An underwater launching device for a drone

Abstract

This invention relates to an underwater launch device for an unmanned aerial vehicle (UAV), comprising a front protective cover, a mid-section, a tail section, and a "three-no" launch system. The front protective cover is located at the foremost end of the underwater launch device and is connected to the mid-section via a separation mechanism. The mid-section has a cylindrical, thin-walled structure. The tail section is located at the rear of the mid-section and is connected to it using an annular sealing ring and double-ended studs. The "three-no" launch system consists of a non-metallic launch tube, a gas generator, a piston, and a brake cable. The gas generator is installed at the bottom of the non-metallic launch tube, and the piston is connected to the gas generator via the brake cable. The tail section is also connected to a counterweight at its end via an underwater separation mechanism. This invention utilizes the garbage ejection device of a submarine to launch the UAV outside the submarine, without occupying any offensive weapon launch system, without altering the existing layout of the submarine, without affecting the submarine's combat capability, and is highly adaptable, feasible, cost-effective, and reliable.

Description

Technical Field

[0001] This invention relates to an underwater launching device, and more particularly to an underwater launching device for a drone. Background Technology

[0002] The United States is a leading representative in the field of underwater drone launches. Since the 1990s, the US has conducted numerous underwater drone launch tests. In 1996, the US Navy submarine USS Asheville successfully test-fired the SeaFerret drone, remotely controlling it from its submerged state by extending its antenna. In mid-November 2007, a US Navy Los Angeles-class nuclear submarine carried the Cormorant drone in a test flight in the Atlantic Ocean, marking the first submarine-launched drone test flight by a US Navy nuclear submarine. From 2008 to 2009, the US Navy completed a test launch of the small Spring Knife drone from the periscope depth of a submarine. This drone was developed by AeroVironment, and the submarine-launched vehicle (SLV) was developed by Raytheon. On December 5, 2013, the U.S. Navy announced the successful completion of a verification test of launching an XFC unmanned aerial vehicle from an underwater submarine. The test was conducted on the U.S. Navy's Los Angeles-class nuclear submarine USS Providence. The unmanned aerial vehicle was carried in a launcher called Sea Robin and launched using the submarine's Tomahawk cruise missile launch system.

[0003] The United States' latest underwater drone launcher is the Sea Robin, developed by National Oceanic and Atmospheric Administration. It is a circular, watertight pontoon that normally houses the drone. In use, it is launched using a Tomahawk cruise missile launch system. After launch, the Sea Robin uses its own buoyancy to move upwards and float on the sea surface. Upon receiving a command from a submarine, the drone is then vertically launched into the air from the Sea Robin using a high-powered motor and propeller in its nose.

[0004] The existing underwater launch system for unmanned aerial vehicles (UAVs) is merely an experimental device with numerous drawbacks. For example, it requires a dedicated cruise missile launch system from a submarine, which undoubtedly reduces the number of missiles that can be deployed, impacting the submarine's overall attack capability. When floating on the surface, the launch system doesn't account for the effects of waves and wind, resulting in poor seaworthiness and limiting its operation to lower sea states. Furthermore, the launch system provides no propulsion for the UAV, which relies on high-powered motors and propellers for takeoff, making the aircraft's design overly complex. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an underwater launch device for unmanned aerial vehicles (UAVs) to solve the problem of launching UAVs from submarines while they are submerged.

[0006] To address the existing technical problems, the present invention adopts the following technical solution: an underwater launch device for unmanned aerial vehicles (UAVs), comprising a front protective cover, a middle compartment, a tail compartment, and a "three-no" (no cover, no launch system) launch system.

[0007] The aforementioned front protective cover is located at the very front of the underwater launch device. The front section of the front protective cover has a standard elliptical curve shape, while the rear section has a cylindrical shape. The front protective cover is connected to the middle compartment through a separation mechanism.

