A parametric design method for flapping-wing devices

Abstract

The present invention discloses a parametric design method for a flapping-wing device, pertaining to the field of aerospace. The method includes determining the flapping amplitude of a designed flapping-wing mechanism; establishing the relationship between the angular velocity #imgabs1# of the crank #imgabs0# rotating about the center of a circle in the slider-crank mechanism and the angular velocity #imgabs3# of the first guide rod #imgabs2# swinging in the swinging guide rod mechanism based on the relationship between the rods and angles in the slider-crank mechanism, transition mechanism, and swinging guide rod mechanism; and determining the rod lengths of each mechanism using the upper limit position, intermediate position, and lower limit position of the mechanism. The parametric design method for a flapping-wing device provided by the present invention derives a flapping-wing mechanism by deducing the laws between geometric dimensions and kinematics, enabling a large flapping amplitude and providing insights into flapping-wing mechanism design.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to a parametric design method for a flapping-wing device. Background Art

[0002] Bionic flapping-wing micro-aircraft (MAVs), driven by the rapid development of aviation technology and the rapid advancement of micro-electromechanical systems (MEMS), have become a current research hotspot and a key development direction for future aircraft. Compared to traditional aircraft, MAVs offer advantages such as small size, enhanced maneuverability, and high stealth. They hold great potential in disaster relief, geological exploration, and military applications, and market demand is steadily increasing.

[0003] While there are many types of flapping-wing micro aircraft currently available, they can generally be divided into two categories: those that mimic bird flight and those that mimic insect flight. Bird-mimicking aircraft are mostly the same size as normal birds and use tail-driven rudders to change their flight attitude. While this improves flight time, it prevents hovering and free takeoff and landing, and is primarily used in open environments. Insect-mimicking aircraft, on the other hand, rely on flapping wings to change their attitude, enabling both hovering and takeoff and landing. They also possess greater maneuverability and are adaptable to more complex environments, making them a major research hotspot.

[0004] However, to ensure accurate mechanical transmission, the flapping mechanisms of most existing insect-like aircraft often employ multi-link or multi-gear structures. The addition of a reduction mechanism often increases the complexity of the structure, making it more difficult to manufacture and design. Of course, overly simple mechanisms such as levers and crank rockers are somewhat inadequate when it comes to mimicking the flapping movements of birds and insects in nature. Summary of the Invention

[0005] The purpose of the present invention is to provide a parametric design method for a flapping-wing device to solve the problems existing in the background technology.

[0006] To achieve the above object, the present invention provides a parametric design method for a flapping wing device, comprising the following steps:

[0007] S1. Determine the flapping amplitude of the designed flapping wing mechanism;

[0008] S2. According to the relationship between each rod and angle in the crank slider mechanism, transition mechanism and swing guide rod mechanism, the crank in the crank slider mechanism is determined. Angular velocity of rotation around the center of a circle With the first guide rod in the swing guide rod mechanism Angular velocity of the swing relationship;

[0009] S3. Obtain the rod length of each mechanism through the upper limit position, middle position and lower limit position of the mechanism.

[0010] Preferably, the slider crank mechanism includes a slider, a first fixed point A, a crank that performs uniform circular motion around the first fixed point A, ,crank A first moving point E is provided at one end away from the first fixed point A, a first connecting rod b is connected between the first moving point E and the slider 1, and an edge f is connected between the first fixed point A and the slider 1;

[0011] The swing guide rod mechanism includes a slider 2 and a second fixed point B, and a first guide rod is connected between the slider 2 and the second fixed point B. A second guide rod is connected between the first fixed point A and the second fixed point B. A third guide rod is connected between the slider 2 and the first fixed point A. ;

[0012] The transition mechanism includes a second moving point F, a third guide rod The extension rod d passing through the first fixed point A is connected to the second moving point F, and a second connecting rod c is hinged between the slider 1 and the second moving point F.

[0013] Preferably, the relationship between each rod and angle in S2 is as follows:

[0014] For the slider-crank mechanism:

[0015] (1)

[0016] (2)

[0017] in, For crank The angle between it and the side f; is the angle between the first link b and the edge f;

[0018] For transition institutions:

[0019] (3)

[0020] (4)

[0021] in, is the angle between the second link c and the edge f; is the angle between the extended rod d and the side f;

[0022] For the swing guide mechanism:

[0023] (5)

[0024] (6)

[0025] in, For the third guide rod and the first guide rod The supplementary angle of an included angle.

