CN114604423A - Bionic bird aircraft - Google Patents

Abstract

The invention discloses a bionic bird aircraft in the technical field of aircraft, comprising a skeleton, a driving mechanism mounting frame is fixedly connected to the front end of the skeleton, and a double-wing flapping mechanism and a wing-wing mechanism are mounted on the driving mechanism mounting frame; The drive mechanism mounting frame includes a frame body that is fixedly connected to the skeleton. In this scheme, a symmetrical double-crank and double-rocker mechanism is adopted through the double-wing flapping mechanism, so that the left and right flapping of the two groups of wing-wing mechanisms is synchronized, so that the device It can fly better, and the degree of freedom of the double-wing flapping mechanism is , which makes the load of the double-wing flapping mechanism lower; through the setting of the tail direction changing mechanism, there are two degrees of freedom, that is, the left tail and right tail can be independent respectively. When the left and right tails swing up and down at the same time, the aerodynamic focus moves backward, which can control the pitching action of the prototype; when the left and right tails swing up and down respectively, the aerodynamic focus shifts, which can control the yaw action of the prototype.

Description

a bionic bird

technical field

The invention relates to the technical field of aircraft, in particular to a bionic bird aircraft.

Background technique

The functions of things are far superior to any artificially manufactured machinery, and bionics is a discipline that aims to realize and effectively apply biological functions in engineering. For example, with regard to information reception, information transmission, automatic control systems, etc., the structure and function of this organism have given great inspiration in mechanical design.

After retrieval, Chinese Patent No. CN202020706203.3 discloses a bionic hummingbird flapping-wing aircraft, including a main fixed bionic shell, a landing support assembly, a bionic wing, a wing drive mechanism, a microcontroller, an inclination sensor, and a wireless communication module , power supply and navigation and positioning module, the main fixed bionic shell is arranged in a streamlined shape like a hummingbird, and the landing support assembly is arranged at the lower end of the main fixed bionic shell.

The beneficial effects of the above device are: reasonable design, easy operation, high bionic, convenient operation, can ensure video anti-shake, imitate hummingbird flapping wings to rise and fall straight, easy to assemble, maintain and improve, facilitate mass production and reduce production cost.

However, in the actual application process, the existing bionic avian aircraft cannot simulate the flapping of the wings of birds, resulting in the inability of the aircraft to run stably during flight, and cannot simulate the effect of the muscles on the wings of birds on feathers, resulting in inability to When the aircraft performs a certain range of motions, a combination of pitching, fluttering and sweeping can be generated. For this purpose, we propose a bionic bird aircraft.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a bionic bird aircraft to solve the above-mentioned problems in the background art.

In order to achieve the above purpose, the present invention provides the following technical solutions: a bionic bird aircraft, including a skeleton, the front end of the skeleton is fixedly connected with a drive mechanism mounting frame, and a double-wing flapping mechanism and a winged flapping mechanism are installed on the drive mechanism mounting frame. wing mechanism;

The drive mechanism mounting frame includes a frame body that is fixedly connected to the frame, the double-wing flapping mechanism includes a motor 1 installed on the frame body, and the output shaft of the motor 1 is meshed with a gear installed on the frame body. , the gear 1 is meshed with the gear 2 hinged on the frame body, the gear 2 is installed on the frame body through the installation shaft 1, and one end of the installation shaft 1 is fixedly connected with the gear 3, the gear 3 and the frame body The upper hinged gears are meshed and connected, the gears are hinged on the frame body through the installation shaft 2, and two sets of gears are hingedly installed on the frame body in a symmetrical distribution, and the two sets of gears are meshed and connected, and the gears The surface of the fourth is fixedly connected with a connecting shaft 1, the connecting shaft 1 is sleeved with a connecting rod 1, the other end of the connecting rod 1 is sleeved on the installation shaft 2, and the connecting shaft 1 is sleeved with a connecting rod 2, so The other end of the second connecting rod is hinged with a driving rod through the second connecting shaft, and the driving rod is hinged on the frame body through the hinge shaft;

The tail end of the skeleton is fixedly connected with a tail direction changing mechanism;

The tail direction changing mechanism includes a plug board inserted at the tail end of the frame, the surface of the plug board is fixedly connected with a third motor, the output shaft of the motor three is connected with the front tail wing hinged on the plug board, and the front tail wing is connected. Two sets of openings are arranged on the surface of the two sets of openings, and two sets of symmetrically distributed rear fins are hingedly installed in the two sets of openings, and two sets of miniature steering gears are installed on the surface of the front fins. The rear rear wing is independently driven and connected.

