Tiltable solar aircraft with four-rotor tandem wing layout and control method thereof

Abstract

The invention discloses a tiltable solar aircraft with a four-rotor tandem wing layout and a control method of the tiltable solar aircraft. The tiltable solar aircraft comprises an aircraft body, a first wing, a second wing, a tiltable power device, an energy system, a vertical tail wing and an aileron, airborne avionics equipment is arranged in the fuselage; the first wings are mounted on two sides of the front part of the fuselage; the second wings are mounted on two sides of the tail part of the fuselage; tilting power devices are symmetrically mounted on the first wing and the second wing; the vertical empennage is positioned at the tail of the fuselage; the aileron is mounted at the rear parts of the first wing and the second wing; the energy system comprises a solar cell panel, a storage battery, an electronic switch, an equipment distributor and an ideal diode; according to the unmanned aerial vehicle, more solar cells can be arranged, the effective area is larger, the endurance time is longer, the overall wingspan is smaller, the unmanned aerial vehicle has higher lift force efficiency, higher cruising speed, better longitudinal stability and shorter take-off and landing distance, and tasks can be executed in a more harsh environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and in particular relates to a solar-powered aircraft with a tiltable quad-rotor tandem wing layout and a control method thereof. Background Art

[0002] Tilt-rotor aircraft combines the advantages of helicopters and fixed-wing aircraft, allowing the aircraft to switch between vertical take-off and landing mode and fixed-wing mode, and can take off and land freely in small spaces or complex terrains. In the cruising state, it has a higher flight speed and a longer cruising range than ordinary aircraft. The tilt-rotor can provide both lift and cruising thrust, so the tilt-rotor aircraft has a larger load-to-weight ratio and a higher overall cost-effectiveness. Tilt-rotor aircraft has extremely high practical value in the low-altitude economic neighborhood.

[0003] Tandem wing aircraft have two main wings, arranged along the longitudinal axis of the aircraft, one main wing is located at the front and the other main wing is located at the rear. Both the front and rear main wings provide lift to make the aerodynamic force distribution more uniform and the wing load smaller. Therefore, tandem wing aircraft have higher lift efficiency, better longitudinal stability, higher fuselage strength, and shorter take-off and landing distances than conventional layout aircraft. At the same time, the overall wingspan of tandem wing aircraft is smaller, which is conducive to reducing wingtip vortex losses and improving lift efficiency. The tandem wing layout is suitable for the optimized design of UAVs and special-purpose aircraft, and has broad research and development space.

[0004] Compared with pure electric aircraft, solar aircraft have longer flight time, lower operating costs, better environmental performance, and can stay in the air for a long time at high altitudes. They are suitable for high-altitude and long-duration flight missions such as monitoring, communication relay, and scientific exploration. Solar aircraft are of great significance in the trend of aviation environmental protection and energy diversification.

[0005] Due to the low energy density of solar energy, solar aircraft require a larger aspect ratio, so conventional solar aircraft have longer wings. However, longer wings increase the difficulty of solar aircraft takeoff and greatly limit the operating environment of solar aircraft. At the same time, the solar panel-MPPT-battery circuit design used in conventional solar aircraft circuits has a large power loss on solar panels, and a more efficient circuit connection method is needed to maximize the benefits of solar energy. Therefore, in order to enable solar aircraft to successfully perform flight missions in more environments, maximize the use of solar energy output, and increase the range of solar aircraft, it is necessary to optimize the overall layout of the aircraft and further optimize the circuit design of conventional solar aircraft. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a solar-powered aircraft with a tiltable four-rotor tandem wing layout and a control method thereof, so as to solve the problems in the prior art that the solar-powered aircraft has long wings, great difficulty in take-off, slow cruising speed and low energy utilization rate. The aircraft of the present invention has shorter wings, higher lift efficiency, faster cruising speed and more stable flight.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The solar powered aircraft of the present invention with a tiltable quad-rotor tandem wing layout comprises: a fuselage, a first wing, a second wing, a tiltable power device, an energy system, a vertical tail and ailerons;

[0009] Airborne avionics equipment is arranged inside the fuselage;