[0026] Preferably, the relationship between each rod and the angle is derived to obtain equation group 1, and the and The relationship is recorded as relationship 1:

[0027] (7)

[0028] (8)

[0029] Taking the derivative of both sides of equation 1 with respect to t, we can get equation 2, and establish and The relationship is recorded as relationship 2:

[0030] (9)

[0031] (10)

[0032] in, For crank The angular velocity of the rotation around the center of the circle is obtained after the motor speed passes through the reduction device and is proportional to the motor speed; express angular velocity; First guide rod Angular velocity of the swing.

[0033] Preferably, in the upper and lower limit positions:

[0034] From the cosine theorem we get:

[0035] (11)

[0036] (12)

[0037] (13)

[0038] in:

[0039] (14)

[0040] in, For the third guide rod With the second guide rod h is the distance between the second slider at the upper limit position of the crank slider mechanism and the first fixed point A; It indicates the distance between slider 1 and point B when the swing guide mechanism is at the upper limit position and the lower limit position.

[0041] Preferably, the relationship obtained in the middle position is as follows:

[0042] (15)

[0043] (16)

[0044] h (h>0) is the distance between the right limit position of the slider-crank mechanism and the first fixed point A. This distance satisfies the following conditions:

[0045] ;

[0046] ;

[0047] ;

[0048] ;

[0049] ;

[0050] ;

[0051] Of course, during the design process, attention should also be paid to the interference between the mechanisms, which is also one of the conditions for limiting h;

[0052] for , which is determined by the designed wing length and the radius of the reduction gear. The longer the wing, The longer, The shorter, the more compact the mechanism; , whose length is and About, in After confirmation, The longer, The longer it is, the more compact the structure. It should not be too long. In addition, , , The three conditions are as follows:

[0053] ;

[0054] ;

[0055] ;

[0056] In determining , Finally, according to the determined flapping angle, determine the angles at the upper and lower limit positions , The value of depends on the size of the gear of the reduction mechanism. The larger the gear, The larger the value of After the length of the rod is determined, the values ​​of the rod length b, c, and d can be obtained by equations (7), (11), (12), and (16). After the rod length and the flapping amplitude are determined, the flapping frequency can be changed by changing the motor speed.

[0057] Therefore, the present invention adopts the above-mentioned parametric design method of a flapping wing device. After determining the flapping amplitude of the designed flapping wing mechanism, the rod length is calculated through the angle. After the rod length and the flapping amplitude are determined, the flapping frequency can be changed by changing the motor speed.

[0058] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 Schematic diagram of a process for parameterized design of a flapping-wing device according to the present invention;

[0060] Figure 2 A schematic diagram of the mechanism of a parametric design method for a flapping-wing device according to the present invention;

[0061] Figure 3 Schematic diagram of the upper limit position of a parametric design method for a flapping-wing device according to the present invention;

[0062] Figure 4 Schematic diagram of the lower limit position of a parametric design method for a flapping-wing device according to the present invention;

[0063] Figure 5 A schematic diagram of an intermediate position of a parametric design method for a flapping-wing device according to the present invention;

[0064] Figure 6 The figure is a schematic diagram of a deceleration mechanism of a parametric design method of a flapping-wing device according to the present invention. DETAILED DESCRIPTION

[0065] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0066] See also Figure 1, a parametric design method for a flapping-wing device, comprising the following steps:

[0067] S1. Determine the flapping amplitude of the designed flapping wing mechanism.

[0068] S2. According to the relationship between each rod and angle in the crank slider mechanism, transition mechanism and swing guide rod mechanism, the crank in the crank slider mechanism is determined. Angular velocity of rotation around the center of a circle With the first guide rod in the swing guide rod mechanism Angular velocity of the swing relationship.

[0069] like Figure 2 The crank slider mechanism includes a slider, a first fixed point A, and a crank that performs uniform circular motion around the first fixed point A. ,crank A first moving point E is provided at one end away from the first fixed point A, a first connecting rod b is connected between the first moving point E and the slider 1, and an edge f is connected between the first fixed point A and the slider 1;

[0070] The swing guide rod mechanism includes a slider 2 and a second fixed point B, and a first guide rod is connected between the slider 2 and the second fixed point B. A second guide rod is connected between the first fixed point A and the second fixed point B. A third guide rod is connected between the slider 2 and the first fixed point A. ;

[0071] The transition mechanism includes a second moving point F, a third guide rod The extension rod d passing through the first fixed point A is connected to the second moving point F, and a second connecting rod c is hinged between the slider 1 and the second moving point F.

