A bevel gear and fin arm integrated transmission bionic flapping wing aircraft

Abstract

This application discloses a biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission, including a fuselage, a drive mechanism, a gear set, wing arms, and wings. The biomimetic flapping-wing aircraft of this application, with its integrated bevel gear and wing arm transmission, completely eliminates the traditional multi-link crank mechanism by employing a direct-drive servo motor combined with an integrated bevel gear-wing arm transmission scheme. This fundamentally eliminates the accumulation of hinge clearance and rod length errors, resulting in a significant improvement in motion accuracy and a substantial extension of the mechanism's fatigue life. Furthermore, this invention utilizes high-strength nylon material for topology optimization and one-piece molding, removing redundant material in non-load-bearing areas, achieving lightweight design, high rigidity, excellent vibration resistance, and strong manufacturability. It can be mass-produced at low cost using either 3D printing or injection molding, with good product consistency and high engineering application value.

Description

Technical Field

[0001] This application relates to the technical field of biomimetic aircraft, and more particularly to a biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission. Background Technology

[0002] As an important branch of the field of intelligent equipment, micro aircraft have shown great application potential in fields such as confined space exploration, ecological monitoring, and popular science education. Among them, flapping-wing micro aircraft have become a research hotspot in the field of bionic machinery at home and abroad due to their natural advantages such as small size, strong stealth, maneuverability, low noise, and high aerodynamic efficiency at low Reynolds numbers.

[0003] However, existing micro flapping-wing aircraft still face significant technical bottlenecks: traditional fixed-wing and rotary-wing aircraft experience a sharp decline in aerodynamic efficiency in low Reynolds number environments, making it impossible to achieve butterfly-like maneuverability and stable gliding; conventional flapping-wing mechanisms mostly employ crank-rocker and multi-link transmission schemes, which suffer from structural redundancy, a large number of parts, large cumulative transmission clearance errors, and insufficient motion precision; most biomimetic designs merely replicate the shape of a butterfly without fully exploring its flapping-wing aerodynamic mechanism, resulting in low lift efficiency, stiff flight attitude, and insufficient biomimicry; at the same time, the complex transmission and control systems also make it difficult to control the overall weight, limiting practicality and widespread adoption. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, one objective of this application is to provide a biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission. The integrated transmission design eliminates cumulative errors and dead points. Combined with topology optimization and integrated molding process, it achieves precise transmission, no impact, lightweight and high reliability. The structure has fewer parts, is easy to assemble, and has excellent vibration resistance and low-cost manufacturability, making it highly valuable for engineering applications.

[0006] To achieve the above objectives, the first aspect of this application proposes a biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission, comprising a fuselage body, a drive mechanism, a gear set, wing arms, and wings. The gear set includes an active bevel gear and a driven bevel gear rotatably disposed on both sides of the fuselage body; the driven bevel gear and the wing arm are integrally formed from the same base; the drive mechanism includes two forewing servos and one rearwing servo disposed at the front of the fuselage; the active bevel gear is fixedly connected to the output shaft of the drive mechanism, and the surface of the active bevel gear meshes with the surface of the driven bevel gear; the fuselage body adopts a topology-optimized integrally formed structure, and the wings are a rigid-flexible coupling structure of a carbon fiber skeleton and a flexible film; the driven bevel gear and the wing arm are also provided with an integrally formed inertia compensation structure for generating a compensating inertial force opposite to the inertial force vector of the wing arm during flapping; the inertia compensation structure includes a balancing boss mounted on the back side of the hub of the driven bevel gear; the balancing boss, the driven bevel gear, and the wing arm are provided with a material reduction and tempering zone.

[0007] In addition, the biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission proposed in this application may also have the following additional technical features: In one embodiment of this application, the driven bevel gear and the wing arm are integrally formed from nylon PA12.

[0008] In one embodiment of this application, the shaft angle of the gear set and the mounting angle of the servo motor are both 30°±5°, so that the wing maintains an angle of attack of 15°±5° during flapping to utilize the swashplate effect.

[0009] In one embodiment of this application, the fuselage is integrally molded from high-strength nylon through topology optimization, and the center of gravity is located in the chest area.

[0010] In one embodiment of this application, the bevel gear has a module m=1, 20 teeth, a pressure angle of 20°, and a shaft intersection angle matched with a biomimetic flapping angle of attack arrangement.

