Underwater control mechanism and cross-medium aircraft

Abstract

The underwater control mechanism comprises a water-jet propeller arranged at the tail of the cross-medium aircraft, and the front end of the water-jet propeller is provided with a vertically-through empennage mounting space; the water-jet propellers are arranged in the front-back direction, the front is a water inlet end, and the rear is a water outlet end. The axis of the water-jet propeller passes through the gravity center of the medium-crossing aircraft; the water-jet propeller is designed at the tail of the cross-medium aircraft, the empennage mounting space is arranged in front of the water-jet propeller, a flow channel can be provided for the water-jet propeller through the empennage mounting space, and good water inlet flowing efficiency is guaranteed; and meanwhile, the axis of the water-jet propeller passes through the gravity center of the cross-medium aircraft, so that the pitch angle change of the cross-medium aircraft caused by the work of the water-jet propeller can be reduced, and the underwater control difficulty is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of underwater control of aircraft, and in particular relates to an underwater control mechanism and a cross-medium aircraft. Background Art

[0002] Underwater vehicles (UVs) are devices capable of autonomous or remotely controlled underwater navigation. They are widely used in marine research, resource exploration, military reconnaissance, and other fields. Control technology for UVs is central to their complex missions, encompassing propulsion systems, attitude control, navigation algorithms, and anti-interference design.

[0003] As a specialized underwater vehicle, a trans-medium aircraft typically uses a tail rudder to control its pitch attitude. Power is generated by a water jet located under the fuselage, which also requires a water inlet. Because the water jet is located under the fuselage, it exerts an upward force on the trans-medium aircraft during underwater navigation, making it more difficult to control. Summary of the Invention

[0004] The purpose of the present invention is to provide an underwater control mechanism and a trans-medium aircraft, in which a tail wing installation space that passes through the tail of the fuselage is opened up and down, and a water jet propulsion device is arranged behind the tail wing installation space, so that the axis of the water jet propulsion device passes through the center of the trans-medium aircraft, thereby reducing the difficulty of underwater control.

[0005] The present invention adopts the following technical solution: an underwater control mechanism includes a water jet propulsion device arranged at the tail of a cross-medium aircraft, and a tail wing installation space is provided at the front end of the water jet propulsion device;

[0006] The water jet propulsion system is arranged in the front and rear directions, with the front as the water inlet end and the rear as the water outlet end;

[0007] The axis of the water jet passes through the center of gravity of the trans-medium vehicle.

[0008] Preferably, a heading rudder is provided directly behind the water jet propulsion unit.

[0009] Preferably, a left wing air chamber and a right wing air chamber are respectively provided at the lower part of the cross-medium aircraft and on both sides of the fuselage;

[0010] The left wing air chamber / right wing air chamber includes a plurality of air bags arranged in sequence in front and behind.

[0011] Preferably, a belly air chamber is also provided below the fuselage.

[0012] Preferably, a gas cylinder is provided on the back of the cross-medium aircraft, and the gas cylinder is connected to the airbag via a pipeline.

[0013] Another technical solution of the present invention: a cross-medium aircraft, comprising an underwater control mechanism according to any one of the above items.

[0014] Preferably, a rotor mechanism and box-type wings are provided on the fuselage;

[0015] There are fixed wings on both sides of the fuselage;

[0016] There is a rotor installation space that runs vertically between the fixed wing and the fuselage;

[0017] A left rotation rod / right rotation rod connected to the fuselage rotation is provided in the rotor installation space, and the left rotation rod and the right rotation rod are coaxially arranged;

[0018] A top power rotor is provided above the left turning lever / right turning lever, and a bottom power rotor is provided below the left turning lever;

[0019] The fuselage and the left rotating rod are connected through a left tilt motor, and the fuselage and the right rotating rod are connected through a right tilt motor.

[0020] Preferably, a trim rotor is provided in the tail wing installation space.

[0021] Preferably, the top power rotor and the bottom power rotor are coaxially arranged and rotate in opposite directions.

[0022] Preferably, ailerons are provided on the outer sides of the fixed wings;

[0023] A box wing is provided on the outer side of the aileron, and the other end of the box wing is connected to the tail of the fuselage.

