A micro ornithopter based on cruciform tail control

Abstract

The application discloses a micro flapping-wing aircraft based on cruciform tail control and belongs to the field of bionic flapping-wing aircrafts. The micro flapping-wing aircraft comprises a tail module, wherein the tail module comprises a cruciform tail, a tail connecting piece, two rudder motor connecting pieces, a rudder motor and a carbon rod connecting piece, the cruciform tail, the carbon rod connecting piece and the two rudder motor connecting pieces are all fixedly provided with the rudder motor, the two rudder motors are both provided with a rudder motor arm, the rudder motor arm of the rudder motor installed on the carbon rod connecting piece is fixedly connected with the two rudder motor connecting pieces, the rudder motor arm of the rudder motor installed on the two rudder motor connecting pieces is fixedly connected with the connecting piece, the cruciform tail is installed on corresponding groove positions of the connecting pieces, the motor is connected with two wings through a crank rocker and a swing guide rod compound mechanism after speed reduction to realize large-angle flapping of the two wings to generate lift, and through tail deflection, down airflow interacts with a wing surface to adjust the attitude of the aircraft.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the field of bionic flapping wing aircraft, and particularly relates to a micro flapping wing aircraft based on cross fin control. BACKGROUND

[0002] Micro aircraft generally refers to aircraft with each dimension less than 15 cm. Researches in bionics and aerodynamics show that when the wingspan is less than 15 cm, flapping wing flight has more advantages than fixed wing flight and rotary wing flight. Flapping wing flight has high efficiency in generating lift, which determines that it has small volume, light weight and low noise, and has strong maneuverability and flexibility. These characteristics make the micro flapping wing aircraft have very wide application prospects. In the current research on micro flapping wing aircraft, how to make the aircraft have sufficient lift is the primary and most critical problem. In numerous studies on flapping wing bionics and aerodynamics, a widely recognized high-lift mechanism is the "Weis-Fogh" mechanism. In order to utilize this mechanism, a key point is that the wings of the aircraft need to have a large flapping angle. In the aspect of attitude control of flapping wing aircraft, the popular scheme is to adjust the attitude of the aircraft body by controlling the direction of the lift generated by the flapping wings. However, this scheme has a problem that the process of adjusting the attitude of the aircraft will affect the lift of the aircraft. In addition, it has always been a design difficulty to realize the miniaturization of the aircraft while ensuring the stability of the structure and sufficient lift. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present disclosure is to provide a micro flapping wing aircraft based on cross fin control, which solves the problem of difficult attitude adjustment of the flapping wing aircraft in the prior art.

[0004] The purpose of the present disclosure can be achieved by the following technical solutions:

[0005] A micro flapping wing aircraft based on cross fin control, comprising a tail module, the tail module comprising a cross fin, a tail connecting piece, two rudder motor connecting pieces, a rudder motor and a carbon rod connecting piece, and a rudder motor, the cross fin, the rudder motor and carbon rod connecting piece and the two rudder motor connecting pieces are all fixedly installed with a rudder motor, the two rudder motors are both provided with a rudder motor arm, the rudder motor installed on the rudder motor and carbon rod connecting piece is fixedly connected with the two rudder motor connecting pieces through the rudder motor arm, the rudder motor installed on the two rudder motor connecting pieces is fixedly connected with the connecting piece through the rudder motor arm, and the cross fin is installed on the corresponding groove of the connecting piece.

[0006] In some of the disclosure, the micro ornithopter comprises a flapping mechanism, the flapping mechanism comprises a frame, two hollow cup motors are fixedly installed on the frame, motor shafts of the hollow cup motors are provided with motor gears, the motor gears, a double gear and a crank gear are fixed on corresponding positions of the frame through pins, the motor gears are meshed with large gears of the double gear, the crank gear is meshed with a small gear of the double gear, a rocker and a guide rod are movably installed on the frame, a connecting rod is arranged between the rocker and the crank gear, and two ends of the connecting rod are movably installed on the rocker and the crank gear respectively, one end of the rocker is movably installed in a sliding groove of the guide rod, and the crank gear, the connecting rod, the rocker and the guide rod form a crank rocker and swing guide rod composite mechanism, and the wing is connected with the guide rod through a wing front edge connecting piece.

[0007] In some of the disclosure, the side edge carbon rod and the front edge carbon rod are installed at a right angle, so that the wing can present a flapping form similar to the hummingbird wing during swinging.

[0008] Advantages of the disclosure:

[0009] 1. The micro bionic ornithopter with a large flapping angle and attitude control through a tail wing is reasonable in layout, compact in mechanism, small in size and light in weight, and can realize the bionic flapping wing function.

[0010] 2. The crank rocker and swing guide rod composite mechanism is used to realize a large angle swinging output while ensuring compact structure layout, so that the wing at the output end can effectively utilize the "Weis-Fogh" mechanism to generate a high lift.