[0008] The overall shape of the middle compartment is a cylindrical thin-walled structure. A folded floating airbag is installed in the annular groove on the outer side of the bottom of the middle compartment. A folded sail is installed in the rectangular groove on the upper outer side of the middle compartment, which is on the same side as the fixed fin. A telemetry transmitting device is installed on the protrusion of the inner wall of the front section of the middle compartment. The sail mast also serves as a telemetry transmitting antenna. The middle compartment has a cylindrical "three-no" transmitting system in the center. A gas generator is installed on the protrusion of the inner wall of the middle section of the middle compartment. It is connected to the floating airbag through a pipeline. After the gas generator is started, it generates high-pressure gas, which is cooled by the pipeline and then inflates the floating airbag.

[0009] The tail section is located at the rear of the middle section and is connected to the middle section by an annular sealing ring and double-headed studs. The front section of the tail section has a two-parameter elliptical curve shape. A flat plate fixing fin is provided on one side of the tail section at the same position as the sail. The rear section of the tail section has a conical shape. The control device is installed inside the tail section, and the main battery pack is installed in the rear section of the tail section.

[0010] The aforementioned "three-no" launch system consists of a non-metallic launch tube, a gas generator, a piston, and a brake rope. The gas generator is installed at the bottom of the non-metallic launch tube, and the piston is connected to the gas generator via the brake rope. Normally, the piston is located at the bottom of the non-metallic launch tube, supporting the drone. After the gas generator is ignited, it generates high-pressure gas, which pushes the piston and the drone to accelerate, propelling the drone out of the non-metallic launch tube. After the gas generator finishes its work, the brake rope tauts to decelerate the piston, causing it to stop when it reaches the top of the non-metallic launch tube.

[0011] To improve the mechanical properties of the middle compartment against external pressure, the inner wall of the middle compartment described in this invention has several crisscrossing reinforcing ribs.

[0012] In order to allow the underwater launcher to sink a certain distance after being ejected from the submarine's waste disposal equipment and to avoid collision with the submarine in its submerged state, the tail section of the present invention is also connected to a counterweight via an underwater separation mechanism. The weight of the counterweight can be adjusted according to the buoyancy and gravity difference of the underwater launcher.

[0013] To facilitate direct wireless communication between the drone and the outside world from inside the tube, the non-metallic transmitting tube of this invention is formed by winding a composite material that transmits electromagnetic waves.

[0014] The underwater launch device for the UAV of the present invention is compatible with both the submarine and the UAV, and is a key link connecting the submarine and UAV systems. It enables the underwater launch of the UAV without changing the existing state of the submarine and the UAV.

[0015] The underwater launch device for unmanned aerial vehicles (UAVs) of this invention utilizes the same launch mechanism as a submarine's garbage ejection system, launching the UAV outside the submarine without occupying any offensive weapon launch systems, altering the existing submarine layout, or affecting its combat effectiveness, thus exhibiting strong adaptability. This invention leverages the combined effects of surface sails and underwater fixed fins with sea breezes and ocean currents, ensuring the underwater launch device is always aligned with the wind direction under the influence of natural mechanical forces. This avoids the need for complex control systems and improves the reliability of UAV takeoff. The surface "three-no" launch method, through a unique catapult system design, achieves a silent, lightless, and smokeless launch effect when launching UAVs from the surface, minimizing the possibility of detection. The recoil elimination method solves the recoil problem associated with launching UAVs from floating surfaces. This invention features a completely covert and silent launch process. Based on the stealth requirements of submarines, the underwater launch device for UAVs takes into account the battlefield needs of covert reconnaissance throughout the entire process, from ejecting outside the submarine to silently surfacing after separation from the water, and then launching the UAV through a "three-no" launch system, minimizing the probability of being detected by the enemy.

[0016] If the launch interface is large enough, this invention can be used for the joint launch of UAVs and air defense missiles. That is, the device can simultaneously install UAVs and missiles. After floating to the sea surface, the UAV will first take off to search for the target. After finding the target, it will transmit the location information to the missile, and then the missile will ignite and launch to attack, forming an independent reconnaissance-attack fire unit.