Preferably, the drive mechanism mounting frame is composed of two sets of frame bodies, reinforcing rods are fixedly connected between the two sets of frame bodies, and the two sets of frame bodies are hollowed out and separated into a plurality of triangular structures.

Preferably, the first gear, the second gear, the third gear and the fourth gear are provided with lightening holes.

Preferably, the wing-wing mechanism includes a mounting plate mounted on the driving rod, the surface of the mounting plate is provided with mounting holes that are equidistant and linearly distributed, and each group of mounting holes on the mounting plate is inserted with a Rotating the fixed shaft, the surfaces of each set of the fixed shafts are fixedly connected with synchronizing wheels, the synchronizing wheels are connected by a synchronous belt, the surface of the mounting plate is fixedly connected with the second motor, and the output shaft of the second motor is connected It is drivingly connected with one set of fixed shafts, and the fixed shafts are fixedly connected with middle-layer fins, outer-layer fins and inner-layer fins.

Preferably, in the adjacent two sets of the fixed shafts, one set of the fixed shafts is fixedly connected with the middle-layer fins, and the other set of the fixed shafts is fixedly connected with the outer-layer fins and the inner-layer fins, and the The outer layer wings are located above the middle layer wings, and the inner layer wings are located below the middle layer wings.

Preferably, the middle-layer fins, the outer-layer fins, and the inner-layer fins are staggered.

Preferably, a wing vein is fixedly connected to the rear empennage.

Preferably, the two sides of the skeleton are fixedly connected with an installation table through struts, and a controller is installed on the installation table, and the controller is provided with a system control module, a wireless transmission module and a sensor detection module.

Compared with the prior art, the beneficial effects of the present invention are:

1. In this scheme, the double-wing flapping mechanism adopts a symmetrical double-crank and double-rocker mechanism, so that the left and right flapping of the two sets of wing-wing mechanisms are synchronized, so that the device can fly better, and the double-wing flapping mechanism The degree of freedom is , which makes the load of the double-wing flapping mechanism lower;

2. In this scheme, the wing mechanism consists of middle-layer wings, outer-layer wings, and inner-layer wings to form bird wings, and the middle-layer wings, outer-layer wings and inner-layer wings simulate the multi-layered wings on bird wings. At the same time, the middle wing, outer wing and inner wing are stacked on each other, so that the overall sealing of the wing mechanism is better, and greater buoyancy can be generated during the flapping process;

3. In this scheme, the middle wing, the outer wing and the inner wing can be steered and adjusted at the same time by driving the second motor, so that the wing mechanism can simulate the effect of the muscles on the bird's wings on the feathers, so that the wing mechanism is flapping. During the process, the flapping surface and position can be changed, so that the wing mechanism can generate better flapping buoyancy;

4. In this scheme, there are two degrees of freedom through the setting of the tail direction changing mechanism, that is, the left tail and right tail can swing up and down independently. When the left and right tail swing up and down at the same time, the aerodynamic focus moves backward, which can control the movement of the prototype. Pitching action; when the left and right tails swing up and down respectively, the aerodynamic focus is shifted, and the yaw action of the prototype can be controlled.

Description of drawings

Fig. 1 is the front view schematic diagram of the structure of the present invention;

Fig. 2 is the rear view schematic diagram of the structure of the present invention;

3 is a schematic top view of the structure of the present invention;

Fig. 4 is the partial structure schematic diagram of the present invention;

5 is a schematic structural diagram of the drive mechanism mounting frame and the double-wing flapping mechanism of the present invention;

6 is a schematic diagram of the structural installation of the wing mechanism of the present invention;

7 is a schematic structural diagram of the wing mechanism of the present invention;

8 is a schematic exploded schematic diagram of the structure of the wing mechanism of the present invention;

FIG. 9 is a schematic structural diagram of the tail direction changing mechanism of the present invention;

10 is a schematic structural diagram of a drive mechanism mounting frame of the present invention;

Figure 11 is a schematic diagram of a bird wing structure;

Figure 12 is a schematic diagram of parameter data;

Figure 13 is a schematic diagram of a common transmission mechanism.

