Self-adaptive carbon fiber lander supporting mechanism of unmanned aerial vehicle

Abstract

The invention discloses a self-adaptive carbon fiber lander supporting mechanism of an unmanned aerial vehicle, and belongs to the technical field of unmanned aerial vehicle landing devices. The mechanism comprises a carbon fiber base, a multi-degree-of-freedom buffer device and a heatable foot pad. The carbon fiber base is formed by 3D printing of polyamide and carbon fiber composite materials, and has the characteristics of light weight and high strength; the multi-degree-of-freedom buffering device is formed by a splayed polyurethane rubber mat and an aviation aluminum connector in an interference fit mode, and + / -15-degree dip angle self-adaptive adjustment can be achieved. The heatable foot pad is integrated with a resistance heating sheet and an aluminum heat conducting plate, and adhesion and desorption of the shape memory bionic adhesion material are achieved through temperature control. The structure weight is obviously reduced, the defects of a traditional landing device in the aspects of adaptability, energy consumption and reliability are overcome through a passive inclination adaptation mechanism and intelligent adhesion control, and an innovative solution is provided for application of the unmanned aerial vehicle in diversified scenes.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicle (UAV) landing devices, and particularly to an adaptive carbon fiber landing support mechanism for UAVs. Background Art

[0002] With the rapid development of UAV technology, the application requirements in complex environments are increasing day by day, such as landing and takeoff on inclined surfaces, inverted surfaces or uneven terrains. However, the following technical bottlenecks exist in traditional UAV landing devices:

[0003] Weight and energy consumption issues: Existing rigid landing mechanisms (such as suction cups, hook claws, etc.) usually adopt metal materials, resulting in a bulky overall structure, increasing the load and energy consumption of the UAV, and affecting flight efficiency and endurance.

[0004] Insufficient adaptability: Traditional landing devices have poor adaptability to inclined or inverted surfaces and are difficult to achieve stable fitting. Especially in complex terrains, slippage or overturning is likely to occur, affecting landing safety and reliability.

[0005] Defects in the desorption mechanism: Although some bionic adhesion materials can achieve passive adhesion, desorption requires the assistance of additional mechanical structures. This not only increases the system complexity but also may cause material damage due to mechanical forces, reducing the service life.

[0006] Limitations in buffering performance: Existing buffering structures are mostly of one-way design and cannot effectively cope with multi-directional impacts. Stress concentration is likely to occur during inclined landings, affecting the stability and durability of the mechanism. Summary of the Invention

[0007] Aiming at the deficiencies of the above-mentioned existing technologies, the purpose of the present invention is to provide an adaptive carbon fiber landing support mechanism for UAVs, which can significantly reduce the structural weight and solve the deficiencies of traditional landing devices in terms of adaptability, energy consumption and reliability through a passive tilt adaptation mechanism and intelligent adhesion control.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] An adaptive carbon fiber landing support mechanism for UAVs, characterized by comprising:

[0010] A carbon fiber base, the material of which is PA12 and 35% CF, and has a cross-shaped frame and a central mounting hole;

[0011] An aviation connector, made of aviation aluminum, with an inner hole for connecting the carbon fiber base and the buffer device;

[0012] Four multi-degree-of-freedom cushioning devices, consisting of figure-eight polyurethane rubber pads and aviation aluminum joints with interference fit, can be adaptively adjusted according to the inclination of the landing surface;

[0013] Heated foot pads, integrated with resistance heating sheet and aluminum heat conducting plate, with temperature controlled by remote control circuit;

[0014] The PA12 specifically refers to polyamide 12, the CF is the abbreviation of Carbon Fiber, specifically refers to carbon fiber, and the 35% CF means that 35% by mass of carbon fiber is added to the PA12 material.

[0015] Furthermore, the figure-eight rubber pad of the buffer device has strong strength and elasticity. Its elasticity is used to pass the aviation aluminum material through the hole of the figure-eight rubber pad and fix it in the groove. At the same time, an inner hole with a tolerance grade less than IT5 based on the basic hole system is opened in the aviation joint. The buffer device can be connected to other structures using a hexagonal cylindrical head screw.

