High-maneuverability control method of bird-imitating flapping-wing aircraft

Abstract

The invention provides a high-maneuverability control method of a bird-imitating flapping-wing aircraft, and belongs to the field of flapping-wing aircrafts, and the method comprises the following steps: adjusting and driving by regulating the raising angles of wings of the bird-imitating flapping-wing aircraft to complete a normal flight switching gliding mode or a normal flight switching diving mode; the flapping frequency of wings on the two sides of the bird-imitating flapping-wing aircraft is instantly increased, and the gravity center position of the bird-imitating flapping-wing aircraft is adjusted, so that normal flight is completed, and a backward somersault mode is switched. According to the control method, high maneuvering actions such as gliding, diving and backward somersault are realized by independently controlling and changing flight parameters such as flapping frequency of the steering engine and raising and turning-down angles of the wings, analysis is carried out by combining a motion capture experiment, and the effectiveness and the accuracy of the method are improved.

Description

Technical Field

[0001] The invention relates to the field of flapping-wing aircraft, and in particular to a high-maneuverability control method for a bird-like flapping-wing aircraft. Background Art

[0002] Flapping-wing flying robots, also known as bionic flapping-wing flying robots, are a new type of drones that are inspired by biological flight patterns and use flapping wings to generate lift thrust. By integrating functions such as climbing, hovering, and propulsion into a flapping-wing system, bionic flapping-wing flying robots can quickly and effectively change the posture of flying robots. Combined with their highly bionic appearance and movement patterns, flapping-wing flying robots have multiple advantages such as strong concealment, high maneuverability, and low energy consumption.

[0003] Unlike fixed-wing drones and rotary-wing drones, flapping-wing flying robots need to flap their left and right wings up and down to generate lift, so the materials used for their wings are generally flexible materials. Flapping-wing flying robots achieve aerial flight by imitating birds, so they can also achieve gliding flight like birds, which makes flapping-wing flight more energy-efficient than rotary-wing flight in theory.

[0004] Compared with fixed-wing UAVs and rotary-wing UAVs, flapping-wing aircraft have greater potential for high maneuverability. They have a smaller turning radius and are more controllable when performing high maneuvers, which significantly improves the operating capabilities of UAVs in some special environments. However, due to the complexity of the aerodynamic model of flapping-wing flying robots and the relatively complex aerodynamic theory, there are relatively few studies on the high maneuverability of flapping-wing flying robots.

[0005] The current medium and large flapping-wing UAVs have problems such as insufficient high maneuverability and lack of relevant motion control modeling. Although flapping-wing robots have made some progress in autonomy and maneuverability, further technological innovation and improvement are still needed to meet future application needs. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a high maneuverability control method for a bird-like flapping-wing aircraft. The present invention independently controls and changes flight parameters such as the flapping frequency of the servo, the upward and downward angles of the wings, etc. to achieve a control method for high maneuvers such as gliding, diving and backflips, and analyzes the method in combination with motion capture experiments to improve the effectiveness and accuracy of the method. Specifically, the method includes:

[0007] A high maneuverability control method for a bird-like flapping-wing aircraft, comprising:

[0008] A bird-like flapping-wing aircraft and a motion capture system, wherein the bird-like flapping-wing aircraft is placed in the motion capture system for mode switching control;

[0009] The bird-like flapping-wing aircraft includes three switching modes: switching from a normal flight to a gliding mode, switching from a normal flight to a diving mode, and switching from a normal flight to a backflip mode;

[0010] By adjusting the upward angle of the wings of the bird-like flapping-wing aircraft, the normal flight is switched to the gliding mode or the normal flight is switched to the diving mode;

[0011] The normal flight mode is switched to the backflip mode by instantaneously increasing the flapping frequency of the wings on both sides of the bird-like flapping-wing aircraft and adjusting the center of gravity position of the bird-like flapping-wing aircraft.