[0010] The first wing is mounted on both sides of the front of the fuselage, and the second wing is mounted on both sides of the rear of the fuselage; the first wing and the second wing are symmetrically mounted with a tilting power device, and the tilting power device comprises a blade, an electric motor, and a tilting servo, wherein the blade is connected to the rotating shaft of the electric motor, and the rotation of the electric motor drives the blade to rotate, and the electric motor is connected to the rotating shaft of the tilting servo through the base, and the rotation of the tilting servo drives the motor and the blade to rotate together;

[0011] The vertical tail is located at the tail of the fuselage;

[0012] The ailerons are mounted on the rear of the first wing and the second wing;

[0013] The energy system includes: solar panels, batteries, electronic switches, equipment distributors, and ideal diodes; the solar panels are evenly laid on the upper surfaces of the fuselage, the first wing, and the second wing; the batteries are installed inside the fuselage; the electronic switches are connected to the solar panels to realize the conversion of power supply between the solar panels and the batteries; the equipment distributor is installed inside the fuselage, the electronic switches and the batteries are connected in parallel to the equipment distributor, and the equipment distributor is also connected to the airborne avionics equipment to realize the power supply and distribution of the airborne avionics equipment; the ideal diodes are installed inside the fuselage, two in number, one is connected in series with the solar panels and the electronic switch, and the other is connected in series with the batteries, so as to prevent the battery and the solar panel from charging each other due to reverse current flow.

[0014] Furthermore, the planar shapes of the middle wing sections of the first wing and the second wing are rectangular, and the planar shapes of the outer wing sections are trapezoidal.

[0015] Furthermore, there are two vertical tail wings, which are symmetrically arranged at the tail of the fuselage.

[0016] Furthermore, the storage battery is a lithium battery that can be charged and discharged cyclically.

[0017] Furthermore, the blades on the first wing are tension propellers; the blades on the second wing are thrust propellers; when the UAV is in the vertical take-off and landing stage of the multi-rotor mode, the axial direction of the blades is vertically upward; when the UAV is in the level flight stage of the fixed-wing mode, the axial direction of the blades is horizontally forward.

[0018] The present invention also provides a control method for a tiltable quadrotor tandem wing solar aircraft. Based on the above aircraft, the method steps are as follows:

[0019] Establish the aircraft body coordinate system, with the origin of the coordinate system being the center of mass of the aircraft, the x-axis being in the aircraft symmetry plane, parallel to the fuselage axis and pointing forward; the z-axis being in the aircraft symmetry plane, pointing upward; and the y-axis being perpendicular to the symmetry plane, pointing to the right.

[0020] Control the tilting servo to make the motor shaft parallel to the z-axis and the blades upward, entering the vertical take-off and landing mode; the motor rotates, the blades generate upward lift to push the aircraft up, and the symmetrical distribution of the blades balances the torque generated by the lift; adjust the motor speed to control the aircraft to rise, hover or descend;

[0021] The tilting servo is controlled to tilt so that the motor shaft is gradually parallel to the x-axis and the blades are forward, and the aircraft switches from the vertical take-off and landing mode to the fixed-wing mode; the motor rotates, and the lift generated by the blades is gradually converted into forward horizontal thrust to push the aircraft forward; the horizontal speed of the aircraft gradually increases, and the lift generated by the first wing and the second wing gradually replaces the lift generated by the blades. When the motor shaft is completely parallel to the x-axis, the aircraft enters the fixed-wing mode;

[0022] Reduce the speed of the motor on the left side of the fuselage and increase the speed of the motor on the right side of the fuselage. The lift difference between the left and right sides of the fuselage will form a counterclockwise torque around the z-axis, and the aircraft will tilt to the left, thereby causing the aircraft to yaw to the left; reduce the speed of the motor on the right side of the fuselage and increase the speed of the motor on the left side of the fuselage. The lift difference between the left and right sides of the fuselage will form a clockwise torque around the z-axis, and the aircraft will tilt to the right, thereby causing the aircraft to yaw to the right.