[0011] 3. The tail wing and the downward airflow of the wing interact to realize the attitude control of the ornithopter, and this attitude control mode does not couple with the overall lift of the aircraft, in other words, the process of attitude adjustment does not affect the overall lift of the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the disclosure or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0013] Figure 1 is a schematic diagram of the overall structure of the present application;

[0014] Figure 2 is a schematic diagram of the flapping mechanism of the present application;

[0015] Figure 3 is a schematic diagram of the frame and the wing of the present application;

[0016] Figure 4 is a schematic diagram of the tail wing structure of the present application;

[0017] In the figure:

[0018] Reference signs: 1 - motor gear, 2 - double gear, 3 - crank gear, 4 - connecting rod, 5 - rocker, 6 - guide rod, 7 - wing leading edge connecting piece, 8 - hollow cup motor, 9 - frame, 10 - wing side edge fixing piece, 11 - wing, 12 - rudder, 13 - rudder and carbon rod connecting piece, 14 - rudder arm, 15 - two rudder connecting pieces, 16 - tail wing connecting piece, 17 - cruciform tail wing, 18 - battery fixing bracket, 19 - lithium battery, 20 - flight control board, 21 - square carbon fiber rod. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present disclosure.

[0020] As Figures 1-4 shown, a micro flapping-wing aircraft based on cruciform tail wing control mainly comprises a flapping mechanism part, a tail wing part, a circuit part and wings 11.

[0021] In the flapping mechanism part, the frame 9 is the main body, the hollow cup motor 8 is fixed on the frame through interference fit with the motor hole, the motor gear 1 is installed on the motor shaft of the hollow cup motor, the motor gear 1, the double gear 2 and the crank gear 3 are fixed on the corresponding positions of the frame through pins, and the gear set composed of the three achieves speed reduction of the motor. The crank gear 3, the connecting rod 4, the rocker 5 and the guide rod 6 constitute a crank rocker and swing guide rod compound mechanism, the hinge between the rod members of the mechanism and between the rod members and the frame is completed by using pins, and the function of the mechanism is to convert the circular motion input by the motor into the swing of the guide rod. The wing leading edge connecting piece 7 can fix the leading edge carbon rod of the wing on the guide rod 6, so that the wing leading edge has the same amplitude of swing as the guide rod. Each of the two wings has a set of the above transmission chain, and the two sets of transmission chains are symmetrically arranged on the frame;

[0022] In some disclosures, the rocker 5 adopts a special-shaped design, the rocker 5 is V-shaped, the length ratio of the two ends is 7.66:6, the included angle is 83.22°, the rocker 5 is movably installed at the middle position of the frame, the two ends of the rocker 5 are movably installed in the sliding grooves of the crank gear and the guide rod respectively, and the special-shaped design of the rocker 5 is to reduce the size of the frame and compress the installation space of the compound mechanism, so as to ensure that the rocker of the crank rocker mechanism can realize 80° swing.

[0023] In some embodiments, the guide rod 6 is shaped like a V, with the angle between the two ends of the V-shaped guide rod being 45°, so that the wings can flap symmetrically about the plane of the fuselage. The middle of the guide rod 6 is movably mounted on the frame, and the sliding groove of the guide rod 6 is arranged at the end away from the mounting point of the rocker and the frame. The other end of the guide rod 6 is connected to the wing leading edge connector.

[0024] In some embodiments, the wing side edge of the aircraft is fixed as follows: the frame 9 is provided with wing side edge fixing members 10 on both sides. The top end of the wing 11 side edge carbon rod is fixed to the frame through the wing side edge fixing member 10, and the low end of the side edge carbon rod is fixed to the frame through the hole on the frame. The wing 11 leading edge carbon rod is fixed to the guide rod 6 through the wing leading edge connector 7. Through the above series of fixation and connection, the wing can achieve single-degree-of-freedom swing with large flapping angle.

[0025] Further, the side edge carbon rod and the leading edge carbon rod are installed at right angles. In this way, the wing can present a flapping form similar to the hummingbird wing during the swing.

[0026] As shown in Figure 4 The tail part of the aircraft is composed of two rudders 12 and their rudder arms 14, rudder and carbon rod connectors 13, two rudder connectors 15, tail connectors 16 and cruciform tail 17. Figure 4 The right middle rudder is installed on the upper surface of the connector 13, and its rudder arm is fixed to the connector 15 through a screw. Figure 4 The left middle rudder is installed on the upper surface of the connector 15, and its rudder arm is fixed to the connector 16 through a screw.

[0027] The cruciform tail 17 is installed on the corresponding groove of the connector 16 and can be fixed by glue. In the above mechanical structure, the two pieces of the cruciform tail are respectively parallel to the rotation axes of the two rudders. Thus, the two rudders can control the swing of the piece of tail parallel to its axis in the direction of the wing surface normal. The swing amplitude determines the size of the force of the wing downward airflow acting on the tail, and the component of the force of the wing downward airflow acting on the tail in the wing surface normal direction will generate a torque relative to the center of gravity of the aircraft, thereby realizing the control of the attitude of the aircraft. While one piece of tail swings, the other piece of tail only rotates in its current plane, and the force of the wing downward airflow acting on it does not change. Therefore, this attitude control method theoretically makes the attitude control in the pitch direction and the roll direction not coupled, so as to reduce the difficulty of attitude control and increase the stability of attitude control.