[0011] A control system for a biomimetic flapping-wing aircraft, wherein the control system uses a cosine function to generate the flapping trajectory and discretizes one flapping cycle into 36 control steps; The control system includes: Signal receiving module: Used to receive multi-channel PPM coded control signals output from an external remote control transmitter; Main control module: integrates an ATmega328P microcontroller, configured to decode PPM encoded signals and generate multi-dimensional PWM control signals; Drive output module: Drives the left front wing servo, right front wing servo, rear wing servo and status indicator lights respectively through PWM signals; Safety protection module: It is configured to monitor electrical and mechanical parameters in real time, and to perform amplitude limiting protection or trigger static gliding mode when the parameters exceed the threshold; Status indicator module: used to provide feedback on flight mode and system operating status; The rear wing servo motor synchronously drives the left and right rear wings through a bevel gear mechanical coupling mechanism to achieve attitude balance assistance.

[0012] In one embodiment of this application, the control logic of the main control module includes the following steps: Signal Decoding: The input multi-channel PPM encoded signal is parsed into 8 channels of instructions, including: throttle (channel 3), steering (channel 1), elevation (channel 2), mechanical fine adjustment (channel 5 / 6), amplitude preset (channel 7), and flight switch (channel 8). Trajectory generation: A complete biomimetic flapping trajectory is generated based on the cosine function algorithm, and the flapping period is discretized into 36 control steps; Differential control: Upon receiving a steering command, differential adjustment is performed on the left and right front wing servos to create a lift difference and achieve steering. Coupling synchronization: Upon receiving a lift / attitude command, the rear wing servo outputs a control signal based on the logic of the left front wing following the pulse width, and drives the left and right rear wings to flap in opposite directions through a bevel gear mechanical coupling mechanism to help balance the fuselage attitude; Linkage compensation: Performs throttle-elevation linkage compensation and steering-lift loss compensation to improve flight stability.

[0013] In one embodiment of this application, the specific functions of the security protection module include: Electrical limiting protection: Limits the pulse width of the servo control signal to the range of 500-2500μs to avoid electrical overload; Mechanical amplitude limiting protection: Limits the pulse width of the servo control signal to the range of 1100-1900μs to avoid mechanical overload; Static gliding mode: When an anomaly is detected (such as signal loss or parameter exceeding limits), static gliding mode is triggered to reduce the flapping frequency or stop flapping to maintain attitude.

[0014] In one embodiment of this application, the pin assignment of the drive output module is as follows: Left front wing servo: Pin A0, function is to output main lift + differential steering control signal; Right front wing servo: Pin A1, function is to output main lift + differential steering control signal; Rear wing servo: Pin A2, function is to output a control signal whose pulse width follows that of the left forewing; Status indicator: Pin 5, function is to indicate flight mode and system status.

[0015] The biomimetic flapping-wing aircraft of this application, with its integrated bevel gear and wing arm transmission, completely eliminates the traditional multi-link crank mechanism by employing a direct drive servo motor combined with an integrated bevel gear-wing arm transmission scheme. This fundamentally eliminates the accumulation of hinge clearance and rod length errors, resulting in a significant improvement in motion accuracy. This transmission method has no mechanical dead points, and the motion process is smooth and impact-free, making it particularly suitable for high-frequency continuous operation and significantly extending the fatigue life of the mechanism. Furthermore, this invention utilizes high-strength nylon material for topology optimization and one-piece molding, removing redundant material in non-load-bearing areas, reducing the number of parts, achieving lightweighting of the entire aircraft, and greatly simplifying the assembly process. It possesses high rigidity and excellent vibration resistance, and exhibits strong manufacturability, enabling low-cost mass production through both 3D printing and injection molding. The products have good consistency and high engineering application value.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of a biomimetic flapping-wing aircraft with an integrated bevel gear and wing arm transmission according to an embodiment of this application; Figure 2 This is a bottom view of the fuselage body according to an embodiment of this application; Figure 3 This is a perspective view of the fuselage body according to one embodiment of this application; Figure 4 This is a perspective view of a driven bevel gear according to an embodiment of this application; Figure 5 This is a schematic diagram of a control system architecture according to an embodiment of this application; Figure 6 This is a schematic diagram of a biomimetic flapping trajectory according to an embodiment of this application; Figure 7 This is a schematic diagram of canard differential amplitude compensation control according to one embodiment of this application; Figure 8 This is a schematic diagram of the aerodynamic forces during a downward fall according to an embodiment of this application; Figure 9 This is a schematic diagram of the aerodynamic forces during a pouncing process according to one embodiment of this application.

