Water-air cross-medium folding-wing UAV

Abstract

The present invention relates to an amphibious folding-wing unmanned aerial vehicle, belonging to the technical field of aircraft. The unmanned aerial vehicle includes a head section, a middle fuselage section, and a tail; the overall fuselage adopts a hollow truss structure; the present invention discloses a streamline shape structure design based on gannets and fish, adopts a bionic structure and a canard layout design, combines the elliptical wing shape with better load utilization rate and the rectangular wing shape with greater stall resistance, and performs an approximate elliptical treatment on the parts with smaller load-bearing at both wing tips respectively, effectively solving the contradiction between the design goals of the aerodynamic force mutation and the center of gravity position change during the variant of the amphibious unmanned aerial vehicle, which leads to the control instability and the control stability, and further improving the stability of amphibious activities.

Description

Technical Field

[0001] The present invention relates to a water-air cross-medium folding-wing unmanned aerial vehicle, belonging to the technical field of aircraft. Background Art

[0002] A water-air cross-medium folding-wing unmanned aerial vehicle is an unmanned aerial vehicle that can be controlled to autonomously achieve water-air transition and air-water transition. When encountering dangerous situations, it can quickly enter the water and is more concealed and safe. During maritime operations, when a warhead is equipped at the head of the unmanned aerial vehicle, it can combine the characteristics of a cruise missile with strong maneuverability and high speed and a torpedo with good concealment.

[0003] At present, the characteristics of the design of related unmanned aerial vehicles are bionic, and most of them adopt a flapping-wing design for the wings, which is not flexible enough. Moreover, the structural strength of its wings is low and cannot adapt to frequent unexpected situations; in terms of structure, since water will generate buoyancy on the navigation object when sailing underwater, the navigation object has to adopt the method of increasing its own weight to overcome the buoyancy and sink smoothly, resulting in an additional useless load, or reducing its own volume to reduce the buoyancy, but this causes the unmanned aerial vehicle to be unable to carry more effective payloads and lose its application value; in terms of power configuration, many designs still adopt a single power, such as only a single motor providing thrust or pulling force, resulting in too slow underwater movement speed. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that the existing technology cannot meet the use requirements, and provide a water-air cross-medium folding-wing unmanned aerial vehicle; the unmanned aerial vehicle is hollow, the wings are folded backward to quickly enter the water; a dual-power system; a carrying device;

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A water-air cross-medium folding-wing unmanned aerial vehicle includes: a head section, a middle fuselage section, and a tail; the overall fuselage adopts a hollow truss structure;

[0007] The head section includes: a foldable propeller, a motor, an electronic speed controller, a first servo, a canard, a power supply device, and an electronic control device placed in a waterproof box; the electronic speed controller converts the direct current of the power supply device into alternating current for driving the motor; the motor drives the foldable propeller to provide pulling force and provide flight power in the air; the first servo is used to control the deflection of the canard, and thus achieve the purpose of attitude control; the electronic control device is used for the overall control of the machine;

[0008] The middle fuselage section includes: wings and a deformation mechanism between the two wings; the deformation mechanism is located between the head section and the tail section and is used to control the unfolding and folding of the wings;

[0009] The deformation mechanism includes: a deformation mechanism base, a central block, wing support rods, and a second servo motor; the deformation mechanism base is fixed to the fuselage; the wing support rods are respectively movably connected to the wings and the central block; the second servo motor is used to provide power for the deformation of the deformation section.

[0010] The deformation mechanism base includes: a rotating shaft connecting rod, a large rotating rod limiting mechanism, and a deformation driving rod; the rotating shaft connecting rod has a thick structure at both ends and a thin middle section for connecting the central block; the large rotating rod limiting mechanism is a fan-shaped structure for limiting the large rotating rod, thereby realizing the folding of the wings; the deformation driving rod is composed of a large rotating rod and a combined universal joint; the universal joints are symmetrically arranged on both sides of the large rotating rod; the large rotating rod slides along the large rotating rod limiting mechanism; the universal joints are used to connect the wing support rods.

