Bionic butterfly aircraft and steering method thereof

Abstract

The present invention provides a bionic butterfly aircraft and a steering method thereof. The bionic butterfly aircraft includes an actuator, a drive mechanism, a butterfly body and a steering mechanism. The actuator includes two connecting rod mechanisms and flapping wings. The steering mechanism includes a wing frame, a gear frame, a first gear, a second gear and a first driving source. The upper end of the connecting rod mechanism and the upper end of the wing frame are both connected to the butterfly body, the lower end of the connecting rod mechanism is connected to the lower end of the gear frame, and the lower end of the wing frame is hinged to the upper end of the gear frame. The first gear is fixed on one side of the wing frame, the first driving source is installed on the butterfly body, and the first driving source is driven and connected to the first gear. The upper end of the second gear is meshed with the first gear, and the lower end of the second gear is respectively connected to the left and right ends of the gear frame. The present invention can realize the effective deflection of the butterfly body and achieve a turning effect, so as to improve the flexibility and reliability of the aircraft.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a bionic butterfly aircraft and a steering method thereof. Background Art

[0002] Aircraft are widely used in industry, agriculture, and the military, especially in agriculture, where they are primarily used for crop sowing and spraying. These aircraft now face high requirements, such as actuators that meet their required functions, achieve the expected movement, force, and speed, possess good adaptability, flexibility, and reliability, and operate stably while withstanding long-term, heavy loads.

[0003] Existing aircraft mainly have the following structures:

[0004] (1) Single-crank dual-rocker mechanism: A crank rotates circumferentially around a pivot point, causing a rocker arm connected to two connecting rods to periodically swing back and forth around another pivot point. The rocker arm is connected to the flapping wings to perform flight maneuvers. The disadvantage of this structure is that the left and right flapping wings move asynchronously and out of phase, resulting in unequal aerodynamic forces acting on the aircraft during flight, which can easily cause the aircraft to fall or crash.

[0005] (2) Crank-slider mechanism: A crank rotates circumferentially around a pivot point, causing a connecting rod to drive a slider to slide along a slideway. Two rocker arms and flapping wings connected to the connecting rod then periodically swing back and forth around another pivot point, performing flight maneuvers. This solves the phase difference problem, but the slider structure results in significant frictional resistance, making wear and tear difficult to control, especially during high-speed flapping.

[0006] (3) Spatial crank rocker mechanism: It has two cranks, one end of each crank is connected to the shaft, and the other end of each crank is hinged to a connecting rod, and each connecting rod is hinged to a rocker arm. The crank is fixed to the shaft and rotates throughout a circle. Through the connecting action of the connecting rod, it drives the rocker and the flapping wing to swing back and forth periodically around the fulcrum. Its advantages are: the two ends of the connecting rod are connected to the active part (crank) and the driven part (rocker arm) by a ball pair, the mechanism is compact, and the movement is reliable and flexible. Its disadvantages are: the solution method is complex and the design process is cumbersome. It is currently mainly used for the drive structure of single-stage bionic flapping-wing aircraft;

[0007] (4) Planar double-crank double-rocker mechanism: For example, the butterfly-like micro flapping-wing aircraft disclosed in Patent Publication No. CN110091988A comprises a frame, a flapping mechanism, and first and second-stage wings. A main shaft gear drives a transmission gear, and a connecting rod converts the gear rotation into rocker swing, achieving flapping motion. This mechanism achieves flipping through the second wing frame, but this flipping motion cannot achieve turns, thus failing to meet the requirements for flexibility and reliability.

[0008] In addition, regarding the names of the directions involved in the present invention, the art generally defines them as follows:

[0009] Front: refers to the direction in which the aircraft is moving;

[0010] Back: the direction opposite to the forward direction of the aircraft;

[0011] Left: on the left side of the aircraft's forward direction;

[0012] Right: On the right side of the aircraft's forward direction. Summary of the Invention

[0013] The object of the present invention is to provide a bionic butterfly aircraft capable of steering and a steering method thereof, so as to improve the flexibility and reliability of the aircraft.