In the figure: 1. Frame; 2. Drive mechanism mounting frame; 201, Frame body; 202, Reinforcing rod; 3. Double-wing flapping mechanism; 301, Motor 1; 302, Gear 1; 303, Gear 2; 304, Installation Shaft one; 305, gear three; 306, gear four; 307, installation shaft two; 308, connecting rod one; 309, connecting shaft one; 310, connecting rod two; 311, connecting shaft two; 312, driving rod; 313, Hinged shaft; 4, wing mechanism; 401, mounting plate; 402, fixed shaft; 403, synchronous wheel; 404, synchronous belt; 405, middle wing; 406, outer wing; 407, inner wing; 408 , Motor 2; 5. Rear direction change mechanism; 501, Insert board; 502, Motor 3; 503, Front tail; 504, Micro steering gear; 505, Rear tail; 506, Wing pulse; 8. Controller.

Detailed ways

Example 1

Please refer to Figure 1-13, the present invention provides a technical solution:

A bionic bird aircraft, the front end of the skeleton 1 is fixedly connected with a drive mechanism mounting frame 2, and the double-wing flapping mechanism 3 and the wing-wing mechanism 4 are installed on the driving mechanism mounting frame 2, so that the double-wing flapping mechanism 3 can be operated after operation. Drive the wing mechanism 4 to move, thereby controlling the skeleton 1 to fly;

The two sets of frame bodies 201 are connected by reinforcing rods 202, so that the overall structure of the drive mechanism mounting frame 2 has strong stability, and the inside of the frame bodies 201 is hollowed out to reduce weight, and is separated into a plurality of triangular mechanisms, so that the frame body 201 is hollowed out to reduce weight. The strength of the body 201 is enhanced;

The double-wing flapping mechanism 3 includes a motor one 301 installed on the surface of the frame body 201, and a gear one 302 is hinged between the two sets of frame bodies 201, and the output shaft of the motor one 301 and the gear one 302 are connected in a driving manner, so that the motor one 301 It can drive the gear one 302 to rotate;

At the same time, the gear two 303 is hingedly connected to the one side of the gear one 302 between the two sets of frame bodies 201 through the mounting shaft one 304, and the gear two 303 is meshed with the mounting shaft one 304;

One end of the first installation shaft 304 is fixedly connected with the third gear 305, and the third gear 305 is meshed with the hinged gear four 306 on the frame body 201. There are two sets of gear four 306 hingedly installed, and the two sets of gear four 306 mesh with each other;

After the motor one 301 is turned on, the motor one 301 drives the gear one 302 to mesh with the gear two 303 to rotate, the gear two 303 drives the gear three 305 to rotate synchronously, and the gear three 305 meshes with the gear four 306 to rotate, and the two sets of gear four 306 mesh with each other, so that the two The four sets of gears 306 can rotate at the same time, and the rotation directions of the four sets of gears 306 are opposite, so that the two sets of gears 306 can drive the two sets of wing mechanisms 4 installed on the drive mechanism mounting frame 2 to flap, so that the skeleton 1 can move. flight;

Gear 1 302, gear 2 303, gear 3 305 and gear 4 306 have lightened holes in order to reduce weight;

Taking a group of gear four 306 as an example, the surface of the gear four 306 is fixedly connected with a connecting shaft one 309, and the connecting shaft one 309 is sleeved with a connecting rod one 308, and the other end of the connecting rod one 308 is sleeved on the installation shaft two 307, When the gear 4 306 rotates, it can drive the connecting rod 1 308 to rotate, and at the same time, the connecting shaft 1 309 is covered with a connecting rod 2 310, and the other end of the connecting rod 310 is hinged with a driving rod 312 through the connecting shaft 2 311, so that the gear 4 306 rotates During the process, the second connecting rod 310 can be driven to rotate, which further enables the second connecting rod 310 to drive the driving rod 312 to rotate. At the same time, the middle position of the driving rod 312 is hinged on the frame body 201 through the hinge shaft 313, so that the driving rod 312 takes the hinge shaft 313 as the center of the circle. Rotate on the frame body 201;

Since the connecting rod 1 308, the connecting rod 2 310 and the driving rod 312 form a connecting rod, the gear 4 306 can drive the driving rod 312 to swing on the frame body 201 with the hinge shaft 313 as the center after a complete circular motion, and further The wing-wing mechanism 4 installed on the drive rod 312 is made to swing, thereby simulating the flapping of the bird's wings, so that the device can fly;