[0016] Furthermore, the buffer device and the base are assembled by interference fit through the base hole and are fastened by the hexagonal cylindrical head screw of the buffer device. The buffer device and the foot pad are also assembled by interference fit through the base hole and are fastened by the hexagonal screw.

[0017] Furthermore, the Mooney-Rivlin hyperelastic parameters of the polyurethane pad include the parameter C that characterizes the elastic contribution of the material under pure shear deformation. 10 , the parameter C of the tensile and compressive elastic contribution of the material under the condition of constant volume 01 , parameter D1 that characterizes the volume incompressibility of the material.

[0018] Furthermore, the parameter C 10 The value of the parameter C is 1.049MPa. 01 The value of is 0.532MPa, and the value of the parameter D1 is 0MPa.

[0019] Furthermore, the heating device includes a boost module, and the response time is less than 2s.

[0020] Furthermore, the heated foot pad has an adaptive inclination angle of ±15° according to the inclination of the landing surface, and a displacement of ≥16.58 mm; during the go-around process of the support mechanism, the response time of the heating system from receiving the remote control signal to the beginning of softening of the shape memory bionic adhesive material is less than 1 second.

[0021] Furthermore, during operation, the temperature uniformity deviation of the resistance heating plate integrated in the heated foot pad is less than ±5°C, and the service life of the resistance heating plate is not less than 1,000 heating cycles. During the entire service life, its heating performance is stable and the power attenuation does not exceed 10%.

[0022] Furthermore, when the temperature exceeds 90°C, the power supply can be automatically cut off within 0.5 s.

[0023] Furthermore, the shape memory bionic adhesion material can still maintain good adhesion performance and switchability in different humidity environments; in a high-humidity environment, its adhesion strength decreases by no more than 10%, and the switching ratio changes by no more than 5%; in a low-humidity environment, the material will not crack or have abnormal performance.

[0024] Compared with the prior art, the present invention adopts the above technical solutions and has the following beneficial effects:

[0025] (1) Using a composite material containing carbon fiber to make relevant components, compared with traditional metal materials, the weight of the support mechanism is greatly reduced, thereby reducing the load of the drone, lowering the flight energy consumption, and improving the flight efficiency and endurance.

[0026] (2) The multi-degree-of-freedom buffer device has a unique structure and can achieve self-adaptive adjustment at a certain angle, enabling the drone to stably fit on an inclined or uneven landing surface, avoiding slipping or tipping, enhancing the safety and reliability of landing on complex terrains, and broadening the application scenarios of the drone.

[0027] (3) The heatable footpad integrates a special device, and the adhesion and detachment of the bionic adhesion material are realized by controlling the temperature, which can operate efficiently during both the landing and takeoff phases. This method does not require additional complex mechanical structures to assist in detachment, reduces the system complexity, and can also prevent the material from being damaged by mechanical forces, prolonging its service life.

[0028] (4) The polyurethane rubber pad is designed according to specific hyperelastic parameters and has excellent multi-directional buffering capabilities. It can effectively disperse and absorb impact forces from different directions, reduce the stress concentration phenomenon during inclined landings, improve the stability and durability of the mechanism, and better protect the drone and the carried equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of a support mechanism of an adaptive carbon fiber lander for a drone proposed by the present invention;

[0030] Figure 2 Simulation diagram of the force on the inverted surface structure of the landing structure;

[0031] Figure 3 Simulation diagram of the total deformation result of the inverted surface structure of the landing structure;

[0032] Figure 4 Simulation diagram of the equivalent stress result of the inverted surface of the landing structure;

[0033] Figure 5Simulation diagram of equivalent elastic strain results of the inverted surface of the landing structure

[0034] Figure 6 Simulation diagram of the force on the "roof-type" double-inclined surface landing structure of the landing device