[0014] The technical solution of the present invention is: a bionic butterfly aircraft, including an actuator, a driving mechanism, a butterfly body and a steering mechanism, the actuator including two connecting rod mechanisms symmetrically arranged on the left and right and flapping wings connected to the connecting rod mechanisms, the driving mechanism is used to drive the connecting rod mechanisms to move so that the flapping wings fly, and the steering mechanism includes a wing frame, a gear frame, a first gear, a second gear and a first driving source; the upper end of the connecting rod mechanism and the upper end of the wing frame are both connected to the butterfly body, the lower end of the connecting rod mechanism is connected to the lower end of the gear frame, and the lower end of the wing frame is hinged to the upper end of the gear frame; the first gear is fixed on one side of the wing frame, the first driving source is installed on the butterfly body, and the first driving source is driven and connected to the first gear; the upper end of the second gear is meshed with the first gear, and the lower end of the second gear is respectively connected to the left and right ends of the gear frame; when the first driving source drives the first gear to rotate relative to the second gear, the wing frame and the connected connecting rod mechanism are tilted to the left or right to achieve steering.

[0015] In the above scheme, by adding a steering mechanism, the effective deflection of the butterfly body is achieved, and the turning effect is achieved to meet the use needs in various fields and to improve the flexibility and reliability of the aircraft.

[0016] Preferably, a portion of first gear teeth is provided on the outer circular surface of the first gear; the second gear includes two rocker arms connected at an obtuse angle, and a portion of second gear teeth is provided at the intersection of the two rocker arms. The ends of the two rocker arms away from the second gear teeth are connected to the gear frame, and the first gear teeth are meshed with the second gear teeth.

[0017] Preferably, the transmission ratio of the second gear is 2:3.

[0018] Preferably, the front end of the butterfly body is connected to the flapping wing through a connecting rod mechanism, and the rear end of the butterfly body is softly connected to the flapping wing through a spring.

[0019] Preferably, the connecting rod mechanism includes a third gear, a connecting rod and a rocker arm, and the driving mechanism includes a second driving source and a fourth gear connected to the second driving source; the second driving source is installed under the butterfly body, and the third gears of the two connecting rod mechanisms are rotatably installed on the gear rack to form a fulcrum O1, and the fourth gear is engaged with one of the third gears; one end of the connecting rod is hinged to the third gear to form a hinge A, and the other end of the connecting rod is hinged to one end of the rocker arm to form a hinge B, and the other end of the rocker arm is connected to the flapping wing, and the rocker arm is rotatably installed on the wing rack to form a fulcrum O2.

[0020] Preferably, the length between O1 and A is , the connecting rod has a length , the rocker arm has a length , a length d is formed between O2 and O1; The rocker arm rotates around the fulcrum O1 and makes a full circle rotation. The rocker arm is connected by a connecting rod to make a periodic reciprocating swing around the fulcrum O2 to form an upward swing angle. and hem angle ;

[0021] The above values ​​are derived from the following formula (1):

[0022] (1)

[0023] in, is the angle between the line connecting O2 and O1 and the horizontal plane; The rocker arm is in the upper swing angle The angle between the position and the line connecting O2 and O1;

[0024] The maximum value of satisfies the following relationship (2):

[0025] (2)

[0026] Among them, D2 is the swing angle of the rocker arm Endpoints at position; is the extreme position angle, which is the upper swing angle formed by the rocker arm and hem angle The angle formed by the connecting rod in the two positions; = ; is the flapping angle, equal to ;

[0027] and The relationship between them is:

[0028] (3)

[0029] like When the length unit is 1, the linkage mechanism satisfies the following relationship (4):

[0030] (4)

[0031]

[0032] After combining formula (4), we can get and The values ​​are:

[0033] (5).

[0034] Preferably, a mounting surface is formed at the front end of the butterfly body, and the head and the connecting rod mechanism are connected to the mounting surface; and a plurality of hollow holes are provided on the butterfly body.