[0024] The beneficial effects of the present invention are as follows: the present invention designs a water jet propulsion device at the tail of the cross-medium aircraft, and provides a tail wing installation space in front of it, which can provide a flow channel for the water jet propulsion device, thereby ensuring better water inlet flow efficiency; at the same time, the axis of the water jet propulsion device passes through the center of gravity of the cross-medium aircraft, which can reduce the pitch angle change of the cross-medium aircraft caused by the operation of the water jet propulsion device, thereby reducing the difficulty of underwater control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the arrangement of an underwater control mechanism on a cross-medium aircraft according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic structural diagram of a power mechanism in an embodiment of the present invention;

[0027] Figure 3 This is a schematic structural diagram of the power mechanism from another perspective in an embodiment of the present invention;

[0028] Figure 4This is a schematic structural diagram of a trans-medium aircraft using a box-wing tilt-rotor design according to an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the structure of the rotor mechanism in an embodiment of the present invention;

[0030] Figure 6 Schematic diagram of force analysis of the rotor mechanism during ascent of a trans-medium aircraft according to an embodiment of the present invention;

[0031] Figure 7 Schematic diagram of force analysis of the rotor mechanism during rolling of a cross-medium aircraft according to an embodiment of the present invention;

[0032] Figure 8 Schematic diagram of force analysis of the rotor mechanism when the cross-medium aircraft turns in an embodiment of the present invention;

[0033] Figure 9 Schematic diagram of the state of the cross-medium aircraft from submergence to vertical takeoff in an embodiment of the present invention;

[0034] Figure 10 A schematic diagram of a state of a cross-medium aircraft from a hovering state to a flying state according to an embodiment of the present invention;

[0035] Figure 11 Schematic diagram of the state of a cross-medium aircraft from a flying state to a water entry state in an embodiment of the present invention.

[0036] Including: 100. fuselage;

[0037] 200. Box wing; 210. Fixed wing; 220. Aileron; 230. Box wing; 240. Elevator; 250. Rudder;

[0038] 300. Rotor mechanism; 310. Top powered rotor; 320. Bottom powered rotor; 330. Trimming rotor; 340. Left tilt motor; 350. Right tilt motor; 360. Left rotation lever; 370. Right rotation lever; 380. Main support rod;

[0039] 410. Left wing air chamber; 420. Right wing air chamber; 430. Belly air chamber; 440. Power mechanism; 441. Tripod rudder; 442. Water jet propulsion; 443. Upper mounting plate; 444. Lower mounting plate. DETAILED DESCRIPTION

[0040] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] The present invention discloses an underwater control mechanism, such as Figure 2 and Figure 3As shown, it includes a water jet propulsion device 442 arranged at the tail of the trans-medium aircraft, and the front end of the water jet propulsion device 442 has a tail wing installation space that passes through from top to bottom; the water jet propulsion device 442 is arranged in the front-to-back direction, with the front end being the water inlet end and the rear end being the water outlet end; the axis of the water jet propulsion device 442 passes through the center of gravity of the trans-medium aircraft.

[0042] The present invention designs the water jet propulsion unit 442 at the tail of the cross-medium aircraft and provides a tail wing installation space in front of the water jet propulsion unit 442. The tail wing installation space can provide a flow channel for the water jet propulsion unit 442, thereby ensuring better water inlet flow efficiency. At the same time, the axis of the water jet propulsion unit 442 passes through the center of gravity of the cross-medium aircraft, which can reduce the pitch angle change of the cross-medium aircraft caused by the operation of the water jet propulsion unit 442 and reduce the difficulty of underwater control.

[0043] In the present invention, a rudder 441 is provided directly behind the water jet propulsion unit 442. The rudder 441 and the water jet propulsion unit 442 together constitute the power mechanism 440 of the present invention.

[0044] The rudder 441 is connected to the fuselage 100 via a pull rod, and the underwater heading of the cross-medium aircraft is controlled by deflecting the rudder 441 .

