A flapping wing module and its wind tunnel experimental test device

Abstract

The present invention relates to the field of ground devices associated with aircraft, and more specifically, to a flapping wing module and a wind tunnel test device thereof. The flapping wing module includes a bionic wing, a rocker arm, a flapping wing fixed shaft seat, and a variable frequency drive system. The bionic wing is fixedly connected to the rocker arm, which is swingably connected to the flapping wing fixed shaft seat. The flapping wing fixed shaft seat is fixedly connected to the variable frequency drive system. The actuator of the variable frequency drive system is transmission-connected to the rocker arm to drive the bionic wing to flap. The wind tunnel test device includes the flapping wing module, an aerodynamic load monitoring system, and a controller. The variable frequency drive system drives the bionic wing to perform flapping motion. In an embodiment of the present invention, the aerodynamic load monitoring system monitors the aerodynamic load of the bionic wing in real time and sends the signal to the controller. The controller issues an instruction to the variable frequency drive system to adjust the flapping frequency, thereby adjusting the flapping frequency of the bionic wing in real time to counteract aerodynamic interference and achieve online aerodynamic performance optimization of the flapping wing module.

Description

Technical Field

[0001] The present invention relates to the field of ground devices associated with aircraft, and in particular to a flapping wing module.

[0002] The invention also relates to a wind tunnel experimental testing device for a flapping wing module. Background Art

[0003] In the field of bionic aircraft research, flapping-wing aircraft have attracted much attention due to their bionic structure and efficient aerodynamic characteristics. However, existing flapping-wing aircraft have some defects that limit their performance and application potential. The main defects are described as follows.

[0004] 1. Flapping wings have difficulty achieving precise high-frequency motion: Existing flapping-wing aircraft drive systems contain gear sets or servo systems with backlash, making it difficult to achieve high-frequency flapping of flapping-wing aircraft. The upper limit of the effective flapping frequency is usually less than 15Hz, which is significantly lower than that of organisms such as bats and insects (whose flapping frequencies can reach 20-30Hz or even higher). This limits the aircraft's ability to mimic the high-speed flight of organisms and their maneuverability. In addition, backlash and inertia problems in the drive system can cause flapping phase lag, affecting the accuracy of high-frequency motion.

[0005] 2. Insufficient adjustment accuracy of flapping parameters: Existing flapping-wing aircraft rely on manual adjustment (such as adjusting the eccentric disk) when adjusting flapping parameters. The ability to accurately adjust the flapping amplitude is limited. It is difficult to quickly and accurately change the flapping parameters to cope with changing flight environments or mission requirements, and it cannot meet the precise control of micro-flapping or complex combined motions.

[0006] 3. Difficulties in detecting aerodynamic loads: When integrating sensors on flapping-wing aircraft to monitor aerodynamic loads in real time, the direct coupling of the sensors with the flapping-wing structure or drive mechanism will introduce additional interference (such as friction, whose impact may exceed the level of a friction coefficient of 0.01), resulting in distortion of the measured aerodynamic data. Summary of the Invention

[0007] The purpose of the present invention is to provide a flapping wing module to solve the defect of traditional flapping wing modules that are difficult to cope with aerodynamic interference. The present invention also provides a wind tunnel experimental testing device for the flapping wing module, which is used to accurately monitor the aerodynamic load of the bionic wing in the wind tunnel, thereby realizing online optimization of the flapping wing module.

[0008] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0009] The present application provides a flapping wing module, including a bionic wing, a rocker arm, a flapping wing fixed shaft seat and a variable frequency drive system, wherein the bionic wing is fixedly connected to the rocker arm, and the rocker arm is swingably connected to the flapping wing fixed shaft seat, so that the bionic wing can flap around the axis of the flapping wing fixed shaft seat, the flapping wing fixed shaft seat is fixedly connected to the variable frequency drive system, and the actuator of the variable frequency drive system is transmission-connected to the rocker arm.

[0010] Furthermore, the variable frequency drive system includes a servo drive system, a distance-adjustable eccentric disk and a centering rod. The servo drive system is used to drive the main shaft of the distance-adjustable eccentric disk to rotate. One end of the centering rod is rotatably connected to the eccentric shaft of the distance-adjustable eccentric disk, and the other end of the centering rod is connected to the rocker rod, so that the distance-adjustable eccentric disk, the centering rod and the rocker rod form a crank-connecting rod mechanism, and the servo drive system drives the bionic wing to swing back and forth through the crank-connecting rod mechanism to realize flapping movement.

