CN112849393A

CN112849393A - Miniaturized duct aircraft

Info

Publication number: CN112849393A
Application number: CN202110092504.0A
Authority: CN
Inventors: 王掩刚; 王思维; 刘汉儒; 周芳
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2021-01-24
Filing date: 2021-01-24
Publication date: 2021-05-28
Anticipated expiration: 2041-01-24
Also published as: CN112849393B

Abstract

The invention relates to a miniaturized ducted aircraft.A camera is arranged right in front of a battery cabin; the battery compartment is positioned at the top of the aircraft, the central axis of the battery compartment is superposed with the axis of the duct, the flight control compartment is positioned between the battery compartment and the motor base, and the axis of the flight control compartment is also superposed with the axis of the duct; the duct lip can reduce the air intake loss of the duct and provide additional thrust for the aircraft, and is positioned right above the duct and tightly connected with the duct; the power device installation axis is superposed with the culvert axis and is positioned below the flight control cabin; the control rudders change the flow direction of airflow at the outlet of the duct, the distribution centers of the four control rudders are overlapped with the axis of the duct and are positioned at the outlet of the duct, and the four control rudder adjusting devices respectively adjust the deflection of the four control rudders; the landing gear is located lowermost in the duct. The miniaturized design scheme of the ducted aircraft can fully compress the size of the aircraft on the premise of realizing autonomous cruising and video transmission, and then the aircraft can autonomously fly in a narrower space.

Description

Miniaturized duct aircraft

Technical Field

The invention belongs to the field of aircraft design, and particularly relates to a miniaturized ducted aircraft.

Background

With the development of science and technology, the variety of aircraft is more and more, for example fixed wing unmanned aerial vehicle, four rotor unmanned aerial vehicle, duct fan unmanned aerial vehicle. In a great deal of aircraft kinds, use the duct aircraft of duct as power, because of it has the duct and for the mode of parcel screw for the flight of this aircraft is safer, can reduce the pneumatic interference of paddle and make pneumatic efficiency higher, but the duct aircraft work in narrow and small environment such as indoor, mine hole simultaneously for the aircraft of duct structure becomes the key of people's research, and the miniaturization is one of the direction of research again.

The existing published technical document 'research review on the development status of the micro unmanned aerial vehicle' (2019 world transportation congress 2019) discusses the wide application value and application prospect of the current micro unmanned aerial vehicle, and the micro unmanned aerial vehicle has very necessary application value in the fields of natural disaster monitoring and rescue or military investigation and aerial detection. The weight of the body of the micro fixed-wing unmanned aerial vehicle can be controlled within 100g, but the vertical take-off and landing function cannot be realized; the weight of the micro flapping wing unmanned aerial vehicle body can be controlled within 10g, but the working radius of the micro flapping wing unmanned aerial vehicle body is very limited; in a certain company with leading commercial unmanned aerial vehicle technology, the size of the body of the micro rotor type unmanned aerial vehicle reaches 198mm under the folding condition; even though the micro ducted fan unmanned aerial vehicle is mentioned, the duct lip is not designed reasonably, so that the pneumatic efficiency is greatly reduced.

Disclosure of Invention

The technical problem solved by the invention is as follows: in order to overcome the defect of low pneumatic efficiency of a small ducted aircraft in the research of the existing ducted aircraft, the invention designs a small ducted aircraft.

The technical scheme of the invention is as follows: a miniaturized ducted aircraft comprises a camera, a battery cabin, a flight control cabin and an undercarriage, and further comprises a lip, a power device, a duct, a control rudder, a steering engine and the undercarriage;

the lip and the duct are coaxially arranged, one end of the lip, which is not arranged with the duct, extends outwards in the radial direction and adopts arc transition, the extending surface forms a curved surface, and the ratio of the maximum diameter of the lip to the inner diameter of the duct is not more than 1.3;

the power device is coaxially positioned in the duct and comprises two groups of structures, and a gap is reserved between the two groups of structures; each group of structures comprises a motor and a counter-rotating fan; the hub of the contra-rotating fan rotor is axially grooved, and the motor is positioned in the groove; the torque generated by the rotation of the blades of the counter-rotating fan during work is mutually offset; the mounting side of the rotor is provided with heat dissipation holes, so that air flow generated in the rotating process can dissipate heat of the motor conveniently; the axial lengths of the two counter-rotating fans are equal to the axial length of the counter-rotating motor; the four control rudders are positioned below the duct and are respectively controlled by the steering engines; the control rudder is integrally of a plate-shaped structure, is uniformly distributed along the circumferential direction of the axial line of the duct, has a wing-shaped section, and has an inclined surface at the lower end of the inner side to prevent collision when the control rudder deflects at an angle; the yaw axis of the control rudder is located at the aerodynamic center or quarter chord of the airfoil,

the distribution centers of the four control rudders are coincident with the axis of the duct and are positioned at the outlet of the duct.