The wing mechanism 4 includes a mounting plate 401 mounted on the driving rod 312. The surface of the mounting plate 401 is provided with mounting holes that are equidistant and linearly distributed, and a rotatable fixed shaft 402 is inserted in each set of mounting holes. The surfaces of 402 are fixedly connected with synchronizing pulleys 403, and the synchronizing pulleys 403 are connected by a synchronizing belt 404 in a driving manner. At the same time, the surface of the mounting plate 401 is fixedly connected with the second motor 408, the output shaft of the second motor 408 and a set of fixed shafts 402. Drive connection, so that the second motor 408 can drive all fixed shafts 402 to rotate synchronously;

In each adjacent two sets of fixed shafts 402, one set of fixed shafts 402 is fixedly connected with the middle-layer fins 405, while the other set of fixed shafts 402 is fixedly connected with the outer-layer fins 406 and the inner-layer fins 407, and the outer-layer fins The wings 406 are located above the middle-layer wings 405, the inner-layer wings 407 are located below the middle-layer wings 405, and the middle-layer wings 405, the outer-layer wings 406, and the inner-layer wings 407 are distributed in a staggered manner. 405. The outer wings 406 and the inner wings 407 simulate the feathers on the wings of birds, so that the double-wing flapping mechanism 3 can fly better during the flapping process of the driving wing mechanism 4;

In addition, the middle-layer wings 405, the outer-layer wings 406, and the inner-layer wings 407 can simulate different feathers on the wings of birds, respectively, and the middle-layer wings 405, the outer-layer wings 406, and the inner-layer wings 407 are staggered. Stacked on each other, the gap between the wing-wing mechanism 4 as a whole is smaller, so that the wing-wing mechanism 4 increases the contact surface with the air during the fluttering process, generating greater buoyancy, so as to fly;

Moreover, the second motor 408 can drive the middle-layer wings 405, the outer-layer wings 406, and the inner-layer wings 407 to rotate at the same time, so that the wing-wing mechanism 4 simulates the muscle movement on the bird's wings, so that the wing-wing mechanism 4 generates during the flapping process. The direction of buoyancy is changed to adjust the flight posture;

The rear end of the skeleton 1 is provided with a vertical slot, and a tail direction changing mechanism 5 is installed in the slot;

The rear direction changing mechanism 5 is inserted into the slot at the rear end of the frame 1 through the insert plate 501. The surface of the insert plate 501 is provided with a horizontal slot, and a rotatable front rear wing 503 is installed in the vertical slot. A third motor 502 is fixedly connected to the surface, and the third motor 502 can drive the front rear wing 503 to rotate, so that the direction of the rear direction changing mechanism 5 is adjusted;

The surface of the front fin 503 is provided with two sets of openings, and two sets of symmetrically distributed rear fins 505 are hingedly installed in the two sets of openings. At the same time, two sets of miniature steering gears 504 and two sets of micro steering gears are installed on the surface of the two sets of front fins 503. The output shafts of the 504 are independently connected with the two sets of rear fins 505, so that the two sets of micro steering gears 504 can drive the two sets of rear fins 505 to rotate independently;

Wing veins 506 are fixedly connected to the rear fin 505, which increases the flexibility of the rear fin 505;

Two sides of the skeleton 1 are fixedly connected with an installation table 7 through the support rod 6, and a controller 8 is installed on the installation table 7;

Embodiment 2

Please refer to Fig. 1-13, on the basis of Embodiment 1, the present invention provides a technical solution:

A bionic bird aircraft, the control system of this scheme is based on the modular design idea, which is divided into three modules: system control module, wireless transmission module and sensor detection module. The whole control hardware system is built with an embedded microcontroller as the core to select sensors. , designed a human-computer interaction window based on Android system;

Due to the strong scalability of the Android platform, the human-computer interaction terminal of the bionic bird can perform functions such as camera, intelligent control, and intelligent obstacle avoidance, which improves the practicability and human-computer interaction performance of the bionic bird, making it convenient and easy to operate. control.

There is a control chip inside the controller 8. The processing chip is the core of the controller. The correct selection of the chip is extremely important for the control of the controller. The principle of selection is to meet the control requirements of the mechanical bird, including real-time, sensitivity, Data processing capability, number of peripheral interfaces and power consumption, etc. In addition, since it is mounted on a mechanical bird and flies in the air, the adaptability of the processing chip to the working environment, volume packaging, etc. must also be considered.

STM32F103RCT6 has I2C, SPI, serial port and other communication interfaces. The program storage capacity is 256K, the program memory is flash memory, the random access memory size is 48K, the speed is 72Mkz, and the package/shell is 64-LQFP. This chip has only 64 leads Feet, but functions and resources have been met.

