CN112867671A

CN112867671A - Vibration mode optimization method, vibration mode optimization device and unmanned aerial vehicle

Info

Publication number: CN112867671A
Application number: CN202080005354.9A
Authority: CN
Inventors: 赵鹏飞; 刘祥
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2020-04-28
Filing date: 2020-04-28
Publication date: 2021-05-28
Also published as: WO2021217437A1

Abstract

A vibration mode optimization method is used for an unmanned aerial vehicle (100), the unmanned aerial vehicle (100) comprises a body (20) and a horn assembly (30), the horn assembly (30) comprises a horn (32) and a motor (34), one end of the horn (32) is rotatably connected with the body (20), the top of the other end of the horn (32) is connected with the motor (34), the bottom of the other end of the horn (32) is connected with a foot rest (40), and an output shaft of the motor (34) is connected with a blade (50); the vibration mode optimization method comprises the following steps: acquiring critical instability paddle frequency (omega) of the paddle (50); at least one of a torsional frequency (ω x) of the horn (32), a distance (h) from a blade plane of the blade (50) to a torsional axis of the horn (32), and a moment of inertia (Mx) of the horn assembly (30) about the torsional axis of the horn (32) is adjusted in accordance with a critical destabilizing blade frequency (ω) of the blade (50). The application also discloses a vibration mode optimizing device (200) and an unmanned aerial vehicle (100).

Description

Vibration mode optimization method, vibration mode optimization device and unmanned aerial vehicle

Technical Field

The application relates to the technical field of unmanned aerial vehicles, in particular to a vibration mode optimization method, a vibration mode optimization device and an unmanned aerial vehicle.

Background

At present, the folding paddle is adopted for the folding portability of the unmanned aerial vehicle. Unmanned aerial vehicle horn is longer relatively, and the motor quality of tip is great, and the foot rest is except playing the supporting role, and other additional functions also, this makes to introduce more quality and inertia to the horn part, takes place the unstability easily when unmanned aerial vehicle is big mobile, paddle high rotational speed, and the violent vibration of horn influences flight security and normal formation of image.

Disclosure of Invention

The embodiment of the application provides a vibration mode optimization method, a vibration mode optimization device and an unmanned aerial vehicle.

The vibration mode optimization method is used for the unmanned aerial vehicle, the unmanned aerial vehicle comprises a body and a horn assembly, the horn assembly comprises a horn and a motor, one end of the horn is rotatably connected with the body, the top of the other end of the horn is connected with the motor, the bottom of the other end of the horn is connected with a foot rest, and an output shaft of the motor is connected with a paddle;

the vibration mode optimization method comprises the following steps:

acquiring critical instability paddle frequency of the paddle;

adjusting at least one of a torsional frequency of the horn, a distance of a blade plane of the blade to a horn twist axis, and a moment of inertia of the horn assembly about the horn twist axis, in accordance with a critical destabilizing blade frequency of the blade.

The vibration mode optimization device comprises a processor, wherein the processor is used for acquiring critical destabilization paddle frequency of the paddles; and the controller is used for adjusting at least one of the torsion frequency of the horn, the distance from the blade plane of the blade to the horn torsion shaft and the inertia moment of the horn assembly about the horn torsion shaft according to the critical instability blade frequency of the blade.

The unmanned aerial vehicle is obtained by optimizing the vibration mode optimization method.

According to the vibration mode optimization method, the vibration mode optimization device and the unmanned aerial vehicle, at least one of the torsion frequency of the horn, the distance from the plane of the blade to the torsion shaft of the horn and the inertia moment of the horn assembly about the torsion shaft of the horn is adjusted by taking the critical destabilizing paddle frequency of the blade as a reference, so that the actual paddle frequency of the blade is lower than the critical destabilizing paddle frequency of the blade. Like this when the paddle rotates at a high speed, can make the vibration minimizing of horn subassembly, guaranteed unmanned aerial vehicle's flight safety and normal work.

Additional aspects and advantages of embodiments of the present 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 embodiments of the present application.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic flow chart of a vibration mode optimization method according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of an unmanned aerial vehicle according to an embodiment of the present application;

fig. 3 is another schematic structural diagram of the drone according to an embodiment of the present application;

FIG. 4 is a block schematic diagram of a vibrational mode optimization apparatus according to an embodiment of the present application;

FIG. 5 is a schematic flow chart diagram of a vibrational mode optimization method according to another embodiment of the present application;

FIG. 6 is a schematic flow chart diagram of a vibrational mode optimization method according to yet another embodiment of the present application;

FIG. 7 is a schematic flow chart diagram illustrating a vibration mode optimization method according to yet another embodiment of the present application;

FIG. 8 is a schematic flow chart diagram of a vibrational mode optimization method according to another embodiment of the present application;

fig. 9 is a schematic structural diagram of a horn of the drone according to an embodiment of the present application;

fig. 10 is a schematic structural view of a foot stool of the unmanned aerial vehicle according to the embodiment of the present application;

fig. 11 is another schematic structural view of a foot stool of the drone according to an embodiment of the present application;

fig. 12 is another schematic structural diagram of the arm assembly of the unmanned aerial vehicle according to the embodiment of the present application.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The following disclosure provides many different embodiments or examples for implementing different features of the application. In order to simplify the disclosure of the present application, specific example components and arrangements are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, examples of various specific processes and materials are provided herein, but one of ordinary skill in the art may recognize applications of other processes and/or use of other materials.