[0035] Figure 7 Simulation diagram of the total deformation of the "roof-type" double-inclined surface landing structure of the landing device

[0036] Figure 8 Simulation diagram of the equivalent stress results of the "roof-type" double-inclined surface landing structure of the landing device

[0037] Figure 9 Simulation diagram of the "roof-type" double-inclined surface of the landing device

[0038] Figure 10 Oblique view of the landing device

[0039] Figure 11 Front view of the landing device

[0040] Figure 12 Left view of the landing device

[0041] Figure 13 Top view of the landing device Specific implementation manner

[0042] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] An adaptive carbon fiber landing support mechanism for an unmanned aerial vehicle, the specific structure of which is as Figure 1 shown, the oblique view, front view, left view, and top view are respectively as Figure 10 , 11 , 12, 13 shown, and it is characterized in that it includes:

[0044] A carbon fiber base, the material used for the carbon fiber base is PA12 and 35% CF, and it has a cross-shaped frame and a central mounting hole;

[0045] An aviation joint, made of aviation aluminum, with an inner hole opened for connecting the carbon fiber base and the buffer device;

[0046] Four multi-degree-of-freedom buffer devices, which are formed by the interference fit of an eight-shaped polyurethane rubber pad and an aviation aluminum joint, and can be adaptively adjusted according to the inclination degree of the landing surface;

[0047] The heatable foot mat integrates a resistive heating sheet and an aluminum heat conducting plate, and controls the temperature through a remote control circuit;

[0048] The PA12 specifically refers to polyamide 12, the CF is the abbreviation of Carbon Fiber, specifically referring to carbon fiber, and the 35% CF means that 35% by mass of carbon fiber is added to the PA12 material.

[0049] Furthermore, the eight-shaped rubber pad of the buffer device has strong strength and elasticity. Using its elasticity, the aviation aluminum material passes through the hole of the eight-shaped rubber pad and is clamped into the groove for fixation. At the same time, the aviation joint is provided with an inner hole based on the basic hole system with a tolerance grade less than IT5. The buffer device can be connected to other structures by using internal hexagon socket head cap screws.

[0050] Furthermore, the buffer device and the base are assembled by interference fit based on the basic hole system and fastened by the internal hexagon socket head cap screws of the buffer device. The buffer device and the foot mat are also assembled by interference fit based on the basic hole system and fastened by internal hexagon screws.

[0051] Furthermore, the Mooney-Rivlin hyperelastic parameters of the polyurethane rubber pad include the parameter C characterizing the elastic contribution of the material under pure shear deformation 10 , the parameter C 01 characterizing the tensile and compressive elastic contributions of the material under the condition of constant volume, and the parameter D1 characterizing the volume incompressibility of the material.

[0052] Furthermore, the value of the parameter C 10 is 1.049 MPa, the value of the parameter C 01 is 0.532 MPa, and the value of the parameter D1 is 0 MPa.

[0053] Furthermore, the heating device includes a boost module, and the response time < 2 s.

[0054] Furthermore, the adaptive inclination angle of the heatable foot mat according to the inclination degree of the landing surface is ±15°, and the displacement ≥ 16.58 mm; during the go-around process of the support mechanism, the response time from the heating system receiving the remote control signal to the shape memory bionic adhesion material starting to soften is less than 1 second.

[0055] Furthermore, during the working process of the resistive heating sheet integrated in the heatable foot mat, the temperature uniformity deviation is less than ±5 °C, the service life of the resistive heating sheet is not less than 1000 heating cycles, and during the entire service life cycle, its heating performance is stable and the power attenuation does not exceed 10%.

[0056] Furthermore, when the temperature exceeds 90 °C, the power supply can be automatically cut off within 0.5 s.

[0057] Furthermore, the shape memory bionic adhesion material can still maintain good adhesion performance and switchability in different humidity environments; in a high humidity environment, its adhesion strength decreases by no more than 10%, and the switching ratio changes by no more than 5%; in a low humidity environment, the material will not crack or have abnormal performance.