In this way, the area of the chip is only 10mm*10mm, which requires a small area of the control board, which is convenient for the installation and carrying of the bionic bird. It is very suitable as a controller for a bionic mechanical bird. Therefore, the main control chip of the bionic mechanical bird embedded flight controller is determined to be the above-mentioned STM32 chip.

The controller 8 is also equipped with a wireless transmission module, which can ensure the mutual communication between the bionic mechanical bird and the ground measurement and control system. In the manual remote controller, the throttle, wings and tail angles of the mechanical bird can be remotely controlled through the 2.4G remote controller. ;

However, another wireless transmission module needs to be added. The embedded aircraft controller of the mechanical bird has a wireless module, and the ground measurement and control system also has a wireless module, and the two communicate with each other.

The bionic mechanical bird embedded flight controller adopts Zigbee wireless module, and uses serial port communication with the main control chip. In this design, serial port 3 (PB10 and PB11) is used. This module is easy to use, and only needs to be set through the serial port according to the protocol. Can. Here, in order to enable the controller to send data in time, the baud rate is set to 115200 and set to broadcast mode, that is, it can send information to multiple mechanical birds at the same time;

Moreover, when the mechanical bird transmits information to the ground, it can also be received by multiple receiving points at the same time, reducing the loss of information.

A sensor module is installed in the controller 8. As the position information sensor of the bionic mechanical bird, the GPS communicates with the main control chip through the serial port. This design uses serial port 2 (PA2 and PA3) in this module, of which PA2 is used as the serial port. Sending pin, PA3 is the receiving pin. In the IO settings, the software sets the send pin as a push-pull output, and the receive pin as a floating input. Initially set the baud rate to 9600, the word length is 8-bit data format, a stop bit, and the mode is set to receive and transmit mode. In order to facilitate sending and receiving, the parameters are packaged into structures when reading and writing GPS. The structure related to position information is used as a structure nmea_msg, the structure related to time is nmea_utc_time, and the structure related to satellite information is used as structure umea_slmsg, which is related to time pulse. The related ones are _ublox_cfg_tp, and the structure related to the message is _ublox_cfg_msg, etc. The purpose of setting the structure is to better group parameters without causing confusion due to too many parameters. In addition, in order to facilitate storage and transmission, integers are used to store, longitude and latitude are expanded by 100,000 times, the altitude is expanded by 10 times, and the speed is expanded by 1,000 times, and, considering the size of the data, the longitude and latitude are stored in 4 bytes. , the altitude is saved by shaping, the speed is saved by two bytes, and other information is also saved by the corresponding number of bytes. The principle is that the size of the data can be accommodated without wasting storage space.

When the GPS is initialized, first check whether the GPS hardware is connected, and then set the positioning information update time, which is set to 200ms here, and then set the baud rate of the module to 38400, and then set UART2 to the same baud rate for correct communication. Then set the receiving and sending buffers of serial port 2, and then receive and interpret through the parameters of GPS.

Embodiment 3

Please refer to Fig. 1-13, on the basis of Embodiment 1, the present invention provides a technical solution:

A design idea of a bionic bird aircraft:

1. Analysis of bird muscle structure: when flying in the air, it has a better aerodynamic shape. The body of birds changes to a certain streamlined contour during flight, which reduces flight resistance and saves energy, and the section of the wings also has the same fixed shape. Wing aircraft airfoil similar curve. When birds fly in the air, through the joint action of body muscles and bones, the wings can produce a combination of pitching, flapping and sweeping movements within a certain limit. The shoulder joint participates in all forms of movement, and the elbow The upper joint mainly produces spanwise folding movement during the upward flapping phase of the wing, and the wrist joint is mainly responsible for all the movement modes of the outer wing. The bird wing structure is shown in Figure 11 of the description.

2. Physiological parameter design: The weight of general birds is 200g to 400g. Through the analysis and estimation of the existing device, it can be determined that the weight of the device is about 220g. According to the data shown in Figure 12 of the manual, it can be obtained Required parameters:

(1) Full wingspan b

b=1.17m ^0.39 ≈0.65(m)

(2) wing area s

s=0.16m ^0.72 ≈0.054(m ² )

(3) Wing load F

F=62.2m ^0.28 ≈ 40.7(N/m ² )

(4) Aspect ratio AR

AR=8.56m ^0.06 ≈7.82

(5) flapping frequency f

f=3.87m- ^0.33 ≈ 6.4(HZ)

(6) Minimum power speed v

v=5.7m ^0.16 ≈ 4.5 (m/s).

