High-altitude solar parawing unmanned aerial vehicle

Abstract

A high-altitude solar parafoil unmanned aerial vehicle comprises a parafoil, a hanging rope and a pod. The parachute wing serves as a lifting surface of the unmanned aerial vehicle and adopts a high aspect ratio aerodynamic layout, a circle of rope surrounds the periphery of the parachute wing and is used for stabilizing the appearance structure, the chordwise camber appearance of the parachute wing is kept through three carbon fiber strip-shaped wing ribs penetrating front and back, two control carbon strips are installed on the rear edge of the parachute wing, and the control capacity is provided on the basis of keeping the spanwise appearance; the two carbon fiber strip-shaped wing ribs on the two sides are respectively connected to the midpoint positions of the two control carbon strips; a solar cell array is laid on the surface of the parasol wing, provides flight power and charges a battery in the pod; the parasol wing is connected with the pod through a plurality of hanging ropes, and two of the hanging ropes are connected to the spanwise center positions of the control carbon strips respectively; an energy storage battery, a task load and a flight control unit are installed in the pod, propellers are installed outside the pod, and the flight control unit controls the propellers to work. The weight of the aircraft is greatly reduced, the flight height is increased, and the long-endurance performance is improved.

Description

Technical Field

[0001] The present invention relates to a high-altitude solar parasol-wing unmanned aerial vehicle, belonging to the technical field of unmanned aerial vehicle design. Background Art

[0002] A solar unmanned aerial vehicle is an electric aircraft powered by solar radiation, which is a product of the combination of aviation science and technology and new energy technology. The solar unmanned aerial vehicle has a long cruising time, a high flight altitude, a wide coverage area, a low use cost, and no pollution to the environment. It can perform various tasks such as communication relay, electronic reconnaissance, and mobile networking. It is an important supplement to flight platforms such as orbital satellites, conventional-powered unmanned aerial vehicles, and high-altitude airships, and has received extensive attention at home and abroad.

[0003] Most of the existing solar unmanned aerial vehicles at home and abroad adopt the conventional layout of "wing + fuselage + tail wing", represented by the "Zephyr" series of QinetiQ Company in the UK and "Solara" of Google Company in the United States. Since the flight power consumption is proportional to the 3 / 2 power of the total weight of the whole aircraft, the structural proportion of the conventional layout solar unmanned aerial vehicle is relatively large, and it is difficult to achieve long-term energy balance during flight above 25,000 m altitude. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: overcoming the deficiencies of the prior art, providing a high-altitude solar parasol-wing unmanned aerial vehicle, simplifying the structural form, reducing the structural weight, reducing the flight power consumption of the unmanned aerial vehicle, increasing the cruising altitude of the unmanned aerial vehicle, and improving the mission payload carrying capacity of the unmanned aerial vehicle.

[0005] The technical solution of the present invention is:

[0006] A high-altitude solar parasol-wing unmanned aerial vehicle, comprising: a parasol wing, suspension ropes, and a nacelle;

[0007] The parasol wing is used as the lift surface of the unmanned aerial vehicle and adopts a large aspect ratio aerodynamic layout. A circle of ropes is wound around the periphery of the parasol wing to stabilize the outer shape structure. The chordwise camber shape of the parasol wing is maintained by three carbon fiber strip wing ribs running through from front to back. Two control carbon strips are installed at the trailing edge of the parasol wing to provide control ability while maintaining the spanwise shape; and the two carbon fiber strip wing ribs on both sides are respectively connected to the midpoint positions of the two control carbon strips; a solar cell array is laid on the surface of the parasol wing to provide flight power and charge the battery in the nacelle;

[0008] The parasol wing is connected to the nacelle by a plurality of suspension ropes, and two of the ropes are respectively connected to the spanwise center positions of the control carbon strips;

[0009] A storage battery, a mission payload, and a flight control unit are installed in the nacelle, and a propeller is installed outside the nacelle. The flight control unit controls the operation of the propeller.

[0010] Furthermore, it also includes a lead screw, which is connected to two ropes that control the carbon strips. By pulling the ropes with the lead screw, the carbon strips on the wing are controlled, thus realizing flight control.

[0011] Furthermore, the wing uses a ribbed skin.

[0012] Furthermore, the control carbon strips are installed along the edge of the wing in a conforming manner and serve as the ailerons of the UAV.

[0013] Furthermore, the suspension ropes are designed with a drag-reducing profile shape according to the oncoming flow direction during actual flight.