[0012] Optionally, the step of adjusting the driving to complete the normal flight and switch to the gliding mode by regulating the upward angle includes:

[0013] S101, adjusting the upward angle of the wing to be between -15° and 15°;

[0014] S102, driving the bird-mimicking flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time;

[0015] S103, obtaining a glide angle of the bird-mimicking flapping-wing aircraft according to a distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and a height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends;

[0016] S104, judging whether the bird-mimicking flapping-wing flight is successfully switched to a gliding state according to the glide angle of the bird-mimicking flapping-wing aircraft;

[0017] If the switching is not successful, the upward angle of the wing is readjusted to a value between -15° and 15° and different from the angle value of the previous upward angle, and the process returns to S102;

[0018] If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

[0019] Optionally, the step of adjusting the upward angle of the wings of the bird-like flapping-wing aircraft to drive the normal flight to switch to the dive mode includes:

[0020] S201, adjusting the upward angle of the wing to be below -30° or above 30°;

[0021] S202, driving the bird-mimicking flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time;

[0022] S203, obtaining a glide angle of the bird-mimicking flapping-wing aircraft according to a distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and a height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends;

[0023] S204, judging whether the bird-mimicking flapping-wing flight is successfully switched to a diving state according to the glide angle of the bird-mimicking flapping-wing aircraft;

[0024] If the switching is not successful, the upward angle of the wing is readjusted to be below -30° or above 30°, and the angle value of the upward angle is different from the previous upward angle, and the process returns to S202;

[0025] If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

[0026] Optionally, the formula for calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time in S102 or S202 is formula (1):

[0027] ; (1)

[0028] Where S is the distance traveled by the center of gravity of the bird-like flapping-wing aircraft;

[0029] X i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the x-axis in the three-dimensional space at the next moment;

[0030] X i is the x-axis component of the center of gravity of the bird-like flapping-wing aircraft in three-dimensional space at the current moment;

[0031] Y i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the next moment;

[0032] Y i is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the current moment;

[0033] Z i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the z-axis in the three-dimensional space at the next moment;

[0034] Z i It is the component of the center of gravity of the bird-like flapping-wing aircraft in the three-dimensional space on the z-axis at the current moment.

[0035] Optionally, the glide angle of the bird-mimicking flapping-wing aircraft is obtained according to the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and the height to which the center of gravity of the bird-mimicking flapping-wing aircraft drops, including formula (2):

[0036] ; (2)

[0037] θ is the glide angle of the bird-mimicking flapping-wing aircraft, and h is the height to which the center of gravity of the bird-mimicking flapping-wing aircraft drops.

[0038] Optionally, judging whether the bird-mimicking flapping-wing flight is successfully switched to the gliding state according to the glide angle of the bird-mimicking flapping-wing aircraft in S104 includes:

[0039] If θ>60°, the bird-like flapping flight is successfully switched to the gliding state, otherwise it is unsuccessful.

[0040] Optionally, judging whether the bird-mimicking flapping-wing flight is successfully switched to a diving state according to the glide angle of the bird-mimicking flapping-wing aircraft in S204 includes:

[0041] If θ<60°, the bird-like flapping flight is successfully switched to the diving state, otherwise it is unsuccessful.

[0042] Optionally, the step of instantaneously increasing the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft and adjusting the center of gravity position of the bird-mimicking flapping-wing aircraft to complete the normal flight and switch to the backflip mode includes:

[0043] S301, when the bird-mimicking flapping-wing aircraft is flying normally, increasing the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft to above 4 Hz within 1 second, and installing the flight control board on the main rod of the fuselage of the bird-mimicking flapping-wing aircraft between the aerodynamic center and the tail of the bird-mimicking flapping-wing aircraft;

[0044] S302: Determine whether a backflip occurs:

[0045] If no backflip occurs, the flight control board is moved in the opposite direction of the fuselage main rod toward the tail wing by a preset distance, and S302 is repeatedly executed;

[0046] If a backflip occurs, the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft and the position of the flight control board on the main rod of the fuselage are recorded.