[0045] In addition, if Figure 1 As shown, a left wing air chamber 410 and a right wing air chamber 420 are located on either side of the fuselage 100, located below the trans-medium aircraft. The left and right wing air chambers 410 and 420 include several airbags arranged in a tandem arrangement. A ventral air chamber 430 is also located below the fuselage 100. Gas cylinders are located on the back of the trans-medium aircraft, connected to the airbags via pipelines.

[0046] The left wing air chamber 410 and the right wing air chamber 420 are used to adjust the roll attitude underwater, and the belly air chamber is used to adjust the pitch attitude. Considering the impact of the airbag on the aerodynamics of the cross-medium aircraft when flying in the air, the airbag adopts a flexible airbag installed in an air chamber with a rigid shell.

[0047] As a preferred implementation, the left wing air chamber 410 and the right wing air chamber 420 are each equipped with three air bags, each of which is controlled by an independent air valve to control the amount of air inflated and deflated. The purpose is to fine-tune the buoyancy and thus achieve fine-tuning of the underwater posture.

[0048] It's important to note that this airbag arrangement further accounts for the varying center of gravity of the trans-medium vehicle when carrying varying payloads. This allows for stable underwater control by fine-tuning the inflation and deflation of each airbag. Furthermore, the displacement of all three airbags when fully inflated far exceeds the buoyancy required to lift the vehicle. Even if one airbag were to fail, the vehicle would not sink.

[0049] The present invention also discloses a cross-medium aircraft, such as Figure 4 and Figure 5 As shown, it includes a fuselage 100, on which a rotor mechanism 300 and a box-type wing 200 are provided; fixed wings 210 are provided on both sides of the fuselage 100; a rotor installation space that passes through the fixed wings 210 and the fuselage 100 is provided; a left rotating rod 360 / right rotating rod 370 connected to the fuselage rotation is provided in the rotor installation space, and the left rotating rod 360 and the right rotating rod 370 are coaxially arranged; a top powered rotor 310 is provided above the left rotating rod 360 / right rotating rod 370, and a bottom powered rotor 320 is provided below; the fuselage 100 and the left rotating rod 360 are connected via a left tilt motor 340, and the fuselage 100 and the right rotating rod 370 are connected via a right tilt motor 350.

[0050] The present invention can perform vertical ascent and descent when crossing a medium by arranging a rotor mechanism 300 on the fuselage, and use box-type wings 200 to improve flight efficiency when flying in the air. At the same time, it meets the fixed-wing flight mode and floating-down water entry mode of large-load cross-medium aircraft, and solves the water-air critical surface conversion problem of large-load cross-medium aircraft.

[0051] The cross-medium aircraft described in the present invention is an aircraft that crosses both water and air. In the prior art, the sliding-down water entry method is generally used for fixed-wing cross-medium aircraft. Due to the fixed-wing design, the aircraft has higher flight efficiency (faster flight speed or longer range at the same energy consumption) and a larger payload. However, this design has the following problems:

[0052] First, the cross-medium landing process is complex. The landing process is similar to that of a fixed-wing seaplane, requiring a descent, a glide, and a dive. The entire process requires precise control over a long period of time. Second, it is sensitive to sea conditions. When wave heights exceed the limit, the aircraft cannot land, and thus cross-medium landing is impossible. Third, there are requirements for the size of the sea area. The glide-into-water process requires a long glide distance, making normal takeoff and landing in narrow inland waterways difficult.

[0053] Splashdown is generally used for trans-medium aircraft with variable-sweep wings. Since they also use fixed-wing designs, the aircraft has good flight efficiency. However, this design has the following problems:

[0054] First, the variable-sweep wing structure is complex. To achieve the retraction and extension of the swept wing, a complex and precise mechanical structure is required. Due to the impact during the cross-medium process, the retraction and extension mechanism is prone to failure. Second, the load is low. Due to the requirements of this method for the power system when exiting the water, the aircraft has a small cross-section and adopts a long water drop structure, resulting in a limited load capacity. Third, it is difficult to mannify. The impact during the air-water cross-medium stage is strong, and the instantaneous acceleration can reach over 9G. Fourth, the structural strength requirements are high. Also due to the impact during the air-water cross-medium stage, extremely high requirements are placed on the structural strength and skin materials.

