An experimental device for measuring the force of the wings of a bionic flapping-wing aircraft

Abstract

The present invention belongs to the technical field of bionic flapping-wing aircraft experimental equipment, specifically an experimental device for measuring the force of a bionic flapping-wing aircraft wing, comprising a flapping-wing aircraft platform, the flapping-wing aircraft platform including two symmetrically arranged flapping rockers, one end of the flapping rocker connected to the drive shaft of a flapping servo, which is mounted on a servo fixed plate, and the other end of the flapping rocker connected to a wing connector via a thrust ring, on which a wing body is mounted; the servo fixed plate is connected rearwardly to two carbon fiber rods, the wing body and the carbon fiber rods are connected by winding iron wire, the carbon fiber rods are installed through a tilting connecting seat, and a tail connecting plate is installed at the end of the carbon fiber rods, which is connected to the tail body; the tilting connecting seat is connected to the tilting servo, which is connected to a force sensor via a force measuring connecting plate, and a connecting support is provided below the force sensor, which is fixed to the top of a bracket. This achieves a test and comparison of the aerodynamic performance of different wings.

Description

Technical Field

[0001] The invention belongs to the technical field of bionic flapping-wing aircraft experimental equipment, and in particular relates to an experimental device for measuring the force of a bionic flapping-wing aircraft wing. Background Art

[0002] In the aviation field, bionic flapping-wing aircraft, with their unique flight method that mimics the flapping of birds' wings, demonstrate high efficiency, high energy utilization, and excellent stealth, and have broad application prospects in various fields, including military, scientific research, and civilian applications. However, the development of flapping-wing aircraft currently faces many bottlenecks, especially in flying wing design technology.

[0003] Existing flapping-wing aircraft generally suffer from light weight, weak payload capacity, and low aerodynamic efficiency, making them difficult to meet practical application requirements. Furthermore, complex incoming flow conditions in actual flight make the flight trajectory and aerodynamic characteristics of flapping-wing aircraft difficult to control and predict, significantly hindering the optimization of flight performance. Furthermore, a lack of efficient research methods and platforms for key flying wing design technologies hinders accurate and in-depth analysis of the aerodynamic performance of different flying wings.

[0004] Existing research on flapping-wing aircraft suffers from numerous shortcomings. For example, some flight test systems perform poorly in terms of vibration isolation, affecting the accuracy of test data. Some drive methods and fuselage structures fail to optimize flight performance while ensuring flapping variations. Small wind tunnel test systems struggle to measure the aerodynamic forces of large wings, and the observable flapping states are relatively limited. Furthermore, the wingbar distribution design of some wings is not conducive to studying the lift-enhancing effects of flexible deformation under different operating conditions. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention proposes an experimental device for measuring the force of the wings of a bionic flapping-wing aircraft, so as to achieve test and comparison of the aerodynamic performance of different wings.

[0006] The present invention provides an experimental device for measuring the force of a bionic flapping-wing aircraft wing, comprising a flapping-wing aircraft platform. The flapping-wing aircraft platform includes two symmetrically arranged flapping rockers, one end of which is connected to a drive shaft of a flapping servo, which is mounted on a servo fixing plate, and the other end of which is connected to a wing connector via a thrust ring, on which a wing body is mounted. The servo fixing plate is rearwardly connected to two carbon fiber rods, the wing body and the carbon fiber rods are connected by winding iron wire, the carbon fiber rods are installed through a tilting connecting seat, and a tail connecting plate is installed at the end of the carbon fiber rods, which is connected to the tail body.

[0007] The tilt connecting seat is connected to the tilt servo, and the tilt servo is connected to the force sensor through the force measuring connecting plate. A connecting support is provided under the force sensor, and the connecting support is fixed to the top of the bracket. A counterweight block is provided at the bottom of the bracket to increase stability.

[0008] The wing body has a semi-elliptical configuration, which includes a wing surface, an inner wing rib is arranged on the inner side of the wing surface, and an outer wing rib is arranged on the outer side. The straight side of the wing body is connected to the wing main beam, and a curved iron wire is also arranged in the center of the inner side of the wing, and a transverse wing sub-beam is arranged from the curved iron wire to the wing surface.

[0009] The tail body is arranged in a quarter-circle configuration, a reinforced carbon fiber sheet is arranged at the front end of the tail body, a tail main rod connected to the tail wing surface is arranged at the center of the tail body, tail edge rods are arranged on both sides of the tail body, and a tail auxiliary rod is arranged on the horizontal surface of the tail body.

[0010] The bottom of the bracket is connected to a fixed base, which includes four diagonal aluminum profiles supported on the bracket. The bottom of the diagonal aluminum profile is connected to the four corners of the grounding aluminum profile. The grounding aluminum profile forms a square with internal diagonals connected, and aluminum alloy fixings are arranged at the four corners of the grounding aluminum profile for reinforcement.