Referring to fig. 1, 2 and 3, a vibration mode optimization method according to an embodiment of the present application is used for an unmanned aerial vehicle 100, where the unmanned aerial vehicle 100 includes a body 20 and a horn assembly 30, the horn assembly 30 includes a horn 32 and a motor 34, one end of the horn 32 is rotatably connected to the body 20, the top of the other end of the horn 32 is connected to the motor 34, the bottom of the other end of the horn 32 is connected to a foot rest 40, and an output shaft of the motor 34 is connected to a blade 50;

the vibration mode optimization method comprises the following steps:

step S11: obtaining critical destabilization paddle frequency omega of the paddle 50;

step S12: at least one of the torsional frequency ω x of the horn 32, the distance h from the blade plane of the blade 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis is adjusted in accordance with the critical destabilizing blade frequency ω of the blade 50.

Wherein, the distance h from the blade plane of the blade 50 to the horn torsion axis is the vertical distance from the gravity center of the blade 50 to the horn torsion axis; the moment of inertia Mx of the arm unit 30 about the arm torsion axis is a moment of inertia of the structure such as the arm 32, the motor 34, and the foot 40 about the arm torsion axis.

Referring to fig. 4, the vibration mode optimization device 200 of the embodiment of the present application is used for the unmanned aerial vehicle 100, the unmanned aerial vehicle 100 includes a body 20 and a horn assembly 30, the horn assembly 30 includes a horn 32 and a motor 34, one end of the horn 32 is rotatably connected to the body 20, the top of the other end of the horn 32 is connected to the motor 34, the bottom of the other end of the horn 32 is connected to a foot rest 40, and an output shaft of the motor 34 is connected to a blade 50. The vibration mode optimization device 200 comprises a processor 201, wherein the processor 201 is used for acquiring a critical destabilization paddle frequency ω of the paddle 50; and for adjusting at least one of the torsional frequency ω x of the horn 32, the distance h of the blade plane of the blade 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis, in accordance with the critical destabilizing blade frequency ω of the blade 50.

The unmanned aerial vehicle 100 according to the embodiment of the present application is optimized by the above vibration mode optimization method.

According to the vibration mode optimization method, the vibration mode optimization device 200 and the unmanned aerial vehicle 100, at least one of the torsional frequency ω x of the horn 32, the distance h from the blade plane to the horn torsional axis and the inertia moment Mx of the horn assembly 30 about the horn torsional axis is adjusted by taking the critical destabilizing paddle frequency ω of the blade 50 as a reference, so that the actual paddle frequency of the blade 50 is lower than the critical destabilizing paddle frequency ω of the blade 50, and thus when the blade 50 rotates at a high speed, the vibration of the horn assembly 30 can be minimized, and the flight safety and the normal operation of the unmanned aerial vehicle 100 are ensured.

Specifically, unmanned aerial vehicle 100 can include the cloud platform, and the cloud platform is installed at fuselage 20, is provided with the shooting device on the cloud platform. So, can unmanned aerial vehicle 100 can possess the shooting function, and the cloud platform can increase steadily and attitude adjustment for shooting the device for shoot the effect better and can satisfy more demands.

It can be understood that, in the related art, the folding paddle is mostly adopted for the unmanned aerial vehicle for the portability of folding. Unmanned aerial vehicle horn is longer relatively, and the motor quality of tip is great, and the foot rest is except playing the supporting role, and other additional functions also, this makes to introduce more quality and inertia to the horn part, takes place the unstability easily when unmanned aerial vehicle is big mobile, paddle high rotational speed, and the violent vibration of horn influences flight security and normal formation of image. Moreover, under the high-temperature and high-humidity environment, the mechanical property of the material is reduced, the vibration of the machine arm is easier to occur, and greater risk is formed for the safe work of the unmanned aerial vehicle.

The related art generally dampens the vibration of the horn in three ways: the paddle rotating speed of the unmanned aerial vehicle is limited so as to avoid vibration under the condition that the changing space is small, and the material with higher modulus is used for the horn structure so as to improve the critical rotating speed of the paddle and use the non-folding paddle.