[0017] Beneficial effects

[0018] The underwater launcher for unmanned aerial vehicles (UAVs) involved in this invention is ejected from rarely used waste disposal equipment, thus not occupying cruise missile launch systems or affecting the attack capabilities of submarines. Furthermore, this invention possesses a rationally designed aerodynamic shape, reducing underwater cavitation and flow noise during surfacing, achieving silent, unpowered ascent. Moreover, the invention's unique wind alignment device is simple, reliable, and highly feasible, making the entire system more functional, reducing costs, and improving reliability. Attached Figure Description

[0019] Appendix Figure 1 This is a flowchart illustrating the working principle of the present invention;

[0020] Appendix Figure 2 This is a fluid profile diagram of the present invention;

[0021] Appendix Figure 3 This is a structural layout diagram of the present invention;

[0022] Appendix Figure 4 This is a diagram of the wind alignment system of the present invention;

[0023] Appendix Figure 5 This is a diagram of the "three-no" launch system of the present invention;

[0024] In the diagram, 1-front protective cover, 2-separation mechanism, 3-middle compartment, 4-floating airbag, 5-tail compartment, 6-sail, 7-telemetry launch device, 8-"three-no" launch system, 9-gas generator, 10-control device, 11-main battery pack, 12-underwater separation mechanism, 13-counterweight, 14-non-metallic launch tube, 15-gas generator, 16-piston, 17-brake rope, 18-fixed fin, 19-UAV. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments.

[0026] As attached Figure 2 As shown, the underwater launch device of the UAV of the present invention adopts a fluid shape. In order to achieve silent launch, it is necessary to minimize water flow resistance, flow noise, and underwater cavitation, which depends on the rational design of the fluid shape of the underwater launch device. The fluid shape of the underwater launch device involved in the present invention adopts a torpedo-proof linear shape, with a standard elliptical curve (round head) at the front end, a cylinder in the middle section, and a tail section composed of a two-parameter elliptical curve and a cone. Considering the influence of surface water flow, a fixed fin 18 is added to the tail section to facilitate wind direction alignment.

[0027] While achieving a reasonable fluid shape, the underwater launcher must have buoyancy greater than its own weight. At the same time, considering that the influence of sea waves will cause the underwater launcher to sway, the tilt center (the position of the resultant force of the underwater part of the buoyancy) of the underwater launcher should be higher than the center of gravity, and there should be a sufficient distance between the two so that the underwater launcher has sufficient restoring torque under the influence of waves and will not capsize, thus having a self-stabilizing function. It is generally recommended that the distance between the tilt center and the center of gravity be greater than 200mm.

[0028] Structural layout:

[0029] As attached Figure 3 The image shows the underwater launching device in its fully deployed state. Figure 4 This is the folded state. The front protective cover 1 is located at the very front of the underwater launch device. Its front section is a standard elliptical curve, and its rear section is cylindrical. It is connected to the middle compartment 3 through the separation mechanism 2. The front protective cover 1 is mainly used to maintain the fluid shape and watertight performance of the underwater launch device under normal conditions. It is separated from the underwater launch device through the separation mechanism 2 before the UAV is launched.

[0030] The middle compartment 3 has an overall cylindrical, thin-walled structure. A folded floating airbag 4 is installed in a ring-shaped groove on its outer side, and a folded sail 6 is installed in a rectangular groove on the same side as the fixed fin 18. The inner wall of the middle compartment 3 has several crisscrossing reinforcing ribs to improve its mechanical performance against external pressure. A telemetry transmitter 7 is installed on the protrusion of the front inner wall, responsible for data processing of telemetry signals. The sail of the sail 6 also functions as a telemetry transmitter antenna. In the center of the middle compartment 3 is a cylindrical "three-no" (no air, no fuel, no grounding) launch system 8, primarily responsible for the surface launch function of the UAV. A gas generator 9 is installed on the protrusion of the middle inner wall of the middle compartment 3, connected to the floating airbag 4 via pipelines. When the gas generator 9 is activated, it produces high-pressure gas, which, after being cooled by the pipelines, inflates the floating airbag 4.

