Small solar unmanned aerial vehicle with solar cell panel and lithium battery pack as power sources

Abstract

The invention provides a small solar unmanned aerial vehicle. The small solar unmanned aerial vehicle comprises a fuselage; a wing; the single motor and the propeller are arranged at the front end of the fuselage; a horizontal empennage and a vertical empennage. Solar cell panel sets (101, 102 and 103) are arranged on the upper surfaces of the upper reverse sections of the left side and the right side of the wing and the upper surface of the middle straight section of the wing respectively, and the solar cell panels are cut and packaged in a multi-layer mode, so that the solar cell panels are perfectly fused with the wing section. In order to save the space in the aircraft and reasonably balance the weight, the lithium battery pack (104) is arranged in the wing rib (105) of the straight section of the wing. The solar cell panel sets are connected in series and provided with an independent maximum power point tracking (MPPT) system, namely an MPPT solar controller (304), so that the output voltage of the solar cell panel sets is adjusted, power is directly supplied to an electronic speed regulator (307) and a motor (308), and it is guaranteed that the aircraft can still glide and land through energy provided by a solar cell array even if the battery power is exhausted. And the reliability and the safety of the aircraft energy management system are greatly improved.

Description

Technical Field

[0001] The invention relates to a low-altitude small solar-powered UAV which takes a solar cell panel and a lithium battery pack as power sources, and belongs to the field of aviation aircraft design. Background Art

[0002] Low-altitude solar aircraft have many advantages, such as providing a communication platform for remote mountainous areas; taking high-resolution pictures close to the ground, and being able to detect forest fires, search and rescue, etc., and have a wide range of applications. Generally, small low-altitude drones that rely on their own fuel as a power source have problems such as short range, short air time, and greatly limited air altitude. In addition, in some cases, small drones are required to perform high-altitude or long-distance missions. Due to the small take-off weight of the drone itself, it cannot carry enough fuel and will not meet the requirements of the flight mission.

[0003] Take border reconnaissance as an example. my country has a vast territory and a complex environment. Using existing reconnaissance aircraft will be affected by the range, flight time and local environment, and it is impossible to achieve 24-hour uninterrupted monitoring. If unmanned reconnaissance aircraft are used to take off multiple times, it will place a great burden on ground maintenance personnel.

[0004] Military aspect: The range and time of long-range early warning, ground reconnaissance and surveillance are limited, and their survivability is low, which seriously restricts the progress of our military's informatization construction.

[0005] Civilian use: Television services, atmospheric environment monitoring and weather forecasting, disaster forecasting and emergency response have limited means and coverage areas.

[0006] Therefore, the present invention designs a small low-altitude solar-powered UAV, which can achieve short-distance flying and gliding landing. Summary of the invention

[0007] For applications such as the border reconnaissance mentioned above, if a solar-powered drone can take off at the border and fly to a designated location, and cooperate with an autopilot system to provide 24-hour full-time monitoring and reconnaissance, it can improve efficiency and greatly reduce the burden on ground personnel. Solar-powered drones are capable of completing such long-term reconnaissance missions.

[0008] Therefore, the purpose of the present invention is to provide a small low-altitude solar-powered UAV.

[0009] According to one aspect of the present invention, there is provided a drone, characterized in that it comprises:

[0010] body,

[0011] An electric motor with a foldable propeller installed at the front of the fuselage is used to provide the aircraft with the power required for flight.

[0012] The wing has a three-section wing design, divided into a mid-section wing and two outer sections.

[0013] The trailing edge of the outer wing is equipped with ailerons.

[0014] The horizontal tail and vertical tail connected to the fuselage.

[0015] The lithium battery pack is arranged in the ribs of the middle wing.

[0016] in:

[0017] The second, first and third solar panel groups are arranged on the upper surfaces of the middle wing and the two outer wings respectively.

[0018] The solar panels in the second, first and third solar panel groups are cut and packaged in multiple layers, and are integrated with the airfoils of the middle wing and the two outer wings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The overall appearance of a small solar-powered drone according to an embodiment of the present invention is shown.