However, limiting the rotational speed of the drone's paddles limits the pulling force and maneuverability of the drone. The corresponding density of the high modulus horn material will generally be greater, and the use of higher modulus material for the horn structure may increase cost or weight. Using non-folding paddles can increase the folding volume of the drone, resulting in reduced portability. Moreover, when the non-folding blade is used, the phenomenon that the vibration of the horn is amplified can also occur.

In the vibration mode optimization method, the vibration mode optimization device 200 and the unmanned aerial vehicle 100 according to the embodiment of the present invention, at least one of the aforementioned parameters is adjusted by using the critical destabilization paddle frequency ω of the paddle 50 as a reference, so that the above problem is avoided, and the actual paddle frequency of the paddle 50 is lower than the requirement of the critical destabilization paddle frequency ω of the paddle 50, so that the vibration of the horn assembly 30 is minimized when the paddle 50 rotates at a high speed, which is beneficial to ensuring the flight safety and normal operation of the unmanned aerial vehicle 100.

Specifically, in step S11, input information may be acquired, and the critical destabilizing paddle frequency ω may be determined based on the input information. In this way, the user can input the input information to the vibration mode optimization device 200, so that the processor 201 obtains the critical destabilizing paddle frequency ω, which is convenient for the user to set and debug by himself/herself. Specifically, the input information may include a critical destabilizing paddle frequency ω, and the processor 201 may identify the input information to obtain the critical destabilizing paddle frequency ω. The input information may also include data for calculating the critical destabilizing paddle frequency ω, from which the processor 201 may calculate the critical destabilizing paddle frequency ω. Specifically, the vibration mode optimization device 200 may be connected with input devices including, but not limited to, a touch screen, buttons (including a mouse and a keyboard), a gesture recognition camera, and a microphone. The input information includes, but is not limited to, information input by a touch screen, key information, gesture information, voice information. The specific form of the input information is not limited herein.

The vibration mode optimization apparatus 200 includes, but is not limited to, a personal computer, a mobile phone, a tablet computer, a notebook computer, and a wearable device. The specific form of the vibration mode optimizing device 200 is not limited herein. The vibrational mode optimization apparatus 200 may include a memory 202, the memory 202 may store a critical destabilizing paddle frequency ω, and the processor 201 may read the critical destabilizing paddle frequency ω from the memory 202. Therefore, user input is not needed, the obtaining speed is high, and the execution time of the vibration mode optimization method is favorably shortened.

It will be appreciated that if the rotational speed of the blade 50 is higher than the critical destabilizing blade frequency ω, the blade 50 is likely to be destabilized, thereby inducing the horn 32 to vibrate. In step S12, in one embodiment, the critical destabilizing paddle frequency ω may be equal to the highest value of the rotational speed of the blade 50, in which case the rotational speed of the blade 50 may not exceed the highest value of the rotational speed of the blade 50, and thus the rotational speed of the blade 50 may not exceed the critical destabilizing paddle frequency ω. Therefore, the rotating speed of the paddle 50 can be prevented from being higher than the critical instability paddle frequency omega, and therefore the vibration of the horn 32 caused by the instability of the paddle 50 can be avoided under the condition that the maneuverability of the unmanned aerial vehicle 100 is guaranteed.

In step S12, one, two or all of the torsional frequency ω x of the horn 32, the distance h from the blade plane of the blade 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis may be adjusted according to the critical destabilizing blade frequency ω of the blade 50.

In one example, the torsional frequency ω x of the horn 32 may be adjusted based on the critical destabilizing blade frequency ω of the blade 50. In another example, the distance h from the blade plane of the blade 50 to the horn twist axis may be adjusted based on the critical destabilizing blade frequency ω of the blade 50. In yet another example, the moment of inertia Mx of the horn assembly 30 about the horn twist axis may be adjusted based on the critical destabilizing pitch frequency ω of the blade 50.

In yet another example, the torsional frequency ω x of the horn 32 and the distance h from the blade plane of the blade 50 to the horn torsional axis may be adjusted based on the critical destabilizing blade frequency ω of the blade 50. In another example, the torsional frequency ω x of the horn 32 and the moment of inertia Mx of the horn assembly 30 about the horn torsional axis may be adjusted based on the critical destabilizing blade frequency ω of the blade 50. In yet another example, the distance h from the blade plane of the blade 50 to the horn twist axis and the moment of inertia Mx of the horn assembly 30 about the horn twist axis may be adjusted based on the critical destabilizing blade frequency ω of the blade 50.

In yet another example, the torsional frequency ω x of the horn 32, the distance h from the blade plane of the blade 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis may be adjusted based on the critical destabilizing blade frequency ω of the blade 50.

Note that the above is merely an example, and the specific content and the specific number of the adjustment parameters are not limited herein.

In some embodiments, the critical destabilizing paddle frequency ω is positively correlated with the torsional frequency ω x of the horn 32; the critical destabilization paddle frequency omega is inversely related to the square h2 of the distance h from the paddle plane to the horn torsion axis; the critical destabilizing pitch frequency ω is inversely related to the moment of inertia Mx of the horn assembly 30 about the horn torsion axis.