[0018] As shown in the figure: 100, main fuselage; 200, drive mechanism; 201, canard servo; 202, aft servo; 300, gear set; 301, driving bevel gear; 302, driven bevel gear; 400, wing arm; 500, wing; 600, inertia compensation structure; 601, balancing boss; 602, material reduction and tempering zone. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0020] The following description, in conjunction with the accompanying drawings, describes a biomimetic flapping-wing aircraft with an integrated bevel gear and wing arm transmission according to an embodiment of this application.

[0021] like Figures 1-9 As shown in the embodiment of this application, a biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission includes a fuselage body 100, a drive mechanism 200, a gear set 300, wing arms 400, and wings 500. The gear set 300 includes an active bevel gear 301 and a driven bevel gear 302 rotatably disposed on both sides of the fuselage body 100. The driven bevel gear 302 and the wing arm 400 are integrally formed from the same base. The drive mechanism 200 includes two forewing servos 201 and one rearwing servo 202 disposed at the front of the fuselage. The active bevel gear 301 is fixedly connected to the output shaft of the drive mechanism 200, and the active bevel gear 301... The surface of the bevel gear 301 meshes with the surface of the driven bevel gear 302; the fuselage body 100 adopts a topology-optimized integrated molding structure, and the wing 500 is a rigid-flexible coupling structure of carbon fiber skeleton and flexible film; the driven bevel gear 302 and the wing arm 400 are also provided with an integrated inertia compensation structure 600, which is used to generate a compensating inertial force opposite to the inertial force vector of the wing arm 400 when the wing arm 400 flaps; the inertia compensation structure 600 includes a balance boss 601 installed on the back side of the hub of the driven bevel gear 302; the balance boss 601, the driven bevel gear 302 and the wing arm 400 are provided with a material reduction and heat treatment area 602.

[0022] Specifically, the servo motor output shaft → is fitted with the drive bevel gear 301, and the axis is denoted as A1; The flapping axis of the wing arm 400 is A2, and the rotation axis of the driven bevel gear 302 is denoted as o; The compensation boss 601 is located on the back side of the hub of the driven bevel gear 302, bulging outward along the A2 axis. The center of mass of the boss falls in the "opposite side" quadrant of the flapping direction of the wing arm 400, and is distributed in the circumferential range of 120°-180°, and needs to avoid the bearing area of ​​the gear ring. The material reduction compensation cavity 602 is located at the connection between the wing root and the hub. Its purpose is to remove the excess inner mass caused by the original "uniform thickening of the hub", which is equivalent to shrinking the center of mass towards the A2 axis. At the same time, it is necessary to ensure that the topological direction of the rib of the material reduction compensation cavity 602 is orthogonally distributed with the main trajectory of the bending stress at the root of the bevel gear. Furthermore, the outer contour of the compensation boss 601 does not exceed the cone projection surface of the gear pitch, so that the compensation mass falls entirely within the projection area on the back side of the gear ring. Therefore, the wing arm carrying wing 500 performs reciprocating flapping motions around axis A2 in an inclined plane, θ(t) = Θ·cos(ωt). The mass of wing 500 is mainly distributed on its spanwise outer side, and the equivalent center of mass Gw is located at the distal end of wing arm 400. This generates a periodic centrifugal couple M on the rotation axis A2 during the flapping process. _res(t)≈m_w·R_eff·ω2·sinθ(t) This force couple is transmitted to the fuselage via the bearing at point O, becoming the main source of vibration at 15–20 Hz; The inertia compensation structure 600 redistributes mass to the balance zone on the back of the gear, causing the resultant static moment of the movable base about the A2 axis to approach zero.

[0023] in Let A2 be the radial projection vector of the mass of each part onto the A2 axis. Therefore, we can conclude that: The centrifugal force bias generated by the downward movement of the wing arm (high thrust section) is partially offset by the "opposite mass distribution" in the phase of the compensation boss 601; at the same time, the material reduction compensation cavity 602 removes the "excess symmetrical mass" inside the hub to avoid overcompensation or lateral weight increase; the alternating lateral load on the bearing at point O is significantly reduced, the additional load fluctuation at the meshing surface of the bevel gear is reduced, and the high-frequency vibration of the whole machine is suppressed.