[0014] Furthermore, after being stored, the UAV is delivered to the near space by means of rocket boost or high-altitude balloon.

[0015] Furthermore, the wing adopts a high aspect ratio aerodynamic layout. Specifically: the wing area is 31.5 m 2 ; the wingspan is 12 m, the lift coefficient is 1; the drag coefficient is 0.067; the lift-to-drag ratio is 15; the surface density of the ribbed skin is 25 g / m 2 , and the total weight is 0.79 kg.

[0016] Furthermore, the carbon fiber strip wing rib is 3 meters long, 5 mm wide, 5 mm thick, the weight of a single strip is 0.4 kg, and the total weight is 1.2 kg; the trailing edge control carbon strip is 0.4 kg per single strip, and the total weight is 0.8 kg;

[0017] There are 18 suspension ropes in total, the chord length is 1 mm, the rope density is 1.25 kg / km, and the maximum load-bearing is 160 kg; the rope length is 10 m, and Kevlar ropes are wound around the periphery of the main wing to ensure the geometric shape, with a length of 35 m, and the total weight of the ropes is 0.3 kg; the paved area of the solar cell array is 4 m 2 , with a weight of 2 kg, and the weight of the energy storage battery is 12 kg.

[0018] Furthermore, during the cruise flight of the UAV, the lift is equal to the gravity:

[0019]

[0020] where m is the total weight, g is the acceleration due to gravity, ρ is the oncoming flow density, S is the wing area, u is the oncoming flow velocity, and C L is the lift coefficient.

[0021] Furthermore, the energy calculation formula of the UAV:

[0022]

[0023] where m is the total weight, g is the acceleration due to gravity, ρ is the oncoming flow density, S is the wing area, u is the oncoming flow velocity, C L is the lift coefficient, and C Dis the drag coefficient, and η is the efficiency of the propulsion system.

[0024] The beneficial effects of the present invention compared with the prior art are as follows:

[0025] (1) For the high-altitude solar umbrella-wing unmanned aerial vehicle of the present invention, the layout is simple, and components such as wing spars, wing ribs, fuselages, and tail booms of conventional solar unmanned aerial vehicles are omitted, greatly reducing the structural weight.

[0026] (2) The high-altitude solar umbrella-wing unmanned aerial vehicle of the present invention can be stored in a very small space and can be delivered to the near space by means such as rocket boosting and high-altitude balloons.

[0027] (3) For the high-altitude solar umbrella-wing unmanned aerial vehicle of the present invention, due to its light weight, the flight power consumption required is small, the solar cell array required is greatly reduced compared with traditional solar unmanned aerial vehicles, and the energy storage battery required is also greatly reduced. Therefore, the cost is low and the weight is light.

[0028] (4) The high-altitude solar umbrella-wing unmanned aerial vehicle of the present invention omits complex control control surfaces. By pulling the suspension ropes with a lead screw, the control carbon bars on the umbrella wing are controlled, thereby realizing flight control. Description of the Drawings

[0029] Figure 1 is a schematic diagram of the overall architecture of the unmanned aerial vehicle of the present invention;

[0030] Figure 2 is a schematic diagram of the pod part of the present invention;

[0031] Figure 3 is a schematic diagram of the wing umbrella part of the present invention;

[0032] Figure 4 is a schematic diagram of the propulsion system of the present invention. Detailed Description of the Invention

[0033] The following further describes the specific embodiments of the present invention in detail with reference to the drawings.

[0034] As Figure 1 and Figure 2 shown, the high-altitude solar umbrella-wing unmanned aerial vehicle proposed by the present invention includes an umbrella wing 1, suspension ropes 2, and a pod 3, omitting structural components such as the fuselage, tail wing, and main beam of traditional unmanned aerial vehicles, greatly reducing the weight of the aircraft and improving the flight altitude and long-endurance performance of the aircraft.

[0035] Parafoil 1: Parafoil 1 is the main lifting surface of the unmanned aerial vehicle (UAV), adopting a high aspect ratio aerodynamic layout. Parafoil 1 uses a high-performance tear-resistant ribbed skin. A rope is wound around the periphery of the parafoil to stabilize the outer shape structure. The chordwise camber shape of the parafoil is maintained by three carbon fiber strip wing ribs 4 running through from front to back. Two control carbon strips 5 are installed at the trailing edge of the parafoil to provide control capabilities while maintaining the spanwise shape. And the two carbon fiber strip wing ribs 4 on both sides are respectively connected to the midpoint positions of the two control carbon strips 5, as Figure 3 shown. A solar cell array is laid on the surface of the parafoil to provide flight power and charge the battery when there is sunlight.