[0058] Furthermore, when a force is applied in the vertical direction, the foot pad will deform and move as a whole along the direction of the force. As shown in Figure 2 , 3 , Figures 4 and 5, under a pressure of 400 Pa, the entire foot pad will move downward by about 10 mm. The stress and strain are mainly concentrated at the connection of the figure-eight rubber pads, and the maximum stress is about 0.39 MPa.

[0059] Furthermore, when pressures of 100 Pa along the z-axis direction and 100 Pa along the x-axis direction are applied, as shown in Figure 6 , 7 , Figures 8 and 9, the maximum deformation occurs at the outermost side of the foot pad, and the deformation amount is about 16.58 mm; at this time, the maximum stress occurs at the connection of the rubber pad and the aviation connector, about 5.72 MPa.

[0060] The structural assembly is as follows:

[0061] 1. Buffer device assembly: Insert the aviation aluminum connector into the inner hole of the polyurethane rubber pad and fasten it with the hexagon socket head cap screw according to GB / T6190 - 1986 to form an elastic joint that can rotate around the X / Y / Z axes, as shown in Figure 1 .

[0062] 2. Connection between the base and the foot pad: The extension arm of the carbon fiber base and the buffer device adopt an interference fit with a basic hole system, and are axially locked with screws to ensure no looseness under the landing impact.

[0063] 3. Heating system integration: The resistance heating sheet is welded to the boost module, and the remote control switch module is embedded in the base cavity, and the overall circuit weight < 20 g.

[0064] In order to further illustrate the above-mentioned support mechanism of the UAV lander, this embodiment will be described in detail in the landing stage and the takeoff stage.

[0065] (1) Landing stage:

[0066] Remotely control to turn on the heating, the foot pad heats up to 80 °C, and the shape memory bionic adhesion structure softens;

[0067] When the UAV vertically contacts the surface, the entire foot pad will move downward by about 10 mm (as shown in Figure 3 ). The stress and elastic strain during the entire deformation process are mainly generated by the polyurethane rubber pad, and the polyurethane rubber pad is compressed and deformed (the maximum stress is 0.39 MPa, asFigure 4 As shown in the figure, this indicates that the polyurethane rubber pad has a good buffering effect on the entire landing structure, and can effectively relieve the impact during landing, protecting the landing structure and the UAV.

[0068] When the UAV contacts the surface at an adaptive tilt angle; when subjected to tilt forces with reverse components along the x-axis and z-axis (as Figure 6 shown), the foot pads will flip around the z-axis to adapt to the tilted surface, enabling the shape memory bionic adhesion structure to fully contact the tilted surface. At this time, while the rubber pad is compressed downward, it will also tilt around the y-axis, and the maximum deformation occurs at the outermost side of the foot pads, with a deformation amount of approximately 16.58 mm (as Figure 7 shown), and the maximum stress at this time occurs at the connection between the rubber pad and the aviation joint, approximately 5.72 MPa (as Figure 8 shown).

[0069] Turn off the heating, and the adhesion structure cools and solidifies, with an adhesion strength reaching 430 kPa (pre-pressure 150 kPa).

[0070] (2) Takeoff stage:

[0071] Remotely control to restart the heating, the adhesion force drops to 80 kPa, and the self-weight of the UAV triggers the desorption.

[0072] Effects of the embodiments:

[0073] 1. Tilt adaptability test: Successful landings were achieved on slopes of 0° to 15°, and the shear stress of the rubber pad < 6 MPa;

[0074] 2. Shock absorption performance: Under a 400 Pa vertical impact, the displacement of the foot pads is 10 mm, and the maximum elastic strain is 0.39 (as Figure 3 shown);

[0075] 3. Weight control: The total weight of the overall mechanism is 124.06 g, which is 52% lighter than the same type of metal structure.