[0024] It should be noted that the wings are the core components that determine the aerodynamic efficiency and biomimetic effect of an aircraft. This design is based entirely on the wing vein structure, wing shape and flapping aerodynamic mechanism of a real butterfly. It innovatively adopts a rigid-flexible coupling biomimetic structure and makes full use of the inclined plate effect and the maximization of wing area under certain conditions to achieve aerodynamic lift enhancement.

[0025] like Figure 8 and Figure 9 As shown, (1) rigid-flexible coupling structure design: the rigid frame adopts a lightweight carbon fiber rod, replicates the distribution pattern of butterfly wing veins, adopts an ultra-light carbon fiber frame, the main wing veins are arranged along the wingspan direction, with a diameter of ∅1.5, to ensure the morphological stability and load-bearing capacity of the bionic wings; the secondary wing veins are ∅1.2, to improve the wings' resistance to deformation, and the wing surface is made of P31N kite cloth, which has extremely low surface density and strong flexibility; during flapping, it can optimize the angle of attack and airflow adhesion effect, improve the thrust-to-weight ratio, and avoid lift attenuation caused by airflow separation; like Figure 8 and Figure 9As shown, (2) Airfoil and flapping law optimization based on the slant effect: The airfoil profile adopts the biomimetic configuration of "triangular main wing + teardrop-shaped aileron" to match the wing proportion of a real butterfly; through fluid dynamics analysis, the servo motor installation angle and bevel gear shaft intersection angle are designed to change the flapping plane, thereby forming the flapping angle of attack, maximizing the lifting effect of the slant effect. During the downward flapping process, the wings are fully extended and the air is flapped at the optimal angle of attack to maximize the frontal area and convert the dynamic pressure of the airflow impact into vertical lift and horizontal forward thrust. The angle of attack decreases synchronously. During the upward flapping process, the flexible wing surface naturally retracts under the action of the airflow, the frontal area is greatly reduced, and the air resistance is significantly reduced. The flexible wing surface stores elastic potential energy when deforming and releases it when flapping changes direction, realizing efficient energy utilization within a flapping cycle.

[0026] like Figure 8 and Figure 9 As shown, (3) Coordinated layout design of front and rear wings: Referring to the distribution ratio and installation angle of the front and rear wings of a real butterfly, the front wing serves as the main lifting surface, providing core lift and steering power; the rear wing serves as the auxiliary stabilizing surface, assisting in balancing the fuselage attitude. At the same time, through the flapping phase coordination of the front and rear wings, the forward flight thrust is further enhanced, improving the stability of the system operation.

[0027] It should be noted that, Figure 6 In the diagram, the continuous curve represents the theoretical cosine motion trajectory, the discrete points represent the 36 control command points actually output by the system, the central dashed line represents the mechanical installation center position of the servo motor (1500μs), and the upper and lower dashed lines represent the dual electrical and mechanical limiting thresholds of the servo motor (1100-1900μs).

[0028] It should be noted that, Figure 7 In the diagram, the curve at both ends, which is at a high position, represents the flapping trajectory of the left forewing during a turn (base amplitude + 50μs compensation), while the other curve represents the flapping trajectory of the right forewing (base amplitude - 50μs compensation). The gray filled area represents the lift difference range within one flapping cycle.

[0029] The DS-S001 micro digital servo motor is selected as the driving element. Each servo motor weighs only 3.7g. Compared with the traditional DC motor + reduction mechanism solution, the servo motor has the advantages of precise angle control, fast response speed, high integration, and no need for an additional reduction mechanism. It can directly output precise reciprocating rotational motion, greatly simplifying the transmission structure and reducing the weight of the whole machine. At the same time, it can precisely control the flapping angle and frequency of the wings.

[0030] Bionic optimization of servo mounting position: Combining the natural flapping angle law of butterflies with the optimal angle of attack range required by the swashplate effect, a servo mounting angle of 30° is selected on the front frame of the fuselage to precisely match the movement trajectory of the wings, so that the wings always maintain the optimal angle of attack of 15° throughout the flapping cycle, maximizing the aerodynamic lift enhancement effect.

