Bionic butterfly aircraft and steering method thereof

Abstract

The invention provides a bionic butterfly aircraft and a steering method thereof. The bionic butterfly aircraft comprises an executing mechanism, a driving mechanism, a butterfly body and a steering mechanism, the executing mechanism comprises two connecting rod mechanisms and flapping wings, and the steering mechanism comprises 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 with the butterfly body, the lower end of the connecting rod mechanism is connected with 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 fixedly arranged on one side of the wing frame, the first driving source is installed on the butterfly body, and the first driving source is in driving connection with 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 connected with the left end and the right end of the gear frame respectively. Effective deflection of the butterfly body can be achieved, the turning effect is achieved, and the flexibility and reliability of the aircraft are improved.

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 industrial, agricultural, military and other fields. Especially in the agricultural field, they are mainly used for sowing crops, spraying pesticides, etc. At present, there are relatively high requirements for aircraft. For example, the actuating mechanism should meet the functions it needs to complete, be able to achieve expected motion, force and speed, have good adaptability, flexibility and reliability, not only be able to operate stably, but also be able to withstand long-term heavy load use, etc.

[0003] The existing aircraft mainly have the following several structures: (1) Single crank double rocker mechanism: A crank rotates circumferentially around a fulcrum, so that a rocker arm connected to two connecting rods swings periodically around another fulcrum, and the rocker arm is connected to a flapping wing to perform a flight action. The disadvantages of this structure are: the actions of the left and right flapping wings are not synchronized, there is a phase difference, resulting in unequal aerodynamic forces on the aircraft during flight, and it is extremely easy to cause phenomena such as falling and crashing; (2) Crank-slider mechanism: A crank rotates circumferentially around a fulcrum, so that a connecting rod drives a slider to slide in a slideway, and two rocker arms and flapping wings connected to the connecting rod swing periodically around another fulcrum to perform a flight action. It solves the problem of phase difference, but this slider structure results in relatively large frictional resistance. Especially during high-speed flapping, the wear caused by friction is difficult to control; (3) Spatial crank rocker mechanism: It has two cranks. One end of each of the two cranks is connected to a shaft, and the other ends of the two cranks are respectively hinged to a connecting rod, and each connecting rod is hinged to a rocker arm. The crank is fixedly connected to the shaft and makes a full-circle rotary motion. Through the connection of the connecting rod, it drives the rocker arm mechanism and the flapping wing to swing periodically around the fulcrum. Its advantages are: both ends of the connecting rod are connected to the driving part (crank) and the driven part (rocker arm) by spherical pairs respectively, and the mechanism is compact, reliable and flexible in motion. Its disadvantages are: the solution method is complex and the design process is cumbersome. At present, it is mainly used for the driving structure of single-segment bionic flapping wing aircraft; (4) Planar double crank double rocker mechanism: Such as the bionic butterfly micro flapping wing aircraft disclosed in the existing patent publication number CN110091988A, which includes a frame, a flapping mechanism, and first and second stage wings. The main shaft gear drives the transmission gear to rotate, and the connecting rod converts the rotation of the gear into the swing of the rocker to achieve flapping. Its turning is realized through the second wing skeleton, and this turning action cannot realize the turning of the aircraft. Therefore, it cannot meet the requirements of flexibility and reliability.

[0004] In addition, for the orientation names involved in the present invention, the following is usually recognized in this field: Front: Refers to the direction in which the aircraft moves forward; Rear: The direction opposite to the forward direction of the aircraft; Left: On the left side in the forward direction of the aircraft; Right: On the right side in the forward direction of the aircraft. Summary of the Invention

[0005] The object of the present invention is to provide a bionic butterfly aircraft capable of steering and its steering method, so as to improve the flexibility and reliability of the aircraft.