[0011] The beneficial effects of the present invention are:

[0012] Compared to existing technologies, this invention achieves variable flapping frequencies and angles for an ornithopter through flapping servos. The tilting servos also accommodate the varying angles of attack encountered during actual flight, allowing for real-time measurement of the aerodynamic forces and torques generated by the wings. Furthermore, the servo rocker arm, connected to the wing connector, allows for interchangeable wings, enabling comparison of their aerodynamic performance. A counterweight is also incorporated into the bottom of the bracket to minimize vibration during the ornithopter force measurement process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments.

[0014] Figure 1 Schematic diagram of the overall structure of the experimental device in the embodiment;

[0015] Figure 2 Schematic diagram of the connection between the flapping-wing aircraft platform and the tilting servo in the experimental device in the embodiment.

[0016] Figure 3 Schematic diagram of the flapping-wing aircraft platform structure in the experimental device in the embodiment.

[0017] Figure 4 Schematic diagram of the explosion at the tilting servo in the experimental device in the embodiment.

[0018] Figure 5 Schematic diagram of part of the structure of the experimental device in the embodiment.

[0019] Figure 6 Schematic diagram of the flying wing body and tail wing body of the experimental device in the embodiment.

[0020] Figure 7 1 is a modal diagram of a force measurement experiment on a flying wing with an angle of attack in an embodiment.

[0021] Figure 8 It is a schematic diagram of the synchronous and asynchronous flapping of the wings on both sides of the flapping-wing platform in the embodiment.

[0022] In the accompanying drawings, the structural names represented by the reference numerals are:

[0023] 1- flapping rocker arm, 2- flapping servo, 3- servo fixing plate, 4- thrust ring, 5- wing connector, 6- tilt connector A, 7- tilt connector B, 8- carbon fiber rod, 9- tilt connector C, 10- tilt fixing part A, 11- tilt servo, 12- tilt connection block, 13- tilt fixing part B, 14- force measuring connecting plate, 15- force measuring sensor, 16- tail connecting plate A, 17- tail connection Plate B, 18-connecting support, 19-bracket, 20-counterweight, 21-diagonal bracing aluminum profile, 22-aluminum alloy fixings, 23-grounding aluminum profile, 24-bent wire, 25-wing inner rib, 26-wing airfoil, 27-wing outer rib, 28-wing secondary beam, 29-wing main beam, 30-reinforced carbon fiber sheet, 31-tail main rod, 32-tail edge rod, 33-tail airfoil, 34-tail secondary rod. DETAILED DESCRIPTION

[0024] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0025] Example 1

[0026] In order to better compare the aerodynamic performance of different wings, in this embodiment, refer to Figures 1 to 6As shown, an experimental device for measuring the force of a bionic flapping-wing aircraft wing is proposed, including a flapping-wing aircraft platform, which includes two symmetrically arranged flapping rockers 1, one end of the flapping rocker 1 is connected to the drive shaft of a flapping servo 2, and the flapping servo 2 is mounted on a servo fixing plate 3 by screws, and the other end of the flapping rocker 1 is connected to a wing connector 5 by a thrust ring 4, and a wing body is mounted on the wing connector 5. The wing body has a semi-elliptical configuration and includes a wing airfoil 26, an inner wing rib 25 is provided on the inner side of the wing airfoil 26, and an outer wing rib 27 is provided on the outer side. The straight side of the wing body is connected to a wing main beam 29, a bent iron wire 24 is further provided at the center of the inner side of the wing, and a transverse wing subbeam 28 is provided from the bent iron wire 24 to the wing airfoil 26. The installation method of the wing body is that the wing main beam 29 of the wing body is fixed by the thrust ring 4 and the threaded washer, and the wing sub-beam 28 is clamped on the bent iron wire 24 fixed on the carbon fiber rod 8, which can realize flapping as the flapping rocker 1 rotates repeatedly. Through this installation design, the wing can be replaced quickly and conveniently.

[0027] The servo fixing plate 3 is connected to two carbon fiber rods 8 at the rear, and the wing body and the carbon fiber rods 8 are connected by winding with bent iron wires 24; the force measurement design of the flapping-wing aircraft force measurement experiment mainly considers the comparison of the results of the wing responding to different angles of attack and incoming flows, so it is necessary to add a part that realizes the change of the wing angle of attack, the carbon fiber rods 8 are installed on the tilting connection seat, and the tail connecting plate is installed at the end of the carbon fiber rods 8, the tail connecting plate is connected to the tail body, the tail connecting plate includes a tail connecting plate A16 fixed on the carbon fiber rods 8, and a tail connecting plate B17 fixed inside the tail connecting plate A16; the tail body is set to a quarter-circle configuration, and the front end of the tail body is provided with a tail connecting plate. The solid carbon fiber sheet 30 is connected to the tail connecting plate B17 by screws. A tail main rod 31 connected to the tail wing surface 33 is set in the center of the tail body, tail edge rods 32 are set on both sides of the tail body, and a tail auxiliary rod 34 is set on the cross surface of the tail body; specifically, the tilt connecting seat is composed of a tilt connecting member A6, a tilt connecting member B7, and a tilt connecting member C9. The tilt connecting seat is connected to the tilt servo 11. The top of the tilt servo 11 is connected through a tilt fixing member A10. The side of the tilt servo 11 is connected to the tilt fixing member B13 through a tilt connecting block 12. The tilt servo 11 is connected to the force sensor 15 through a force measuring connecting plate 14. The force sensor 15 is an ATI GAMMA model. A connecting support 18 is set under the force sensor 15. The connecting support 18 is fixed to the top of the bracket 19. A counterweight block 20 is set at the bottom of the bracket 19 to increase stability.