[0031] Integrated bevel gear transmission design: Power transmission adopts high-precision bevel gear pair meshing transmission, which can accurately change the direction of power transmission. The gear meshing shaft angle is consistent with the angle between the gear and the forewing servo, converting the rotational motion of the servo into the up-and-down flapping motion of the wing. At the same time, the bevel gear output end and the wing arm are integrated into the design, eliminating intermediate transmission links and reducing the transmission chain length to the limit. This completely eliminates the cumulative error of multi-link transmission, greatly improving motion accuracy and transmission response speed. In addition, it solves the problems of limited maximum swing angle and uncontrollability of the actuator in traditional multi-link transmission mechanisms. It also reduces the number of parts, reduces structural weight and assembly difficulty. The bevel gear is made of high wear-resistant nylon material PA12, which has self-lubricating properties and can effectively reduce transmission friction loss. The transmission pair adopts a double fixing method of interference fit + adhesive bonding to avoid loosening problems during long-term operation and ensure the reliability of continuous operation of the whole machine.

[0032] Main parameters of bevel gears:

[0033] It should be noted that the entire aircraft adopts a realistic butterfly-style three-section biomimetic layout of head-chest-abdomen, with the center of gravity concentrated in the chest of the fuselage, ensuring flight stability from a structural perspective. The entire system is divided into three core modules, which work together to achieve biomimetic flight functions. The overall architecture is as follows: (1) Bionic structural system: It includes two core components: a high-strength nylon one-piece molded fuselage and rigid-flexible coupled wings. It is the main load-bearing body and the source of aerodynamic lift of the aircraft. The lift-enhancing effect of the inclined plate effect is maximized through bionic structural design. (2) Mechanical transmission and drive system: The three-servo direct drive scheme is adopted, and the bevel gear-wing arm integrated transmission mechanism is innovatively designed to accurately convert the rotational motion of the servo into the biomimetic flapping of the wings, while realizing the coordinated movement of the front and rear wings, which is the core of the aircraft's power. (3) Electronic control and control system: The ATmega328P microcontroller is the core. It receives remote control commands through PPM signals and completes the coordinated differential control of the three servos, the generation of bionic flapping trajectory, attitude calculation and safety protection. It is the control center of the aircraft.

[0034] In one embodiment of this application, such as Figures 1-4 As shown, the driven bevel gear 302 and the wing arm 400 are integrally formed from nylon PA12.

[0035] It should be noted that the fuselage, as the load-bearing base of the entire aircraft, must simultaneously meet the three core requirements of high strength, vibration resistance, and lightweight. This design adopts a topology optimization + unibody molding solution. The main material is high-strength nylon, which is processed by 3D printing. It has the advantages of high toughness, high wear resistance, self-lubrication, and low density, which can effectively absorb the vibration impact caused by continuous wing flapping and avoid structural resonance. By eliminating redundant materials in non-load-bearing areas through topology optimization, the weight of the fuselage is minimized while ensuring the structural rigidity of the fuselage, the positioning accuracy of the servo mounting position, and the assembly stability of the transmission mechanism. The fuselage adopts a three-section biomimetic layout, with core components such as batteries and main control boards concentrated in the chest area, so that the center of gravity of the entire aircraft coincides with the center of lift, improving flight stability from the structural root and ultimately achieving the design goal of strictly controlling the weight of the entire aircraft to within 80g.

[0036] In one embodiment of this application, such as Figures 1-4 As shown, the shaft intersection angle of the gear set 300 and the servo mounting angle are both 30°±5°, so that the wing maintains an angle of attack of 15°±5° during flapping to utilize the swashplate effect.

[0037] In one embodiment of this application, such as Figures 1-4 As shown, the fuselage is made of high-strength nylon through topology optimization and integral molding, with the center of gravity located in the chest area.

[0038] In one embodiment of this application, such as Figures 1-4 As shown, the bevel gear has a module m=1, 20 teeth, a pressure angle of 20°, and a shaft intersection angle matched with a biomimetic flapping angle of attack arrangement.

[0039] In one embodiment of this application, such as Figures 5-7 As shown, a control system for a biomimetic flapping-wing aircraft is described. The control system uses a cosine function to generate the flapping trajectory and discretizes one flapping cycle into 36 control steps.