[0006] The technical solution of the present invention is: a bionic butterfly aircraft, including an actuator, a drive mechanism, a butterfly body and a steering mechanism. The actuator includes two link mechanisms symmetrically arranged on the left and right and flapping wings connected to the link mechanisms. The drive mechanism is used to drive the link mechanisms to act so that the flapping wings fly. The steering mechanism includes a wing frame, a gear frame, a first gear, a second gear and a first drive source. The upper ends of the link mechanisms and the upper end of the wing frame are both connected to the butterfly body. The lower end of the link mechanism is connected to the lower end of the gear frame. The lower end of the wing frame is hinged to the upper end of the gear frame. The first gear is fixedly arranged on one side of the wing frame. The first drive source is installed on the butterfly body and is drivingly connected to the first gear. The upper end of the second gear meshes 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 drive source drives the first gear to rotate relative to the second gear, the wing frame and the connected link mechanism are inclined to the left or right to achieve steering.

[0007] In the above solution, by adding a steering mechanism, the effective deflection of the butterfly body is realized, and the turning effect is achieved to meet the use requirements in various fields and improve the flexibility and reliability of the aircraft.

[0008] Preferably, part of the first teeth are provided on the outer circumferential surface of the first gear. The second gear includes two swing rods connected at an obtuse angle. Part of the second teeth are provided at the intersection of the two swing rods. The ends of the two swing rods far from the second teeth are connected to the gear frame, and the first teeth mesh with the second teeth.

[0009] Preferably, the transmission ratio of the second gear is 2:3.

[0010] Preferably, the front end of the butterfly body is connected to the flapping wing through a link mechanism, and the rear end of the butterfly body is softly connected to the flapping wing through a spring.

[0011] Preferably, the link mechanism includes a third gear, a link and a rocker arm. The drive mechanism includes a second drive source and a fourth gear connected to the second drive source. The second drive source is installed below the butterfly body, and the third gears of the two link mechanisms are rotatably installed on the gear frame to form a fulcrum O 1, the fourth gear meshes with one of the third gears; one end of the connecting rod is hinged to the third gear to form hinge point A, the other end of the connecting rod is hinged to one end of the rocker arm to form hinge point B, the other end of the rocker arm is connected to the flapping wing, and the rocker arm is rotatably installed on the wing frame to form a fulcrum O 2 .

[0012] Preferably, O 1 forms a length between A , the connecting rod has a length , the rocker arm has a length , O 2 forms a length d with O 1 ; Rotates a full circle around the fulcrum O 1 , and drives the rocker arm to reciprocate periodically around the fulcrum O 2 to form an upswing angle and a downswing angle ; The following formula (1) is obtained from the above values: (1) Wherein, is the angle between the connection line of O 2 and O 1 and the horizontal plane; is the angle between the rocker arm and the connection line of O at the upswing angle 2 and O 1 ; The maximum value of satisfies the following relationship (2): (2) Wherein, D 2 is the end point of the rocker arm at the downswing angle ; is the extreme position angle, and the extreme position angle is the angle formed by the connecting rod when the rocker arm forms the upswing angle and the downswing angle at two positions; = ; is the flapping angle, which is equal to ; The relationship between and is: (3) If is 1 in length unit, the connecting rod mechanism satisfies the following relationship (4): (4)

[0013] After combining the simultaneous equations (4), we respectively obtain and The value of is: (5).

[0014] Preferably, an installation surface is formed at the front end of the butterfly body, and a head and the link mechanism are connected to the installation surface; a plurality of hollow holes are provided on the butterfly body.

[0015] The present invention also provides a method for steering using the above bionic butterfly aircraft, including: Start the first drive source to drive the first gear to rotate relative to the second gear; the wing frame swings left or right by a certain angle; the link mechanism connected to the wing frame swings together, causing the butterfly body and the flapping wing center of gravity to deflect and perform steering; after the steering is completed, start the first drive source to drive the first gear to rotate in the reverse direction relative to the second gear to reset.

[0016] Preferably, the deflection of the butterfly body and the flapping wing center of gravity is sensed by the center of gravity position sensing system.

