locking part after receiving a release command, and the movable end of the buoyancy strap separates from the locking part under the buoyancy of the buoyancy strap, thereby releasing the drone.

2. The underwater hovering system according to claim 1, characterized in that, The locking part is configured as a release hook that can be opened to the side, and the movable end of the buoyancy strap is connected to the release hook.

3. The underwater hovering system according to claim 2, characterized in that, When the drone is hovering underwater, the release hook is located at the top of the release device.

4. The underwater hovering system according to claim 2, characterized in that, The buoyancy strap includes a loop at the movable end, the loop being shaped like an "O" and connected to the release hook.

5. The underwater hovering system according to claim 4, characterized in that, The buoyancy strap body includes a buoyancy bar and a Kevlar fiber rope extending through the buoyancy bar.

6. The underwater hovering system according to claim 4, characterized in that, The buoyancy straps consist of two straps, which are crisscrossed to secure the drone.

7. The underwater hovering system according to any one of claims 2 to 6, characterized in that, The release device includes a release device body, two release device float support rods and two release device floats. The release hook is disposed on the top of the release device body. One end of each of the two release device float support rods is connected to both sides of the release device body. The two release device floats are respectively connected to the suspended ends of the two release device float support rods. The release buoy is configured such that the net buoyancy of the release is positive.

8. The underwater hovering system according to claim 7, characterized in that, The release device includes a release device ring disposed at the bottom of the release device body; The underwater hovering assembly also includes a support rod, a first rope, a second rope, and a third rope. One end of the support rod is connected to the release shackle via the first rope, and the other end of the support rod is connected to the equipment float via the second rope. The equipment counterweight is connected to the support rod via the third rope.

9. The underwater hovering system according to any one of claims 1 to 6, characterized in that, The underwater hovering system is applied to the ocean, and the underwater hovering component also includes a Beidou user terminal sea surface beacon terminal located on the top of the equipment float. The Beidou user terminal sea surface beacon terminal is connected to the release device via a cable.

10. A method for underwater hovering and release of a drone, characterized in that, The underwater hovering system as described in any one of claims 2 to 6 is used to hover and remotely release the drone underwater. The underwater hovering step includes using a buoyancy strap to secure the drone to a release device so that the drone is suspended in the water. The movable end of the buoyancy strap is releasably connected to the release hook of the release device. The remote release step includes the BeiDou user terminal transmitting a release command to the UAV from the ground end, the BeiDou user terminal receiving the release command at the sea surface end and forwarding it to the release device, the release device opening the release hook after receiving the release command, the movable end of the buoyancy strap separating from the release hook under the action of buoyancy, thereby releasing the UAV, and the UAV rising under the action of its buoyancy.

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