[0023] Furthermore, in the vertical take-off and landing mode, the speed of the electric motor on the first wing is increased, and the speed of the electric motor on the second wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise torque around the y-axis, thereby lifting the nose of the aircraft; the speed of the electric motor on the second wing is increased, and the speed of the electric motor on the first wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise torque around the y-axis, thereby lifting the tail of the aircraft.

[0024] Furthermore, in the fixed-wing mode, the ailerons on the first wing are controlled to deflect downward, and the ailerons on the second wing are controlled to deflect upward, and the lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise torque around the y-axis, thereby lifting the nose of the aircraft; the ailerons on the second wing are controlled to deflect downward, and the ailerons on the first wing are controlled to deflect upward, and the lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise torque around the y-axis, thereby lifting the tail of the aircraft.

[0025] Beneficial effects of the present invention:

[0026] Compared with solar aircraft with ordinary layout, the present invention can arrange more effective area of ​​solar cells, has a longer flight time, a smaller overall wingspan, higher lift efficiency, higher cruising speed, higher solar energy utilization, better longitudinal stability, higher fuselage strength, shorter take-off and landing distances, and can perform missions in more harsh environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the aircraft of the present invention;

[0028] Figure 2 is a top view of the aircraft of the present invention;

[0029] Figure 3 It is a schematic diagram of the energy system structure in the present invention;

[0030] In the figure, 1-fuselage, 2-first wing, 3-second wing, 4-solar panel, 5-blade, 6-electric motor, 7-tilt servo, 8-vertical tail, 9-aileron, 10-battery, 11-ideal diode, 12-electronic switch. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0032] Reference Figures 1 to 3 As shown, a solar powered aircraft with a tiltable quad-rotor tandem wing layout of the present invention comprises: a fuselage 1, a first wing 2, a second wing 3, a tiltable power device, an energy system, a vertical tail 8 and ailerons 9;

[0033] Aircraft avionics equipment is arranged inside the fuselage 1;

[0034] The first wing 2 is mounted on both sides of the front part of the fuselage 1, and the second wing 3 is mounted on both sides of the rear part of the fuselage 1; the first wing 2 and the second wing 3 are symmetrically mounted with a tilting power device, and the tilting power device comprises a blade 5, a motor 6, and a tilting steering gear 7. The blade 5 is connected to the rotating shaft of the motor 6, and the motor 6 drives the blade 5 to rotate when the motor 6 rotates. The motor 6 is connected to the rotating shaft of the tilting steering gear 7 through a base, and the tilting steering gear 7 drives the motor 6 and the blade 5 to rotate together when the tilting steering gear 7 rotates;

[0035] The vertical tail 8 is located at the tail of the fuselage 1;

[0036] The aileron 9 is mounted at the rear of the first wing 2 and the second wing 3;

[0037] The energy system includes: a solar panel 4, a battery 10, an electronic switch 12, an equipment distributor, and an ideal diode 11; the solar panel 4 is evenly laid on the upper surface of the fuselage 1, the first wing 2 and the second wing 3; the battery 10 is installed inside the fuselage 1; the electronic switch 12 is connected to the solar panel 4 to realize the conversion of power supply between the solar panel 4 and the battery 10; the equipment distributor is installed inside the fuselage 1, the electronic switch 12 and the battery 10 are connected in parallel to the equipment distributor, and the equipment distributor is also connected to the airborne avionics equipment to realize the power supply and distribution of the airborne avionics equipment; the ideal diode 11 is installed inside the fuselage 1, and there are two of them, one is connected in series with the solar panel 4 and the electronic switch 12, and the other is connected in series with the battery 10, which is used to prevent the reverse flow of current from causing mutual charging between the battery and the solar panel.

[0038] Specifically, the planar shape of the middle wing sections of the first wing 2 and the second wing 3 is a rectangle, and the planar shape of the outer wing sections is a trapezoid.

[0039] Specifically, there are two vertical tail wings 8 symmetrically arranged at the tail of the fuselage 1 .

[0040] Specifically, the storage battery adopts a lithium battery which can be charged and discharged cyclically.

[0041] Specifically, the blades 5 on the first wing are tension propellers; the blades 5 on the second wing are thrust propellers; when the UAV is in the vertical take-off and landing stage of the multi-rotor mode, the axial direction of the blades 5 is vertically upward; when the UAV is in the level flight stage of the fixed-wing mode, the axial direction of the blades 5 is horizontally forward.