[0040] Specifically, the drive system consists of three micro digital servo mechanisms. The left and right front wings are directly driven by two independent servo motors, while the rear wing is driven by one servo motor. The left rear wing is driven synchronously by the right rear wing through mechanical coupling via a bevel gear pair. The core of the control system is the ATmega328P microcontroller, which receives PPM commands from the remote controller and performs calculations. To achieve a biomimetic flapping trajectory, the control system uses a cosine function to generate a continuous and smooth flapping cycle and discretizes it into 36 precise control points, which drive the mechanism to rotate through PWM signals. The rotational power of the servo is transmitted to a pair of high-precision bevel gears on its output shaft. The shaft angle of the gear pair and the installation angle of the servo (both are 30°) are precisely matched to directly convert the rotational motion into the reciprocating flapping of the wings in the set plane, completely eliminating the traditional multi-link mechanism. During the flapping process, the wing structure plays a key role: the wings adopt a rigid-flexible coupling biomimetic design, with a lightweight carbon fiber rod as the skeleton to replicate the veins of butterfly wings, and covered with a P31N flexible wing membrane. During the downward flapping phase of power output, the servo and bevel gear transmission control the wings to flap the air at an optimized angle of attack close to 15°. This utilizes the "slope plate effect"—efficiently converting the dynamic pressure of the airflow into vertically upward lift and horizontally forward thrust. At the same time, the flexible wing membrane fully unfolds to maximize the frontal area. During the upward flapping phase, the flexible wing membrane is passively contracted under the action of the airflow, and the angle of attack decreases simultaneously, thereby significantly reducing air resistance. Furthermore, the elastic potential energy stored in the deformation of the wing membrane is released during the flapping reversal, achieving efficient utilization of energy within one flapping cycle. Through this cycle of "high-efficiency lift from downward flapping and low-energy recovery from upward flapping," the aircraft obtains continuous net lift and forward propulsion. Regarding flight attitude control, the steering function is achieved through differential control of the two canard servos: the system dynamically adjusts the flapping amplitude of the left and right canards to create a lift difference between the two sides. This lift difference generates a steering torque around the longitudinal axis of the fuselage, thereby achieving smooth steering. At the same time, the movement of the rear wing servo logically follows the left canard. Through the mechanical reverse characteristics of the bevel gear, the rear wing moves synchronously to assist in balancing the fuselage attitude.

[0041] It should be noted that the servo motor receives control signals and outputs rotational power, which is transmitted through a bevel gear-wing arm integrated mechanism to drive the fore and rear wings to flap up and down according to the natural flapping angle of a butterfly. During the downward flapping, the wings beat the air at an optimized angle of attack, efficiently converting air pressure into vertical lift and horizontal thrust through the swashplate effect. During the upward flapping, the flexible wing surface naturally retracts and the angle of attack decreases, significantly reducing air resistance and achieving net lift and forward flight power output within one flapping cycle. By adjusting the flapping frequency and amplitude of the left and right forewings, a lift difference is created on both sides to achieve smooth turning. The rear wing provides attitude balance assistance through synchronous coupling via bevel gears, ultimately achieving stable and highly biomimetic flapping flight.

[0042] In one embodiment of this application, such as Figures 5-7 As shown, the control system includes: Signal receiving module: Used to receive multi-channel PPM coded control signals output from an external remote control transmitter; Main control module: integrates an ATmega328P microcontroller, configured to decode PPM encoded signals and generate multi-dimensional PWM control signals; Drive output module: Drives the left front wing servo, right front wing servo, rear wing servo and status indicator lights respectively through PWM signals; Safety protection module: It is configured to monitor electrical and mechanical parameters in real time, and to perform amplitude limiting protection or trigger static gliding mode when the parameters exceed the threshold; Status indicator module: used to provide feedback on flight mode and system operating status; The rear wing servo motor synchronously drives the left and right rear wings through a bevel gear mechanical coupling mechanism to achieve attitude balance assistance.

[0043] In one embodiment of this application, such as Figures 5-7 As shown, the control logic of the main control module includes the following steps: Signal Decoding: The input multi-channel PPM encoded signal is parsed into 8 channels of instructions, including: throttle (channel 3), steering (channel 1), elevation (channel 2), mechanical fine adjustment (channel 5 / 6), amplitude preset (channel 7), and flight switch (channel 8). Trajectory generation: A complete biomimetic flapping trajectory is generated based on the cosine function algorithm, and the flapping period is discretized into 36 control steps; Differential control: Upon receiving a steering command, differential adjustment is performed on the left and right front wing servos to create a lift difference and achieve steering. Coupling synchronization: Upon receiving a lift / attitude command, the rear wing servo outputs a control signal based on the logic of the left front wing following the pulse width, and drives the left and right rear wings to flap in opposite directions through a bevel gear mechanical coupling mechanism to help balance the fuselage attitude; Linkage compensation: Performs throttle-elevation linkage compensation and steering-lift loss compensation to improve flight stability.