[0031] The stern compartment 5 is located at the rear of the mid-section 3 and is connected to the mid-section 3 by an annular sealing ring and double-headed studs. At the same position as the sail 6, the stern compartment 5 has a flat fixed fin 18, with a two-parameter elliptical curve at the front and a conical shape at the rear. The stern compartment 5 houses a control device 10 responsible for distributing control commands and calculating attitude. The main battery pack 11 is also installed at the rear, providing power to the entire underwater launch device. The end of the stern compartment 5 is connected to a counterweight 13 via an underwater separation mechanism 12. The weight of the counterweight can be adjusted according to the buoyancy and gravity difference of the underwater launch device, allowing it to sink a certain distance after being ejected from the submarine's waste disposal equipment, thus avoiding collision with the submerged submarine.

[0032] Wind direction alignment method:

[0033] Since the underwater launcher targets small, fully folding-wing UAVs with limited wing area, it is necessary to launch from the sea surface facing the wind to increase lift. Using a side-thrust propeller in the underwater section for wind alignment would require a complex measurement and control system, resulting in high costs and reduced system reliability. The wind alignment method used in this invention employs a purely mechanical structure. The underwater section has a fixed fin 18 mounted on the tail section, while the surface section has a sail 6 mounted on the midsection. The sail 6 is normally folded and retracted, not affecting the hydrodynamic shape of the underwater launcher, and is unlocked and deployed upon reaching the surface. Because the wind and current at sea level are generally in the same direction, the sail 6 and the fixed fin together generate a deflection torque under the influence of the wind and current. Hydrodynamic analysis shows that this torque can completely overcome the resistance of the current, ensuring the UAV launch direction is aligned with the wind. This wind alignment method is simple in structure, easy to implement, highly reliable, and economical.

[0034] "Three-no" launch system:

[0035] Traditional rocket-assisted launch methods generate significant sound, light, and smoke signatures, which are detrimental to achieving covert reconnaissance objectives. The underwater launch device for unmanned aerial vehicles (UAVs) involved in this invention achieves a "three-no" launch effect—no sound, no light, and no smoke—when launching UAVs from a floating position on the sea surface. Detailed components of the "three-no" launch system of this invention are shown in the appendix. Figure 5 The system mainly consists of a non-metallic launch tube 14, a gas generator 15, a piston 16, and a brake rope 17. The non-metallic launch tube 14 is made of electromagnetic wave-transmitting composite material, allowing the UAV to directly transmit wireless information to the outside world from inside the tube. The gas generator 15 is the power source for the entire launch system. After ignition, it generates high-pressure gas, which propels the piston 16 and the UAV 19 to accelerate. Through a reasonable internal ballistic design, the launch overload can be less than 100g. The piston 16 normally supports the UAV 19, and during launch, its high-speed motion pushes the UAV 19 out of the non-metallic launch tube 14. The brake rope 17 is woven from high-strength Kevlar fiber, with one end connected to the gas generator and the other end connected to the piston. The length of the brake rope 17 is reasonably designed so that after the gas generator has finished working, the brake rope 17 tauts to decelerate the piston 16, causing the piston 16 to stop when it reaches the top of the launch system. This prevents gas leakage and eliminates the sound and light effects, achieving a "three-no" launch (no gas leakage, no sound or light effects).

[0036] Methods to eliminate recoil:

[0037] After launching the drone, the underwater launcher needs to remain on the water for a period of time as a relay station for air and underwater information transmission. Therefore, it is necessary to eliminate the recoil force during drone launch to prevent capsizing. Since the underwater launcher floats on the sea surface without any leverage, a floating airbag is designed in the rear section of the mid-cabin. During drone launch, the airbag will sink due to the recoil force, but as long as it maintains sufficient capacity, the underwater launcher will move up and down on the water surface to dissipate the recoil force and eventually return to its equilibrium position.