[0035] The present invention also provides a method for steering the bionic butterfly aircraft, comprising:

[0036] The first driving source is started to drive the first gear to rotate relative to the second gear; the wing frame is tilted to the left or right by a certain angle; the connecting rod mechanism connected to the wing frame is tilted together, causing the center of gravity of the butterfly body and flapping wings to deflect and perform steering; after the steering is completed, the first driving source is started to drive the first gear to rotate in the opposite direction relative to the second gear to reset.

[0037] Preferably, the deflection of the center of gravity of the butterfly body and flapping wings is sensed by a center of gravity position sensing system.

[0038] Compared with the related art, the present invention has the following beneficial effects:

[0039] 1. The present invention realizes effective deflection of the butterfly body and achieves a turning effect by adding a steering mechanism, so as to meet the use requirements of various fields and improve the flexibility and reliability of the aircraft;

[0040] Second, the front end of the butterfly body is connected to the flapping wings through a connecting rod mechanism, and the rear end of the butterfly body is connected to the flapping wings through a spring, realizing a combination of rigidity and flexibility. This achieves precise transmission of the front end of the flapping wings and flexible shock absorption of the rear end of the flapping wings, greatly improving the stability of the flapping wings during flight and extending their service life.

[0041] Third, the steering of the present invention realizes bionic butterfly double-wing flapping differential turning and eccentric turning by changing the wing frame swing angle position and deflecting the center of gravity, thereby improving stability and accuracy during turning;

[0042] 4. The drive mechanism is installed under the butterfly body, which makes the center of gravity of the aircraft lower and has a better regulating effect on the overall stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic structural diagram of the bionic butterfly aircraft provided by the present invention from a first perspective;

[0044] Figure 2 This is a schematic structural diagram of the bionic butterfly aircraft provided by the present invention from a second perspective, with the flapping wings and head removed;

[0045] Figure 3 This is a schematic structural diagram of the bionic butterfly aircraft provided by the present invention from a third perspective with the head removed;

[0046] Figure 4 is a structural schematic diagram of the first gear;

[0047] Figure 5 is a structural schematic diagram of the second gear;

[0048] Figure 6 Schematic diagram of the structure of the wing frame;

[0049] Figure 7 Schematic diagram of the structure of the gear rack;

[0050] Figure 8 This is a schematic diagram of the steering mechanism turning to the left;

[0051] Figure 9 This is a schematic diagram of the steering mechanism turning to the right;

[0052] Figure 10 It is a structural diagram of the actuator;

[0053] Figure 11 It is a structural diagram of the connecting rod mechanism;

[0054] Figure 12 is a schematic diagram of the connecting rod mechanism at the minimum transmission angle position;

[0055] Figure 13 Schematic diagram of the relationship between the minimum transmission angle and the frame length.

[0056] In the accompanying drawings: 1. actuator; 11. connecting rod mechanism; 111. third gear; 112. connecting rod; 113. rocker arm; 12. flapping wing; 2. driving mechanism; 21. second driving source; 22. fourth gear; 3. butterfly body; 31. mounting surface; 32. hollow hole; 33. block; 4. spring; 5. steering mechanism; 51. wing frame; 511. slot; 512. fourth hole; 513. fifth hole; 52. gear frame; 53. first gear; 531. first gear tooth; 532. first hole; 54. second gear; 541. rocker arm; 542. second gear tooth; 543. second hole; 544. third hole; 55. first driving source; 6. head. DETAILED DESCRIPTION

[0057] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments may be combined unless they conflict. For ease of description, the words "upper," "lower," "left," and "right" appear below merely to indicate the directions of upper, lower, left, and right in the accompanying drawings and do not limit the structure.

[0058] like Figure 1 、 Figure 2 As shown, the bionic butterfly flying vehicle provided in this embodiment includes an actuator 1, a driving mechanism 2, a butterfly body 3, a spring 4, a steering mechanism 5 and a head 6.

[0059] like Figure 1 The front end of the butterfly body 3 is formed with a mounting surface 31, and the mounting surface 31 is connected to the head 6. The butterfly body 3 is provided with a plurality of hollow holes 32.