[0011] Furthermore, the adjustable distance eccentric disc includes a main eccentric disc and a secondary eccentric disc, the servo drive system is connected to the main shaft of the main eccentric disc, the eccentric shaft of the main eccentric disc is connected to the main shaft of the secondary eccentric disc, the eccentric shaft of the secondary eccentric disc is connected to the rocker arm, and the secondary eccentric disc can rotate relative to the main eccentric disc or maintain synchronous movement with the main eccentric disc.

[0012] Furthermore, the main eccentric disc and the auxiliary eccentric disc are connected via a locking screw or an electromagnetic clutch.

[0013] Furthermore, the servo drive system includes a servo motor and a reducer, the servo motor is connected to the main shaft of the adjustable pitch eccentric disk through the reducer, and the servo motor and the reducer are integrated in the flapping wing fixed shaft seat.

[0014] Furthermore, the centering rod includes a first rod, a second rod, and a threaded sleeve connecting the first rod and the second rod, and the thread directions of the first rod and the second rod are opposite.

[0015] Furthermore, the bionic wing includes a skeleton and a skin, the skeleton is made of high-strength and lightweight material, and the skin is made of flexible material.

[0016] The present application also provides a wind tunnel experimental testing device for a flapping wing module, including a flapping wing module, an aerodynamic load monitoring system and a controller. The variable frequency drive system drives the bionic wing to perform flapping motion. The aerodynamic load monitoring system monitors the aerodynamic load of the bionic wing in real time and sends a signal to the controller. The controller sends an instruction to the variable frequency drive system to adjust the flapping frequency.

[0017] Furthermore, the aerodynamic load monitoring system includes a first linear track and a second linear track that intersect each other perpendicularly, and a first force sensor and a second force sensor, wherein the variable frequency drive system, the first linear track and the second linear track are connected in sequence, the first force sensor is connected to the moving part of the first linear track, and the second force sensor is connected to the moving part of the second linear track. The first force sensor and the second force sensor send the measured tension or pressure signals to the controller in real time, and the controller dynamically adjusts the flapping frequency of the bionic wing to balance the aerodynamic interference.

[0018] Furthermore, it also includes an adapter plate and a wind tunnel cover, wherein the adapter plate is fixedly connected to the non-moving part of the second linear track, the adapter plate is electrically connected to the variable frequency drive system, the first force sensor, the second force sensor and the controller, the wind tunnel cover is fixedly connected to the flapping wing fixed shaft seat, and the wind tunnel cover is used to connect the wind tunnel experimental section so that the bionic wing is exposed to the inside of the wind tunnel.

[0019] Compared with the prior art, this application has the following beneficial effects:

[0020] Provided are a flapping wing module and a wind tunnel experimental test device thereof. The wind tunnel experimental test device monitors the aerodynamic load of a bionic wing in real time through an aerodynamic load monitoring system, thereby adjusting the flapping frequency of the bionic wing of the flapping wing module in real time to counteract aerodynamic interference and achieve online aerodynamic performance optimization of the flapping wing module. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0022] Figure 1 A perspective view of an embodiment of the present invention;

[0023] Figure 2 A front view of an embodiment of the present invention;

[0024] Figure 3 A side view of an embodiment of the present invention;

[0025] Figure 4 A top view of an embodiment of the present invention;

[0026] Figure 5 A bottom view of an embodiment of the present invention;

[0027] The numbers in the figure represent the following:

[0028] 1-bionic wing; 11-rocker; 2-flapping wing fixed shaft seat; 3-wind tunnel cover; 4-variable frequency drive system; 41-servo drive system; 411-servo motor; 412-reducer; 42-adjustable eccentric disc; 421-main eccentric disc; 422-auxiliary eccentric disc; 43-centering rod; 431-first rod; 432-second rod; 433-threaded sleeve; 5-pneumatic load monitoring system; 51-first linear track; 52-second linear track; 53-first force sensor; 54-second force sensor; 6-adapter plate; 61-plug. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] In order to solve the problems existing in the traditional flapping wing module, the present application provides a flapping wing module, which will be combined with Figures 1 to 5 To illustrate the structure of the flapping wing module, it should be noted that the attached drawings show the flapping wing module used for wind tunnel testing and do not represent the shape, size, proportion and structure of the final product of the flapping wing module.

[0031] refer to Figure 1 The flapping wing module includes a bionic wing 1 and a variable frequency drive system 4, and the variable frequency drive system 4 drives the bionic wing 1 to perform flapping motion.

[0032] For the specific structure of the bionic wing 1, please refer to Figure 1 and Figure 4 .

