CN116395156A

CN116395156A - Control method of flapping wing aircraft based on gravity center position and aircraft thereof

Info

Publication number: CN116395156A
Application number: CN202310520255.XA
Authority: CN
Inventors: 邓慧超; 罗心韵; 王韫; 肖胜杰
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2023-05-10
Filing date: 2023-05-10
Publication date: 2023-07-07

Abstract

The invention discloses a control method of a flapping-wing aircraft based on a gravity center position and the aircraft thereof, and belongs to the field of miniature flapping-wing aircrafts. The bionic flapping wing aircraft comprises a flapping mechanism, a driving module, wings, a control module and a fuselage. The flapping mechanism is arranged on the machine body, the driving module provides power by using the hollow cup motor, and transmits power to the flapping mechanism through gear transmission, so that flapping of wings according to a preset track is realized and lifting force is provided. The control module utilizes the battery body as a balancing weight, and two steering engines which are vertically distributed respectively control the pose of the battery body in the rolling and pitching directions, and the overall gravity center position of the aircraft is regulated and controlled in real time according to feedback regulation so as to realize the pose control of the aircraft. The aircraft of the invention has no traditional tail wing, has the characteristics of compact structure, light weight and the like, is beneficial to improving the lifting ratio and has higher flight efficiency.

Description

Control method of flapping wing aircraft based on gravity center position and aircraft thereof

Technical Field

The invention belongs to the field of flapping wing aircrafts, and particularly relates to a control method of a flapping wing aircrafts based on a gravity center position and an aircraft thereof.

Background

According to different flight principles, micro-aircraft can be divided into three types, namely fixed-wing aircraft, rotary-wing aircraft and flapping-wing aircraft. Research results show that compared with other two flight modes, the flapping wing aircraft with the main size smaller than 15cm has larger lift-drag ratio, stronger anti-interference capability and more flexible maneuverability. Therefore, the miniature ornithopter will take the leading role in the development of the miniature aerocraft, has wide application prospect in the military and civil fields, and can be used for executing the tasks of reconnaissance in a narrow space, rescue detection in a multi-obstacle environment and the like.

The flight performance of the miniature bionic ornithopter is greatly influenced by structural design and control modes. The flapping frequency of the aircraft is high, the structure is changeable, and the timely and effective control of the gesture of the miniature bionic flapping wing aircraft is a key point and a difficult point in the research process. The existing gesture control of the miniature bionic ornithopter mainly realizes the gesture adjustment of the aircraft by changing the attack angle of the ornithopter and controlling the tail wing or the wing root. These control modes generally require more complex mechanical structures, which can increase the dead weight of the machine body, reduce the lifting ratio and reduce the flight efficiency. The miniature bionic ornithopter and the gesture control method based on the gravity center thereof can improve the lifting weight ratio of the ornithopter on the basis of the prior art, and obtain better flight performance.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a miniature bionic ornithopter and a gesture control method based on the gravity center thereof, which solve the problems of difficult gesture control and stable flight of the aircraft in the prior art.

The aim of the invention can be achieved by the following technical scheme:

the invention provides a miniature bionic ornithopter, which mainly comprises: the device comprises a flapping mechanism, wings, a driving module, a control module and a machine body.

The control module comprises a battery body, wherein the battery body is arranged on the machine body through a connecting mechanism, and the connecting mechanism is used for controlling the pose of the battery body to adjust the gravity center of the pitching direction and the rolling direction of the aircraft.

Further, the flapping mechanism consists of a frame, a pair of crank slide block mechanisms and a swinging guide rod mechanism, wherein the crank slide block mechanisms comprise meshing gears, a center rod, a center slide block and an upper frame, and the swinging guide rod mechanism consists of a left wing connecting rod, a right wing connecting rod, a left wing guide rod frame, a right wing guide rod frame and an upper frame. The crank sliding block mechanism and the swing guide rod mechanism are connected through a central sliding block, a sliding block groove on the connecting rod bracket and a connecting hole on the central rod. The upper frame and the lower frame are made of resin materials through a 3D printing process and are used for connecting and positioning all parts, and the whole weight is light. The upper frame and the lower frame structure comprise a plurality of positioning end faces which can be mutually aligned and are connected through pins. The meshing gear forms a crank in the crank slide block mechanism, the meshing gear is arranged on the lower frame and is connected with the central slide block through the central rod, and the central slide block drives the two wing connecting rods to move at the same time, so that the symmetry of the movement of the two side mechanisms is guaranteed. The machine frame, the meshing gear, the center rod, the connecting rod and the guide rod frame are all connected by adopting pins, the meshing gear and the pins connected between the lower machine frame are in interference fit, the connecting rod, the guide rod frame and the pins connected between the upper machine frame are in interference fit, and the meshing gear, the center rod, the connecting rod, the guide rod frame and the pins are in clearance fit so as to ensure the stability of transmission.