[0055] Floating-type water-entry aircraft typically utilize a multi-rotor layout. This arrangement results in a compact structure and relatively simple attitude control. However, these aircraft present the following challenges: First, low flight efficiency. Due to the lack of fixed wings, the aircraft consumes high energy, has a short range, and carries a low payload. Second, the powertrain is poorly matched. The engine must provide power both in the air and underwater. Especially underwater, due to the high viscosity of water, conventional motors are prone to overpowering and failure. To maintain adequate underwater controllability, the propellers must sacrifice aerodynamic performance in the air.

[0056] To improve the aerial capabilities of a floating, cross-medium aircraft, Shanghai Jiao Tong University's "Nezha 3" fuses fixed-wing and multi-rotor aircraft, employing a tilt-rotor design. However, due to the lack of fixed-wing design requirements during the design phase (fixed-wing aircraft developed based on multi-rotor aircraft, rather than multi-rotor aircraft developed based on fixed-wing aircraft), the fixed-wing aircraft exhibits poor aerodynamic performance during level flight, requiring complex attitude control.

[0057] For cross-medium aircraft that use fixed wings + gliding water entry, since they completely adopt a fixed-wing layout, the process of crossing the air-water interface is complicated and has high requirements for sea conditions and sea areas, resulting in deployment restrictions.

[0058] For cross-medium aircraft that use variable swept wings + splashdown, due to its high water entry speed, the aircraft load is limited in order to meet the requirements for fuselage strength in the event of impact.

[0059] For a multi-rotor + floating cross-medium aircraft, since it completely uses rotors to provide lift, its flight efficiency is low, the range is short, and the payload is small.

[0060] To solve the above problems, a tiltrotor + floating-down design was adopted. This solution takes into account the low entry speed requirement of the floating-down design and the high flight efficiency and large payload advantages brought by the fixed-wing design.

[0061] Shanghai Jiao Tong University's "Nezha 3" cross-medium aircraft incorporates fixed wings on top of a multi-rotor system. However, its aerodynamic layout is still primarily multi-rotor, so the aircraft cannot fully achieve level flight like a fixed-wing aircraft, resulting in a shorter range.

[0062] The design concept of this invention is to add a multi-rotor design to a fixed-wing aircraft. The rotors are incorporated into the fixed-wing body using a coaxial engine arrangement, resulting in a more compact and stronger overall structure. Furthermore, the invention utilizes high-torque servos to tilt the rotors, enabling flexible switching between rotor and fixed-wing flight attitudes. This resolves the conflict between vertical takeoff and landing (VTOL) and long range, achieving the design criteria of a cross-medium, vertical takeoff and landing (VTOL) aircraft with a high payload, high maneuverability, and a long range.

[0063] Furthermore, the present invention utilizes a box-shaped wing to shift the center of lift behind the center of gravity (nose forward, tail aft), ensuring static stability during level flight. During vertical takeoff and landing, the center of gravity lies within the closed plane formed by the lift points of each engine, ensuring that each engine generates positive lift. This design balances stability and power requirements in both flight attitudes.

[0064] Specifically, in the present invention, the left and right rotation levers 360 and 370 can rotate along their respective axes, and during this rotation, they simultaneously drive the top powered rotor 310 and the bottom powered rotor 320 to turn. When the left and right rotation levers 360 and 370 are in their initial state, the rotation axes of the top and bottom powered rotors 310 and 320 are both vertically arranged, which can drive the trans-medium aircraft to rise or fall in the vertical direction. When the left and right rotation levers 360 and 370 are rotated, the rotation axes of the top and bottom powered rotors 310 and 320 are arranged in the front-to-back direction of the trans-medium aircraft, which can provide the trans-medium aircraft with forward or backward power, thereby achieving the switching between rotary-wing flight and fixed-wing flight.

[0065] In an embodiment of the present invention, the rotor mechanisms 300 and fixed wings 200 on both sides of the fuselage 100 are symmetrically arranged relative to the fuselage, a balancing rotor is provided at the tail of the fuselage 100, and the top power rotor 310 and the bottom power rotor 320 are coaxially arranged and rotate in opposite directions.