[0033] The bionic wing 1 includes a skeleton and a skin. The skeleton is made of high-strength and lightweight materials (such as a carbon fiber skeleton), and the skin is made of flexible materials (such as a silicone membrane). The composite design of the bionic wing 1 can dynamically simulate the rigid-flexible coupling characteristics of biological wings, thereby achieving better aerodynamic efficiency and robustness.

[0034] The bionic wing 1 is fixedly connected to a rocker arm 11, which is swingably connected to the flapping wing fixed shaft seat 2. The bionic wing 1 flaps around the axis of the flapping wing fixed shaft seat 2. The rocker arm 11 is made of aviation aluminum alloy to ensure structural stability under high-frequency flapping.

[0035] The flapping wing fixed shaft seat 2 is detachably connected to the wind tunnel cover 3 of the flapping wing module, so that the flapping wing module supports rapid replacement of bionic wings 1 of different sizes, thereby adapting to different climatic conditions and mission requirements.

[0036] For the specific structure of the variable frequency drive system 4, please refer to Figure 1 、 Figure 2 、 Figure 3 .

[0037] The frequency conversion drive system 4 includes a servo drive system 41, a distance-adjustable eccentric disk 42 and a centering rod 43. The servo drive system 41 is used to drive the main shaft of the distance-adjustable eccentric disk 42 to rotate. One end of the centering rod 43 is rotatably connected to the eccentric shaft of the distance-adjustable eccentric disk 42, and the other end of the centering rod 43 is connected to the rocker arm 11, so that the distance-adjustable eccentric disk 42, the centering rod 43 and the rocker arm 11 form a crank-connecting rod mechanism.

[0038] The centering rod 43 is connected to the pitch-adjusting eccentric disc 42 and the rocker arm 11 through two PHSCM3 bearings. The servo drive system 41 drives the bionic wing 1 to perform variable-frequency flapping motion through a crank-connecting rod mechanism, and the swing frequency can reach 30 Hz.

[0039] Specifically, the servo drive system 41 includes a servo motor 411 and a reducer 412. The servo motor 411 is connected to the main shaft of the adjustable eccentric disk 42 through the reducer 412. The servo motor 411 adopts a frameless motor. The servo motor 411 and the reducer 412 are integrated in the flapping wing fixed shaft seat 2 to reduce mechanical transmission loss and improve dynamic response speed.

[0040] Preferably, the reducer 412 adopts a reversible worm gear reducer, which is a precise backlash-free reversing mechanism, allowing the bionic wing 1 to flap at a higher and more stable frequency.

[0041] It should be noted that the bionic wing 1 in the accompanying drawings appears too small, while the servo drive system 41 appears too large, but this is not the size of the final product of the flapping wing module.

[0042] Furthermore, the eccentric distance (radial distance between the main axis and the eccentric axis) of the adjustable eccentric disk 42 can be adjusted, thereby achieving continuous adjustment of the flapping amplitude of the bionic wing 1 within the range of 0-10 mm.

[0043] Specifically, the adjustable eccentric disc 42 includes a main eccentric disc 421 and a secondary eccentric disc 422 . The servo drive system 41 is connected to the main shaft of the main eccentric disc 421 . The eccentric shaft of the main eccentric disc 421 is connected to the main shaft of the secondary eccentric disc 422 . The eccentric shaft of the secondary eccentric disc 422 is connected to the rocker arm 11 .

[0044] The adjustable eccentric disk 42 uses the main axis of the main eccentric disk 421 as its own main axis and the eccentric axis of the auxiliary eccentric disk 422 as its own eccentric axis. By rotating the auxiliary eccentric disk 422 to adjust the radial distance between the main axis of the main eccentric disk 421 and the eccentric axis of the auxiliary eccentric disk 422, the eccentric distance of the adjustable eccentric disk 42 is adjustable.

[0045] Preferably, the material of the adjustable eccentric disk 42 is duplex stainless steel, and the CNC machining accuracy reaches ±0.05 mm, which supports precise matching of micro-flapping.

[0046] The attached figure shows a pitch-adjustable eccentric disk 42 whose eccentricity can be manually adjusted. During operation, the locking screw (M4×8) used to lock the auxiliary eccentric disk 422 is loosened, and the auxiliary eccentric disk 422 is rotated to the target phase angle (scale accuracy ± 0.5°). After re-tightening, the eccentricity of the pitch-adjustable eccentric disk 42 can be fixed, thereby fixing the flapping amplitude of the bionic wing 1.