[0011] The central block is a circular structure.

[0012] The wings are of a double-layer structure, with a foam board on the upper layer and a 3D printed part (photosensitive resin) on the lower layer.

[0013] The tail of the aircraft is of a hollow structure, and the third servo motor is used to control the deflection of the tail fin; the pump jet is placed near the middle section of the fuselage at the tail for providing underwater power.

[0014] The working process of an amphibious folding-wing UAV:

[0015] Step 1: During the level flight stage of the UAV, cruise at a constant speed and constant angle of attack.

[0016] Step 2: When the UAV makes an "air-water" transition, the fuselage dives at a negative angle of attack, and at the same time the wings fold. The folding process is as follows:

[0017] Viewed from the outside, when the UAV enters the water in the air, the main wing rotates counterclockwise around the Y-axis until the wing chord is perpendicular to the X-axis, and then rotates counterclockwise around the Z-axis until the wing is close to the fuselage, completing the "air-water" whole-aircraft attitude conversion. Viewed from the inside, the servo motor drives the central block to rotate through the ball head buckle pull rod, and the central block then drives the deformation driving rod to rotate. Under the movement restriction of the chute on the central block and the large rotating rod, the deformation driving rod pulls the wing support rod towards the central block. While the first wing support rod closes towards the central block, it will pull the second wing support rod, driving the wing to move downward, realizing the wing contraction. The unfolding process of the wing is the reverse process of the contraction process. At the same time, the tail rudder and canard control the attitude stability of the whole aircraft. When the pitch angular velocity of the fuselage is greater than 5 m / s during the attitude conversion of the UAV, the tail rudder deflects to generate aerodynamic moment, reducing the pitch angular velocity and maintaining the attitude stability of the whole aircraft; the angle of attack of the canard increases, improving the response speed of attitude control. During the water entry process, water enters through the water entry hole, and the water flows into the fuselage, accelerating the sinking of the fuselage. At the same time, the underwater power pump jet starts to work.

[0018] Step 3: When the UAV is submerged underwater, the pump jet provides power, the wings remain in a folded state, and the attitude of the UAV is stabilized by the combined action of the tail wing and the canard wing.

[0019] Step 4: When the UAV undergoes the "water-air" transition, externally, the wings rotate clockwise around the y-axis until the wing chord is parallel to the X-axis, and then the wings rotate around the X-axis until they are fully extended. The internal mechanism movement process is the reverse of the above "air-water" process. During the transition, the tail rudder deflects in the negative direction to generate a nose-up moment, and the canard wing is deflected to prevent the airframe from rolling. The throttle value of the underwater power pump jet is increased to the maximum, enabling the UAV to emerge from the water in a high angle-of-attack attitude.

[0020] Beneficial effects:

[0021] (1) The streamline shape structure design based on gannets and fish disclosed in the present invention adopts a bionic structure and a canard layout design, and combines the elliptical wing shape with better load utilization and the rectangular wing shape with greater stall resistance. The parts with smaller load-bearing at both wing tips are ellipticized. Aerodynamically, it effectively solves the contradiction between the sudden change of aerodynamic force and the change of the center of gravity position during the variant of the trans-medium UAV, resulting in the contradiction between the design objectives of handling instability and control stability, and thus improves the stability of amphibious activities.

[0022] (2) The design of the aircraft deformation mechanism with servo-linkage in the present invention ensures the flight stability through a strong-linkage mechanism, and has the advantages of easy assembly, compact structure, high transmission and deformation efficiency.

[0023] (3) The design of the airframe water inlet and sinking structure in the present invention makes the fuselage, wings and tail wings into hollow and interconnected shells, and designs water inlets and outlets. In the submerged state, water flows into the fuselage from the water inlet, is accelerated by the pump jet and then ejected from the water outlet at the tail of the aircraft. When taking off from the water, the UAV takes off at a large elevation angle, discharges the water in the fuselage from the water outlet, and a drain pipe is designed for diversion, meeting the requirements of the aircraft weight in both media and effectively reducing the volume of the UAV.