Therefore, the parameters can be adjusted more accurately and rapidly through the correlation between the critical instability paddle frequency omega and the parameters, and the adjustment time is shortened and the adjustment efficiency is improved. In the present embodiment, the correlation between the critical destabilizing paddle frequency ω and the above parameters can be expressed by the following formula:

where ω is the critical destabilizing paddle frequency, ω x is the torsional frequency of the horn 32, K is the influencing factor, h is the distance from the paddle plane to the horn torsional axis, and Mx is the moment of inertia of the horn assembly 30 about the horn torsional axis.

It will be appreciated that the critical destabilizing pitch frequency ω is inversely related to the impact factor K, which is positively related to the square of the distance h from the blade plane to the horn torsion axis and to the moment of inertia Mx of the horn assembly 30 about the horn torsion axis, so the critical destabilizing pitch frequency ω is inversely related to the square of the distance h of the horn torsion axis and to the moment of inertia Mx of the horn assembly 30 about the horn torsion axis.

Thus, by reducing the distance h from the blade plane to the horn torsion axis, the rotor can be made to rotate

Increasing the value of the frequency to the value of the obtained critical instability paddle frequency omega; can also be realized by reducing the inertia moment Mx of the torsion shaft of the machine arm

Increasing the value of the frequency to the value of the obtained critical instability paddle frequency omega; it is also possible to increase the torsional frequency ω x of the horn 32 so that

The value of (c) is increased to the value of the obtained critical destabilizing paddle frequency omega. Like this, because in the actual operation, in the unmanned aerial vehicle 100 who obtains through this application embodiment, the rotational frequency of the paddle 50 of installation on the horn 32 can not exceed critical unstability paddle frequency omega, consequently, the unmanned aerial vehicle design of this application embodiment can satisfy critical unstability paddle frequency omega's requirement to when the paddle 50 rotates at a high speed, make the vibration minimizing of horn subassembly 30, thereby guarantee unmanned aerial vehicle 100's flight safety and normal work.

Further, a set distance range can be obtained, and the distance h from the blade plane to the horn torsion axis can be adjusted within the distance range. Thus, unstable vibration of the horn 32 caused by the distance h from the blade plane to the horn torsion axis exceeding the set distance range can be avoided. The set distance may be in the range of 1-5 cm. For example, 1cm, 2cm, 2.5cm, 3cm, 4cm, or 5 cm. The specific numerical values of the set distance ranges are not limited herein.

In some embodiments, a method of vibrational mode optimization comprises:

the torsional frequency ω x of the horn 32 is adjusted by adjusting at least one of the radius r of the horn 32, the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the moment of inertia I of torsion of the horn 32.

In some embodiments, the processor 201 is configured to adjust at least one of the radius r of the horn 32, the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the moment of inertia I of the horn 32 to adjust the torsional frequency ω x of the horn 32.

In this manner, in the case where the parameter to be adjusted in step S12 includes the torsional frequency ω x of the horn 32, the adjustment of the torsional frequency ω x of the horn 32 can be achieved by the above-described method.

Specifically, the above parameters may be adjusted to adjust one, two, three, four, or all of the radius r of the horn 32, the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the moment of inertia I of torsion of the horn 32 to adjust the torsion frequency ω x of the horn 32. The number of parameters to be set is not limited here.

Further, in the case of adjusting a plurality of parameters, the radius r of the horn 32 may be preferentially adjusted. It can be understood that, among the above parameters, the radius r of the horn 32 has a large influence on the torsional frequency ω x, in other words, adjusting the radius r of the horn 32 is effective for adjusting the torsional frequency ω x. Therefore, the radius r of the horn 32 can be preferentially adjusted, thereby improving the adjustment efficiency. It is understood that in other embodiments, the plurality of parameters may be adjusted in different sequences according to specific practical situations, and is not limited to adjusting the radius of the horn 32 first.

Further, a set radius range may be obtained and the radius r of the horn 32 may be adjusted within the set radius range. So, can avoid the radius r of horn 32 to hang down or too high, and lead to horn 32 to interfere with unmanned aerial vehicle 100's other structures, or broken through the restraint of unmanned aerial vehicle 100 appearance molding.

Further, a set wall thickness range may be obtained and the wall thickness t of the horn 32 may be adjusted within the set wall thickness range. So, can avoid the wall thickness t of horn 32 to hang down excessively, and lead to the reliability of horn 32 to hang down excessively, and can avoid the wall thickness t of horn 32 to hang down excessively, and lead to unmanned aerial vehicle 100's too big, the resistance is too high.

Further, a set length range may be obtained and the length L of the horn 32 may be adjusted within the set length range. As such, the length L of the horn 32 can be avoided from being too low or too high, and causing the horn 32 to interfere with other structures of the drone 100, or causing the performance of the drone 100 to be poor.