3. Overall mechanical structure design: Through the above calculation, it can be seen that the flapping frequency of the aircraft is 6.4HZ. Because the flapping aircraft is different from birds, the flapping frequency is set to 7HZ, and the rated voltage of the selected battery is 7.4V , The motor in the double-wing flapping mechanism is a commonly used kv2400 motor such as a model aircraft, so it can be seen that the speed of the motor is 17760r/min. In order to meet the requirements of the flapping frequency, this scheme is divided into two stages of gear reduction according to the overall function. Group, two-wing flapping mechanism, tail changing mechanism;

The double-wing flapping mechanism is powered by KV2400 DC motor. After passing through the secondary gear reduction group, it is transmitted to the double-crank and double-rocker mechanism of the wings;

(1) Design of two-stage gear reduction group

The motor speed of the commonly used model aircraft KV2400 is high, so the gear reduction group needs to be designed, and the secondary gear reducer of the flapping aircraft needs to meet certain requirements:

1. In the secondary reducer, in order to prevent interference and reduce the bending deformation of the shaft under the action of the bending moment, the arrangement of the high-speed gear should be away from the torque input end;

2. Most of the secondary reducers use involute standard spur gears, and the pressure angle α is selected as 20°;

3. The standard value of the first series should be selected first for the wheel modulus. Usually, in order to avoid gear undercut, the number of teeth of the gear z ≥ 17 is selected.

The flapping frequency of this scheme is 7HZ. After consulting the data, it can be seen that the speed of the motor will be reduced to 50%-60% after the load is applied, so the transmission ratio range can be calculated to be 21-25. According to the secondary gear reducer set According to the transmission ratio distribution principle of the expansion type, the transmission ratio of the primary gear is i ₁ =5.6, and the transmission ratio of the secondary gear is i ₂ =4.3. Through the design of the secondary gear reduction group, the final gear parameters are:

gear one gear two gear three gear four modulus 0.5 0.5 0.5 0.5 number of teeth 17 95 17 73 Index circle diameter 8.5 47.5 8.5 36.5 Addendum diameter 9.5 48.5 8.5 37.5 Root circle diameter 7.25 46.25 7.25 35.25 tooth width 10 8 10 8

(2) Design of double-wing flapping mechanism

In order to avoid excessive load, the double-wing flapping mechanism should adopt a flapping mechanism with a degree of freedom of 1. The common transmission mechanism is shown in Figure 13 in the specification;

(a) The left and right joysticks in the scheme are inconsistent, causing the left and right wings to flap significantly asymmetrically, resulting in aerodynamic imbalance and poor stability of the aircraft;

(b) In the scheme, the left and right completely symmetrical flapping can be achieved, but the use of sliders has large frictional force, large energy loss and low transmission efficiency;

(d) The mechanism in the scheme is relatively complex, and the theoretical calculation requirements are high.

In order to make the mechanism have good transmission efficiency, reduce the complexity of the mechanism, and have the same flapping performance of the left and right wings, we choose (c) scheme, using a double crank and double rocker mechanism.

(3) Design of the rear direction changing mechanism

When flying, large birds cannot flexibly control their wings like insects. They often need to use the auxiliary function of the tail to balance their bodies, and in the symmetrical double-crank and double-rocker mechanism, due to the consistency of the left and right flapping patterns, Movements such as steering and yaw are not possible. Therefore, the tail mechanism has a great influence on the moment balance state of the flapping prototype during flight. The static stability of the prototype can be achieved by moving the aerodynamic focus behind the center of gravity by the tail mechanism, and the steering torque required for the deflection of the prototype can also be achieved. By controlling the tail mechanism;

Observing the body structure of large birds, it can be found that there is a bone joint at the connection between the bird's tail and the body, which can make the tail swing horizontally, vertically and rotate around the axis of the body;

However, in the actual prototype design process, if there are too many degrees of freedom of the tail, it will inevitably increase the weight of the fuselage and make the control of the tail more complicated;

Therefore, the tail mechanism designed in this scheme has only two degrees of freedom, that is, the left tail and right tail can swing up and down independently, as shown in Figure 9 of the manual; Control the pitching action of the prototype; when the left and right tails swing up and down respectively, the aerodynamic focus is shifted, and the yaw action of the prototype can be controlled.