Further, the wings are of a single flapping wing structure and consist of wing rods, wing films and wing veins. The wing film is made of flexible PET material and is adhered to the wing rod. The wing rod is a carbon fiber material round rod with the diameter of 0.8 mm. Two wing veins are carbon fiber round bars with the diameter of 0.5mm, and are mutually parallel and adhered to the wing film. The flapping mechanism can drive the connected wings to realize flapping action, the wings comprise wing rods, wing films and wing veins, the wing rods form the outer outline of the wings, the edges of the top ends of the wing films are curled to form a hollow structure, and the wing rods penetrate through the hollow structure.

Further, the driving module consists of a hollow cup motor, a motor shaft, a motor gear and a transmission gear. The hollow cup motor is arranged in the middle of one side of the frame. The motor shaft is connected with the motor gear to output power, the transmission gear is formed by connecting a duplex gear with the frame in an interference fit way through a pin, one side of the transmission gear is meshed with the motor gear, and the other side of the transmission gear is meshed with the gear meshed with the flapping mechanism to transmit power.

Further, the control module is composed of a flight control board, a battery support frame, an upper rudder rack, a lower rudder rack, an upper steering engine, a lower steering engine, a battery body and a wire guide ring. The flight control board is arranged in the middle of the machine body. The battery body is connected with the lower steering engine frame through the battery support frame and the battery support rod, the steering engine is meshed with the steering engine frame through gears and is connected with the steering engine frame through pins, and the battery body line is connected with the flight control board through the wire ring.

Further, the machine body takes carbon fiber material as a main body, the structure is simple and reliable, and the flapping mechanism, the driving module and the control module are arranged on the machine body so as to realize the flight and gesture control of the single-flapping-wing aircraft.

According to the attitude control method based on the gravity center, the steering engine is controlled to control the positions of the battery support frame and the battery body, and as the battery support frame and the battery body have certain weight, the overall gravity center position of the aircraft can be adjusted through controlling the position and the attitude of the battery support frame and the battery body, attitude data of the settlement aircraft are acquired in real time by the flight control system, control signals are obtained according to expected attitude feedback and are transmitted to the steering engine to be adjusted, and thus attitude control of the aircraft based on gravity center regulation is achieved.

The invention has the beneficial effects that:

1. the bionic flapping wing device has a compact and simple mechanical structure and a small volume, and can realize the bionic flapping wing function;

2. most parts of the invention are made by adopting the additive technology, and part of the parts are made of plastic gears, so that the whole machine is low in quality, low in cost and easy to modify, optimize and assemble in a real object;

3. the invention adopts the design without the tail wing, has simple structure and low dead weight of the machine body, and effectively improves the lift-weight ratio of the aircraft;

4. the attitude control mode based on the gravity center position is simple to realize, and the rolling, pitch angle attitude and lifting motion of the miniature bionic ornithopter can be controlled by only four paths of control output.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to those skilled in the art that other drawings can be obtained according to these drawings without inventive effort.

FIG. 1 is a schematic diagram of a miniature bionic ornithopter in accordance with the present invention;

FIG. 2 is a schematic view of a flapping mechanism and wings of a miniature bionic ornithopter of the present invention;

FIG. 3 is a schematic diagram of a driving module of the miniature bionic ornithopter of the present invention;

FIG. 4 is a schematic diagram of a control module of the miniature bionic ornithopter of the present invention;

in the drawings, the list of components represented by the various numbers is as follows:

1-flapping mechanism, 2-wing, 3-drive module, 4-control module, 5-fuselage, 101-upper frame, 102-lower frame, 103-meshing gear, 104-center bar, 105-center slider, 106-left wing link, 107-left wing guide bar frame, 108-right wing link, 109-right wing guide bar frame, 201-wing bar, 202-wing membrane, 203-wing pulse, 301-coreless motor, 302-motor shaft, 303-motor gear, 304-transmission gear, 401-flight control plate, 402-guide wire ring, 403-upper rudder frame, 404-lower rudder frame, 405-upper steering engine, 406-lower steering engine, 407-battery body, 408-battery support frame, 409-battery support bar.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1: a miniature bionic ornithopter and a gesture control method based on the gravity center thereof are shown in figure 1, and comprise a flapping mechanism 1, wings 2, a driving module 3, a control module 4 and a fuselage 5. The driving module 3 comprises a hollow cup motor 301, a motor shaft 302, a motor gear 303 and a transmission gear 304, wherein the hollow cup motor 301 generates driving force and transmits the driving force to the flapping mechanism 1 through the transmission gear 304 and the meshing gear, and the flapping mechanism 1 generates corresponding flapping tracks to enable the aircraft to obtain required lifting force.

The flapping mechanism 1 is shown in fig. 2, and consists of an upper frame 101, a lower frame 102, a meshing gear 103, a center rod 104, a center slide 105, a left wing connecting rod 106, a left wing connecting rod frame 107, a right wing connecting rod 108 and a right wing connecting rod frame 109. The frame, the connecting rod and the guide rod frame are all made of resin by a 3D printing process, and the printing precision is high. From the beginning of power transmission, the meshing gear 103, the center rod 104, the center slide 105 and the upper frame 101 form a group of crank slide block mechanisms, the meshing gear 103 is fixed on the frame 101 and serves as a crank to move, and the rotation of the meshing gear 103 drives the center slide block 105 connected with the left wing connecting rod 106 and the right wing connecting rod 108 to slide. The left wing connecting rod 106, the left wing guide rod frame 107, the right wing connecting rod 108, the right wing guide rod frame 109 and the upper frame 101 respectively form a pair of swinging guide rod mechanisms, and the sliding of the central sliding block 105 is converted into the swinging of the guide rod frame, so that the wings 2 connected with the guide rod frame can realize flapping tracks according to requirements.

The driving module 3 is shown in fig. 3, and consists of a hollow cup motor 301, a motor shaft 302, a motor gear 303 and a transmission gear 304. The hollow cup motor 301 is installed at the middle of one side of the frame 101 symmetrically for providing power. The cup motor 301 is connected with a motor gear 303 through a motor shaft 302, and outputs power to the motor gear 303, and the motor gear 303 is meshed with a transmission gear 304, and the transmission gear 304 is meshed with a meshing gear of the flapping mechanism 1 so as to drive the meshing gear to rotate and transmit driving force.

The control module 4 is shown in fig. 4, and is composed of a flight control board 401, a battery support frame 408, a battery support rod 409, a battery body 407, an upper steering engine frame 403, a lower steering engine frame 404, an upper steering engine 405, a lower steering engine 406 and a wire loop 402. The flight control board 401 is fixed in the middle of the machine body 5 and provides control signals. The battery body 407 is mounted on the battery support frame 408, and the battery support frame 408 is connected with the lower steering engine frame 404 through two battery support rods 409, so that the pose of the battery body 407 can be controlled by the upper steering engine 405 and the lower steering engine 406. The upper steering engine frame 403 and the lower steering engine frame 404 are respectively connected with an upper steering engine 405 and a lower steering engine 406 through gears and pins, and the upper steering engine frame 403 is connected with the machine body 5 through square holes. Therefore, the upper steering engine 405 adjusts the center of gravity of the pitching direction of the aircraft by controlling the pose of the battery body 407, and the lower steering engine 406 adjusts the center of gravity of the rolling direction of the aircraft by controlling the pose of the battery body 407 so as to achieve the aim of controlling the pose of the aircraft.

The attitude control method based on the gravity center of the miniature bionic ornithopter comprises the following implementation modes: when the flight control system detects that the pitching angle of the aircraft needs to be adjusted, a control signal can be obtained through feedback of a PID algorithm according to the expected attitude, and is transmitted to the upper steering engine 405 and the upper steering frame 403 is controlled to rotate in real time so as to adjust the pitching attitude of the aircraft. When the flight control system detects that the rolling angle of the aircraft needs to be adjusted, a control signal can be obtained through feedback of a PID algorithm according to the expected attitude, and is transmitted to the lower steering engine 406 and controls the lower steering engine frame 404 to rotate in real time so as to adjust the rolling attitude of the aircraft. Meanwhile, since the battery body 407 needs to be connected with an electric wire to supply power to the flight control board 401 by the output voltage, a wire ring 402 is installed on the machine body between the flight control board 401 and the upper steering engine frame 403, and the electric wire is penetrated out along holes on the upper steering engine frame 403 and the wire ring 402 when the machine body is assembled, so that the power wire is prevented from being wound with the machine body 5.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing has shown and described the basic principles, principal features and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims.