[0047] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0048] The bird-like flapping-wing flying robot mentioned in the present invention uses a servo to control the flapping of the wings. The decoupling of the wing motion is relatively simple, and the lift angle is defined, that is, the dihedral angle formed by the wing and the fuselage plane when the wing stops flapping and starts gliding. The lift received is changed by controlling the size of the lift angle, thereby realizing two high-maneuverability actions of gliding and diving. When the wing stops flapping, the larger the absolute value of the lift angle is, the smaller the lift received is, and the smaller the absolute value of the lift angle is, the greater the lift received is. When the absolute value of the lift angle is large enough, due to the effect of gravity, a diving action can be realized.

[0049] The present invention helps to achieve a backflip action by vibrating the wings or adjusting the flapping amplitude and frequency of the wings. Since the carbon rods at the leading edge of the wings are relatively dense when the prototype fuselage is designed, the lift generated by the leading edge of the wings is greater than that of the trailing edge of the wings. Therefore, when the flapping frequency is increased, a pitch moment relative to the center of gravity of the fuselage is generated, and the pitch angle increases continuously. At the same time, as the flapping frequency increases, it can be known from the formula that the lift will also increase. Under the joint action of the pitch moment and the lift, the height and the pitch angle increase simultaneously and rapidly, causing the fuselage to tilt backward, thereby achieving a backflip action.

[0050] The present invention realizes relatively precise control by changing the wing lift angle and flapping frequency of a medium-to-large flapping-wing aircraft, and realizes various high-maneuverability actions of the flapping-wing aircraft in a relatively simple control manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 : is a schematic diagram of the structure of a bird-like flapping-wing aircraft provided by an embodiment of the present invention, in which:

[0053] 1-servo arm; 2-servo, 3-fuselage main rod, 4-flight control board, 5-wing, 6-tail;

[0054] Figure 2 Schematic diagram of the upward pitch angle for controlling the maneuvering of a flapping-wing aircraft provided by an embodiment of the present invention;

[0055] Figure 3 Schematic diagram of the glide angle for controlling the gliding and diving of a flapping-wing aircraft provided by an embodiment of the present invention;

[0056] Figure 4 is a schematic diagram of the forces when controlling the gliding of a flapping-wing aircraft provided by an embodiment of the present invention;

[0057] Figure 5 is a schematic diagram of the forces when controlling a flapping-wing aircraft to dive, provided by an embodiment of the present invention;

[0058] Figure 6 It is a schematic diagram of the forces when controlling a flapping-wing aircraft to do a backflip provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0061] It should be noted that the terms "up", "down", "left", "right", "front" and "back" used in the present invention are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0062] like Figures 1 to 6 As shown, a high maneuverability control method for a bird-like flapping-wing aircraft comprises:

[0063] A bird-like flapping-wing aircraft and a motion capture system, wherein the bird-like flapping-wing aircraft is placed in the motion capture system for mode switching control;

[0064] In the embodiment of the present invention, a bird-like flapping-wing aircraft directly driven by a steering gear has a wingspan of 80 cm and an empty weight of 85 g. Figure 1 The flapping-wing aircraft comprises a steering gear arm 1, a steering gear 2, a fuselage main rod 3, a flight control board 4, wings 5, and a tail 6.

[0065] The servo arm 1 is made of 3D printing and is responsible for connecting the servo 2 and the span-wise main rod of the wing 5. The servo 2 constitutes the lift driving part of the flapping-wing aircraft. The servo model used in the present invention is HV1295, and its flapping frequency can be adjusted between 1Hz and 5Hz to meet the flight lift requirements.

[0066] The middle part of the fuselage main rod 3 is fixed with a flight control board 4, and the end is fixed with a tail wing 6. The flight control board 6 uses a stm32f103 chip to simulate and generate a PWM wave signal, controls the position of the servo by changing the duty cycle, and is provided with a communication module.

[0067] The present invention arranges a plurality of infrared cameras above a flying field of a bird-like flapping-wing aircraft to capture images of the flapping-wing aircraft; processes the captured images based on motion capture software to calculate the position and attitude information of the flapping-wing aircraft.