Further, the shear modulus G of the horn 32 is related to the material of the horn 32. In this manner, the shear modulus G of the horn 32 can be adjusted by selecting different materials.

Further, the material of the horn 32 may include Polyamide (PA), or a mixture of PA and glass fiber. In this manner, the shear modulus G of the horn 32 can be made high. Moreover, the performance of such a material is less likely to change with temperature and less likely to change with humidity, and the weight of the horn 32 can be reduced.

In one example of the present embodiment, PA612 and glass fiber 55 may be used as the material of the horn 32. Thus, the moisture absorption performance of the arm 32 can be improved, and the performance degradation due to excessive moisture absorption can be avoided. In addition, the PA612 and the glass fiber 55 are plastic materials, and the material performance can be changed by changing the fiber content.

In addition, the density of the material of the horn 32 increases, and the moment of inertia I of the horn 32 increases in equal proportion. Therefore, the torsional moment of inertia I of the horn 32 can be adjusted by adjusting the density of the material of the horn 32.

In some embodiments, the torsional frequency ω x of the horn 32 is positively correlated with the radius r of the horn 32; the torsional frequency ω x of the horn 32 is positively correlated with the wall thickness t of the horn 32; the torsional frequency ω x of the horn 32 is inversely related to the length L of the horn 32; the torsional frequency ω x of the horn 32 is positively correlated with the shear modulus G of the horn 32; the torsional frequency ω x of the horn 32 is inversely related to the torsional moment of inertia I of the horn 32.

Thus, the parameters can be adjusted more quickly and accurately through the correlation between the torsional frequency ω x of the horn 32 and the parameters, which is beneficial to shortening the adjustment time and improving the adjustment efficiency. In the present embodiment, the correlation between the torsional frequency ω x of the horn 32 and the above-described parameter can be expressed by the following equation:

where ω x is the torsional frequency of the horn 32, G is the shear modulus of the horn 32, J is the horn factor, L is the length of the horn 32, and I is the torsional moment of inertia of the horn 32. The horn factor J is proportional to r3 t. r is the radius of the horn 32 and t is the wall thickness of the horn 32.

It can be understood that the torsional frequency ω x is positively correlated with the horn factor J, the horn factor J is positively correlated with the radius r of the horn 32, and is positively correlated with the wall thickness t of the horn 32, so the torsional frequency ω x is positively correlated with the radius r of the horn 32, and is positively correlated with the wall thickness t of the horn 32.

Therefore, the torsional frequency ω x can be increased by increasing the radius r of the horn 32, thereby making it possible to increase the torsional frequency ω x

Increasing the value of the frequency to the value of the obtained critical instability paddle frequency omega; the torsional frequency ω x can be increased by increasing the wall thickness t of the horn 32, thereby allowing for an increase in the torsional frequency ω x

The value of (c) is increased to the value of the obtained critical destabilizing paddle frequency omega. Like this, can make the actual oar frequency of paddle 50 be less than the requirement of critical unstability oar frequency omega to when paddle 50 rotates at a high speed, make the vibration minimization of horn subassembly 30, thereby guarantee unmanned aerial vehicle 100's flight safety and normal work.

Referring to fig. 5, in some embodiments, the method for optimizing a vibration mode includes:

step S1311: determining a critical destabilization torsion frequency omega x1 of the horn 32 according to the critical destabilization paddle frequency omega of the paddle 50, the distance h from the paddle plane of the paddle 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis;

step S1312: determining a critical instability radius r1 of the horn 32 according to the critical instability torsional frequency ω x1 of the horn 32, the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32 and the torsional moment inertia I of the horn 32;

step S1313: the range of values of the radius r of the horn 32 corresponding to the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32 is determined based on the critical buckling radius r1 of the horn 32.

In some embodiments, processor 201 is configured to determine a critical destabilizing torsional frequency ω x1 of horn 32 based on the critical destabilizing paddle frequency ω of blade 50, a distance h from a blade plane of blade 50 to the horn torsion axis, and a moment of inertia Mx of horn assembly 30 about the horn torsion axis; and determining a critical buckling radius r1 of the horn 32 according to the critical buckling torsion frequency ω x1 of the horn 32, the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsion moment of inertia I of the horn 32; and a value range for determining the radius r of the horn 32 corresponding to the wall thickness t of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32, based on the critical buckling radius r1 of the horn 32.

Therefore, under the condition that the critical instability torsional frequency ω x1 of the horn 32 is determined, the critical instability radius r1 of the horn 32 is determined, and the value range of the radius r of the horn 32 is further determined, so that the radius r of the horn 32 can be adjusted within the value range of the radius r to adjust the torsional frequency ω x, and the adjustment efficiency is improved.