The further technical scheme of the invention is as follows: the motor is provided with a motor mounting hole for mounting a motor base; the motor cabinet connects the motor, the flight control cabin and the duct coaxially.

The further technical scheme of the invention is as follows: the control rudder is connected with the lower part of the duct through a control rudder connecting device.

The further technical scheme of the invention is as follows: the duct is an annular structure formed by rotating a closed geometric shape around a certain axis, and the axis of the duct is the central axis of the unmanned aerial vehicle.

The further technical scheme of the invention is as follows: the culvert is made of carbon fiber materials and comprises an upper culvert and a lower culvert, and the culvert is convenient to disassemble and assemble; the two ducts are coaxially and fixedly connected; the lip is connected with the upper duct as a whole.

The further technical scheme of the invention is as follows: the control rudder is made of carbon fiber materials, and is obtained by selecting an NACA 0065 basic wing profile and stretching the wing profile along the normal direction.

The further technical scheme of the invention is as follows: the change range of the deflection angle of the control rudder is +/-10 degrees.

The further technical scheme of the invention is as follows: the lip is in a lemniscate shape, and the inner wall surface is a curved surface formed by the rotation of a curve of the lemniscate in the first quadrant around the axis of the duct; the inner wall surface curve of the lip gradually expands outwards along the direction of the duct outlet, namely, the sectional area of the lip gradually increases along the direction of the duct outlet.

The further technical scheme of the invention is as follows: one end of the undercarriage is hinged with the lower duct, and a supporting point is provided for the takeoff and landing of the aircraft.

The further technical scheme of the invention is as follows: the quantity of the blades on the counter-rotating fans in the two groups of structures is different, so that the upper rotor and the lower rotor are prevented from generating great noise and vibration due to resonance when in work due to the fact that the blades are the same.

Effects of the invention

The invention has the technical effects that: the miniature ducted aircraft has a vertical take-off and landing function, the working radius is far larger than that of a miniature flapping wing unmanned aerial vehicle, the size of the aircraft body is smaller than that of a miniature rotor wing unmanned aerial vehicle, the pneumatic efficiency of the aircraft is improved due to the reasonable design of the duct lip, and the specific advantages are as follows:

(1) the special structural design of the lip enables the bypass flow of the airflow at the duct lip to reduce the inlet loss of the duct and provide additional thrust for the aircraft. The reasonable design of the lip of the invention can provide 50% of lift for the aircraft.

(2) The torques generated by the counter-rotating fans during working are mutually offset, the control difficulty of the flight control system is reduced, and meanwhile, the balance of the control rudder to the torques in the flight process of the aircraft is avoided.

(3) The motor wraps up inside the wheel hub of rotor, has reduced the axial dimensions of aircraft.

(4) A1 mm gap is reserved between the outer side of the motor and a rotor hub for heat dissipation, and heat dissipation holes are formed in the mounting side of the rotor, so that air flow generated in the rotation process of the rotor is used for heat dissipation of the motor.

(5) Divide into upper and lower two parts with the duct, convenient to detach and installation are convenient for technical staff to inspect duct inner structure simultaneously.

(6) One side of the control rudder is designed into an airfoil structure, so that the pneumatic efficiency is improved, and the resistance generated on the control surface is reduced; one end angle of the other side of the control rudder is set to be an inclined plane, so that the control rudder is effectively prevented from colliding during angle conversion. The control rudder provided by the invention ensures that the course of the aircraft can be flexibly changed under the condition of not changing the flight inclination angle, and compared with the existing straight plate-shaped control rudder, the wing-shaped control rudder can reduce the resistance generated on the control rudder.

(7) The camera is arranged right in front of the battery compartment and provides a wide field of view.

(8) The battery compartment is located the aircraft top, and its center pin and duct axle center coincide, and the battery compartment provides the mounted position of battery and camera, is located the aircraft topmost and is convenient for the dismantlement and the change of battery.