[0020] Figure 2 A diagram showing the solar panel arrangement of a small solar-powered drone according to an embodiment of the present invention is shown.

[0021] Figure 3 A schematic diagram of the lithium battery arrangement of a small solar-powered drone according to an embodiment of the present invention is shown.

[0022] Figure 4 A solar panel assembly packaging diagram of a small solar-powered drone according to an embodiment of the present invention is shown.

[0023] Figure 5 A schematic structural diagram of an energy management system for a small solar-powered UAV according to an embodiment of the present invention is shown.

[0024] Figure 6 A control flow chart of an energy management system for a small solar-powered UAV according to an embodiment of the present invention is shown.

[0025] Figure 7 The figure shows the appearance of a foldable propeller of a small solar-powered drone according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to solve the problems of limited range, hovering time and flight altitude of existing UAVs, and to expand the functions of small UAVs so that they can rely on their own power to complete high-altitude, long-range and long-duration flight missions that were originally impossible to complete, the inventors have designed a small UAV that is powered by solar energy, has a certain mission payload, can complete tasks such as surveying and reconnaissance, and can be applied to various application fields such as meteorological surveying and mapping.

[0027] The power source of solar drones is solar energy, and the capture of solar energy is achieved through solar panels arranged on the aircraft. Due to the different intensities of sunlight under different climate and time conditions, the power that can be supplied by solar panels also changes accordingly. In order to ensure the normal and stable operation of solar drones, it is necessary to perform energy management and status monitoring on the energy system composed of solar panels, motors and lithium batteries. To this end, the present invention designs an energy management system suitable for long-flight drones to ensure the efficient and stable operation of the energy system under different working conditions.

[0028] Existing solar panels are divided into flexible solar panels and non-flexible panels. Among them, flexible solar panels are expensive and cannot be used on a large scale; non-flexible solar panels cannot be bent due to material reasons. In order to make the solar panel fit the curvature of the wing surface, the present invention cuts the solar panel so that it can fit on the wing surface. At the same time, during the packaging process of the solar panel, the present invention adheres a light-transmitting film to its surface, thereby improving the light-gathering ability of the solar panel.

[0029] The overall layout of the solar-powered drone according to the present invention

[0030] The small UAV according to one embodiment of the present invention adopts a conventional aerodynamic layout, such as Figure 1 and Figure 2 As shown, it has an upper wing design, and an electric motor (1) with a foldable propeller (9) is installed at the front end of the fuselage (2) to provide the aircraft with the power required for flying.

[0031] The wing plane is rectangular in shape and has no sweep angle. The three-section wing design is divided into a middle wing (5) and outer wings (7) and (8). The outer wings (7) and (8) have a 5° dihedral angle to increase flight stability. The trailing edge of the outer wing is provided with an aileron (6). The horizontal tail (3) and the vertical tail (4) are connected to the fuselage (2). In a specific embodiment, the fuselage (2) adopts a carbon fiber composite material round tube. The small solar-powered UAV of the present invention does not have a landing gear, and takes off by short-distance throwing, does not require a runway, and lands by gliding.

[0032] Arrangement of solar panels and lithium batteries

[0033] According to one embodiment of the present invention, Figure 2 and Figure 3 As shown, a solar panel group (101, 102, 103) is arranged on the upper surface of the left upper reverse section, the middle straight section, and the right upper reverse section of the wing respectively. The solar panels are cut and multi-layer packaged so as to be perfectly integrated with the airfoil. At the same time, in order to save space inside the aircraft and reasonably balance the weight, the present invention arranges the lithium battery group (104) in the wing rib (105) of the straight section of the wing. The outer side of the wing rib is coated with a skin (106). The solar panel group (102) is attached to the upper surface of the skin (106). At the same time, the leading edge of the wing is covered with a composite material shell (107).

[0034] Solar panel packaging method

[0035] According to one embodiment of the present invention, Figure 4 As shown, a plurality of monocrystalline silicon solar panels are cut and packaged on a solar panel group (102) in a multi-layer packaging manner.