[0068] In order to describe the control quantity of controlling the flapping-wing aircraft to glide and dive, the present invention introduces the wing pitch angle, which is defined as follows: Figure 2 As shown. The dihedral angle formed by the wing and the fuselage plane when the wing stops flapping and starts gliding is defined as the pitch angle. By controlling the size of the pitch angle, the lift it receives can be changed, thereby achieving two high-maneuverability actions, gliding and diving. When the wing stops flapping, the larger the absolute value of the pitch angle, the smaller the lift it receives, and the smaller the absolute value of the pitch angle, the greater the lift it receives. When the absolute value of the pitch angle is large enough, due to the effect of gravity, a dive action can be achieved.

[0069] The specific control method of the bird-like flapping wing based on the above structure includes:

[0070] The bird-like flapping-wing aircraft includes three switching modes: switching from a normal flight to a gliding mode, switching from a normal flight to a diving mode, and switching from a normal flight to a backflip mode;

[0071] By adjusting the upward angle of the wings of the bird-like flapping-wing aircraft, the normal flight is switched to the gliding mode or the normal flight is switched to the diving mode;

[0072] The normal flight mode is switched to the backflip mode by instantaneously increasing the flapping frequency of the wings on both sides of the bird-like flapping-wing aircraft and adjusting the center of gravity position of the bird-like flapping-wing aircraft.

[0073] In a specific implementation manner, the step of adjusting the driving by adjusting the upward angle to complete the normal flight and switching to the gliding mode includes:

[0074] S101, adjusting the upward angle of the wing to be between -15° and 15°;

[0075] S102, driving the bird-like flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-like flapping-wing aircraft within the fixed time;

[0076] The formula for calculating the distance traveled by the center of gravity of the bird-like flapping-wing aircraft within the fixed time is formula (1):

[0077] ; (1)

[0078] Where S is the distance traveled by the center of gravity of the bird-like flapping-wing aircraft;

[0079] X i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the x-axis in the three-dimensional space at the next moment;

[0080] X i is the x-axis component of the center of gravity of the bird-like flapping-wing aircraft in three-dimensional space at the current moment;

[0081] Y i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the next moment;

[0082] Y i is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the current moment;

[0083] Z i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the z-axis in the three-dimensional space at the next moment;

[0084] Z i It is the component of the center of gravity of the bird-like flapping-wing aircraft in the three-dimensional space on the z-axis at the current moment.

[0085] S103, obtaining a glide angle of the bird-mimicking flapping-wing aircraft according to a distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and a height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends;

[0086] ; (2)

[0087] θ is the glide angle of the bird-mimicking flapping-wing aircraft, and h is the height to which the center of gravity of the bird-mimicking flapping-wing aircraft drops.

[0088] S104, judging whether the bird-mimicking flapping-wing flight is successfully switched to a gliding state according to the glide angle of the bird-mimicking flapping-wing aircraft;

[0089] If θ>60°, the bird-like flapping flight is successfully switched to the gliding state, otherwise it is unsuccessful.

[0090] If the switching is not successful, the upward angle of the wing is readjusted to a value between -15° and 15° and different from the angle value of the previous upward angle, and the process returns to S102;

[0091] If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

[0092] In a specific implementation manner, the step of adjusting the upward angle of the wings of the bird-like flapping-wing aircraft to drive the normal flight to switch to the dive mode includes:

[0093] S201, adjusting the upward angle of the wing to be below -30° or above 30°;

[0094] S202, driving the bird-like flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-like flapping-wing aircraft within the fixed time, wherein the calculation method follows formula (1);

[0095] S203, obtaining the glide angle of the bird-mimicking flapping-wing aircraft according to the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and the height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends, wherein the calculation method follows formula (2);

[0096] S204, judging whether the bird-mimicking flapping-wing flight is successfully switched to a diving state according to the glide angle of the bird-mimicking flapping-wing aircraft;

[0097] If the switching is not successful, the upward angle of the wing is readjusted to be below -30° or above 30°, and the angle value of the upward angle is different from the previous upward angle, and the process returns to S202;

[0098] If θ<60°, the bird-like flapping flight is successfully switched to a diving state, otherwise it is unsuccessful;

[0099] If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

[0100] According to formula (1) and formula (2), it can be known that the smaller cosθ is, the better the gliding performance is; the larger cosθ is, the worse the gliding performance is. The quantification of dive is the opposite. The smaller cosθ is, the worse the dive performance is; the larger cosθ is, the better the dive performance is. Here, the distance S is selected instead of the distance between two points. The prototype will spiral down during the gliding process. If the displacement between two points is used instead of the distance traveled, the data will be invalid. In order to improve the feasibility of the experiment, the distance S is selected instead of the displacement. h is obtained by subtracting the ordinate transformation.