[0036] Suspension ropes 2: Parafoil 1 is connected to the pod 3 through multiple suspension ropes 2. Two of the ropes are respectively connected to the spanwise center positions of the control carbon strips 5. The suspension ropes 2 are designed with a drag-reducing profile shape according to the oncoming flow direction of the actual flight.

[0037] Pod 3: An energy storage battery, a mission payload, and a flight control unit are installed in the pod 3. A propeller 6 is installed outside the pod 3. The flight control unit controls the operation of the propeller 6, as Figure 4 shown.

[0038] The control carbon strip serves as the aileron of the UAV, forming the control surface of the UAV. The present invention also includes a lead screw 7, which is connected to the two ropes connecting the control carbon strip 5, and the ropes are pulled by the lead screw 7.

[0039] The high-altitude solar parafoil UAV of the present invention eliminates components such as wing spars, wing ribs, fuselages, and tail booms of conventional solar UAVs, greatly reducing the structural weight and making the proportion of the structural weight in the total weight of the entire UAV drop below 15%. The UAV can be stored in a very small space and can be quickly deployed to the near space through methods such as rocket boosting. For the high-altitude solar parafoil UAV of the present invention, due to its light weight, it requires less flight power consumption, the required solar cell array is greatly reduced compared to traditional solar UAVs, and the required energy storage battery is also greatly reduced, so the cost is low. The high-altitude solar parafoil UAV of the present invention eliminates complex control rudder surfaces, pulls the suspension ropes through a lead screw, and then controls the control carbon strips on the parafoil to achieve flight control.

[0040] Embodiment:

[0041] 1. Basic configuration:

[0042] Wing area 31.5 m 2 ; Wingspan 12 m, the top view is as Figure 3 shown. Lift-drag characteristics: Lift coefficient 1; Drag coefficient 0.067; Lift-drag ratio 15.

[0043] 2. Weight assessment:

[0044] (1) Structural system

[0045] The surface density of the ribbed skin is 25 g / m 2 , 31.5 m 2 of the paving area, with a total weight of 0.79 kg.

[0046] There are 3 carbon fiber ribs, each about 3 meters long, 5 mm wide, and 5 mm thick. The weight of a single rib is 0.4 kg, and the total weight is 1.2 kg.

[0047] There are 2 carbon fiber trailing edge control surfaces, each weighing 0.4 kg, with a total weight of 0.8 kg.

[0048] The gondola is suspended by 18 ropes with a chord length of 1 mm. The density of the pulling ropes is 1.25 kg / km, and the maximum load capacity is 160 kg. The length of each rope is about 10 m. Kevlar ropes surround the outer perimeter of the main wing to ensure the geometric shape, with a length of about 35 m. The total weight of the ropes is 0.3 kg.

[0049] (2) Energy system

[0050] The paving area of the solar panels is 4 m 2 , with a weight of 2 kg. The solar panel controller and wires weigh about 1.4 kg, and the total weight is 3.4 kg. The weight of the energy storage battery is 12 kg.

[0051] (3) Gondola weight

[0052] The propulsion system weighs 1 kg. The propulsion system uses a single motor to control the propeller 6 for propulsion. According to the current technical level, the efficiency is calculated as 0.8. The propulsion system is installed below the gondola as shown Figure 4 below. The control system includes a flight control computer (0.2 kg) and two control lead screw mechanisms, each weighing 0.5 kg. The mission payload is 6 kg, and the total weight is 1.2 kg.

[0053] In summary, the total weight of the aircraft is 26.7 kg.

[0054] 3. Energy assessment:

[0055] The battery weighs 12 kg, the battery energy density is 450 wh / kg, and the total battery capacity is 5.4 kwh.

[0056] During the cruise flight of the UAV, the lift is equal to the gravity, so the following relationship is satisfied:

[0057]

[0058] where m is the total weight, g is the acceleration due to gravity, ρ is the oncoming flow density, S is the wing area, u is the oncoming flow velocity, and C L is the lift coefficient.

[0059] Energy calculation formula:

[0060]

[0061] Among them, m is the total weight, g is the acceleration due to gravity, ρ is the oncoming flow density, S is the wing area, u is the oncoming flow velocity, C L is the lift coefficient, C D is the drag coefficient, and η is the efficiency of the propulsion system.

[0062] At an altitude of 25,000 m, the power consumption during level flight at night is 447 W, and the flight speed is 20.5 m / s. The power consumption in 12 hours at night is 5.36 kWh.