[0017] Compared with the related art, the beneficial effects of the present invention are: First, by adding a steering mechanism, the present invention realizes the effective deflection of the butterfly body, achieves a turning effect, meets the usage requirements in various fields, and improves the flexibility and reliability of the aircraft; Second, the front end of the butterfly body is connected to the flapping wing through a link mechanism, and the rear end of the butterfly body is connected to the flapping wing through a spring, realizing a combined connection method of rigidity and flexibility, that is, achieving precise transmission at the front end of the flapping wing and realizing flexible shock absorption at the rear end of the flapping wing, greatly improving the stability of the flapping wing during flight and extending its service life; Third, the steering of the present invention combines the change of the wing frame swing angle position and the deflection of the center of gravity, realizes the differential amplitude turning and eccentric turning of the bionic butterfly double flapping wings, and improves the stability and accuracy during turning; Fourth, the drive mechanism is installed below the butterfly body, making the center of gravity of the aircraft relatively low, which has a good regulating effect on the overall stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the bionic butterfly aircraft provided by the present invention from the first perspective; Figure 2 is a schematic structural diagram of the bionic butterfly aircraft provided by the present invention from the second perspective and removing the flapping wings and the head; Figure 3 is a schematic structural diagram of the bionic butterfly aircraft provided by the present invention from the third perspective and removing the head; Figure 4Schematic structural diagram of the first gear; Figure 5 Schematic structural diagram of the second gear; Figure 6 Schematic structural diagram of the wing frame; Figure 7 Schematic structural diagram of the gear frame; Figure 8 Schematic diagram when the steering mechanism turns to the left; Figure 9 Schematic diagram when the steering mechanism turns to the right; Figure 10 Schematic structural diagram of the actuator; Figure 11 Schematic structural diagram of the linkage mechanism; Figure 12 Schematic diagram of the linkage mechanism at the minimum transmission angle position; Figure 13 Schematic diagram of the relationship between the minimum transmission angle and the length of the frame.

[0019] In the attached drawings: 1. Actuator; 11. Linkage mechanism; 111. Third gear; 112. Link; 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. Card slot; 512. Fourth hole; 513. Fifth hole; 52. Gear frame; 53. First gear; 531. First tooth; 532. First hole; 54. Second gear; 541. Swing rod; 542. Second tooth; 543. Second hole; 544. Third hole; 55. First driving source; 6. Head. Detailed implementation manners

[0020] The present invention will be described in detail below with reference to the attached drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. For the convenience of description, words such as "upper", "lower", "left", and "right" in the following text only represent the same directions as the upper, lower, left, and right directions of the attached drawings themselves, and do not limit the structure.

[0021] As Figure 1 、 Figure 2 shown, a bionic butterfly aircraft 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.

[0022] As Figure 1 described, a mounting surface 31 is formed at the front end of the butterfly body 3, and a head 6 is connected to the mounting surface 31. A plurality of hollow holes 32 are provided on the butterfly body 3.

[0023] 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 .

[0024] The actuator 1 includes two connecting rod mechanisms 11 and two flapping wings 12 that are symmetrically arranged. 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.

[0025] 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 the motor shaft. The third gears 111 of the two connecting rod mechanisms 11 are rotatably installed on the gear frame 52 to form a fulcrum O. 1 The fourth gear 22 is meshed with one of the third gears 111, and the two third gears 111 are meshed. One end of the connecting rod 112 is hinged with the third gear 111 to form a hinge point A, and the other end of the connecting rod 112 is hinged with one end of the rocker arm 113 to form a hinge point B. The other end of the rocker arm 113 is connected to the flapping wing 12. The rocker arm 113 is hinged with the mounting surface 31 to form a fulcrum O 2 The rear end of the butterfly body 3 is softly connected to the flapping wing 12 via a spring 4 .

[0026] like Figure 10 , Figure 11 As shown, O 1 The length between A , the connecting rod 112 has a length , the rocker arm 113 has a length , O 2 With O 1 The length d is formed between them; Around the pivot O 1 Make a full circle rotation motion, driving the rocker arm around the fulcrum O through the connecting rod 2 Make periodic reciprocating swing to form an upward swing angle and hem angle The above values ​​are expressed in mm.

[0027] The above values ​​are derived into the following formula (1): (1) in, O 2 and O 1 The angle between the line connecting the two and the horizontal plane; is the angle between the rocker arm at the upper swing angle position and the connecting lines of O 2 and O 1 .