[0038] Working principle:

[0039] The working principle flowchart is attached. Figure 1Before launch, parameters are set, the timer starts, and the underwater launcher is ejected from the submarine via a debris ejection device. Under the influence of the counterweight, the underwater launcher sinks to a certain depth, creating a safe distance from the submarine. Then, the underwater separation mechanism connecting the counterweight and the launcher activates, separating the launcher from the counterweight and allowing it to silently rise to the surface under its own buoyancy. Upon reaching the surface, the gas generator inflates the floating airbags. After inflation, the folding and unfolding mechanism unlocks, the sails unfold, and the underwater launcher automatically aligns itself with the wind direction through the combined effects of the torque generated by the wind on the sails and the hydrodynamic force of the ocean currents on the fixed fins. Upon receiving the launch command from the submarine, the forward protective cover is jettisoned by the separation mechanism, the gas generator ignites, and the drone is launched into the air.

[0040] This device can be applied to conventional submarines and attack nuclear submarines, enabling submarines to acquire information on surface and air targets while submerged. It has the potential to break the traditional pattern of superiority over space and inferiority over submarines in naval warfare and is a force multiplier for underwater combat.

[0041] The invention has proven feasible through software simulation analysis and ground testing.

Claims

1. An underwater launch device for an unmanned aerial vehicle (UAV), comprising a front protective cover (1), a mid-section (3), a tail section (5), and a launch system (8), characterized in that: The front protective cover (1) is located at the front end of the underwater launch device. The front section of the front protective cover (1) is in the shape of a standard elliptical curve, and the rear section is in the shape of a cylinder. The front protective cover (1) is connected to the middle compartment (3) through the separation mechanism (2). The overall shape of the middle compartment (3) is a cylindrical thin-walled structure. A folded floating airbag (4) is installed in the annular groove on the outer side of the bottom end of the middle compartment (3). A folded sail (6) is installed in the rectangular groove on the same side as the fixed fin (18) on the upper middle outer side of the middle compartment (3). A telemetry transmitting device (7) is installed on the protrusion of the inner wall of the front section of the middle compartment (3). The sail of the sail (6) also serves as a telemetry transmitting antenna. A cylindrical transmitting system (8) is located in the middle of the middle compartment (3). A gas generator (9) is installed on the protrusion of the inner wall of the middle section of the middle compartment (3). It is connected to the floating airbag (4) through a pipeline. After the gas generator (9) is started, it generates high-pressure gas, which is cooled by the pipeline and then inflates the floating airbag (4). The tail section (5) is located at the rear end of the middle section (3) and is connected to the middle section (3) by an annular sealing ring and a double-headed stud. The front section of the tail section (5) has a double-parameter elliptical curve shape. A fixed fin (18) is provided on one side of the tail section (5) at the same position as the sail (6). The rear section of the tail section (5) has a conical shape. A control device (10) is installed inside the tail section (5). The main battery pack (11) is installed in the rear section of the tail section (5). The launch system (8) consists of a non-metallic launch tube (14), a gas generator (15), a piston (16), and a brake rope (17). The gas generator (15) is installed at the bottom of the non-metallic launch tube (14). The piston (16) is connected to the gas generator (15) through the brake rope (17). Normally, the piston (16) is located at the bottom of the non-metallic launch tube (14) to support the drone (19). After the gas generator (15) is ignited, it generates high-pressure gas, which pushes the piston (16) and the drone (19) to accelerate and push the drone (19) out of the non-metallic launch tube (14). After the gas generator (15) finishes working, the brake rope (17) is taut to decelerate the piston (16) so that the piston (16) stops when it reaches the top of the non-metallic launch tube (14).

2. The underwater launching device according to claim 1, characterized in that: The inner wall of the middle compartment (3) has several crisscrossing reinforcing ribs.

3. The underwater launching device according to claim 1, characterized in that: The tail section (5) is also connected to the end of the tail section (5) by an underwater separation mechanism (12) and a counterweight (13).

4. The underwater launching device according to claim 3, characterized in that: The non-metallic transmitter tube (14) is formed by winding a composite material that is transparent to electromagnetic waves.

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