(9) The quantity of the blades on the counter-rotating fans (15) in the two groups of structures is different, so that the upper rotor and the lower rotor are prevented from generating great noise and vibration due to resonance during working due to the fact that the blades are the same.

Drawings

Figure 1 is a structural schematic view of a miniaturized design of a ducted aircraft of the present invention.

Figure 2 is a cross-sectional view of a miniaturized design of a ducted aircraft of the present invention.

Figure 3 is a power system installation schematic of a miniaturized design of the ducted aircraft of the present invention.

Figure 4 is a schematic view of the control rudder installation for a ducted aircraft of the present invention in a miniaturized design.

In the figure: 1. camera 2, battery compartment 3, flight control compartment 4, lip 5, power device 6, duct 7, control rudder 8, steering engine 9, landing gear 10, upper duct 11, lower duct 12, motor base 13, motor mounting hole 14, motor 15, blade 16, connecting hole 17 of motor and blade, heat dissipation hole 18, control rudder connecting device

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Referring to fig. 1-4, a miniaturized ducted aircraft includes a camera, a battery compartment, a flight control compartment, a duct lip, a duct, a power device, a control rudder adjustment device, and an undercarriage.

The aircraft belongs to a single duct aircraft. The maximum diameter of the ducted aircraft is not more than 250mm, and the maximum flying weight is not more than 1.2 kg.

The camera is arranged right in front of the battery compartment and provides a wide field of view. The camera communicates with the flight control device through a data line, and provides visual positioning and video acquisition for the aircraft.

The battery compartment is located the aircraft top, and its center pin and duct axle center coincide, and the battery compartment provides the mounted position of battery and camera, is located the aircraft topmost and is convenient for the dismantlement and the change of battery.

The flight control cabin provides a flight control installation position, is positioned between the battery cabin and the motor base, and the axis of the flight control cabin is also coincided with the axis of the duct.

The bypass of the airflow at the duct lip can reduce the intake loss of the duct and provide additional thrust for the aircraft, and the bypass is positioned right above the duct and is tightly connected with the duct. The inner wall surface curve of the duct lip is in a shape gradually expanding outwards along the direction of the duct outlet, namely, the sectional area of the lip is gradually increased along the direction of the duct outlet. The duct lip can reduce the air intake loss of the duct and provide additional thrust for the aircraft, and is positioned right above the duct and tightly connected with the duct;

the duct is an annular structure formed by rotating a closed geometric shape around a certain axis, and the axis of the duct is the central axis of the unmanned aerial vehicle.

The power device provides power for the aircraft, the installation axis of the power device coincides with the axis of the duct, the power device is positioned below the flight control cabin, and the motor, the motor seat, the flight control cabin and the duct are connected through the motor seat connected with the duct. The power device comprises: a counter-rotating fan and a counter-rotating motor.

The torques generated by the counter-rotating fans during operation are mutually offset; in order to reduce the axial size of the aircraft, the motor is wrapped inside a hub of the rotor; in order to meet the heat dissipation requirement of the motor, a 1mm gap is reserved between the outer side of the motor and the hub of the rotor for heat dissipation, and meanwhile, heat dissipation holes are formed in the mounting side of the rotor, so that air flow generated in the rotation process of the rotor is used for heat dissipation of the motor.

The control rudder is through changing the flow direction of duct export air current to for unmanned aerial vehicle provides every single move, roll, driftage moment, the control rudder is the platelike structure of four disturbed flows, the distribution center of four control rudders coincides and is located the duct exit with the duct axis, four control rudders pass through connecting piece interconnect. The four control rudder adjusting devices respectively adjust the deflection of the four control rudders and are positioned at the outlets of the ducts; the landing gear provides a support point for the aircraft during takeoff and landing, which is located at the exit of the duct, i.e. lowermost.

The landing gear provides a support point for the aircraft during takeoff and landing, which is located at the lowermost portion of the duct.

The invention is further illustrated by the following examples.

The invention adopts the single-duct aircraft, the single-duct aircraft can inhibit the formation of the tip vortex of the blade and reduce the wake flow loss due to the duct, and the duct lip can provide additional lift force, so that under the same size, compared with a multi-rotor aircraft, the duct aircraft can provide higher thrust force, and under the premise of needing the same thrust force, the duct aircraft needs smaller size. The ducted aircraft can therefore be made smaller while achieving the same mission and carrying the same loads.