[0101] Gliding can be achieved when the upward angle is between -15° and 15°. As the speed increases, the optimal upward angle for gliding also increases. When the downward angle is greater than 60°, it is in the gliding state. When the downward angle is less than 60°, the prototype is in the diving state. There are two ways to achieve a dive. One is to make the upward angle very large, and the other is to flip the wings down instead of up, and achieve a dive by flipping down. When the wings flip down to less than -15° and rise to more than 30°, the fuselage will fall rapidly due to gravity factors, achieving a dive.

[0102] In a specific implementation manner, the step of instantaneously increasing the flapping frequency of the wings on both sides of the bird-like flapping-wing aircraft and adjusting the center of gravity position of the bird-like flapping-wing aircraft to complete the normal flight and switch to the backflip mode includes:

[0103] S301, when the bird-mimicking flapping-wing aircraft is flying normally, increasing the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft to above 4 Hz within 1 second, and installing the flight control board on the main rod of the fuselage of the bird-mimicking flapping-wing aircraft between the aerodynamic center and the tail of the bird-mimicking flapping-wing aircraft;

[0104] S302: Determine whether a backflip occurs:

[0105] If no backflip occurs, the flight control board is moved in the opposite direction of the fuselage main rod toward the tail wing by a preset distance, and S302 is repeatedly executed;

[0106] If a backflip occurs, the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft and the position of the flight control board on the main rod of the fuselage are recorded.

[0107] Changing the lift by changing the wing flapping frequency is shown below:

[0108] ;

[0109] Among them, F is lift; f is flapping frequency; S is total wing area; E is expected flapping angle; k is lift coefficient.

[0110] The present invention controls the wing lift angle so that the lift angle Maintaining a relatively small range to achieve the gliding of the aircraft, the flight force diagram is shown in the figure below. Figure 4 When the upward angles of the wings on both sides are the same, the lift generated by the wings on both sides is and The lateral components of the fuselage will cancel each other out, while the components perpendicular to the fuselage plane can be expressed as

[0111] ;

[0112] in is the wing pitch angle.

[0113] It can be seen from the above formula that when the absolute value of the upward angle is kept small, the lift of the aircraft is large and gliding action can be achieved.

[0114] The present invention controls the upward angle Maintaining a large range to achieve the dive of the aircraft, the flight force diagram is as follows Figure 5 As shown in the above formula, it can be seen that at this time, the component of the aircraft lift in the vertical fuselage plane is small, and it can perform a dive maneuver under the action of gravity.

[0115] The present invention realizes the backflip of the aircraft by controlling the instantaneous increase of the flapping frequency f. The schematic diagram of the flight force is shown in FIG. Figure 6 As shown. A flapping-wing aircraft needs to have sufficient speed and height when performing a backflip. Since the carbon rods at the leading edge of the wing are denser when the prototype fuselage is designed, the lift generated by the leading edge of the wing is greater than the trailing edge of the wing. By adjusting the center of gravity of the flapping-wing aircraft, the aerodynamic center of the aircraft is located in front of its center of gravity. In the initial stage of a flapping-wing aircraft backflip, the aircraft will increase the angle of attack instantly by instantly increasing the flapping frequency f. This will increase the lift and cause the airflow angle to change dramatically. At the lift F R and F L , the negative lift D generated by the tail t The combined effect of the force G and gravity causes the aircraft to generate an instantaneous rotational torque, triggering a backflip. During the backflip, the aircraft needs to lock its wings to maintain a stable attitude during the flip to avoid a failed or incomplete flip due to excessive control or unstable aerodynamic effects. After the flip is completed, the flapping-wing aircraft needs to adjust the angle of attack and flapping frequency to return to a normal flight state.