[0047] Furthermore, in order to achieve the purpose of adjusting the flapping amplitude of the bionic wing 1 in real time according to its own aerodynamic load, an electromagnetic clutch (not shown) can also be used instead of the locking screw to connect the main eccentric disc 421 and the secondary eccentric disc 422. When the electromagnetic clutch is connected, the main eccentric disc 421 and the secondary eccentric disc 422 rotate synchronously. When the electromagnetic clutch is disengaged, since the secondary eccentric disc 422 is always connected to the centering rod 43, when the main eccentric disc 421 rotates, the eccentric shaft of the secondary eccentric disc 422 will be pulled to the side close to the rocker arm 11 by the centering rod 43. When the main eccentric disc 421 rotates to the target angle, the connection of the electromagnetic clutch is restored, which can achieve the purpose of rotating the secondary eccentric disc 422 to the target phase angle.

[0048] Specifically, the centering rod 43 includes a first rod 431 , a second rod 432 , and a threaded sleeve 433 connecting the first rod 431 and the second rod 432 . The thread directions of the first rod 431 and the second rod 432 are opposite.

[0049] The operator can adjust the length of the centering rod 43 by rotating the threaded sleeve 433 , and achieve precise centering of the flapping wing balance position (centering accuracy ± 0.05 mm) through manual or electric adjustment, eliminating the influence of assembly errors on the test results.

[0050] Furthermore, in order to prevent the threaded sleeve 433 from rotating due to vibration during the reciprocating motion of the centering rod 43, resulting in a change in the length of the centering rod 43, a rotation-stopping structure is also provided on the centering rod 43, such as thread glue, anti-loosening nut, etc.

[0051] refer to Figure 1 The flapping wing module includes a bionic wing 1, a variable frequency drive system 4, an aerodynamic load monitoring system 5 and a controller. The variable frequency drive system 4 drives the bionic wing 1 to perform flapping motion. The aerodynamic load monitoring system 5 monitors the aerodynamic load of the bionic wing 1 in real time and sends a signal to the controller. The controller sends an instruction to the variable frequency drive system 4 to adjust the flapping frequency.

[0052] The flapping wing module is not shown in the figure. The flapping wing module includes at least two symmetrically arranged flapping wing modules. The controller receives the aerodynamic load of each bionic wing 1 monitored in real time by the aerodynamic load monitoring system 5, and sends an instruction to the variable frequency drive system 4 to adjust the flight posture of the flapping wing module to achieve online aerodynamic performance optimization of the flapping wing module.

[0053] On the other hand, in order to facilitate the testing of the performance of the flapping wing module in a wind tunnel, a wind tunnel experimental testing device for the flapping wing module is also provided below.

[0054] refer to Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 ,The wind tunnel experimental test device includes a flapping wing module, an aerodynamic load monitoring system 5 and a controller.

[0055] The pneumatic load monitoring system 5 includes a first linear rail 51 and a second linear rail 52 that intersect each other perpendicularly, as well as a first force sensor 53 and a second force sensor 54, wherein the servo drive system 41, the first linear rail 51 and the second linear rail 52 are connected in sequence, the first force sensor 53 is connected to the moving part of the first linear rail 51, and the second force sensor 54 is connected to the moving part of the second linear rail 52.

[0056] The first linear track 51 and the second linear track 52 both use low-friction (friction coefficient <0.008) roller linear tracks, and the track surface is sprayed with a molybdenum disulfide lubricating coating. This design can effectively isolate mechanical vibration interference, realize the decoupled measurement of aerodynamic load and mechanical vibration, and ensure the accuracy of the collected aerodynamic load data of the bionic wing 1.

[0057] The first force sensor 53 and the second force sensor 54 send the measured tension / pressure signals to the controller in real time. If the controller determines that the flow field force fluctuates, it dynamically adjusts the speed of the servo motor 411 and / or opens and closes the electromagnetic clutch based on the adaptive algorithm to change the eccentricity of the adjustable eccentric disk 42, optimize the flapping motion parameters, balance the aerodynamic interference, and realize closed-loop control of the aerodynamic performance.

[0058] In addition, the flapping wing module also includes an adapter plate 6, which is fixedly connected to the aerodynamic load monitoring system 5 (the non-moving part of the second linear track 52). The adapter plate 6 includes a plug 61 that electrically connects the controller and the servo motor 411. The plug 61 is used to electrically connect to the socket of the flapping wing module (not shown in the figure).

[0059] The operator connects the plug 61 of the adapter plate 6 to the socket of the wind tunnel experiment test device, and then connects the flapping wing fixed shaft seat 2 to the wind tunnel cover 3 to complete the fixation and power supply of the flapping wing module. The wind tunnel experiment test device supplies power or transmits data to the controller and servo motor 411 through the adapter plate 6.

[0060] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the spirit and scope of protection of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the embodiments of the present invention.