In the above-mentioned miniaturized design technical scheme, preferably, the duct adopts the processing mode that upper and lower duct processed respectively, chooses for use carbon fiber material processing, and four directions of upper and lower duct respectively have a connecting seat to carry out the connection of upper and lower duct, and the duct diameter is 154 mm. The inner diameter of the duct is 154mm, the maximum diameter of the aircraft is 200mm, and the maximum weight is 800 g.

In the technical scheme of above-mentioned camera, preferably, the camera chooses for use binocular camera, and binocular camera can help the aircraft to carry out space positioning and independently keep away the barrier, provides accurate positional information for the aircraft.

In the above-mentioned technical solution of the battery compartment, preferably, the size of the battery compartment is consistent with the radial size of the flight control compartment, and the battery compartment is connected with the flight control compartment through screws.

In the above technical solution of the flight control cabin, preferably, the electric tuning, the data transmission, the image processing system, the remote controller receiver, and the like are all integrated in the flight control or are installed in the flight control cabin by adopting a modular design scheme, and the flight control and the camera are connected through a data line.

In the above technical solution of the lip, preferably, the lip is a lemniscate-shaped lip, and the maximum diameter of the lip is 200 mm. The inner wall surface of the culvert lip is a curved surface formed by rotating a curve of a lemniscate in a first quadrant around the axis of the culvert, and the ratio of the maximum diameter of the lip to the inner diameter of the culvert is not more than 1.3. In this example, the diameter of the inner wall surface of the duct is 154mm, the lip is a lemniscate shape, and the maximum diameter is 200 mm.

In the above technical solution of the duct, preferably, the duct has a ring structure in which a ring or an airfoil formed by a rectangle rotating around a parallel line of a certain long side rotates around a straight line parallel to an airfoil chord line; for the convenience of guaranteeing power device installation and unmanned aerial vehicle maintenance, the selectable duct divide into upper and lower duct two parts with the duct to through screwed connection.

In the technical scheme of the power device, preferably, the power system consists of a pair of counter-rotating fans and a coaxial counter-rotating motor, so that the yaw moment generated by the blades to the unmanned aerial vehicle during rotation is weakened, and in order to ensure the reasonable utilization of space, the fan blades are sleeved outside the motor in design, so that the axial lengths of the two counter-rotating fans are equal to the axial length of the counter-rotating motor.

In the above technical solution of the counter-rotating fan, preferably, the torques generated by the counter-rotating fan when the counter-rotating fan operates at the same rotation speed are equal in magnitude and opposite in direction, so that the generated torques are offset with each other, the control difficulty of the flight control system is reduced, and the balance of the control rudder to the torques in the flight process of the aircraft is avoided.

In the above technical solution of the control rudder, preferably, four control rudders are installed at the exit of the duct in a cross shape, in order to improve the rudder effect of the control rudders, the control rudders should be geometric formed by stretching a certain basic wing profile in the normal direction, and the deflection angle variation range of the control rudders is ± 10 °; the yaw axis of the control rudder is located at the aerodynamic center or quarter chord of the airfoil.

In the above technical solution for controlling the rudder adjusting device, preferably, four steering engines are used as the adjusting device for controlling the rudder, and the rotation axes of the steering engines and the rotation axis of the control rudder coincide with each other. The control rudder is obtained by selecting an NACA 0065 basic wing profile and stretching the wing profile along the normal direction, and is also made of carbon fiber materials.

In above-mentioned counter-rotating fan's technical scheme, preferably, the counter-rotating fan of same rotational speed, with the moment of torsion is selected for use to the rotor, and the blade number is 5 blades on the rotor, and 6 blades on the rotor down prevent that the rotor from top to bottom because the blade is the same makes because resonance produces very big noise and vibration at the during operation, and the blade is the carbon fiber material processing.

In the above-mentioned technical scheme of control rudder adjusting device, preferably, with the mounted position of undercarriage as the steering wheel in order to improve the space utilization of aircraft.