[0042] The present invention also provides a control method for a tiltable quadrotor tandem wing solar aircraft. Based on the above aircraft, the method steps are as follows:

[0043] Establish the aircraft body coordinate system, with the origin of the coordinate system being the center of mass of the aircraft, the x-axis being in the aircraft symmetry plane, parallel to the fuselage axis and pointing forward; the z-axis being in the aircraft symmetry plane, pointing upward; and the y-axis being perpendicular to the symmetry plane, pointing to the right.

[0044] Control the tilting servo to make the motor shaft parallel to the z-axis and the blades upward, entering the vertical take-off and landing mode; the motor rotates, the blades generate upward lift to push the aircraft up, and the symmetrical distribution of the blades balances the torque generated by the lift; adjust the motor speed to control the aircraft to rise, hover or descend;

[0045] In the vertical take-off and landing mode, the speed of the motor on the first wing is increased, and the speed of the motor on the second wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise torque around the y-axis, thereby lifting the nose of the aircraft; the speed of the motor on the second wing is increased, and the speed of the motor on the first wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise torque around the y-axis, thereby lifting the tail of the aircraft;

[0046] The tilting servo is controlled to tilt so that the motor shaft is gradually parallel to the x-axis and the blades are forward, and the aircraft switches from the vertical take-off and landing mode to the fixed-wing mode; the motor rotates, and the lift generated by the blades is gradually converted into forward horizontal thrust to push the aircraft forward; the horizontal speed of the aircraft gradually increases, and the lift generated by the first wing and the second wing gradually replaces the lift generated by the blades. When the motor shaft is completely parallel to the x-axis, the aircraft enters the fixed-wing mode;

[0047] In the fixed-wing mode, the ailerons on the first wing are controlled to deflect downward, and the ailerons on the second wing are controlled to deflect upward. The lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise moment around the y-axis, thereby lifting the nose of the aircraft. The ailerons on the second wing are controlled to deflect downward, and the ailerons on the first wing are controlled to deflect upward. The lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise moment around the y-axis, thereby lifting the tail of the aircraft.

[0048] Reduce the speed of the motor on the left side of the fuselage and increase the speed of the motor on the right side of the fuselage. The lift difference between the left and right sides of the fuselage will form a counterclockwise torque around the z-axis, and the aircraft will tilt to the left, thereby causing the aircraft to yaw to the left; reduce the speed of the motor on the right side of the fuselage and increase the speed of the motor on the left side of the fuselage. The lift difference between the left and right sides of the fuselage will form a clockwise torque around the z-axis, and the aircraft will tilt to the right, thereby causing the aircraft to yaw to the right.

[0049] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A solar powered aircraft with a tiltable quad-rotor tandem wing layout, characterized in that: include: Fuselage, first wing, second wing, tilting power unit, energy system, vertical tail and ailerons; Airborne avionics equipment is arranged inside the fuselage; The first wing is mounted on both sides of the front of the fuselage, and the second wing is mounted on both sides of the rear of the fuselage; the first wing and the second wing are symmetrically mounted with a tilting power device, and the tilting power device comprises a blade, an electric motor, and a tilting servo, wherein the blade is connected to the rotating shaft of the electric motor, and the rotation of the electric motor drives the blade to rotate, and the electric motor is connected to the rotating shaft of the tilting servo through the base, and the rotation of the tilting servo drives the motor and the blade to rotate together; The vertical tail is located at the tail of the fuselage; The ailerons are mounted on the rear of the first wing and the second wing; The energy system includes: solar panels, batteries, electronic switches, equipment distributors and ideal diodes; the solar panels are evenly laid on the upper surfaces of the fuselage, the first wing and the second wing; The battery is installed inside the fuselage; the electronic switch is connected to the solar panel to realize the conversion of power supply between the solar panel and the battery; the equipment distributor is installed inside the fuselage, the electronic switch and the battery are connected in parallel to the equipment distributor, and the equipment distributor is also connected to the airborne avionics equipment to realize the power supply and distribution of the airborne avionics equipment; the ideal diode is installed inside the fuselage, two in number, one is connected in series with the solar panel and the electronic switch, and the other is connected in series with the battery, so as to prevent the reverse flow of current from causing mutual charging between the battery and the solar panel.