[0036] According to one embodiment of the present invention, the solar panel group uses a soft plastic film as a base film (201); according to a specific embodiment of the packaging method, there is a layer of EVA (ethylene-vinyl acetate copolymer) hot melt adhesive film (202) between the solar panel (203) and the base film (201); the upper surface of the solar panel (203) is also covered with a layer of EVA hot melt adhesive film (204); on the upper surface of the upper layer of EVA hot melt adhesive film (204), a layer of light-transmitting film (205) is packaged, and the light-transmitting film can improve the light-collecting ability of the solar panel group; wherein, the EVA hot melt adhesive film (202, 204) plays a role in bonding the base film (201), the solar panel (203), and the light-transmitting film (205), thereby ensuring the stability of the solar panel packaging structure. In addition, in order to make the solar panel fit the wing curve better and improve the flight efficiency, each solar panel is cut along the span direction.

[0037] According to one embodiment of the present invention, the solar cell panel (203) uses a conventional monocrystalline silicon cell panel and is combined with the wing by cutting a multi-layer packaging method. The lithium battery is embedded in the carbon tube of the wing rib, and an integrated design is performed to increase the wing strength and reduce the occupied space.

[0038] Energy Management System

[0039] The structure diagram of the solar aircraft energy management system according to one embodiment of the present invention is as follows: Figure 5As shown. The first solar panel group (301), the second solar panel group (302), and the third solar panel group (303) are respectively arranged on the upper surface of the left upper reverse section, the middle straight section, and the right upper reverse section of the wing in the circuit; the lithium battery group (306) is the representation of the solar cell group arranged in the middle straight section of the wing in the circuit. The system is composed of solar panel groups (301, 302, 303) through a maximum power point tracking (MPPT) system, that is, an MPPT solar controller (304) to the lithium battery group (306) and an electric motor (308) controlled by an electronic speed regulator (307) (that is, Figure 1 The motor (1) in the power supply is directly powered. When the motor (308) needs a large power, the lithium battery group (306) and the first to third solar panel groups (301, 302, 303) simultaneously power the motor (308). At the same time, an anti-backflow diode (309) is connected in series after the MPPT solar controller (304) to protect the stable operation of the solar panel groups (301, 302, 303).

[0040] The first to third solar panel groups (301, 302, 303) are connected in series in a circuit, and the MPPT solar controller (304) is used to adjust the output voltage of the solar panel group and directly supply power to the electronic speed regulator (307) and the motor (308), thereby ensuring that even when the battery power is exhausted, the solar aircraft can still glide and land through the energy provided by the solar panel group, thereby greatly improving the reliability and safety of the entire solar aircraft energy management system.

[0041] The lithium battery pack (306) is equipped with an overcharge protection system (305) to prevent the battery from being overcharged, thereby protecting the normal operation of the lithium battery pack and extending the battery life.

[0042] The control flow chart of the solar aircraft energy management system according to one embodiment of the present invention is as follows: Figure 6As shown, the energy management system is mainly implemented by an energy management module (310). During operation, the energy management module is in real-time standby mode to monitor and control the operation of the energy system in real time. When the energy system starts to work (3001), it first reads the power data (3002), including the output power of the MPPT solar controller (304) and the power consumption of the motor (308); then enters the judgment process (3003). When the aircraft is taking off and climbing, the output power of the solar panel is generally less than the power consumption of the motor. At this time, it enters the lithium battery discharge mode (3005). The energy management module controls the circuit breakers (311, 312) at the input and output ends of the lithium battery group to discharge the lithium battery group (306). At this time, the lithium battery group (306) and the solar panel group (301, 302, 303) are connected together. The electric motor (308) controlled by the electronic speed controller (307) is powered to provide sufficient power for take-off. When the aircraft is in a level flight state, the output power of the solar panel is generally greater than the power consumed by the motor. At this time, the lithium battery discharge mode (3004) is entered. The energy management module controls the circuit breakers (311, 312) at the input and output ends of the lithium battery group to charge the lithium battery group (306). At this time, the solar panel group (301, 302, 303) receives solar energy to charge the lithium battery group (306) and power the electric motor (308) controlled by the electronic speed controller (307). The aircraft can completely rely on solar power for level flight. After the lithium battery charging mode is changed, the control process ends (3006).