[0028] The bottom of the bracket 19 is connected to a fixed base. The design of the fixed base needs to ensure firmness, stability, vibration isolation, and high load-bearing capacity. To this end, this embodiment uses a fixed base based on a triangular structure with a stable design. The angle between the two aluminum alloy profiles connected to each other is 45 degrees, and the two are fixed by aluminum alloy connectors and screws. The aluminum profile base designed based on the triangular structure with a stable design reduces the vibration effect of the flapping process of the flapping-wing aircraft and ensures the accuracy of the force measurement data. Specifically, the fixed base includes four diagonal aluminum profiles 21 supported on the bracket 19. The bottom of the diagonal aluminum profile 21 is connected to the four corners of the grounding aluminum profile 23. The grounding aluminum profile 23 forms a square with diagonally connected internal parts, and aluminum alloy fixings 22 are provided at the four corners of the grounding aluminum profile 23 for reinforcement.

[0029] See Figure 7 As shown, a high-torque tilting servo 11 was selected to address the changing angle of attack. This tilting servo 11 was used to maintain a specific angle of attack during wing force measurement, simulating actual flight conditions. The actual force measurement conditions were designed to range from 0 to 30 degrees. With the wing mounted at a 0-degree angle, the overall windward surface of the flapping-wing platform increases as the angle of attack changes, consistent with actual flight conditions.

[0030] The specific force measurement experimental process of this experimental device is that the remote control terminal provides control signals to the corresponding flapping servo 2 and tilting servo 11, thereby changing the flapping frequency, flapping amplitude, angle of attack and other parameters of the flapping wing aircraft. At the same time, the computer terminal controls the wind wall or wind tunnel equipment to generate certain inflow conditions. After the inflow wind speed stabilizes, it starts to measure the data of the force sensor 15 in real time, focusing on the aerodynamic force and torque data, and compares them. The initial flapping amplitude of the flapping wing aircraft is set to -30 degrees to +30 degrees, and the flapping frequency is between 2 Hz and 6 Hz. The synchronous and asynchronous flapping principles of the flapping wing platform are as follows: Figure 8 As shown in the figure, the flapping modes corresponding to the flapping wing platform include synchronous flapping, which corresponds to the change of the flapping center position and the difference in flapping amplitude. Through the direct drive of the servo, the effect of the flapping mode of the flying wing on the overall aerodynamic characteristics of the flying wing can be analyzed from multiple angles.

[0031] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification.

Claims

1. An experimental device for measuring the force of a bionic flapping-wing aircraft wing, characterized in that: The flapping-wing aircraft platform comprises two symmetrically arranged flapping rockers (1), one end of the flapping rocker (1) is connected to the driving shaft of a flapping servo (2), the flapping servo (2) is mounted on a servo fixed plate (3), the other end of the flapping rocker (1) is connected to a wing connecting piece (5) via a thrust ring (4), and a wing main body is mounted on the wing connecting piece (5); the servo fixed plate (3) is connected to two carbon fiber rods (8) at the rear, the wing main body and the carbon fiber rods (8) are connected by winding iron wires, the carbon fiber rods (8) are installed through the tilting connecting seat, and a tail connecting plate is installed at the end of the carbon fiber rod (8), and the tail connecting plate is connected to the tail main body; The tilting connection seat is connected to the tilting servo (11), and the tilting servo (11) is connected to the force sensor (15) through the force measuring connection plate (14). A connecting support (18) is provided under the force sensor (15), and the connecting support (18) is fixed to the top of the bracket (19). A counterweight (20) is provided at the bottom of the bracket (19) to increase stability. The wing body is semi-elliptical in shape and includes a wing surface (26). The inner side of the wing surface (26) is provided with a wing inner rib (25), and the outer side is provided with a wing outer rib (27). The straight side of the wing body is connected to a wing main beam (29). A bent iron wire (24) is further provided at the center of the inner side of the wing, and a wing sub-beam (28) is provided transversely from the bent iron wire (24) to the wing surface (26). The tail body is arranged in a quarter-circle configuration, a reinforced carbon fiber sheet (30) is arranged at the front end of the tail body, a tail main rod (31) connected to the tail wing surface (33) is arranged at the center of the tail body, tail edge rods (32) are arranged on both sides of the tail body, and a tail auxiliary rod (34) is arranged on the transverse surface of the tail body; The bottom of the bracket (19) is connected to a fixed base, and the fixed base includes four diagonal aluminum profiles (21) supported on the bracket (19). The bottom of the diagonal aluminum profile (21) is connected to the four corners of the grounding aluminum profile (23). The grounding aluminum profile (23) forms a square with internal diagonal connections, and aluminum alloy fixing pieces (22) are arranged at the four corners of the grounding aluminum profile (23) for reinforcement.

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