[0063] At an altitude of 0 m, the power consumption during level flight at night is 80.64 W, and the flight speed is 3.18 m / s.

[0064] 4. Flight control system:

[0065] As shown in Figure 1 and Figure 2 , by connecting a lead screw to a rope, adjusting the length of the lead screw 7 changes the bearing condition of the carbon fiber strip 5 at the trailing edge of the main wing, changes the shape of the main wing, and realizes the pitch and yaw adjustment of the aircraft.

[0066] The solar-powered unmanned aerial vehicle proposed by the present invention can replace the solar-powered unmanned aerial vehicle with a traditional layout and can be used as a high-altitude long-endurance flight platform in the near space to perform related tasks.

[0067] The parts not detailed in the present invention belong to the common general knowledge of those skilled in the art.

Claims

1. A high-altitude solar paraglider drone, characterized in that include: A parachute wing (1), a hanging rope (2) and a pod (3); The parachute wing, as the lifting surface of the unmanned aerial vehicle, adopts a large aspect ratio aerodynamic layout. A circle of ropes is wrapped around the outer periphery of the parachute wing (1) to stabilize the external structure. The chord-wise curvature of the parachute wing is maintained by three carbon fiber strip wing ribs (4) running through the front and rear. Two control carbon strips (5) are installed on the trailing edge of the parachute wing (1) to provide control capability on the basis of maintaining the span-wise external shape. The two carbon fiber strip wing ribs (4) on both sides are respectively connected to the midpoints of the two control carbon strips (5). A solar cell array is laid on the surface of the parachute wing (1) to provide flight power and charge the battery in the pod (3). The parachute wing (1) is connected to the pod (3) via a plurality of hanging ropes (2), two of which are respectively connected to the spanwise center position of the control carbon strip (5); An energy storage battery, a mission payload and a flight control unit are installed in the pod (3), a propeller (6) is installed outside the pod (3), and the flight control unit controls the operation of the propeller.

2. A high altitude solar powered paraglider drone according to claim 1, characterized in that: It also includes a lead screw (7) connected to two ropes connected to the control carbon strips (5). The lead screw (7) pulls the ropes to control the control carbon strips on the paraglider, thereby achieving flight control.

3. A high altitude solar powered paraglider drone according to claim 1, characterized in that: The parachute wing (1) adopts a ribbed skin.

4. The high-altitude solar paraglider drone according to claim 1, characterized in that: The control carbon strip (5) is installed along the edge of the parachute wing (1) to serve as the aileron of the UAV.

5. The high-altitude solar paraglider drone according to claim 1, characterized in that: The drag reduction cross-section shape of the hanging rope (2) is designed according to the incoming flow direction of the actual flight.

6. The high-altitude solar paraglider drone according to claim 1, characterized in that: After being stored, the drone is launched into near space by rocket boost or high-altitude balloon.

7. The high-altitude solar paraglider drone according to claim 1, characterized in that: The wing adopts a large aspect ratio aerodynamic layout, specifically: wing area 31.5m 2 ; Wingspan 12m, lift coefficient 1; drag coefficient 0.067; lift-to-drag ratio 15; ribbed skin surface density 25g / m 2 , total weight: 0.79kg.

8. The high-altitude solar paraglider drone according to claim 1, characterized in that: The carbon fiber strip rib is 3 meters long, 5mm wide, 5mm thick, weighs 0.4kg per strip, and weighs 1.2kg in total. The trailing edge control carbon strip weighs 0.4kg per strip, and weighs 0.8kg in total. There are 18 hanging ropes in total, with a chord length of 1mm, a rope density of 1.25kg / km, and a maximum load of 160kg; the rope length is 10m, and the Kevlar rope around the main wing ensures the geometric shape, with a length of 35m and a total rope weight of 0.3kg; the solar cell array paving area is 4m 2 , weight is 2kg, and the energy storage battery weighs 12kg.

9. The high-altitude solar paraglider drone according to claim 1, characterized in that: The lift force is equal to the gravity force during the cruising flight of the drone: Where m is the total weight, g is the acceleration of gravity, ρ is the flow density, S is the wing area, u is the flow velocity, C L is the lift coefficient.

10. A high altitude solar powered paraglider drone according to claim 9, characterized in that: Drone energy calculation formula: Where m is the total weight, g is the acceleration of gravity, ρ is the flow density, S is the wing area, u is the flow velocity, C L is the lift coefficient, C D is the drag coefficient and η is the propulsion system efficiency.

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