[0043] Folding propeller design

[0044] The appearance of the foldable propeller (9) of a solar powered aircraft according to an embodiment of the present invention is shown in FIG. Figure 7 As shown. The two blades (401, 402) are connected to the blade clamp (405) through two rotating shafts (403, 404) respectively; the blade clamp (405) is connected to the motor (1) through the shaft hole (406). The blades (401, 402) can rotate around the rotating shafts (403, 404) to achieve folding of the blades. When the motor (1) drives the propeller to rotate, the blades (401, 402) will open under the action of centrifugal force to provide thrust for the drone. The beneficial effect of this design is that when the drone lands, the motor (1) stops rotating and the blades (401, 402) will automatically retract, which can effectively prevent the blades from colliding with the ground and causing damage to the motor.

[0045] The advantages and beneficial effects of the present invention include:

[0046] 1) The solar-powered UAV adopts a conventional layout, a single tail strut, and an inverted T-shaped tail, and has high reliability.

[0047] 2) Compared with conventional powered small drones, this aircraft is powered by solar panels and lithium battery packs, has a longer flight time and a longer distance, and can perform long-term cruising missions.

[0048] 3) Use conventional monocrystalline silicon solar panels and combine them with the wings by cutting and packaging multiple layers. The lithium batteries are embedded in the wing ribs and integrated into the design to increase the strength of the wing and reduce the space occupied.

[0049] 4) It takes off with the power provided by solar panels and lithium battery packs, and can fly completely with solar power in level flight. 5) It uses a single-engine electric motor as the driving power, which has the advantages of high power efficiency, high torque and low speed.

[0050] 6) The solar panel group is equipped with a maximum power point tracking system, which enables the solar panels to work at the optimal power point, ensuring that the solar panel group can work under conditions with higher output power, while ensuring the stability of the aircraft power supply system.

[0051] 7) The lithium battery pack is equipped with an overcharge protection system to prevent the battery from overcharging and extend the battery life.

[0052] 8) A foldable propeller design is adopted, and the present invention does not have a landing gear, so that a short-distance throw without a runway requirement can be achieved during take-off, and a gliding landing can be achieved during landing.

Claims

1. A drone, characterized in that include: Body (2), An electric motor (1) with a foldable propeller (9) installed at the front end of a fuselage (2) is used to provide the aircraft with the power required for flight. The wing has a three-section wing design, which is divided into a middle wing (5) and two outer wings (7, 8), an aileron (6) arranged at the trailing edge of the outer wing (7, 8), A horizontal tail (3) and a vertical tail (4) connected to the fuselage (2), The lithium battery pack (104) is embedded in the carbon tube in the rib (105) of the mid-section wing (5). in: The second, first and third solar cell panel groups (101, 102, 103) are arranged on the upper surfaces of the middle wing (5) and the two outer wings (7, 8), respectively. The solar panels in the second, first and third solar panel groups (101, 102, 103) are cut and packaged in multiple layers, and are integrated with the airfoils of the middle wing (5) and the two outer wings (7, 8).

2. The drone according to claim 1, wherein: The drone is a small drone with a conventional aerodynamic layout and a high-wing design. The fuselage (2) is made of carbon fiber composite material round tube The drone does not have landing gear. It takes off by throwing it a short distance and lands by gliding. The wing plane shape is rectangular, without sweep angle. The outer wings (7, 8) have a 5° dihedral angle to improve flight stability.

3. The drone according to claim 1, characterized in that: The middle wing (5) and the two outer wings (7, 8) each include wing ribs. The outer side of the rib is covered with a skin (106). The solar panel group is attached to the upper surface of the skin (106), The leading edge of the mid-section wing (5) is covered with a composite material shell (107).

4. The drone according to claim 1, characterized in that: Each of the solar panel groups comprises a plurality of monocrystalline silicon solar panels (203), The plurality of monocrystalline silicon solar cell panels (203) are cut and packaged into the solar cell panel group in a multi-layer packaging manner.