The mounting steps of the structure are as follows:

(1) connecting the upper duct with the lip or integrally processing the upper duct and the lip during processing;

(2) integrally mounting the motor, the motor base and the flight control cabin in the upper duct through mounting holes of the motor;

(3) avionics equipment such as flight control, electric regulation, data transmission and the like are installed in the flight control cabin, and a camera data line is led out;

(4) the flight control cabin is connected with the battery cabin through screws;

(5) mounting a camera outside the battery compartment;

(6) sleeving the upper rotor into an upper motor and installing the upper rotor through screws;

(7) integrally mounting a motor, a motor base and a control rudder connecting device in the lower duct;

(8) sleeving the lower rotor into a lower motor and installing the lower rotor through screws;

(9) connecting the upper duct and the lower duct through screws;

(10) inserting the four control rudders into a control rudder connecting device;

(11) attaching four landing gears to the lower duct;

(12) the four steering engines are connected with the control rudder and the undercarriage.

Claims

1. A miniaturized ducted aircraft comprises a camera (1), a battery cabin (2), a flight control cabin (3) and an undercarriage (9), and is characterized by further comprising a lip (4), a power device (5), a duct (6), a control rudder (7), a steering engine (8) and the undercarriage (9);

the lip (4) and the duct (6) are coaxially arranged, one end, which is not arranged with the duct, of the lip (4) extends outwards in the radial direction and adopts arc transition, the extending surface forms a curved surface, and the ratio of the maximum diameter of the lip to the inner diameter of the duct is not more than 1.3;

the power device (5) is coaxially positioned in the duct (6) and comprises two groups of structures, and a gap is reserved between the two groups of structures; each set of structures comprises a motor (14) and a counter-rotating fan (15); the hub of the contra-rotating fan rotor is axially grooved, and the motor (14) is positioned in the groove; the torque generated by the rotation of the blades of the counter-rotating fan during work is mutually offset; the mounting side of the rotor is provided with heat dissipation holes, so that air flow generated in the rotating process can dissipate heat of the motor conveniently; the axial lengths of the two counter-rotating fans are equal to the axial length of the counter-rotating motor;

the four control rudders (7) are positioned below the duct (6) and are respectively controlled by the steering engines (8); the control rudder (7) is integrally of a plate-shaped structure, is uniformly distributed along the circumferential direction of the axial line of the duct, has a wing-shaped section, and has an inclined surface at the lower end of the inner side to prevent collision when the control rudder (7) deflects at an angle; the deflection axis of the control rudder (7) is positioned at the aerodynamic center or quarter chord length of the wing profile,

the distribution centers of the four control rudders (7) are coincident with the axis of the duct and are positioned at the outlet of the duct.

2. The miniature ducted aircraft according to claim 1, wherein said motor (14) has a motor mounting hole for mounting a motor mount (12); the motor, the flight control cabin and the duct are coaxially connected through the motor base (12).

3. A miniaturised ducted aircraft according to claim 1 characterised in that the control rudder (7) is connected with the duct (6) below by means of a control rudder connection.

4. The miniature ducted aircraft according to claim 1, wherein said duct is an annular structure of closed geometry rotated about an axis, said axis being the central axis of said drone.

5. The miniaturised ducted aircraft according to claim 1, characterized in that the duct (6) is made of carbon fibre material, comprising an upper duct (10) and a lower duct (11), which are easy to disassemble and assemble; the two ducts are coaxially and fixedly connected; the lip (4) is connected with the upper duct (10) as a whole.

6. A miniaturised ducted aircraft according to claim 1 characterized in that the control rudder (7) is made of carbon fibre material, chosen from NACA 0065 base airfoil profile and stretched in the normal direction.

7. A miniaturised ducted aircraft according to claim 5 characterized in that the deflection angle of the control rudder (7) varies within a range of ± 10 °.

8. The miniature ducted aircraft according to claim 1, wherein said lip (4) is in the shape of a lemniscate, and the inner wall surface is a curved surface formed by a curve of the lemniscate in the first quadrant rotating around the axis of the ducted section; the inner wall surface curve of the lip (4) gradually expands outwards along the direction of the outlet of the duct, namely, the sectional area of the lip gradually increases along the direction of the outlet of the duct.

9. A miniaturised ducted aircraft according to claim 1 wherein the landing gear (9) is hinged at one end to the lower duct (11) to provide a support point for the aircraft during take-off and landing.

10. A miniaturised ducted aircraft according to claim 1 characterized in that the number of blades on the counter-rotating fans (15) in the two sets of structures is different, preventing the upper and lower rotors from generating extreme noise and vibrations due to resonance during operation, due to the same blades.