[0044] In one embodiment of this application, such as Figures 5-7 As shown, the specific functions of the security protection module include: Electrical limiting protection: Limits the pulse width of the servo control signal to the range of 500-2500μs to avoid electrical overload; Mechanical amplitude limiting protection: Limits the pulse width of the servo control signal to the range of 1100-1900μs to avoid mechanical overload; Static gliding mode: When an anomaly is detected (such as signal loss or parameter exceeding limits), static gliding mode is triggered to reduce the flapping frequency or stop flapping to maintain attitude.

[0045] In one embodiment of this application, the pin assignment of the drive output module is as follows: Left front wing servo: Pin A0, function is to output main lift + differential steering control signal; Right front wing servo: Pin A1, function is to output main lift + differential steering control signal; Rear wing servo: Pin A2, function is to output a control signal whose pulse width follows that of the left forewing; Status indicator: Pin 5, function is to indicate flight mode and system status.

[0046] Working principle: Based on the closed-loop logic of multi-channel PPM signal reception, real-time calculation by the main control module, and multi-servo motor collaborative drive, the system realizes precise flight control of the bionic flapping-wing aircraft. Specifically, the system receives 8-channel PPM encoded signals from the Fuss i6X remote controller through the A8X receiver and transmits the single-line PPM signal to the ATmega328P microcontroller. The main control module first decodes and filters the PPM signal to extract channel commands such as throttle, steering, ascent and descent, mechanical fine adjustment, amplitude preset, and flight mode. Subsequently, the main control module executes the core control algorithm: it generates a complete biomimetic flapping trajectory based on the cosine function and discretizes it into 36 precise control steps to ensure smooth and impact-free wing flapping. For flight attitude control, the system adopts a canard differential control mechanism—when a steering command is received, it dynamically adjusts the flapping amplitude of the left and right canard servos to create a lift difference on both sides to achieve fuselage steering; at the same time, the rear wing servos output control signals based on the logic of "pulse width following the left canard wing" to drive the bevel gear mechanical coupling mechanism to synchronously drive the left and right rear wings to flap in opposite directions, assisting in balancing the fuselage attitude; In addition, the system integrates a multi-dimensional hybrid control compensation algorithm, including throttle-elevation linkage compensation (to avoid loss of control during throttle changes) and steering-lift loss compensation (to avoid a sudden drop in lift during steering), which greatly improves flight stability. To ensure system safety, the control logic has built-in dual limiting protection: electrical limiting (limiting the pulse width of the servo control signal within the range of 500-2500μs) and mechanical limiting (limiting the pulse width of the servo control signal within the range of 1100-1900μs) to prevent electrical overload and mechanical interference. When an anomaly is detected (such as signal loss or parameter exceeding limits), the system can automatically trigger a static gliding mode to reduce the flapping frequency or stop flapping to maintain attitude. Finally, the multi-channel PWM control signals generated by the main control module drive the left front wing servo, right front wing servo, rear wing servo, and status indicator lights respectively, realizing a complete, stable, and safe conversion from remote control commands to bionic flapping actions.

[0047] In summary, the biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission in this embodiment of the application completely eliminates the traditional multi-link crank mechanism by adopting a direct drive servo combined with an integrated bevel gear-wing arm transmission scheme. This fundamentally eliminates the accumulation of hinge clearance and rod length errors, resulting in a significant improvement in motion accuracy. This transmission method has no mechanical dead points, and the motion process is smooth and impact-free, making it particularly suitable for high-frequency continuous operation and significantly extending the fatigue life of the mechanism. At the same time, this invention utilizes high-strength nylon material for topology optimization and one-piece molding, eliminating redundant material in non-load-bearing areas, reducing the number of parts, achieving lightweighting of the entire machine, and greatly simplifying the assembly process. It has high rigidity and excellent vibration resistance, and possesses strong manufacturability. Whether through 3D printing or injection molding, low-cost mass production can be achieved, with good product consistency and extremely high engineering application value.