Specifically, the critical instability torsional frequency ω x1 of the horn 32 can be determined by the formula (1), and the critical instability radius r1 of the horn 32 can be determined by the formula (2), so that the value range of the radius r of the horn 32 can be determined. In one embodiment, the range of values for the radius r may be stored in the memory 202 and used as the radius range set in the above embodiments. In another embodiment, in a case where the source of the radius range set in the above embodiment is independent of the value range of the radius r, for example, the radius range set in the foregoing is preset by a user, and the value range of the radius r and the value range set in the foregoing may intersect to update the value range of the radius r.

Referring to fig. 6, in some embodiments, the method for optimizing a vibration mode includes:

step S1321: determining a critical destabilization torsion frequency omega x1 of the horn 32 according to the critical destabilization paddle frequency omega of the paddle 50, the distance h from the paddle plane of the paddle 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis;

step S1322: determining the critical instability wall thickness t1 of the horn 32 according to the critical instability torsion frequency ω x1 of the horn 32, the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32 and the torsion moment of inertia I of the horn 32;

step S1323: the value ranges of the wall thickness t of the horn 32 corresponding to the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32 are determined according to the critical buckling wall thickness t1 of the horn 32.

In some embodiments, processor 201 is configured to determine a critical destabilizing torsional frequency ω x1 of horn 32 based on the critical destabilizing paddle frequency ω of blade 50, a distance h from a blade plane of blade 50 to the horn torsion axis, and a moment of inertia Mx of horn assembly 30 about the horn torsion axis; and determining the critical buckling wall thickness t1 of the horn 32 according to the critical buckling torsion frequency ω x1 of the horn 32, the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32 and the torsion moment of inertia I of the horn 32; and a value range for determining the wall thickness t of the horn 32 corresponding to the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32, based on the critical buckling wall thickness t1 of the horn 32.

Regarding the explanation and explanation of this part, similar to the explanation and explanation of step S1311, step S1312, and step S1313, the explanation and explanation of step S1311, step S1312, and step S1313 may be referred to, and are not described again here to avoid redundancy.

Referring to fig. 7, in some embodiments, the method for optimizing a vibration mode includes:

step S1331: determining a critical destabilization torsion frequency omega x1 of the horn 32 according to the critical destabilization paddle frequency omega of the paddle 50, the distance h from the paddle plane of the paddle 50 to the horn torsion axis, and the moment of inertia Mx of the horn assembly 30 about the horn torsion axis;

step S1332: determining the critical instability length L1 of the horn 32 according to the critical instability torsion frequency omega x1 of the horn 32, the wall thickness t of the horn 32, the radius r of the horn 32, the shear modulus G of the horn 32 and the torsion moment of inertia I of the horn 32;

step S1333: the range of values of the length L of the horn 32 corresponding to the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32 is determined based on the critical buckling length L1 of the horn 32.

In some embodiments, processor 201 is configured to determine a critical destabilizing torsional frequency ω x1 of horn 32 based on the critical destabilizing paddle frequency ω of blade 50, a distance h from a blade plane of blade 50 to the horn torsion axis, and a moment of inertia Mx of horn assembly 30 about the horn torsion axis; and determining the critical buckling length L1 of the horn 32 according to the critical buckling torsion frequency omega x1 of the horn 32, the wall thickness t of the horn 32, the radius r of the horn 32, the shear modulus G of the horn 32 and the torsion moment of inertia I of the horn 32; and a value range for determining the length L of the horn 32 corresponding to the radius r of the horn 32, the length L of the horn 32, the shear modulus G of the horn 32, and the torsional moment of inertia I of the horn 32, based on the critical buckling length L1 of the horn 32.

Referring to fig. 8 and 9, in some embodiments, the method for optimizing the vibration mode includes:

step S151: dividing the horn 32 into a plurality of horn portions along the length direction of the horn 32;

step S152: sensitivity analysis is carried out on the plurality of horn parts respectively to obtain the influence strength of each horn part on the torsional frequency omega x of the horn 32;

step S153: and carrying out structural optimization on a plurality of machine arm parts according to the influence intensity from large to small.

In some embodiments, the processor 201 is configured to divide the horn 32 into a plurality of horn sections along a length of the horn 32; and is used for carrying on the sensitivity analysis to the multiple horn positions separately in order to obtain each horn position to the influence intensity of the torsional frequency ω x of the horn 32; and the device is used for carrying out structural optimization on a plurality of machine arm parts according to the influence strength from large to small.

In this way, the horn 32 can be made uniform and smooth in the length direction of the horn 32, so that the outer diameter of the horn 32 is prevented from being changed locally and drastically, for example, the opening and the drastic contraction, and particularly, the outer diameters at the two ends of the horn 32 can be prevented from being changed drastically, thereby ensuring the smooth transition of the line of the horn 32 and adjusting the torsional frequency ω x. Specifically, the horn 32 is curved, and the sharp contraction means that the curved surface is bent sharply, or the curvature is large and the curvature radius is small. The uniformity of the horn 32 is poor at the points of severe constriction.