[0024] (4) The traditional single power system has the problem of too slow underwater movement speed. The "air-underwater dual power system" disclosed in the present invention uses a foldable propeller with blades in combination with an electric motor and a pump jet as the power system of the whole machine. In the air, the high-speed foldable propeller and the electric motor provide power, and in the water, the UAV is propelled by two pump jets. Compared with the scheme of a single electric motor providing thrust or pulling force, the underwater movement speed is effectively improved. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the external structure of the nose section of the water-air trans-medium folding-wing UAV of the present invention;

[0026] Figure 2 Schematic diagram of the internal structure of the nose section of the water-air cross-medium folding-wing UAV of the present invention;

[0027] Figure 3 Schematic diagram of the internal structure of the deformation mechanism of the water-air cross-medium folding-wing UAV of the present invention;

[0028] Figure 4 Schematic diagram of the external structure of the deformation mechanism of the water-air cross-medium folding-wing UAV of the present invention;

[0029] Figure 5 Schematic diagram of the tail section structure of the water-air cross-medium folding-wing UAV of the present invention;

[0030] Figure 6 Schematic diagram of the air and underwater power of the water-air cross-medium folding-wing UAV of the present invention;

[0031] Figure 7 Schematic diagram of the wing of the water-air cross-medium folding-wing UAV of the present invention;

[0032] Figure 8 Schematic diagram of the wing folding of the water-air cross-medium folding-wing UAV of the present invention;

[0033] Figure 9 Schematic diagram of the wing deployment of the water-air cross-medium folding-wing UAV of the present invention;

[0034] Figure 10 Schematic diagram of the operation of the water-air cross-medium folding-wing UAV of the present invention;

[0035] Figure 11 Supplementary schematic diagram of the tail section structure of the water-air cross-medium folding-wing UAV of the present invention;

[0036] Wherein, 1 - foldable rotor, 2 - canard, 3 - nose section fairing shell, 4 - fairing, 5 - motor, 6 - air electronic speed controller, 7 - first servo, 8 - electronic control equipment (flight control board), 9 - battery, 10 - electronic control equipment (receiver), 11 - waterproof box, 12 - deformation drive rod, 13 - combined universal joint, 14 - deformation mechanism base, 15 - center block support seat, 16 - second servo, 17 - center block support seat, 18 - wing (main wing), 19 - 4mm carbon tube, 20 - servo pull rod, 21 - center block connecting rod, 22 - center block, 23 - T-shaped rod (deformation drive rod), 24 - wing support rod, 24a - second wing support rod, 24b - first wing support rod, 25 - third servo, 26 - pump jet, 26a - water inlet, 27 - vertical tail, 28 - tail section fairing shell, 29 - pump jet fixing part, 30 - horizontal tail, 31 - air power device (motor), 32 - water power device (double pump jet), 33 - wing servo, 34 - aileron, 35 - main wing, 36 - center block connecting piece, 37 - large rotating rod. Detailed implementation mode

[0037] In order to better illustrate the purpose and advantages of the present invention, the following further describes the content of the invention with reference to the accompanying drawings and examples.

[0038] Embodiment 1:

[0039] As Figure 8 、 Figure 9 shown, this embodiment discloses the folding and unfolding postures of the water-air cross-medium folding-wing UAV, including Figure 1 Figure 2 the nose section structure, Figure 3 Figure 4 the deformation section structure, Figure 5 the tail section structure and Figure 7 the wing structure..

[0040] As Figure 1 shown, the main shaft of the canard 2 forms a coaxial fit with the small holes on the side plate of the nose mask frame 3 and is fixed to the fixing part of the mask frame 3 inside, and is driven by the servo 7. The fairing 4 is fitted through the mortise and tenon structure formed with the mask frame and fixed with glue.