[0048] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission, characterized in that, It includes the fuselage body (100), drive mechanism (200), gear set (300), wing arms (400), and wings (500), among which, The gear set (300) includes a driving bevel gear (301) and a driven bevel gear (302) rotatably disposed on both sides of the main body (100). The driven bevel gear (302) and the wing arm (400) are integrally formed from the same base; The drive mechanism (200) includes two canard servos (201) and one aft servo (202) located at the front of the fuselage. The driving bevel gear (301) is fixedly connected to the output shaft of the drive mechanism (200), and the surface of the driving bevel gear (301) meshes with the surface of the driven bevel gear (302); The fuselage body (100) adopts a topology-optimized integrated molding structure, and the wings (500) are a rigid-flexible coupling structure of carbon fiber skeleton and flexible film. The driven bevel gear (302) and the wing arm (400) are also provided with an integrally formed inertia compensation structure (600), which is used to generate a compensating inertial force opposite to the inertial force vector of the wing arm (400) when the wing arm (400) flaps. The inertia compensation structure (600) includes a balance boss (601) mounted on the back side of the hub of the driven bevel gear (302). The balance boss (601), driven bevel gear (302) and wing arm (400) are provided with a material reduction and heat treatment zone (602).

2. The biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission according to claim 1, characterized in that, The driven bevel gear (302) and the wing arm (400) are integrally formed from nylon PA12.

3. The biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission according to claim 1, characterized in that, The shaft intersection angle of the gear set (300) and the servo mounting angle are both 30°±5°, so that the wing maintains an angle of attack of 15°±5° during flapping to take advantage of the swashplate effect.

4. The biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission according to claim 1, characterized in that, The fuselage is made of high-strength nylon through topology optimization and integral molding, with the center of gravity located in the chest area.

5. The biomimetic flapping-wing aircraft with integrated bevel gear and wing arm transmission according to claim 1, characterized in that, The bevel gear has a module m=1, 20 teeth, a pressure angle of 20°, and a biomimetic flapping angle of attack arrangement matching the shaft intersection angle.

6. A control system for a biomimetic flapping-wing aircraft, characterized in that, The control system uses a cosine function to generate the flapping trajectory, discretizing one flapping cycle into 36 control steps. The control system includes: Signal receiving module: Used to receive multi-channel PPM coded control signals output from an external remote control transmitter; Main control module: integrates an ATmega328P microcontroller, configured to decode PPM encoded signals and generate multi-dimensional PWM control signals; Drive output module: Drives the left front wing servo, right front wing servo, rear wing servo and status indicator lights respectively through PWM signals; Safety protection module: It is configured to monitor electrical and mechanical parameters in real time, and to perform amplitude limiting protection or trigger static gliding mode when the parameters exceed the threshold; Status indicator module: used to provide feedback on flight mode and system operating status; The rear wing servo motor synchronously drives the left and right rear wings through a bevel gear mechanical coupling mechanism to achieve attitude balance assistance.

7. The control system of the biomimetic flapping-wing aircraft according to claim 6, characterized in that, The control logic of the main control module includes the following steps: Signal Decoding: The input multi-channel PPM encoded signal is parsed into 8 channels of instructions, including: throttle (channel 3), steering (channel 1), elevation (channel 2), mechanical fine adjustment (channel 5 / 6), amplitude preset (channel 7), and flight switch (channel 8). Trajectory generation: A complete biomimetic flapping trajectory is generated based on the cosine function algorithm, and the flapping period is discretized into 36 control steps; Differential control: Upon receiving a steering command, differential adjustment is performed on the left and right front wing servos to create a lift difference and achieve steering. Coupling synchronization: Upon receiving a lift / attitude command, the rear wing servo outputs a control signal based on the logic of the left front wing following the pulse width, and drives the left and right rear wings to flap in opposite directions through a bevel gear mechanical coupling mechanism to help balance the fuselage attitude; Linkage compensation: Performs throttle-elevation linkage compensation and steering-lift loss compensation to improve flight stability.

8. The control system of the biomimetic flapping-wing aircraft according to claim 6, characterized in that, The specific functions of the security protection module include: Electrical limiting protection: Limits the pulse width of the servo control signal to the range of 500-2500μs to avoid electrical overload; Mechanical amplitude limiting protection: Limits the pulse width of the servo control signal to the range of 1100-1900μs to avoid mechanical overload; Static gliding mode: When an anomaly is detected (such as signal loss or parameter exceeding limits), static gliding mode is triggered to reduce the flapping frequency or stop flapping to maintain attitude.

9. The control system of the biomimetic flapping-wing aircraft according to claim 6, characterized in that, The pin assignment of the drive output module is as follows: Left front wing servo: Pin A0, function is to output main lift + differential steering control signal; Right front wing servo: Pin A1, function is to output main lift + differential steering control signal; Rear wing servo: Pin A2, function is to output a control signal whose pulse width follows that of the left forewing; Status indicator: Pin 5, function is to indicate flight mode and system status.

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