In step S151, in one example, the boom 32 may be divided into 7 boom portions along the longitudinal direction of the boom 32, and as shown in fig. 2 and 9, the 7 boom portions are, in the direction from the body 20 to the motor 34, a boom portion P1, a boom portion P2, a boom portion P3, a boom portion P4, a boom portion P5, a boom portion P6, and a boom portion P7, respectively. Wherein, the robot arm position P6 is severely contracted from the robot arm position P5 to the robot arm position P7 according to the structure and parameter threshold.

In other examples, the number of arm positions divided may also be 2, 3, 4, 5, 6, 8, or other numbers. And are not limited herein.

Sensitivity analysis is a method of studying and analyzing the sensitivity of a system (or model) to changes in the state or output of the system to changes in system parameters or ambient conditions. Specifically, in step S152, the influence strength of each horn portion on the torsional frequency ω x of the horn 32 is determined by sensitivity analysis. Specifically, the stiffness, material parameters, dimensional parameters, and other parameters of each horn section can be adjusted respectively, and the degree of change in the torsional frequency ω x is measured, thereby determining the strength of the influence of each horn section on the torsional frequency ω x of the horn 32.

In step S153, the plurality of horn portions are structurally optimized from the large to the small in the influence strength, that is, the horn portion having the large influence strength is optimized first, and then the horn portion having the small influence strength is optimized. Therefore, the optimization efficiency can be improved, and the optimization time can be shortened. In addition, when the optimized part of the horn positions already meets the requirement of the torsional frequency ω x, namely the requirement of the critical instability paddle frequency ω, the rest of the horn positions may not be optimized.

With respect to the horn 32 in fig. 9, it is determined through sensitivity analysis that the horn portion having the highest influence strength on the torsional frequency ω x of the horn 32 is the horn portion P6, the horn portion P7 times, the horn portion P3 times, the horn portion P5 times, the horn portion P4 times, the horn portion P2 times, and the horn portion P1 is the lowest. Based on this, the arm part P6, the arm part P7, the arm part P3, the arm part P5, the arm part P4, the arm part P2, and the arm part P1 can be adjusted.

In certain embodiments, step S153 includes:

increasing the radius of the arm part, and/or increasing the rib position at the arm part.

In some embodiments, the processor 201 is configured to increase the radius of the horn region; and/or processor 201 may be configured to add rib positions at the arm positions.

Therefore, structural optimization of the plurality of machine arm parts from large to small according to the influence strength is realized. In one example, the radius is enlarged for a sharply contracted curved surface of the horn portion; in another example, the lower portion of the horn section is curved with an opening, and the opening is moved downward so that the lower surface is substantially flush with the lowermost lower surface of the horn. In another example, a rib position is added to the horn position to reinforce the horn position and prevent the horn position from deforming. In yet another example, the radius of the horn section is increased, and the rib section is added to the horn section. And are not limited herein.

In some embodiments, the vibrational mode optimization method comprises at least one of:

adjusting the rigidity of the structure at the joint of the foot rest 40 and the horn 32 to adjust the torsional frequency ω x of the horn 32;

adjusting the length of the foot 40 to adjust the torsional frequency ω x of the horn 32;

the mass of the lower end of the foot stand 40 is adjusted to adjust the torsional frequency ω x of the horn 32.

In certain embodiments, the processor 201 is configured to perform at least one of the following methods: adjusting the rigidity of the structure at the joint of the foot rest 40 and the horn 32 to adjust the torsional frequency ω x of the horn 32; adjusting the length of the foot 40 to adjust the torsional frequency ω x of the horn 32; the mass of the lower end of the foot stand 40 is adjusted to adjust the torsional frequency ω x of the horn 32.

In this way, the torsional frequency ω x of the horn 32 is adjusted by adjusting the foot 40 to meet the requirement of the critical destabilizing blade frequency ω of the blade 50.

Specifically, the torsional frequency ω x of the horn 32 is positively correlated with the rigidity of the structure at the junction of the foot rest 40 and the horn 32; the torsional frequency ω x of the horn 32 is inversely related to the length of the foot rest 40; the torsional frequency ω x of the horn 32 is inversely related to the mass of the lower end of the foot rest 40. Thus, the parameters can be adjusted more accurately and rapidly through the correlation between the torsional frequency ω x of the horn 32 and the parameters, which is beneficial to shortening the adjustment time and improving the adjustment efficiency.

The rigidity of the structure at the joint of the foot rest 40 and the horn 32 can be adjusted by reinforcing the foot rest 40, thickening the foot rest 40 and increasing the connecting piece of the foot rest 40 and the horn 32, so that the foot rest 40 and the horn 32 do not shake or the shaking range is in a desired range.