[0060] like Figure 2 、 Figure 3 As shown, the steering mechanism 5 includes a wing frame 51 , a gear frame 52 , a first gear 53 , a second gear 54 and a first driving source 55 .

[0061] The actuator 1 includes two connecting rod mechanisms 11 and two flapping wings 12 that are symmetrically arranged on both sides. Figure 2 、 Figure 3 、 Figure 10 As shown, the connecting rod mechanism 11 includes a third gear 111, a connecting rod 112 and a rocker arm 113. The driving mechanism 2 includes a second driving source 21 and a fourth gear 22 connected to the second driving source 21.

[0062] The second driving source 21 is installed below the butterfly body 3. The second driving source 21 is a brushless motor, and the fourth gear 22 is installed on its motor shaft. The third gears 111 of the two connecting rod mechanisms 11 are rotatably installed on the gear rack 52 to form a fulcrum O1. The fourth gear 22 is engaged with one of the third gears 111, and the two third gears 111 are engaged. One end of the connecting rod 112 is hinged to the third gear 111 to form a hinge A, and the other end of the connecting rod 112 is hinged to one end of the rocker arm 113 to form a hinge B. The other end of the rocker arm 113 is connected to the flapping wing 12. The rocker arm 113 is hinged to the mounting surface 31 to form a fulcrum O2. The rear end of the butterfly body 3 is softly connected to the flapping wing 12 through a spring 4.

[0063] like Figure 10 、 Figure 11 As shown, the length between O1 and A is , the connecting rod 112 has a length , the rocker arm 113 has a length , a length d is formed between O2 and O1; The rocker arm rotates around the fulcrum O1 and makes a full circle rotation. The rocker arm is connected by a connecting rod to make a periodic reciprocating swing around the fulcrum O2 to form an upward swing angle. and hem angle The above values ​​are in mm.

[0064] The above values ​​are derived from the following formula (1):

[0065] (1)

[0066] in, is the angle between the line connecting O2 and O1 and the horizontal plane; The rocker arm is in the upper swing angle The angle between the position and the line connecting O2 and O1.

[0067] is the rack length, and its maximum value satisfies the following relationship (2):

[0068] (2)

[0069] Among them, D2 is the swing angle of the rocker arm Endpoints at position; is the extreme position angle, which is the upper swing angle formed by the rocker arm and hem angle The angle formed by the connecting rod in the two positions; R= ; equal .

[0070] and The relationship between them is:

[0071] (3)

[0072] like When the length unit is 1, the linkage mechanism satisfies the following relationship (4):

[0073] (4)

[0074]

[0075] After combining formula (4), we can get and The values ​​are:

[0076] (5).

[0077] like Figure 12As shown, the minimum transmission angle of the connecting rod mechanism 11 is at position B3. At this time, the following relationship exists:

[0078] (6)

[0079] From this, the minimum transmission angle and the frame The length relationship is:

[0080] (7)

[0081] in:

[0082] (8)

[0083] in, : is the flapping angle The squared sine value associated with the polar angle θ reflects the overall swing range of the aircraft;

[0084] :For the flapping angle The ratio defined by the angle θ and the pole position angle is used to adjust the geometric relationship in the transmission angle calculation;

[0085] : is the square sine value related to the extreme position angle θ, which affects the minimum transmission angle boundary conditions.

[0086] To ensure good transmission performance of the mechanical system, the minimum transmission angle γmin≥40°, the extreme position angle θ is 15°, and the flapping angle is designed is 60°, where the upper swing angle to 45° and adjust the rocker arm length Take it as 1, and substitute the design parameters into formula (3) and (8) to obtain:

[0087]

[0088] Substituting the above values ​​into formula (7), the minimum transmission angle obtained is The length relationship is:

[0089] .