[0066] Specifically, the entire aircraft adopts a box-type wing layout, and the main wing portion of the wing adopts a medium aspect ratio layout with a small sweep angle. The purpose is to move the aerodynamic center toward the tail while ensuring a high lift coefficient. Under the coupling effect of the box wing and the main wing, the aerodynamic center of the aircraft of the present invention is located behind the center of gravity, making the aircraft's level flight state a statically stable state, thereby improving flight stability.

[0067] Compared to conventional high-aspect-ratio aircraft (such as passenger and transport aircraft), the aircraft of the present invention lacks leading-edge slats and trailing-edge flaps. This is because slats and flaps are primarily used to increase wing camber during takeoff and landing, thereby achieving a higher lift coefficient. However, the aircraft of the present invention utilizes vertical takeoff and landing, eliminating the need for wing camber adjustment and, therefore, eliminating the need for slats and flaps.

[0068] In one embodiment, ailerons 220 are disposed on the outside of fixed wings 210; box wings 230 are disposed on the outside of ailerons 220, with the other end of box wings 230 connected to the tail of fuselage 100. Vertical stabilizers are disposed on both sides above the tail of fuselage 100, each equipped with a rudder 250. A horizontal stabilizer is disposed between the tops of the two vertical stabilizers, with an elevator 240 mounted on each horizontal stabilizer. The tail end of box wings 230 is connected to the top of the corresponding vertical stabilizer.

[0069] The aircraft of the present invention utilizes a V-shaped vertical tail with a trim rotor 330 positioned in the center. A horizontal stabilizer (i.e., horizontal tail) spans the vertical stabilizer (i.e., vertical tail), further enhancing the structural strength of the tail section. Furthermore, both the vertical and horizontal stabilizers are swept back to prevent the aircraft structure from affecting the aerodynamic efficiency of the trim rotor.

[0070] The present invention includes four lift rotors (two top powered rotors 310 and two bottom powered rotors 320), a trim rotor 330, and two tilting motors. The rotor system is connected to the fuselage via a carbon fiber tube. The power and tilting motors are arranged on a cross-shaped structure made of carbon fiber and aviation aluminum alloy, which has a high rigidity (compared to the fuselage). This prevents vibration from the motors from causing resonance in the fuselage, which could lead to strength issues.

[0071] The power rotor adopts a coaxial layout scheme, with the upper and lower sets of motors rotating in opposite directions, and the motors on the left and right wings rotating in opposite directions. Figure 6 、 Figure 7 and Figure 8 For force analysis of this arrangement, the torques generated by the upper and lower coaxial motors cancel each other out, with the trim rotor counteracting the tilt torque generated by the powered rotor. Adjusting the output power of the trim rotor 330 enables pitch control of the aircraft during hover. The trim rotor also generates a tilt torque, which is largely offset by the tilted trim tail 300. Fine-tuning the remaining torque is achieved by adjusting the rotational speed of the coaxial upper and lower powered rotors.

[0072] exist Figure 7 and Figure 8Increasing the power output of one power motor on either side simultaneously can cause the aircraft to fly sideways in the opposite direction. Simultaneously adjusting the power output of the powered rotors on both sides can steer the aircraft to one side while maintaining the total lift. In summary, by adjusting the rotor power output, the aircraft of the present invention can achieve flight maneuvers similar to those of traditional rotorcraft (multi-rotor drones, helicopters).

[0073] To facilitate transport and quick installation of the aircraft, this invention incorporates quick-install mechanisms at the wing-to-fuselage and wing-to-tail connections. The main wings (i.e., fixed wings) are bolted to the fuselage, positioned by overlapping them. The box wings are also bolted to the tail, also using overlapping connections.

[0074] Due to the structural strength requirements of the bolted connection's preload, the wing is constructed of nylon carbon fiber. To increase wing rigidity, transverse and longitudinal ribs are installed within the wing. Carbon fiber tubes run through the wing to further enhance rigidity. At the quick-release connection, bolts are preloaded to secure the carbon fiber tubes and connect the two adjacent components.

[0075] The fuselage 100 is provided with a main strut 380 (i.e., the aforementioned carbon fiber tube; if the main strut 380 is hollow, it forms a tube). The center of gravity of the trans-medium aircraft is located on the main strut 380, behind the left rotation rod 360 and the right rotation rod 370. The trim rotor 330 is mounted on the main strut 380.