Claims

1. The miniature bionic ornithopter comprises a control module and is characterized in that the control module comprises a battery body, the battery body is arranged on a machine body through a connecting mechanism, and the connecting mechanism is used for controlling the pose of the battery body to adjust the pitching direction and the rolling direction gravity center of the aircraft.

2. The miniature bionic ornithopter of claim 1, wherein the control module comprises a battery support frame, a battery support bar, an upper rudder frame, a lower rudder frame, an upper rudder and a lower rudder, wherein the battery body is arranged on the battery support frame, the battery support frame is connected with the lower rudder frame through two battery support bars, the upper rudder frame and the lower rudder frame are respectively connected with the upper rudder and the lower rudder through gears and pins, the upper rudder frame is connected with the airframe, and the lower rudder frame is connected with the upper rudder frame; the control module comprises a flight control board, and the flight control board is fixedly arranged in the middle of the machine body.

3. The miniature bionic ornithopter of claim 1, wherein the aircraft comprises a flapping mechanism, the flapping mechanism comprises an upper frame, a lower frame, a meshing gear, a central rod, a central slider, a left wing connecting rod, a left wing guide rod frame, a right wing connecting rod and a right wing guide rod frame, the upper frame and the lower frame are fixedly arranged on the aircraft body, the meshing gear is arranged on the lower frame, two ends of the central rod are respectively movably arranged on the side face of the meshing gear and the central slider, the central slider passes through an installation chute of the upper frame, two sides of the upper frame are provided with a left wing connecting rod and a right wing connecting rod, two ends of the left wing connecting rod are respectively movably arranged on the central slider and the left wing guide rod frame, two ends of the right wing connecting rod are respectively movably arranged on the central slider and the right wing guide rod frame, and the left wing guide rod frame are connected with corresponding wings.

4. A miniature bionic ornithopter as claimed in claim 3, wherein the wings comprise wing bars, wing films and wing veins, the wing bars form the outer contours of the wings, the wing films are filled on the wing profiles formed by the wing bars, the wing veins are adhered to the wing films in parallel, the wing films are made of flexible materials, the edges of the top ends of the wing films are curled to form a hollow structure, and the wing bars pass through the hollow structure.

5. The miniature bionic ornithopter of claim 4, wherein the meshing gears are driven by a drive module comprising a cup motor, a motor shaft, a motor gear, and a drive gear, wherein the cup motor generates drive force and transmits the drive force to the flapping mechanism via the drive gear and the meshing gears.

6. A miniature bionic ornithopter as claimed in claim 2, wherein a wire loop is mounted on the fuselage between the flight control board and the upper steering frame, and wires are threaded out along holes in the upper steering frame and the wire loop when the fuselage is assembled.

7. A miniature bionic ornithopter according to claim 2 or 6, wherein the flight control board comprises a microprocessor and a six degree of freedom inertial measurement unit.

8. A method for controlling the attitude based on the position of the center of gravity, which is applicable to the miniature bionic ornithopter according to any one of claims 1 to 7, and is characterized by comprising the following steps: a) When the flight control system detects that the pitching angle of the aircraft needs to be adjusted, a control signal is fed back through a PID algorithm according to the expected attitude and is transmitted to the upper steering engine, and the upper steering engine frame is controlled to rotate in real time so as to adjust the pitching attitude of the aircraft; b) When the flight control system detects that the rolling angle of the aircraft needs to be adjusted, a control signal is fed back through a PID algorithm according to the expected attitude and is transmitted to the lower steering engine, and the lower steering engine frame is controlled to rotate in real time so as to adjust the rolling attitude of the aircraft; c) The gravity center of the pitching direction and the rolling direction of the aircraft is adjusted by controlling the pose of the battery body so as to achieve the aim of controlling the pose of the aircraft.

9. The attitude control method according to claim 8, wherein the battery body attitude is a rotation angle of the battery body with respect to the body.

10. The attitude control method based on the center of gravity position according to any one of claims 8 to 9, wherein the flight control system includes a microprocessor and a six-degree-of-freedom inertial measurement unit, the microprocessor being configured to receive and process data from the six-degree-of-freedom inertial measurement unit, and output control signals to the upper steering engine and the lower steering engine.