[0041] As Figure 2 shown, the foldable rotor 5 is fixed to the motor 31 by screws, and the motor 31 is fitted with the circular hole structure formed by the mask frame 3 and fixed with glue; the electronic speed controller 6 is in external fit with the connecting part fixed by the mask frame 3 and completely fixed with glue, where the left electronic speed controller is installed from top to bottom, and the right electronic speed controller is inserted from right to left and then fixed with glue. The servo 7 also forms a shape fit with the mask frame 3 and is inserted from right to left and fixed with glue as Figure 2 shown. The electronic control devices 8, 9, and 10 are placed through the opening of the waterproof box 11 and fixed by the fitting structure inside the waterproof box 11. The lid of the waterproof box 11 is sealed with waterproof glue after being covered, and the plug-in electrical connection parts around it are sealed with waterproof glue after connecting the circuit. The waterproof box 11 is placed into the inside of the mask frame 3 from right to left, where the left side is closely attached to the carbon plate and fixed with glue, and the fitting structure at the bottom with the frame 3 is fixed with glue.

[0042] As Figure 3 Figure 4As shown, the central block support base 15 forms a fit with the 4mm carbon tube 19, the nose section panel framework 3, and the tail section panel framework 28, and is fixed with glue. The deformation mechanism base 14 forms a fit with the central block support base 15 through a mortise and tenon structure formed at the bottom, and is fixed with glue. The servo 16 is fixed to the central block support base 15 through a bolt structure. The servo 16 drives the central block 22 to rotate through the ball head buckle pull rod 21. Among them, the servo pull rod 20 and the ball head buckle pull rod 21 form a coaxial fit at the end holes, and the ball head buckle pull rod 21 and the central block 22 form a coaxial fit through a hole structure. The central block 22 then drives the deformation drive rod 12 to rotate. Among them, the central block connecting piece 36 forms a fit with the central blocks 22 on both sides through a jack structure, and is fixed with glue. The middle groove of the combined universal joint 13 is fixed to the large rotating rod 37 with glue, and the large rotating rod 37 forms a coaxial fit with the center of the fan-shaped structure on the left side of the deformation mechanism base 14. Under the movement restrictions of the chute on the central block 22 and the deformation mechanism base 14, the deformation drive rod 12 pulls the wing support rod 24 towards the central block. While the first wing support rod 24b closes towards the central block, it will pull the second wing support rod 24a, driving the wing 18 to move downward, realizing the contraction of the wing 18. Among them, the wing support rods 24 form coaxial fits with each other, and with the protrusion fitting structures on the central block 22 and the wing 18 respectively, and are fixed with stainless steel optical axes.

[0043] As Figure 5 shown, the servo 25 forms a fit with the connecting piece of the tail panel framework 28. One servo 25 on the left that controls the rudder surface of the vertical tail 27 is inserted upward from the bottom and fixed with glue. The two servos 25 on the right that control the rudder surfaces of the horizontal tails 30 are placed symmetrically bottom to bottom, inserted into the connecting piece from right to left, and fixed with glue. The pump jet 26 is fixed to the tail panel framework 28 with screws by the pump jet fixing piece 29. The vertical tail 27 and the horizontal tails 30 form a fit through the special openings of the panel framework 28 and the slots on themselves for the framework, and are fixed with glue. The following are the folding and unfolding steps of the water-air cross-medium folding-wing unmanned aerial vehicle.

[0044] Step 1: During the level flight stage of the unmanned aerial vehicle, cruise at a constant speed and constant angle of attack;

[0045] Step 2: When the unmanned aerial vehicle makes a "air-water" transition, the fuselage dives at a negative angle of attack, and at the same time the wing 18 folds; the folding process is as follows:

[0046] As Figure 8As shown, when viewed from the outside, when the drone enters the water in the air, after the main wing 18 rotates counterclockwise around the Y axis until the wing chord line is perpendicular to the X axis, it then rotates counterclockwise around the Z axis until the wing is close to the fuselage, completing the "air-water" whole-machine attitude conversion. When viewed from the inside, the servo 16 drives the center block 22 to rotate through the ball head buckle pull rod 21, and the center block 22 then drives the deformation drive rod 12 to rotate; under the movement restrictions of the chute and the large rotating rod 37 on the center block 22, the deformation drive rod 12 pulls the wing 18 support rod 24 towards the center block; while the first wing support rod 24b closes towards the center block, it will pull the second wing support rod 24a, driving the wing to move downward, realizing the contraction of the wing 18; the unfolding process of the wing 18 is the reverse process of the contraction process; at the same time, the tail rudder 30 and the canard 2 control the attitude stability of the whole machine. When the pitch angular velocity of the fuselage is greater than 5 m / s during the attitude conversion of the drone, the tail rudder 30 deflects to generate an aerodynamic moment, reducing the pitch angular velocity and maintaining the stable attitude of the whole machine; the angle of attack of the canard 2 increases, improving the response speed of attitude control; during the water entry process, water enters through the water inlet hole, and the water flows into the fuselage, accelerating the sinking of the fuselage. At the same time, the underwater pump jet 26 starts to work.

[0047] Step three: As Figure 6 shown, when the drone is submerged underwater, the pump jet 26 provides power, the wing 18 remains in the folded state, and the tail fin 30 and the canard 2 work together to control the stability of the drone's attitude.

[0048] Step four: As Figure 9 shown, when the drone makes the "water-air" transition, when viewed from the outside, the wing 18 rotates clockwise around the y axis until the wing chord line is parallel to the X axis, and then the wing rotates around the X axis until the wing is unfolded. The internal mechanism movement process is the reverse process of the above "air-water"; during the transition, the tail rudder 30 deflects in the negative direction to generate a nose-up moment, and the canard 2 is deflected to prevent the fuselage from rolling. The throttle value of the underwater pump jet 26 is increased to the maximum, enabling the drone to emerge from the water with a large angle of attack attitude.

[0049] In summary, the overall deformation process is as Figure 10 shown

[0050] Embodiment 2:

[0051] As Figure 6 shown, the water inlet of the double pump jet 32 forms a position fit with the water inlet 26a on the tail fairing skeleton 28, and the water outlet of the double pump jet 32 forms a coaxial fit with the round holes on the carbon plates in the upper right and lower right of the tail fairing skeleton 28.

[0052] In the submerged state, the water flow is from the water inlet 26a, as Figure 11As shown in the figure, it flows into the fuselage, is accelerated by the pump jet 30 and then ejected from the water outlet at the tail of the aircraft. When taking off while discharging water, the UAV takes off with a large elevation angle, discharges the water in the fuselage from the water outlet, and a drain pipe is designed for diversion, meeting the requirements of the two media for the aircraft weight and effectively reducing the volume of the UAV. Compared with other cross-media UAVs, the present invention ensures the loading capacity while meeting the volume constraint.

[0053] Embodiment 3:

[0054] As Figure 6 shown in the figure, the "air - underwater dual - power system" adopts the foldable propeller blades 5 in combination with the motor 31 and the pump jet 26 as the power system of the whole machine. When in the air, the high - speed foldable propeller 5 and the motor 31 provide power; when the UAV enters the water, the motor 31 stops rotating, and the power is switched to the pump jet 26, and when underwater, it is propelled by the double pump jets 32.