[0076] A trans-medium aircraft consists of an airframe, rotor propulsion system, underwater navigation system, and flight control system. The airframe provides the fundamental structural strength of the aircraft, while the rotor propulsion system enables vertical takeoff and landing (VTOL) and aerial flight. The underwater navigation system provides underwater propulsion and attitude control for the aircraft. The flight control system controls the aircraft's flight, navigation, and trans-medium attitude.

[0077] In one embodiment, the aircraft has a wingspan of 2990 mm and a fuselage length of 2560 mm. It adopts a straight-swept box-wing layout with an aspect ratio of 3.7. The power system consists of four coaxially arranged 6.8 kg propellers, resulting in a thrust-to-weight ratio of 2.25. The aircraft has a designed takeoff weight of 12 kg, with the engines operating at 50% power output. The redundant power is used for attitude control and short-term acceleration during the rotor-to-fixed wing attitude transition.

[0078] The cross-media method of the present invention is as follows Figure 9 、 Figure 10 and Figure 11 As shown. Figure 9As shown, in the submerged state, the airbags installed inside the floats are inflated, increasing the buoyancy of the aircraft and allowing it to float from the submerged state to the surface. When floating on the surface, the motors are above the water level, at which point the power rotors and trim rotors are activated, allowing the aircraft to take off vertically from the water. To prevent accidental activation of the power rotors and trim rotors 330 during underwater navigation, which could damage the motors, these motors are locked while underwater. They automatically unlock when they clear the water.

[0079] like Figure 10 As shown, when the aircraft is in hover, the tilt motors tilt the powered rotors, accelerating the aircraft forward and transitioning from hover to fixed-wing flight. The aircraft's attitude is controlled by the control surfaces, and the flight control laws are the same as those of traditional fixed-wing aircraft. In level flight, the trim rotors are disabled, and pitch control relies entirely on the elevators.

[0080] like Figure 11 As shown, the aircraft decelerates at a high pitch angle to return to a hovering state from a level flight state, and inflates the airbags. It then floats down to the water surface, relocking the motors of the power and trim rotors 330. The airbags are then deflated, allowing the aircraft to re-enter the water.

[0081] In summary, the overall design of the cross-medium aircraft has been completed, especially the design of a box-wing layout, coaxial rotors, and tilt-rotors, which resolves the contradiction between cross-medium and long range and heavy load. Flexible floats are used to control diving and underwater posture; a floating-down method is used to cross the water-air medium; and a tilt-rotor is used to switch flight posture (rotor-fixed wing). The rotor system of the present invention is not a traditional four-rotor or six-rotor layout. It adopts a coaxial arrangement of power rotors and a rotor system with a balancing rotor to adjust the posture.

[0082] Furthermore, the traditional splashdown method requires high structural strength and a smooth fuselage, which limits the aircraft's external payload capacity. The present invention utilizes tiltrotors and floats for a gentler crossover process while maintaining significantly higher efficiency than the "slip-down" method. However, the tiltrotor and float method requires the aircraft to switch between fixed-wing and rotary-wing configurations, especially at low altitudes during these transitions, which shortens the time required for emergency response. This necessitates the flight control system to sense the aircraft's configuration in real time and rapidly control power output.

[0083] To maintain rapid control of the propulsion system, the primary power source utilizes a brushless motor, which is highly susceptible to power overload and even short circuit upon contact with water. Therefore, the motor must be shut down before the aircraft fully touches the water. Determining the shutdown altitude requires extensive simulation calculations to ensure that the propellers stop upon contact with the water while also ensuring that the impact with the water does not exceed the structural strength limits of the aircraft.