[0090] like Figure 13 As shown, When γ is 1.255, the minimum transmission angle γmin takes the maximum value of 41.23°>40°, which meets the transmission angle design requirements. Substituting this result into formula (5), the values ​​of the connecting rod mechanism 11 are obtained as follows:

[0091]

[0092] Substituting the above result into formula (1), we obtain δ = 77.64°. During the flapping of flapping wing 12, rocker arm 113 drives the entire flapping wing 12 to flap. While ensuring that all components operate normally and do not interfere with each other, the size of rocker arm 113 should be designed to be as large as possible.

[0093] In this embodiment, the angle θ of the flapping wing 12 is 50 degrees, and the crank length =3mm, rack length =24.5mm, rocker arm length =5mm, confirm the connecting rod length by calculation =23.8mm. The second driving source 21 is a brushless motor with a speed of about 4000 revolutions per minute. A gear reduction mechanism with a transmission ratio of 1:10 is used to make the flapping frequency of the butterfly's wings 12 close to that of a real butterfly, about 6 to 7 times per second.

[0094] like Figure 4 As shown, a portion of first gear teeth 531 is provided on the outer circumference of the first gear 53. A first hole 532 is provided on the first gear 53. Figure 5 As shown, the second gear 54 includes two swing rods 541 connected at an obtuse angle. A portion of the second gear teeth 542 is provided at the intersection of the two swing rods 541. The second gear 54 is provided with a second hole 543 and a third hole 544 located at the ends of the two swing rods 541. Figure 6 As shown, the upper middle end of the wing frame 51 is provided with a slot 511, the lower middle end is provided with a fifth hole 513, and the upper left and right sides of the wing frame 51 are each provided with a fourth hole 512. Figure 7 As shown, the gear rack 52 has a sixth hole 521 and a seventh hole 522 below the sixth hole 521 in the middle. An eighth hole 523 is formed on each of the left and right sides of the upper end of the gear rack 52, and a ninth hole 524 is formed on each of the left and right sides of the lower end of the gear rack 52.

[0095] like Figure 2 As shown, the first gear 53 is fixed to the rear surface of the wing frame 51. The first drive source 55 is a steering gear, and the steering gear's power output shaft is inserted and fixed in the first hole 532 of the first gear 53. The gear frame 52 is located at the lower end of the wing frame 51, and the second gear 54 is located at the lower end of the first gear 53. The first gear teeth 531 mesh with the second gear teeth 542. The transmission ratio of the second gear 54 is 2:3, and its deflection angle is derived as follows:

[0096] Assume that the driving gear rotation angle is λ and the driven gear rotation angle is ,but .

[0097] The rotation angle of the third gear 111 is converted into the wing surface deflection angle of the aircraft flapping wing through the connecting rod mechanism 11 , experimentally measured =0.2 , when λ=40°, , which can effectively deflect the aircraft by 12 degrees, shift the center of gravity, and achieve the effect of turning. The fifth hole 513, the sixth hole 521 and the second hole 543 are aligned and hinged by bolts or pins, so that the wing frame 51, driven by the first gear 53, can deflect to the left or right relative to the gear frame 52 (such as Figure 8 、 Figure 9 as shown), to achieve center of gravity shift.

[0098] like Figure 2 Figure 3 As shown, the fourth hole 512 on the wing frame 51 is screwed to the mounting surface 31 of the butterfly body 3. A clamping block 33 is connected to the front end of the butterfly body 3, and the clamping block 33 is clamped into the clamping slot 511. The wing frame 51 is tilted, and the clamping slot 511 drives the clamping block 33 and the butterfly body 3 to tilt together to achieve steering.

[0099] The seventh hole 522 on the gear rack 52 is used to pass through the motor shaft of the second drive source 21. The two third holes 544 on the rocker 541 are respectively hingedly connected to the two eighth holes 523 on the gear rack 52 via bolts or pins. The two ninth holes 524 on the gear rack 52 are respectively hingedly connected to one of the third gears 111.