[0028] The circuit part of the aircraft is mainly composed of a battery fixing frame 18, a lithium battery 19 and a flight control board 20, as shown in Figure 1As shown, the battery holder is fixed on the square carbon fiber rod 21 for mounting the lithium battery. The flight control board can be directly fixed on the carbon fiber rod 21 by hot melt glue.

[0029] The rack 9, the connecting piece 13 and the battery holder 18 are collectively fixed on the square carbon fiber rod 21, so that the flapping mechanism part, the tail part and the circuit part form an integral whole.

[0030] Further, most parts of the aircraft can be made of low-density high-strength materials by injection molding or 3D printing technology, the strength of the parts is large, the weight of the whole machine is light, and it is easy to modify and optimize.

[0031] Working principle:

[0032] The present application provides two motors through a crank rocker and a swing guide rod compound mechanism to realize large-angle flapping of two wings after reduction, the flapping form of the wings and the lift generation mode are similar to the hummingbird, Figure 1 The attitude of the aircraft is its normal flight attitude. Due to the similar flight mode of the hummingbird, the aircraft can easily realize vertical take-off and hovering flight, the lift generated by the wings is vertically upward, so the airflow generated by the wing flapping is vertically downward, when the tail wing deflects, the downward airflow will interact with the wing surface, thereby adjusting the attitude of the aircraft. The rudder drives the wing surface parallel to the shaft to deflect and the wing surface parallel to the shaft to deflect, respectively realizing the attitude adjustment of the aircraft in the roll direction and the pitch direction, and the energy and instructions for the action of the motor and the rudder come from the battery and the program inside the flight control board.

[0033] In the description of the present application, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0034] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A miniature ornithopter based on cruciform tail control comprising a tail module, characterized in that, The tail module comprises a cruciform tail, a tail connecting piece, two rudder connecting pieces, a rudder and a carbon rod connecting piece, and the cruciform tail, the rudder and the carbon rod connecting piece are all fixedly provided with the rudder, the rudders are all provided with rudder arms, the rudder installed on the carbon rod connecting piece is fixedly connected with the two rudder connecting pieces, the rudder arms of the rudders installed on the two rudder connecting pieces are fixedly connected with the connecting pieces, and the cruciform tail is installed on the corresponding groove positions of the connecting pieces. The micro flapping-wing aircraft comprises a flapping mechanism, the flapping mechanism comprises a frame, two hollow cup motors are fixedly installed on the frame, motor shafts of the hollow cup motors are provided with motor gears, the motor gears, a double gear and a crank gear are fixed on corresponding positions of the frame through pins, the motor gears and large gears of the double gear are mutually engaged, the crank gear and small gears of the double gear are mutually engaged, a rocker and a guide rod are movably installed on the frame, a connecting rod is arranged between the rocker and the crank gear, and both ends of the connecting rod are movably installed on the rocker and the crank gear respectively, one end of the rocker is movably installed in a sliding groove of the guide rod, and the crank gear, the connecting rod, the rocker and the guide rod form a crank rocker and swinging guide rod compound mechanism, and wings are connected with the guide rod through wing leading edge connecting pieces. The rocker adopts a special-shaped design, the rocker is V-shaped, the length ratio of both ends is 7.66:6, the included angle is 83.22°, and the rocker is movably installed at a middle position of the frame. The guide rod adopts a special-shaped design, the guide rod is V-shaped, the included angle of both ends is 45°, the guide rod is movably installed at a middle position of the frame, and the sliding groove of the guide rod is arranged at one end away from the rocker and the installation point of the frame.

2. A flapping micro air vehicle based on cruciform tail control as claimed in claim 1, wherein, The micro flapping-wing aircraft comprises a circuit module, and the circuit module is used for controlling the rudders and the hollow cup motors.

3. A flapping micro air vehicle based on cruciform tail control as claimed in claim 1, wherein, The two hollow cup motors fixedly installed on the frame are arranged in a central symmetry.

4. A flapping micro air vehicle based on cruciform tail control as claimed in claim 1, wherein, The cruciform tail comprises a wing surface for controlling a pitching attitude and a wing surface for controlling a rolling attitude, the two wing surfaces are perpendicular to each other, in an initial state, the wing surface for controlling the pitching attitude is substantially coplanar with a forward plane of the aircraft, and the wing surface for controlling the rolling attitude is substantially coplanar with a lateral plane of the aircraft.

5. A flapping micro air vehicle based on cruciform tail control as claimed in claim 1, wherein, The wings adopt PET polyester film, and the leading edge, the wing root and the wing vein of the wings are all bonded with carbon fiber rods.

6. A flapping micro air vehicle based on cruciform tail control as claimed in claim 1, wherein, Both sides of the frame are provided with wing side edge fixing pieces, top ends of wing side edge carbon rods are fixed on the frame through the wing side edge fixing pieces, low ends of the side edge carbon rods are fixed on the frame through hole positions of the frame, and a wing leading edge carbon rod is fixed on the guide rod through a wing leading edge connecting piece.

7. A flapping micro air vehicle based on cruciform tail control as claimed in claim 6, wherein, The side edge carbon rod and the leading edge carbon rod are installed at a right angle.

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