[0084] Compared with traditional cross-medium aircraft with multi-rotor layout, the cross-medium process has less impact on the fuselage structure due to the lack of large aspect ratio wings. However, under the layout adopted by the present invention, during the cross-medium stage of the water-air critical surface, the wing root position will be impacted by bending and torsional loads. Therefore, the present invention adopts a fusion design of winglets and wing-body (that is, the wing in the present invention integrates the winglets, and the winglets extend continuously from the front end of the fuselage to the rear end of the fuselage), the connection area between the wing and the fuselage is larger, and the structural strength is higher; at the same time, the presence of the winglets makes the connection between the wing and the fuselage have no sharp angles, reduces stress concentration, and improves the strength of the structure. In addition, the present invention adopts a box-type wing layout, which makes the fuselage stronger. However, the complex wing surface design makes the aerodynamic structure of the aircraft different from the traditional aircraft configuration, the aerodynamic characteristics are complex, and the control difficulty is also greater.

[0085] After the floats are inflated, the buoyancy generated will completely lift the aircraft out of the water, which requires the floats to have sufficient displacement. When the aircraft dives, the buoyancy generated by the fuselage must be less than the gravity of the aircraft. However, in order to reduce weight, aircraft designs usually have a smaller gravity, which means that the buoyancy (volume) of the aircraft fuselage needs to be strictly limited. Therefore, after estimating the total mass of the aircraft, the present invention strictly checks the volume of the fuselage, and ensures through detailed calculations that the displacement of the aircraft fuselage is slightly less than its total mass, wherein the position of the lift engine eliminates most of the fuselage volume. Therefore, the aircraft fuselage structure of the present invention is compact, and the appearance of the aircraft is more agile. However, this design requires repeated iterations, and the structural design is extremely difficult.

Claims

1. An underwater control mechanism, characterized in that: The invention comprises a water jet propulsion device (442) arranged at the tail of a cross-medium aircraft, wherein the front end of the water jet propulsion device (442) is provided with a tail wing installation space which is passed through vertically; The water jet propulsion device (442) is arranged in the front-to-back direction, with the front being the water inlet end and the rear being the water outlet end; The axis of the water jet propulsion unit (442) passes through the center of gravity of the trans-medium aircraft.

2. An underwater control mechanism according to claim 1, characterized in that: A heading rudder (441) is provided directly behind the water jet propulsion unit (442).

3. An underwater control mechanism according to claim 2, characterized in that: A left wing air chamber (410) and a right wing air chamber (420) are respectively provided at the lower part of the cross-medium aircraft and on both sides of the fuselage (100); The left wing air chamber (410) / right wing air chamber (420) includes a plurality of air bags sequentially arranged in front and back.

4. An underwater control mechanism according to claim 3, characterized in that: An organic belly air chamber (430) is also provided below the fuselage (100).

5. An underwater control mechanism according to claim 4, characterized in that: A gas cylinder is provided on the back of the cross-medium aircraft, and the gas cylinder is connected to the airbag through a pipeline.

6. A cross-medium aircraft, characterized in that: The invention comprises an underwater control mechanism according to any one of claims 1 to 5.

7. The cross-medium aircraft according to claim 6, characterized in that: The fuselage (100) is provided with a rotor mechanism (300) and a box-type wing (200); Fixed wings (210) are provided on both sides of the fuselage (100); A rotor installation space is provided between the fixed wing (210) and the fuselage (100), which is connected vertically. A left rotation rod (360) and a right rotation rod (370) rotatably connected to the fuselage are provided in the rotor installation space, and the left rotation rod (360) and the right rotation rod (370) are coaxially arranged; A top power rotor (310) is provided above the left rotation rod (360) / right rotation rod (370), and a bottom power rotor (320) is provided below the left rotation rod (360) / right rotation rod (370); The fuselage (100) and the left rotating rod (360) are connected via a left tilt motor (340), and the fuselage (100) and the right rotating rod (370) are connected via a right tilt motor (350).

8. The cross-medium aircraft according to claim 7, characterized in that: A trim rotor (330) is provided in the tail installation space.

9. The cross-medium aircraft according to claim 8, characterized in that: The top power rotor (310) and the bottom power rotor (320) are coaxially arranged and rotate in opposite directions.

10. A cross-medium aircraft according to claim 8 or 9, characterized in that: An aileron (220) is provided on the outer side of the fixed wing (210); A box wing (230) is provided on the outer side of the aileron (220), and the other end of the box wing (230) is connected to the tail of the fuselage (100).

Images