2. The tiltable quad-rotor tandem wing solar aircraft according to claim 1, characterized in that: The plan shapes of the middle wing sections of the first wing and the second wing are rectangular, and the plan shapes of the outer wing sections are trapezoidal.

3. The tiltable quad-rotor tandem wing solar aircraft according to claim 1, characterized in that: There are two vertical tail wings, which are symmetrically arranged at the tail of the fuselage.

4. The tiltable quad-rotor tandem wing solar aircraft according to claim 1, characterized in that: The storage battery is a lithium battery which can be charged and discharged cyclically.

5. The tiltable quad-rotor tandem wing solar aircraft according to claim 1, characterized in that: The blades on the first wing are tension propellers; the blades on the second wing are thrust propellers; when the UAV is in the vertical take-off and landing stage of the multi-rotor mode, the axial direction of the blades is vertically upward; when the UAV is in the level flight stage of the fixed-wing mode, the axial direction of the blades is horizontally forward.

6. A control method for a tiltable quadrotor tandem wing solar powered aircraft, based on the aircraft according to any one of claims 1 to 5, characterized in that: The steps are as follows: Establish the aircraft body coordinate system, with the origin of the coordinate system being the center of mass of the aircraft, the x-axis being in the aircraft symmetry plane, parallel to the fuselage axis and pointing forward; the z-axis being in the aircraft symmetry plane, pointing upward; and the y-axis being perpendicular to the symmetry plane, pointing to the right. Control the tilting servo to make the motor shaft parallel to the z-axis and the blades upward, entering the vertical take-off and landing mode; the motor rotates, the blades generate upward lift to push the aircraft up, and the symmetrical distribution of the blades balances the torque generated by the lift; adjust the motor speed to control the aircraft to rise, hover or descend; The tilting servo is controlled to tilt so that the motor shaft is gradually parallel to the x-axis and the blades are forward, and the aircraft switches from the vertical take-off and landing mode to the fixed-wing mode; the motor rotates, and the lift generated by the blades is gradually converted into forward horizontal thrust to push the aircraft forward; the horizontal speed of the aircraft gradually increases, and the lift generated by the first wing and the second wing gradually replaces the lift generated by the blades. When the motor shaft is completely parallel to the x-axis, the aircraft enters the fixed-wing mode; Reduce the speed of the motor on the left side of the fuselage and increase the speed of the motor on the right side of the fuselage. The lift difference between the left and right sides of the fuselage will form a counterclockwise torque around the z-axis, and the aircraft will tilt to the left, thereby causing the aircraft to yaw to the left; reduce the speed of the motor on the right side of the fuselage and increase the speed of the motor on the left side of the fuselage. The lift difference between the left and right sides of the fuselage will form a clockwise torque around the z-axis, and the aircraft will tilt to the right, thereby causing the aircraft to yaw to the right.

7. The control method of the tiltable quadrotor tandem wing solar aircraft according to claim 6, characterized in that: In the vertical take-off and landing mode, the speed of the electric motor on the first wing is increased, and the speed of the electric motor on the second wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise torque around the y-axis, thereby lifting the nose of the aircraft; the speed of the electric motor on the second wing is increased, and the speed of the electric motor on the first wing is reduced. The lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise torque around the y-axis, thereby lifting the tail of the aircraft.

8. The control method of the tiltable quadrotor tandem wing solar aircraft according to claim 6, characterized in that: In the fixed-wing mode, the ailerons on the first wing are controlled to deflect downward, and the ailerons on the second wing are controlled to deflect upward. The lift difference between the front and rear of the aircraft causes the aircraft to generate a counterclockwise moment around the y-axis, thereby lifting the nose of the aircraft; the ailerons on the second wing are controlled to deflect downward, and the ailerons on the first wing are controlled to deflect upward. The lift difference between the front and rear of the aircraft causes the aircraft to generate a clockwise moment around the y-axis, thereby lifting the tail of the aircraft.

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