[0072] The crank slider mechanism adopts the concentric form to eliminate the quick return characteristic. The first fixed point A makes uniform circular motion, driving the first connecting rod B to drive the slider to make reciprocating linear motion; in order to make the mechanism more compact, the first fixed point A is used as the third guide rod in the swing guide rod mechanism. The swing center of the third guide rod The extension rod d is hinged to the second connecting rod c, thereby driving the third guide rod The first guide rod is driven by the second slider Swing back and forth.

[0073] The relationship between the rods and angles is as follows:

[0074] For the slider-crank mechanism:

[0075] (1)

[0076] (2)

[0077] in, For crank The angle between it and the side f; is the angle between the first link b and the edge f;

[0078] For transition institutions:

[0079] (3)

[0080] (4)

[0081] in, is the angle between the second link c and the edge f; is the angle between the extended rod d and the side f;

[0082] For the swing guide mechanism:

[0083] (5)

[0084] (6)

[0085] The above formula is derived to obtain equation group 1, which establishes and The relationship is recorded as relationship 1:

[0086] (7)

[0087] (8)

[0088] Taking the derivative of both sides of equation 1 with respect to t, we can get equation 2, and establish and The relationship is recorded as relationship 2:

[0089] (9)

[0090] (10)

[0091] in, For crank The angular velocity of the rotation around the center of the circle is obtained after the motor speed passes through the reduction device and is proportional to the motor speed; express angular velocity; First guide rod Angular velocity of the swing.

[0092] S3. Obtain the rod length of each mechanism through the upper limit position, middle position and lower limit position of the mechanism. The establishment of the mechanism rod length can be established according to the limit position of the mechanism, such as Figure 3 and Figure 4 shown.

[0093] In the upper and lower limit positions:

[0094] From the cosine theorem we get:

[0095] (11)

[0096] (12)

[0097] (13)

[0098] in:

[0099] (14)

[0100] in, For the third guide rod With the second guide rod h is the distance between the second slider at the upper limit position of the crank slider mechanism and the first fixed point A; It indicates the distance between slider 1 and point B when the swing guide mechanism is at the upper limit position and the lower limit position.

[0101] like Figure 5 , the relationship obtained in the middle position is as follows:

[0102] (15)

[0103] (16)

[0104] in, Indicates the distance between slider 1 and point B when the swing guide mechanism is in the middle position;

[0105] h (h>0) is the distance between the second slider and the first fixed point A at the upper limit position of the slider crank mechanism. This distance satisfies the following conditions:

[0106] ;

[0107] ;

[0108] ;

[0109] ;

[0110] ;

[0111] ;

[0112] Of course, during the design process, attention should also be paid to the interference between the mechanisms, which is also one of the conditions for limiting h;

[0113] for , which is determined by the designed wing length and the radius of the reduction gear. The longer the wing, The longer, The shorter, the more compact the mechanism; , whose length is and About, in After confirmation, The longer, The longer it is, the more compact the structure. It should not be too long. In addition, , , The three conditions are as follows:

[0114] ;

[0115] ;

[0116] ;

[0117] In determining , Finally, according to the determined flapping angle, determine the angles at the upper and lower limit positions , The value of depends on the size of the gear of the reduction mechanism. The larger the gear, The larger the value of After the length of the rod is determined, the values ​​of the rod length b, c, and d can be obtained by equations (7), (11), (12), and (16). After the rod length and the flapping amplitude are determined, the flapping frequency can be changed by changing the motor speed.

[0118] Example 1:

[0119] If we need to design a flapping mechanism with a flapping amplitude of 120°, the deceleration mechanism is as follows: Figure 6 As shown, the largest gear on the left and right is m=0.5, z=56, the upper layer of the double-layer gear is z=10, the lower layer is z=44, and the smallest gear is z=10.

[0120] Step 1: Determine the swing guide rod mechanism.

[0121] Since the radius of the tooth top circle of the 56-tooth gear is 14.5 mm, in order to avoid the rotation pair at point B intersecting with the gear, Initially set at 17 mm, Initially set to 17 mm. From formula (15), we can get: =34 mm. Given that the flapping amplitude is 120°, when it is at the upper or lower limit position, the cosine theorem and equation (13) yield: 22.15 mm, after inspection, meets the triangle conditions.

[0122] Step 2: Determine the slider-crank mechanism.