Claims

1. A flapping wing module, characterized in that: The invention comprises a bionic wing (1), a swing rod (11), a flapping wing fixed shaft seat (2) and a variable frequency drive system (4), wherein the bionic wing (1) is fixedly connected to the swing rod (11), and the swing rod (11) is swingably connected to the flapping wing fixed shaft seat (2), so that the bionic wing (1) can flap around the axis of the flapping wing fixed shaft seat (2), the flapping wing fixed shaft seat (2) is fixedly connected to the variable frequency drive system (4), and the actuator of the variable frequency drive system (4) is transmission-connected to the swing rod (11); The variable frequency drive system (4) includes a servo drive system (41), a pitch-adjustable eccentric disk (42) and a centering pull rod (43), wherein the servo drive system (41) is used to drive the main shaft of the pitch-adjustable eccentric disk (42) to rotate, one end of the centering pull rod (43) is rotatably connected to the eccentric shaft of the pitch-adjustable eccentric disk (42), and the other end of the centering pull rod (43) is connected to the rocker rod (11), so that the pitch-adjustable eccentric disk (42), the centering pull rod (43) and the rocker rod (11) form a crank-connecting rod mechanism, and the servo drive system (41) drives the bionic wing (1) to swing back and forth through the crank-connecting rod mechanism to achieve a flapping motion; The adjustable eccentric disc (42) comprises a main eccentric disc (421) and a secondary eccentric disc (422); the servo drive system (41) is connected to the main shaft of the main eccentric disc (421); the eccentric shaft of the main eccentric disc (421) is connected to the main shaft of the secondary eccentric disc (422); the eccentric shaft of the secondary eccentric disc (422) is connected to the rocker (11); the secondary eccentric disc (422) can maintain synchronous movement with the main eccentric disc (421), and the secondary eccentric disc (422) can rotate relative to the main eccentric disc (421) when operated.

2. A flapping wing module according to claim 1, characterized in that: The main eccentric disc (421) and the auxiliary eccentric disc (422) are connected via a locking screw or an electromagnetic clutch.

3. The flapping wing module according to claim 1, characterized in that: The servo drive system (41) comprises a servo motor (411) and a reducer (412); the servo motor (411) is connected to the main shaft of the pitch-adjustable eccentric disc (42) through the reducer (412); and the servo motor (411) and the reducer (412) are integrated in the flapping-wing fixed shaft seat (2).

4. The flapping wing module according to claim 1, characterized in that: The centering rod (43) comprises a first rod (431), a second rod (432), and a threaded sleeve (433) connecting the first rod (431) and the second rod (432), wherein the thread directions of the first rod (431) and the second rod (432) are opposite.

5. The flapping wing module according to claim 1, characterized in that: The bionic wing (1) comprises a skeleton and a skin, the skeleton is made of a high-strength lightweight material, and the skin is made of a flexible material.

6. A wind tunnel test device for a flapping wing module, characterized in that: The invention comprises a flapping wing module according to any one of claims 1 to 5, an aerodynamic load monitoring system (5) and a controller, wherein the variable frequency drive system (4) drives the bionic wing (1) to perform flapping motion, the aerodynamic load monitoring system (5) monitors the aerodynamic load of the bionic wing (1) in real time and sends a signal to the controller, and the controller sends an instruction to the variable frequency drive system (4) to adjust the flapping frequency.

7. The wind tunnel test device for a flapping wing module according to claim 6, characterized in that: The aerodynamic load monitoring system (5) includes a first linear track (51) and a second linear track (52) that intersect each other perpendicularly, and a first force sensor (53) and a second force sensor (54), wherein the variable frequency drive system (4), the first linear track (51) and the second linear track (52) are connected in sequence, the first force sensor (53) is connected to the moving part of the first linear track (51), and the second force sensor (54) is connected to the moving part of the second linear track (52), and the first force sensor (53) and the second force sensor (54) send measured tension or pressure signals to the controller in real time, and the controller dynamically adjusts the flapping frequency of the bionic wing (1) to balance the aerodynamic interference.

8. The wind tunnel test device for a flapping wing module according to claim 7, characterized in that: It also includes an adapter plate (6) and a wind tunnel cover plate (3), wherein the adapter plate (6) is fixedly connected to the non-moving part of the second linear track (52), the adapter plate (6) is electrically connected to the variable frequency drive system (4), the first force sensor (53), the second force sensor (54) and the controller, and the wind tunnel cover plate (3) is fixedly connected to the flapping wing fixed shaft seat (2), and the wind tunnel cover plate (3) is used to connect the wind tunnel experimental section so that the bionic wing (1) is exposed inside the wind tunnel.

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