[0055] The above - mentioned specific description further details the purpose, technical solution and beneficial effects of the invention. It should be understood that the above - mentioned is only the specific embodiment of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A water-air cross-medium folding-wing unmanned aerial vehicle, characterized in that: Comprising: A head section, a middle fuselage section, and a tail; The head section includes: a foldable propeller, a motor, an electronic speed controller (ESC), a first servo, a canard, a power supply device, and an electronic control device placed in a waterproof box; the ESC converts the direct current of the power supply device into alternating current to drive the motor; the motor drives the foldable propeller to provide thrust for flight in the air; the first servo is used to control the deflection of the canard to achieve attitude control; the electronic control device is used for overall control of the aircraft; The middle fuselage section includes: wings and a deformation mechanism between the two wings; the deformation mechanism is located between the head section and the tail section and is used to control the deployment and folding of the wings; The tail is a hollow structure, and a third servo is used to control the deflection of the tail fin; a pump jet is placed near the middle fuselage section of the tail to provide underwater power; The deformation mechanism includes: a deformation mechanism base, a center block, first and second wing support rods, a ball head buckle pull rod, and a second servo; the deformation mechanism base is fixed to the fuselage; the wing support rods are respectively movably connected to the wing and the center block; the second servo is used to provide power for the deformation of the deformation section; The deformation mechanism base includes: a rotating shaft connecting rod, a large rotating rod limiting mechanism, and a deformation driving rod; the rotating shaft connecting rod has a thick structure at both ends and a thin middle section for connecting the center block; the large rotating rod limiting mechanism is a fan-shaped structure for limiting the large rotating rod to achieve wing folding; the deformation driving rod is composed of a large rotating rod and a combined universal joint; the universal joints are symmetrically arranged on both sides of the large rotating rod; the large rotating rod slides along the large rotating rod limiting mechanism; the universal joint is used to connect the first and second wing support rods; The center block is a circular structure; The deformation mechanism includes: the wing is a double-layer structure, with a foam board on the upper layer and a photosensitive resin 3D printed part on the lower layer.

2. The water-air cross-medium folding-wing UAV according to claim 1, wherein: The overall fuselage adopts a hollow truss structure.

3. The water-air cross-medium folding-wing UAV according to claim 1, wherein: An inlet is provided on the tail.

4. The water-air cross-medium folding-wing UAV according to any one of claims 1 to 3, characterized in that: Working process: Step 1: During the level flight stage of the UAV, cruise at a constant speed and constant angle of attack; Step 2: When the UAV is making an "air-water" transition, the fuselage dives at a negative angle of attack, and at the same time the wings fold; the folding process is as follows: Viewed from the outside, when the UAV enters the water in the air, the main wing rotates counterclockwise around the Y-axis until the wing chord is perpendicular to the X-axis, and then rotates counterclockwise around the Z-axis until the wing is close to the fuselage, completing the "air-water" overall attitude conversion. Viewed from the inside, the servo drives the center block to rotate through the ball head buckle pull rod, and the center block then drives the deformation driving rod to rotate; under the movement restriction of the chute on the center block and the large rotating rod, the deformation driving rod pulls the wing support rod towards the center block; while the first wing support rod closes towards the center block, it will pull the second wing support rod, driving the wing to move downward to achieve wing contraction; the wing deployment process is the reverse of the contraction process; at the same time, the tail rudder and canard control the attitude stability of the whole aircraft. When the pitch angular velocity of the fuselage is greater than 5 m / s during the attitude conversion of the UAV, the tail rudder deflects to generate an aerodynamic moment to reduce the pitch angular velocity and maintain the attitude stability of the whole aircraft; the angle of attack of the canard increases to improve the response speed of attitude control; during the water entry process, water enters through the water inlet, and the water flows into the fuselage to accelerate the sinking of the fuselage. At the same time, the underwater power pump jet starts to work; Step 3: When the UAV is underwater and diving, the pump jet provides power, the wings remain in a folded state, and the tail wing and canard wing work together to control the stability of the UAV's attitude; Step 4: When the UAV makes a "water-air" transition, externally, the wings rotate clockwise around the y-axis until the wing chord is parallel to the X-axis, and then the wings rotate around the X-axis until they are fully extended. The internal mechanism's movement process is the reverse of the above "air-water" process; simultaneously during the transition, the tail rudder deflects in the negative direction to generate a nose-up moment, and the canard wing is deflected to prevent the airframe from rolling. The throttle value of the underwater power pump jet is increased to the maximum, enabling the UAV to emerge from the water in a high angle-of-attack attitude.

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