[0028] is the length of the frame, and its maximum value satisfies the following relationship (2): (2) where D 2 is the end point of the rocker arm at the lower swing angle position; is the extreme position angle. The extreme position angle is the angle formed by the connecting rod when the rocker arm forms the upper swing angle and the lower swing angle at two positions; R = ; is equal to .

[0029] The relationship between is: (3) If the length unit is 1, the linkage mechanism satisfies the following relationship (4): (4)

[0030] After combining formula (4), the values of and are: (5).

[0031] As Figure 12 shown, the minimum transmission angle of the linkage mechanism 11 is at position B 3 , and at this time, there is the following relationship: (6) From this, the relationship between the minimum transmission angle and the length of the frame is: (7) where: (8) where : is the square sine value related to the flapping angle and the extreme position angle θ, which reflects the overall swing range of the aircraft; : is determined by the flapping angle The ratio defined by the extreme position included angle θ, which is used to adjust the geometric relationship in the transmission angle calculation; : is the square sine value related to the extreme position included angle θ, which affects the boundary condition of the minimum transmission angle of.

[0032] To ensure good force transmission performance of the mechanical system, the minimum transmission angle γmin≥40°, the extreme position included angle θ is taken as 15°, and the flapping angle is designed to be 60°, where the upward swing angle is 45°, and the length of the rocker arm is taken as 1. Substituting the design parameters into formulas (3) and (8), we get:

[0033] Substituting the above values into formula (7), the relationship between the obtained minimum transmission angle and the length of the frame is: .

[0034] As Figure 13 shown, when it is 1.255, the minimum transmission angle γmin takes the maximum value of 41.23°>40°, meeting the design requirements of the transmission angle. Substituting this result into formula (5), the values of each part of the link mechanism 11 are obtained as:

[0035] Substituting the above results into formula (1), we get δ = 77.64°. During the flapping process of the flapping wing 12, the rocker arm 113 drives the entire flapping wing 12 to flap. Under the condition of ensuring normal operation of the components without interference, the size of the rocker arm 113 should be designed as large as possible.

[0036] In this embodiment, the extreme position included angle θ of the flapping wing 12 is 50 degrees, the length of the crank = 3mm, the length of the frame = 24.5mm, the length of the rocker arm = 5mm. By calculation, it is confirmed that the length of the connecting rod = 23.8mm. The second drive source 21 is a brushless motor, and the motor rotates about 4000 revolutions per minute. A gear reduction mechanism with a transmission ratio of 1:10 is adopted to make the flapping frequency of the flapping wing 12 of the butterfly similar to that of a real butterfly, about 6 - 7 times per second.

[0037] As Figure 4 shown, part of the first wheel teeth 531 are provided on the outer circumferential surface of the first gear 53. A first hole 532 is provided on the first gear 53. As Figure 5As shown, the second gear 54 includes two swing rods 541 connected at an obtuse angle. A partial second gear tooth 542 is provided at the intersection of the two swing rods 541. A second hole 543 and third holes 544 located at the ends of the two swing rods 541 are provided on the second gear 54. As Figure 6 shown, a clamping groove 511 is provided at the upper middle of the wing frame 51, a fifth hole 513 is provided at the lower middle, and fourth holes 512 are respectively opened on the left and right sides of the upper end of the wing frame 51. As Figure 7 shown, a sixth hole 521 and a seventh hole 522 located below the sixth hole 521 are opened in the middle of the gear frame 52. Eighth holes 523 are respectively opened on the left and right sides of the upper end of the gear frame 52, and ninth holes 524 are respectively opened on the left and right sides of the lower end of the gear frame 52.

[0038] As Figure 2 shown, the first gear 53 is fixedly provided on the rear surface of the wing frame 51, the first driving source 55 is a servo motor, and the power output shaft of the servo motor 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, the second gear 54 is located at the lower end of the first gear 53, and the first gear teeth 531 are engaged with the second gear teeth 542. The transmission ratio of the second gear 54 is 2:3, and its deflection angle is deduced as follows: Let the rotation angle of the driving gear be λ, and the rotation angle of the driven gear be , then .