Embodiment 4

Please refer to Figures 1-13. On the basis of Embodiment 3, the present invention provides a technical solution:

Electronic hardware selection of a bionic bird aircraft:

1. Selection of power motor

The power required for the flapping of the wings in the prototype is mainly provided by the brushless motor. The reason is that the DC brushless motor has the following excellent characteristics: high quality assurance, good workmanship and strong controllability.

In this work, an aircraft model grade DC brushless motor is selected as the power input unit of the flapping wing prototype, and a corresponding brushless electronic governor is matched to control the rotation speed of the DC motor. For the selection of the motor, this work mainly considers that the power required for the flapping of the wings is 7HZ. After consulting the data, the input power of the motor can be expressed as:

S _L ——the lift safety factor of the wing, which is taken as 2 here;

m——the mass of the prototype (kg), which is taken as 0.22 here;

τ _b ——the effective arm length (m) of the wing to generate lift, which is taken as 0.6 here;

ω——The angular velocity of the wing flapping (rad/s)

λ——The transmission efficiency of the flapping mechanism, which is taken as 0.8 here.

Substitute the specific parameters to get P _d = 71.12W. Considering that the wingspan of the flapping wing prototype is relatively large, a brushless motor with high torque, the ECO second-generation KV2400 motor, is selected in this paper.

2. Selection of brushless ESC

The principle of the model aircraft-grade DC brushless motor is to control it through PWM pulse width modulation, so a special driver is required for the brushless motor to work. In this project, the brushless ESCs sold in the market are directly selected as the driver, which not only reduces the design workload but also improves the reliability of the driving circuit. According to the power and maximum working current of the selected DC motor, the ESC model selected for this project is the XRotor series 10A brushless ESC.

3. Selection of steering gear

The steering gear is an important power source for controlling the flight attitude of the prototype. The tail wing designed in this topic needs the synergy of the two steering gears to realize the adjustment of its action. Under normal circumstances, the selection of the steering gear mainly considers two issues: the torque should be able to meet the rotation requirements; the quality of the steering gear itself should be minimized. Due to the large rotational torque required by the tail, the model D10012MG steering gear was selected for this project, with a mass of 5.75g and a torque of 1.2kg·cm (4.8V).

Fourth, the selection of remote control equipment

The control system of the entire aircraft mainly includes: remote control, ESC, signal receiver, tail rudder and other parts. According to the established transmission scheme in Chapter 2, the power source of the prototype is a brushless motor and two torsion steering gears. Under the comprehensive consideration, this project selected Tiandifei six-channel remote controller WFT06X-A2 with strong anti-interference ability and matching 2.4GHz receiver WFR06S to achieve precise control of the motor and torsion servo. The receiver WFR06S can pass the identification code. Connect the communication data to control the movement attitude of the prototype, and the straight-line distance between it and the ground can exceed 900 meters;

The receiver and the brushless motor are powered by the lithium battery through the ESC. The ESC can control the rotation speed of the brushless motor according to the control signal to change the flapping frequency of the wings, thereby realizing the acceleration and deceleration of the aircraft and the forward flight control; it can also be adjusted by adjusting The turning angle of the tail servo is used to control the pitch and yaw attitude transition of the aircraft.

Embodiment 5

Please refer to Figures 1-13. On the basis of Embodiment 3, the present invention provides a technical solution:

A gear design for a bionic bird vehicle:

For common aircraft, we generally use the model aircraft KV2400 motor, and the motor rotates faster, so the secondary gear reduction group is designed. For general gears, to avoid the occurrence of undercutting, the number of teeth of the pinion is generally required to be greater than or equal to 17, so the number of teeth of the pinion is initially designed to be 17. At the same time, in order to avoid the gear size being too large, the modulus should be reduced, taking 0.5 mm.

(1) Calculation of _total transmission ratio i

The flapping frequency of the bionic bird is 7HZ, so there are:

i _total =n ₀ ×50%～60%/60f

The _total value range of i is 21.14～25.37, and the transmission ratio is 24.

(2) Distribution of gear ratios

According to the spread transmission ratio distribution principle of the secondary gear reducer group, the transmission ratio distribution is:

i ₂ =i _total /i ₁ ≈4.3

According to this, the module of gear 1 in the primary gear is m=0.5, the number of teeth z ₁ =17, the module of gear 2 is m=0.5, the number of teeth z ₂ =95, the gear three in the secondary gear is the same as the gear one, and the gear four The number of teeth z ₄ =73.

取b₂＝8mm，则b₁＝10mm，b₃＝10mm。Tooth width:

Taking b ₂ =8mm, then b ₁ =10mm and b ₃ =10mm.