5. The drone according to claim 4, characterized in that: The solar panel assembly uses a soft plastic film as a base film (201); A first ethylene-vinyl acetate copolymer hot melt adhesive film (202) is provided between the solar cell panel (203) and the base film (201); A second ethylene-vinyl acetate copolymer hot melt adhesive film (204) is coated on the upper surface of the solar cell panel (203); A layer of light-transmitting film (205) is encapsulated on the upper surface of the second ethylene-vinyl acetate copolymer hot-melt adhesive film (204) to improve the light-collecting capability of the solar cell panel group; The first and second ethylene-vinyl acetate copolymer hot melt adhesive films (202, 204) are used to bond the base film (201), the solar cell panel (203), and the light-transmitting film (205) to ensure the stability of the packaging structure of the solar cell panel. Each solar panel is cut along the span direction to make the panel better fit the wing curve and improve flight efficiency.

6. The drone according to any one of claims 1 to 5, characterized in that: The second, first and third solar panel groups directly supply power to the electric motor controlled by the lithium battery group and the electronic speed regulator (307) through a maximum power point tracking solar controller (304). When the motor needs high power, the lithium battery pack and the first to third solar panel groups supply power to the motor at the same time. The first to third solar panel groups are connected in series in the circuit. The maximum power point tracking solar controller (304) is used to adjust the output voltage of the solar panel group so that the solar panel group directly supplies power to the electronic speed regulator (307) and the motor, ensuring that even when the battery power is exhausted, the solar aircraft can still glide and land relying on the energy provided by the solar panel group.

7. The drone according to claim 6, characterized in that: During the take-off process of the aircraft, the lithium battery group (306) and the solar panel group (301, 302, 303) jointly supply power to the electric motor controlled by the electronic speed regulator (307). In the process of the aircraft being able to fly completely on solar power, the solar panels (301, 302, 303) receive solar energy to charge the lithium battery (306) and supply power to the electric motor (308) controlled by the electronic speed controller (307). The solar cell panel (203) uses a conventional monocrystalline silicon cell panel. An anti-reverse-feed diode (309) is connected in series after the maximum power point tracking solar controller (304) to protect the stable operation of the solar panel group. The lithium battery pack (306) is equipped with an overcharge protection system (305) to prevent the battery from being overcharged, thereby protecting the normal operation of the lithium battery pack and extending the battery life.

8. The drone according to any one of claims 1 to 5, characterized in that: The foldable propeller (9) comprises two blades (401, 402). The two blades (401, 402) are connected to the blade clamp (405) via two rotating shafts (403, 404) respectively. The paddle clamp (405) is connected to the motor (1) through the shaft hole (406). in, The blades (401, 402) can rotate around the rotation shafts (403, 404) to achieve folding of the blades. When the motor (1) drives the propeller to rotate, the blades (401, 402) will open under the action of centrifugal force to provide thrust for the drone. When the drone lands, the motor (1) stops rotating and the blades (401, 402) are automatically retracted, thereby preventing the blades from colliding with the ground and possibly damaging the motor.

9. The drone according to any one of claims 1 to 5, characterized in that: The lithium battery and carbon tube have an integrated design, which increases the strength of the wing and reduces the occupied space.

10. An energy management method based on a drone according to any one of claims 1 to 9, characterized in that include: A) reading power data (3002) including output power of the MPPT solar controller (304) and power consumption of the motor (308); B) Enter Judgment (3003), and: When the output power of the solar panel is less than the power consumption of the motor, the lithium battery discharge mode (3005) is entered, and the lithium battery group (306) is discharged by controlling the circuit breakers (311, 312) at the input end and / or the output end of the lithium battery group, so that the lithium battery group (306) and the solar panel group (301, 302, 303) jointly supply power to the motor (308) controlled by the electronic speed regulator (307), thereby providing sufficient power. When the output power of the solar panel is greater than the power consumed by the motor, the lithium battery discharge mode (3004) is entered, and the lithium battery group (306) is charged by controlling the circuit breakers (311, 312) at the input end and / or the output end of the lithium battery group. At this time, the solar panel group (301, 302, 303) receives solar energy, charges the lithium battery group (306) and supplies power to the motor (308) controlled by the electronic speed regulator (307).

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