[0100] The present invention also provides a method for steering the bionic butterfly aircraft, comprising:

[0101] S1, start the first driving source 55 to drive the first gear 53 to rotate relative to the second gear 54;

[0102] S2, the wing frame 51 is tilted to the left or right by a certain angle (such as Figure 8 、 Figure 9 As shown); drives the rocker arm 113 connected to the wing frame 51 to rotate together, so that the center of gravity of the butterfly body 3 and the flapping wings 12 deflects, and senses the center of gravity deflection of the butterfly body 3 and the flapping wings 12 through the center of gravity position sensing system to perform steering; the center of gravity position sensing system includes a combination structure of a screw rod and a resistance sensor to form a closed-loop sensing system, so that the aircraft can use the center of gravity to control the rise and descent of the butterfly;

[0103] S3, after the steering is completed, the first driving source 55 is started to drive the first gear 53 to rotate in the opposite direction relative to the second gear 54 and reset.

[0104] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A bionic butterfly aircraft, comprising an actuator and a drive mechanism, wherein the actuator comprises two symmetrically arranged connecting rod mechanisms and flapping wings connected to the connecting rod mechanisms, and the drive mechanism is used to drive the connecting rod mechanisms to enable the flapping wings to fly, characterized in that: It also includes a butterfly body and a steering mechanism, the steering mechanism includes a wing frame, a gear frame, a first gear, a second gear and a first driving source; the upper end of the connecting rod mechanism and the upper end of the wing frame are both connected to the butterfly body, the lower end of the connecting rod mechanism is connected to the lower end of the gear frame, and the lower end of the wing frame is hinged to the upper end of the gear frame; the first gear is fixed on one side of the wing frame, the first driving source is mounted on the butterfly body, and the first driving source is connected to the first gear; the upper end of the second gear is meshed with the first gear, and the lower end of the second gear is respectively connected to the left and right ends of the gear frame; when the first driving source drives the first gear to rotate relative to the second gear, the wing frame and the connected connecting rod mechanism are tilted to the left or right to achieve steering.

2. The bionic butterfly aircraft according to claim 1, characterized in that: A portion of first gear teeth is provided on the outer circular surface of the first gear; the second gear includes two rocker arms connected at an obtuse angle, and a portion of second gear teeth is provided at the intersection of the two rocker arms. The ends of the two rocker arms away from the second gear teeth are connected to the gear frame, and the first gear teeth are meshed with the second gear teeth.

3. The bionic butterfly aircraft according to claim 2, characterized in that: The transmission ratio of the first gear and the second gear is 2:

3.

4. The bionic butterfly aircraft according to claim 1, characterized in that: The front end of the butterfly body is connected to the flapping wing through a connecting rod mechanism, and the rear end of the butterfly body is softly connected to the flapping wing through a spring.

5. The bionic butterfly aircraft according to claim 1, characterized in that: The connecting rod mechanism includes a third gear, a connecting rod and a rocker arm, and the driving mechanism includes a second driving source and a fourth gear connected to the second driving source; the second driving source is installed under the butterfly body, and the third gears of the two connecting rod mechanisms are rotatably installed on the gear rack to form a fulcrum O1, and the fourth gear is engaged with one of the third gears; one end of the connecting rod is hinged to the third gear to form a hinge A, and the other end of the connecting rod is hinged to one end of the rocker arm to form a hinge B, and the other end of the rocker arm is connected to the flapping wing, and the rocker arm is rotatably installed on the wing rack to form a fulcrum O2.

6. The bionic butterfly aircraft according to claim 1, characterized in that: A mounting surface is formed at the front end of the butterfly body, and the head and the connecting rod mechanism are connected to the mounting surface; a plurality of hollow holes are provided on the butterfly body.

7. A method for steering the bionic butterfly aircraft according to any one of claims 1 to 6, characterized in that: include: The first driving source is activated to drive the first gear to rotate relative to the second gear; the wing frame is tilted to the left or right by a certain angle; The connecting rod mechanism connected to the wing frame deflects together, causing the center of gravity of the butterfly body and flapping wings to deflect and perform steering; After the steering is completed, the first driving source is started to drive the first gear to rotate in the opposite direction relative to the second gear to reset.

8. The steering method of the bionic butterfly aircraft according to claim 7, characterized in that: The center of gravity position sensing system senses the deflection of the butterfly body and flapping wings.

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