[0123] In step 1, the three sides of the triangle at the extreme position are known, so the sizes of the internal angles of the triangle at the extreme position can be obtained. ≈34.34°. To make the mechanism compact, h is initially set to 10 mm, and the length of a does not exceed the radius of the 56-tooth gear. In this example, the pitch circle radius of the 56-tooth gear is 14 mm, so a is initially set to 5 mm. Based on the cosine theorem (Equations 11 and 12) and the relationship between the rods (Equation 7), taking each extreme position yields:

[0124] ;

[0125] ;

[0126] ;

[0127] ;

[0128] ;

[0129] Solving them together we can get b, c, and d.

[0130] The solution is: b=15 mm, c≈16.69 mm, d≈8.86 mm.

[0131] After testing, it was found that the required flapping action can be achieved.

[0132] Therefore, the present invention adopts the above-mentioned parametric design method of a flapping-wing device, and derives a flapping-wing mechanism by the law between geometric dimensions and kinematics, which can achieve a larger flapping amplitude and provide ideas for the design of the flapping-wing mechanism.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A parametric design method for a flapping wing device, characterized in that: The following steps are involved: S1. Determine the flapping amplitude of the designed flapping wing mechanism; S2. According to the relationship between each rod and angle in the crank slider mechanism, transition mechanism and swing guide rod mechanism, the crank in the crank slider mechanism is determined. Angular velocity of rotation around the center of a circle With the first guide rod in the swing guide rod mechanism Angular velocity of the swing relationship; The relationship between the rods and angles is as follows: For the slider-crank mechanism: (1) (2) in, For crank The angle between it and the side f; is the angle between the first link b and the edge f; For transition institutions: (3) (4) in, is the angle between the second link c and the edge f; is the angle between the extended rod d and the side f; For the swing guide mechanism: (5) (6) in, For the second guide rod and the first guide rod Angle; S3. Obtain the rod length of each mechanism through the upper limit position, middle position and lower limit position of the mechanism; The relationship between each rod and the angle is derived to obtain equation group 1, which establishes and The relationship is recorded as relationship 1: (7) (8) Derivatives of both sides of equation 1 with respect to t yield equation 2, establishing and The relationship is recorded as relationship 2: (9) （10） in, For crank The angular velocity of the rotation around the center of the circle is obtained after the motor speed passes through the reduction device and is proportional to the motor speed; express angular velocity; For guide rod Angular velocity of the swing; In the upper and lower limit positions: From the cosine theorem we get: (11) (12) (13) in: (14) in, For the third guide rod With the second guide rod Angle; is the distance between the second slider at the upper limit position of the slider crank mechanism and the first fixed point A; Indicates the distance between the slider 1 and point B when the swing guide mechanism is at the upper limit position and the lower limit position; The relationship obtained in the middle position is as follows: (15) (16) in, Indicates the distance between slider 1 and point B when the swing guide mechanism is in the middle position; h is the distance between the second slider at the upper limit position of the crank slider mechanism and the first fixed point A. This distance satisfies the following conditions: ； ； ； ； ； ； Interference between institutions is also a limitation one of the conditions; for , which is determined by the designed wing length and the radius of the reduction gear. The longer the wing, The longer, The shorter, the more compact the mechanism; , whose length is and About, in After confirmation, The longer, The longer, the more , , The three conditions are as follows: ； ； ； In determining , Finally, according to the determined flapping angle, determine the angles at the upper and lower limit positions , The value of depends on the size of the gear of the reduction mechanism. The larger the gear, The larger the value of After determining the length of the rod, the rod lengths b, c, and d can be obtained using equations (7), (11), (12), and (16).

2. The parametric design method for a flapping-wing device according to claim 1, wherein: The crank slider mechanism includes a slider, a first fixed point A, and a crank that performs uniform circular motion around the first fixed point A. ,crank A first moving point E is provided at one end away from the first fixed point A, a first connecting rod b is connected between the first moving point E and the slider 1, and an edge f is connected between the first fixed point A and the slider 1; The swing guide rod mechanism includes a slider 2 and a second fixed point B, and a first guide rod is connected between the slider 2 and the second fixed point B. A second guide rod is connected between the first fixed point A and the second fixed point B. A third guide rod is connected between the slider 2 and the first fixed point A. ; The transition mechanism includes a second moving point F, a third guide rod The extension rod d passing through the first fixed point A is connected to the second moving point F, and a second connecting rod c is hinged between the slider 1 and the second moving point F.

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