[0116] When the flapping frequency is less than 3.5Hz, a backflip cannot be achieved. However, when the flapping frequency is greater than 4Hz, a significant backflip can be achieved. Due to the inertia of the fuselage itself, after completing the backflip, the fuselage will quickly return to the level flight attitude.

[0117] The technical solution adopted by the present invention to solve the above-mentioned problem is to change the flapping of the left and right wings to direct drive by a servo. Since the servo is an actuator that controls the output gear to rotate to a specified angle and maintain the angle by the pulse width of a PWM signal, and has a large torque and response speed, it meets the driving requirements of the wings of a flapping-wing flying robot. By periodically changing the duty cycle of the PWM wave (the high level time accounts for the time of a PWM wave cycle) to control the servo arm to swing back and forth between -60° and 60°, the flapping of the wings can be simulated. The swing frequency of the servo arm can be changed by changing the frequency of the PWM wave duty cycle change, thereby realizing the change of the flapping frequency of the wings of the bird-like flapping-wing flying robot, and the servo arm can also be fixed at a certain position to achieve gliding. However, it takes a certain amount of time for the servo arm to rotate. The servo model used in the present invention is HV1295. After testing, it takes 100ms for this servo to rotate from -60° to 60° at the fastest. Therefore, under the design scheme introduced, the wing flapping frequency can only be adjusted between 1Hz~5Hz, but the flight lift requirements have been met.

[0118] The bird-like flapping-wing flying robot mentioned in the present invention uses a servo to control the flapping of the wings. The decoupling of the wing motion is relatively simple, and the lift angle is defined, that is, the dihedral angle formed by the wing and the fuselage plane when the wing stops flapping and starts gliding. The lift received is changed by controlling the size of the lift angle, thereby realizing two high-maneuverability actions of gliding and diving. When the wing stops flapping, the larger the absolute value of the lift angle is, the smaller the lift received is, and the smaller the absolute value of the lift angle is, the greater the lift received is. When the absolute value of the lift angle is large enough, due to the effect of gravity, a diving action can be realized.

[0119] The present invention helps to achieve a backflip action by vibrating the wings or adjusting the flapping amplitude and frequency of the wings. Since the carbon rods at the leading edge of the wings are relatively dense when the prototype fuselage is designed, the lift generated by the leading edge of the wings is greater than that of the trailing edge of the wings. Therefore, when the flapping frequency is increased, a pitch moment relative to the center of gravity of the fuselage is generated, and the pitch angle increases continuously. At the same time, as the flapping frequency increases, it can be known from the formula that the lift will also increase. Under the joint action of the pitch moment and the lift, the height and the pitch angle increase simultaneously and rapidly, causing the fuselage to tilt backward, thereby achieving a backflip action.

[0120] The following points need to be explained:

[0121] (1) The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0122] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0123] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0124] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A high maneuverability control method for a bird-like flapping-wing aircraft, characterized in that: include: A bird-like flapping-wing aircraft and a motion capture system, wherein the bird-like flapping-wing aircraft is placed in the motion capture system for mode switching control; The bird-like flapping-wing aircraft includes three switching modes: switching from a normal flight to a gliding mode, switching from a normal flight to a diving mode, and switching from a normal flight to a backflip mode; By adjusting the upward angle of the wings of the bird-like flapping-wing aircraft, the normal flight is switched to the gliding mode or the normal flight is switched to the diving mode; The normal flight mode is switched to the backflip mode by instantaneously increasing the flapping frequency of the wings on both sides of the bird-like flapping-wing aircraft and adjusting the center of gravity position of the bird-like flapping-wing aircraft.

2. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 1, characterized in that: The step of adjusting the driving by adjusting the upward angle to complete the normal flight and switch to the gliding mode includes: S101, adjusting the upward angle of the wing to be between -15° and 15°; S102, driving the bird-mimicking flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time; S103, obtaining a glide angle of the bird-mimicking flapping-wing aircraft according to a distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and a height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends; S104, judging whether the bird-mimicking flapping-wing flight is successfully switched to a gliding state according to the glide angle of the bird-mimicking flapping-wing aircraft; If the switching is not successful, the upward angle of the wing is readjusted to a value between -15° and 15° and different from the angle value of the previous upward angle, and the process returns to S102; If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

3. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 2, characterized in that: The step of adjusting the angle of the wing upward angle of the bird-like flapping-wing aircraft to drive and complete the normal flight to switch to the dive mode comprises: S201, adjusting the upward angle of the wing to be below -30° or above 30°; S202, driving the bird-mimicking flapping-wing aircraft to fly for a fixed time after adjusting the upward angle, and calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time; S203, obtaining a glide angle of the bird-mimicking flapping-wing aircraft according to a distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft and a height to which the center of gravity of the bird-mimicking flapping-wing aircraft descends; S204, judging whether the bird-mimicking flapping-wing flight is successfully switched to a diving state according to the glide angle of the bird-mimicking flapping-wing aircraft; If the switching is not successful, the upward angle of the wing is readjusted to be below -30° or above 30°, and the angle value of the upward angle is different from the previous upward angle, and the process returns to S202; If the switch is successful, the size of the upward angle when switching from normal flight to gliding mode is recorded.

4. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 3, characterized in that: The formula for calculating the distance traveled by the center of gravity of the bird-mimicking flapping-wing aircraft within the fixed time in S102 or S202 is formula (1): ；（1） Where S is the distance traveled by the center of gravity of the bird-like flapping-wing aircraft; X i+1 is the x-axis component of the center of gravity of the bird-like flapping-wing aircraft in the three-dimensional space at the next moment; X i is the x-axis component of the center of gravity of the bird-like flapping-wing aircraft in three-dimensional space at the current moment; Y i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the next moment; Y i is the component of the center of gravity of the bird-like flapping-wing aircraft in the y-axis in the three-dimensional space at the current moment; Z i+1 is the component of the center of gravity of the bird-like flapping-wing aircraft in the z-axis in the three-dimensional space at the next moment; Z i It is the component of the center of gravity of the bird-like flapping-wing aircraft in the three-dimensional space on the z-axis at the current moment.

5. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 4, characterized in that: The glide angle of the bird-like flapping-wing aircraft is obtained according to the distance traveled by the center of gravity of the bird-like flapping-wing aircraft and the height to which the center of gravity of the bird-like flapping-wing aircraft drops, including formula (2): ；（2） θ is the glide angle of the bird-mimicking flapping-wing aircraft, and h is the height to which the center of gravity of the bird-mimicking flapping-wing aircraft drops.

6. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 3, characterized in that: The step S104 of judging whether the bird-mimicking flapping-wing flight is successfully switched to the gliding state according to the glide angle of the bird-mimicking flapping-wing aircraft comprises: If θ>60°, the bird-like flapping flight is successfully switched to the gliding state, otherwise it is unsuccessful.

7. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 3, characterized in that: The step S204 of judging whether the bird-mimicking flapping-wing flight has successfully switched to a diving state according to the glide angle of the bird-mimicking flapping-wing aircraft includes: If θ<60°, the bird-like flapping flight is successfully switched to the diving state, otherwise it is unsuccessful.

8. The high maneuverability control method of a bird-like flapping-wing aircraft according to claim 3, characterized in that: The method of instantaneously increasing the flapping frequency of the wings on both sides of the bird-like flapping-wing aircraft and adjusting the center of gravity position of the bird-like flapping-wing aircraft to complete the normal flight and switch to the backflip mode includes: S301, when the bird-mimicking flapping-wing aircraft is flying normally, increasing the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft to above 4 Hz within 1 second, and installing the flight control board on the main rod of the fuselage of the bird-mimicking flapping-wing aircraft between the aerodynamic center and the tail of the bird-mimicking flapping-wing aircraft; S302: Determine whether a backflip occurs: If no backflip occurs, the flight control board is moved in the opposite direction of the fuselage main rod toward the tail wing by a preset distance, and S302 is repeated; If a backflip occurs, the flapping frequency of the wings on both sides of the bird-mimicking flapping-wing aircraft and the position of the flight control board on the main rod of the fuselage are recorded.

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