[0039] The rotation angle of the third gear 111 is converted into the wing surface deflection angle of the flapping wing of the aircraft through the link mechanism 11 , and it is experimentally measured that = 0.2 , when λ = 40°, , it can effectively deflect the aircraft by 12 degrees, offset the center of gravity, and achieve the turning effect. 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 swings left or right relative to the gear frame 52 under the drive of the first gear 53 (as Figure 8 , Figure 9 shown), realizing the offset of the center of gravity.

[0040] As Figure 2 Figure 3 shown, the fourth holes 512 on the wing frame 51 are installed on the mounting surface 31 of the butterfly body 3 by screws. A clamping block 33 is connected to the front end of the butterfly body 3, and the clamping block 33 is clamped in the clamping groove 511. When the wing frame 51 swings, the clamping block 33 and the butterfly body 3 are driven to swing together through the clamping groove 511 to achieve steering.

[0041] The seventh hole 522 on the gear bracket 52 is used for passing through the motor shaft of the second drive source 21. The two third holes 544 on the swing rod 541 are respectively hinged to the two eighth holes 523 on the gear bracket 52 by bolts or pins. The two ninth holes 524 on the gear bracket 52 are respectively hinged to one of the third gears 111.

[0042] The present invention also provides a method for steering by using the above-mentioned bionic butterfly aircraft, including: S1, start the first drive source 55 to drive the first gear 53 to rotate relative to the second gear 54; S2, the wing bracket 51 swings left or right by a certain angle (such as Figure 8 , Figure 9 shown); drive the rocker arm 113 connected to the wing bracket 51 to rotate together, so that the center of gravity of the butterfly body 3 and the flapping wings 12 deflects, and the center of gravity deflection of the butterfly body 3 and the flapping wings 12 is sensed by the center of gravity position sensing system, and steering is performed; the center of gravity position sensing system includes a screw rod and a resistance sensor combination structure, forming a closed-loop sensing system, so that the aircraft can control the ascent and descent of the butterfly by the center of gravity; S3, after the steering is completed, start the first drive source 55 to drive the first gear 53 to rotate in the reverse direction relative to the second gear 54 to reset.

[0043] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A bionic butterfly flying machine, comprising an actuator and a driving mechanism, wherein the actuator comprises two connecting rod mechanisms arranged symmetrically on the left and right and flapping wings connected to the connecting rod mechanisms, and the driving mechanism is used to drive the connecting rod mechanisms to move so that the flapping wings can fly, characterized in that: It also includes a butterfly body and a steering mechanism, which 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 drivingly 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 arranged on the outer circumferential surface of the first gear; the second gear includes two swing rods connected at an obtuse angle, and a portion of second gear teeth is arranged at the intersection of the two swing rods. One end of the two swing rods away from the second gear teeth is connected to the gear frame, and the first gear teeth are meshed with the second gear teeth.

3. The bionic butterfly flying machine according to claim 2, characterized in that: The transmission ratio of 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 flying machine 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 frame to form a fulcrum O1, and the fourth gear is meshed 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 frame to form a fulcrum O2.

6. The bionic butterfly flying machine according to claim 5, characterized in that: The length between O1 and A , the connecting rod has a length , the rocker arm has a length , a length d is formed between O2 and O1; The swing arm makes a full-circle rotation around the fulcrum O1, and the swing 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 derived into the following formula (1): （1） 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; The maximum value of satisfies the following relationship (2): （2） Among them, D2 is the swing angle of the rocker arm. The endpoint of the position; is the extreme angle; R= ; equal ; The relationship between and d is: （3） like When the length unit is 1, the linkage mechanism satisfies the following relationship (4): （4） ； After combining formula (4), we can get and The values ​​are: （5）。 7. The bionic butterfly flying machine 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 arranged on the butterfly body.

8. A method for steering using the bionic butterfly aircraft according to any one of claims 1 to 7, characterized in that: include: 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 deflects together, causing the center of gravity of the butterfly body and flapping wings to deflect and perform steering; After the turning 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.

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

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