[0076] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive carbon fiber landing support mechanism for an unmanned aerial vehicle, characterized in that, Including: A carbon fiber base, the material of the carbon fiber base is PA12 and 35% CF, and it has a cross-shaped frame and a central mounting hole; An aviation connector, made of aviation aluminum, with an inner hole opened for connecting the carbon fiber base and the buffer device; Four multi-degree-of-freedom buffer devices, composed of an eight-shaped polyurethane rubber pad and an aviation aluminum joint in interference fit, which can be adaptively adjusted according to the inclination degree of the landing surface; A heatable foot pad, integrating a resistance heating sheet and an aluminum heat conduction plate, and controlling the temperature through a remote control circuit; The PA12 specifically refers to polyamide 12, the CF is the abbreviation of Carbon Fiber, specifically referring to carbon fiber, and the 35% CF means that 35% by mass percentage of carbon fiber is added to the PA12 material.

2. The support mechanism of an adaptive carbon fiber landing gear for a drone according to claim 1, wherein The eight-shaped rubber pad of the buffer device has strong strength and elasticity. Using its elasticity, the aviation aluminum passes through the hole of the eight-shaped rubber pad and is fixed in the groove by being clamped. At the same time, the aviation connector has an inner hole based on the basic hole system with a tolerance grade less than IT5, and this buffer device can be connected to other structures by using an internal hexagon socket head cap screw.

3. The support mechanism of an adaptive carbon fiber landing gear for an unmanned aerial vehicle according to claim 1, characterized in that, The buffer device and the base are assembled by interference fit based on the basic hole system and are fastened by the internal hexagon socket head cap screw of the buffer device. The buffer device and the foot pad are also equipped by interference fit based on the basic hole system and are fastened by internal hexagon screws.

4. The support mechanism of an unmanned aerial vehicle adaptive carbon fiber landing gear according to claim 1, characterized in that, The Mooney-Rivlin hyperelastic parameters of the polyurethane rubber pad include the parameter C that characterizes the elastic contribution of the material under pure shear deformation 10 , the parameter C that represents the tensile and compressive elastic contributions of the material under the condition of constant volume 01 , and the parameter D1 that characterizes the volume incompressibility of the material.

5. The Mooney-Rivlin hyperelastic parameters of the polyurethane rubber pad according to claim 4, characterized in that, The parameter C 10 has a value of 1.049 MPa, and the parameter C 01 has a value of 0.532 MPa. The value of the parameter D1 is 0 MPa.

6. The support mechanism of an adaptive carbon fiber landing gear for a drone according to claim 1, characterized in that, The heating device includes a boost module, and the response time is less than 2 seconds.

7. An adaptive carbon fiber landing gear support mechanism for an unmanned aerial vehicle according to claim 1, characterized in that, The adaptive inclination angle of the heatable foot pad according to the inclination degree of the landing surface is ±15°, and the displacement is ≥16.58 mm; during the go-around process of the support mechanism, the response time from the heating system receiving the remote control signal to the shape memory bionic adhesion material starting to soften is less than 1 second.

8. An adaptive carbon fiber landing gear support mechanism for a drone according to claim 1, characterized in that, During the working process of the resistance heating sheet integrated in the heatable foot pad, the temperature uniformity deviation is less than ±5 °C. The service life of the resistance heating sheet is not less than 1000 heating cycles. During the entire service life cycle, its heating performance is stable, and the power attenuation does not exceed 10%.

9. The support mechanism of an adaptive carbon fiber landing gear for a drone according to claim 1, characterized in that, When the temperature exceeds 90 °C, the power supply can be automatically cut off within 0.5 s.

10. An adaptive carbon fiber landing gear support mechanism for a drone according to claim 1, characterized in that, The shape memory bionic adhesion material can still maintain good adhesion performance and switchability in different humidity environments; in a high humidity environment, its adhesion strength decreases by no more than 10%, and the switching ratio changes by no more than 5%; in a low humidity environment, the material will not crack or have abnormal performance.

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