Claims (8)

1. A bionic bird aircraft comprises a framework (1), and is characterized in that: the front end of the framework (1) is fixedly connected with a driving mechanism mounting rack (2), and a double-wing flapping mechanism (3) and a wing mechanism (4) are mounted on the driving mechanism mounting rack (2);

the driving mechanism mounting rack (2) comprises a rack body (201) fixedly connected to a framework (1), the double-wing flapping mechanism (3) comprises a motor I (301) installed on the rack body (201), an output shaft of the motor I (301) and a gear I (302) installed on the rack body (201) are meshed and connected, a gear I (302) and a rack body (201) are meshed and connected with a hinged gear II (303), a gear II (303) is installed on the rack body (201) through an installation shaft I (304), one end of the installation shaft I (304) is fixedly connected with a gear III (305), the gear III (305) and the rack body (201) are meshed and connected with a hinged gear IV (306), the gear IV (306) is hinged on the rack body (201) through an installation shaft II (307), the rack body (201) is hinged with two sets of gears IV (306) and is symmetrically distributed, the two groups of gears four (306) are connected in a meshed manner, the surface of the gear four (306) is fixedly connected with a first connecting shaft (309), a first connecting rod (308) is sleeved on the first connecting shaft (309), the other end of the first connecting rod (308) is sleeved on a second mounting shaft (307), a second connecting rod (310) is sleeved on the first connecting shaft (309), the other end of the second connecting rod (310) is hinged to a driving rod (312) through a second connecting shaft (311), and the driving rod (312) is hinged to the frame body (201) through a hinge shaft (313);

the tail end of the framework (1) is fixedly connected with a tail steering mechanism (5);

afterbody steering gear (5) are including inserting picture peg (501) of establishing skeleton (1) tail end, the fixed surface of picture peg (501) is connected with motor three (502), articulated preceding fin (503) transmission is connected on the output shaft of motor three (502) and picture peg (501), the surface of preceding fin (503) is provided with rear fin (505) that two sets of symmetric distribution were installed to articulated in two sets of openings and two sets of openings, the surface mounting of preceding fin (503) has two sets of miniature steering wheel (504), and is two sets of the output shaft of miniature steering wheel (504) is connected with two sets of rear fin (505) independent transmission respectively.

2. The bionic bird aircraft of claim 1, wherein: actuating mechanism mounting bracket (2) comprise two sets of support bodies (201), and are two sets of fixedly connected with stiffener (202) between support body (201) are two sets of support body (201) all adopt the fretwork design and separate and be a plurality of triangle-shaped structures.

3. The bionic bird aircraft of claim 1, characterized in that: lightening holes are formed in the first gear (302), the second gear (303), the third gear (305) and the fourth gear (306).

4. The bionic bird aircraft of claim 1, wherein: wing mechanism (4) are including installing mounting panel (401) on actuating lever (312), the surface of mounting panel (401) is provided with the mounting hole that equidistance linear distribution, it can rotate fixed axle (402) all to insert in every group mounting hole on mounting panel (401), every group the equal fixedly connected with synchronizing wheel (403) in surface of fixed axle (402), connect through hold-in range (404) transmission between synchronizing wheel (403), the fixed surface of mounting panel (401) is connected with motor two (408), the output shaft of motor two (408) and one of them group fixed axle (402) transmission are connected, fixedly connected with middle level wing (405), outer layer wing (406) and inner layer wing (407) on fixed axle (402).

5. The bionic bird aircraft of claim 4, wherein: in two adjacent groups of the fixed shafts (402), a middle-layer wing (405) is fixedly connected to one group of the fixed shafts (402), an outer-layer wing (406) and an inner-layer wing (407) are fixedly connected to the other group of the fixed shafts (402), the outer-layer wing (406) is located above the middle-layer wing (405), and the inner-layer wing (407) is located below the middle-layer wing (405).

6. The bionic bird aircraft of claim 5, wherein: the middle layer wing (405), the outer layer wing (406) and the inner layer wing (407) are distributed in a staggered manner.

7. The bionic bird aircraft of claim 1, wherein: the rear empennage (505) is fixedly connected with an airfoil (506).

8. The bionic bird aircraft of claim 1, wherein: the two sides of the framework (1) are fixedly connected with a mounting table (7) through a supporting rod (6), a controller (8) is mounted on the mounting table (7), and a system control module, a wireless transmission module and a sensing detection module are arranged in the controller (8).

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