Referring to fig. 10 and 11, in one example, the stand 40 includes a connection portion 401 and a support portion 402, and the connection portion 401 connects the support portion 402 and the arm 32. The connection portion 401 is formed with a connection hole 4011, and the leg frame 40 and the horn 32 can be connected by three screws inserted into the connection hole 4011. And then the foot rest 40 and the horn 32 are connected by a fourth screw in a direction perpendicular to the fixing plane of the first three screws, i.e., the plane of the connecting portion 401. Thus, no gap is ensured between the foot stand 40 and the arm 32, and no shaking is caused. It can be understood that when the connection between the stand 40 and the horn 32 is weak, the stand 40 is likely to vibrate locally, so that the torsional frequency ω x of the horn 32 is reduced, and the vibration of the horn 32 is more severe. In this way, the region 403 to be reinforced in fig. 11 can be reinforced. Note that in fig. 11, different gray levels of the region 403 to be enhanced represent different degrees of enhancement.

The moment of inertia I of the foot 40 can be reduced by reducing the length of the foot 40, thereby increasing the torsional frequency ω x. Specifically, the length of the foot rest 40 can be adjusted within a preset foot rest length range to avoid that the function of the foot rest 40 is affected by adjusting the length of the foot rest 40. The foot rest length range may be determined based on the performance of the antenna housed within the foot rest 40, or may be determined based on the height requirements of the drone 100 from the ground, or the like, i.e. to ensure that the foot rest 40 meets the additional functionality, the length of the foot rest 40 is adjusted.

The torsional frequency ω x can be increased by reducing the mass of the lower end of the foot 40. For example, a lighter material may be used to reduce the mass of the lower end of the foot 40.

In some embodiments, the material of the foot rest 40 is related to the torsional frequency ω x of the horn 32. In particular, high modulus, low density and low moisture absorption materials may be employed. For example, when Polycarbonate (PC) material is changed into PA material, the PC modulus is low, usually only 2.2, the PA modulus is 4.6, and the moisture absorption is high. In this way, the torsional frequency ω x of the arm 32 can be increased, the risk of arm vibration can be reduced, and the environmental suitability can be improved.

Referring to fig. 12, in some embodiments, the lower end surface of the foot 40 is provided with a gasket 42, and the material and mass of the gasket 42 are related to the torsional frequency ω x of the horn 32.

So, through setting up at the gasket 42 of the lower terminal surface of foot rest 40, can make unmanned aerial vehicle 100 when falling to the ground foot rest 40 more wear-resisting. The shim 42 may be designed to reduce weight, for example, by limiting the thickness of the shim 42 to a predetermined thickness range. Thus, the shim 42 is made thinner and lighter, which is beneficial for increasing the torsional frequency ω x.

In certain embodiments, the material of the gasket 42 comprises a Thermoplastic polyurethane elastomer rubber (TPU) material. The TPU material has light weight and good adhesive property of glue, and the gasket 42 made of the TPU material can reduce the weight of the gasket 42 and ensure that the gasket 42 is more stably connected with the foot rest 40.

Referring to fig. 12, in some embodiments, the arm 32 is rotatably connected to the body 20 through a rotating shaft 3201, and the vibration mode optimization method includes:

the structural rigidity at the rotation shaft 3201 is adjusted to adjust the torsional frequency ω x of the horn 32.

In some embodiments, the horn 32 is rotatably coupled to the body 20 via a rotating shaft 3201, and the processor 201 is configured to adjust the structural stiffness at the rotating shaft 3201 to adjust the torsional frequency ω x of the horn 32.

In this manner, it is possible to adjust the torsional frequency ω x of the horn 32 by adjusting the structure at the rotation shaft 3201. It can be understood that the torsional frequency ω x is severely reduced by the virtual position and the shaking of the structure at the rotating shaft 3201, so that the actual paddle frequency of the paddle blade cannot be lower than the requirement of the critical instability paddle frequency ω, and the vibration is amplified. And the structural rigidity at the rotating shaft 3201 is adjusted, so that the virtual position gap can be eliminated at the rotating shaft 3201, and the shaking in all directions is eliminated.

Specifically, the torsional frequency ω x of the horn 32 is positively correlated with the structural rigidity at the rotation shaft 3201. Therefore, the structural rigidity at the rotating shaft 3201 can be increased to increase the torsional frequency ω x, so that the actual paddle frequency of the paddle blade is lower than the requirement of the critical unstable paddle frequency ω.

For example, an interference may be provided at the rotation shaft 3201 such that the horn 32 is interference-fitted with the body 20 by rotation of the rotation shaft 3201.

For another example, the opening angle at the rotating shaft 3201 can be avoided, so as to ensure no shaking and avoid a virtual position, and the arm 32 rotates through the rotating shaft 3201 to be tightly matched with the body 20.

In the example of fig. 10, the horn torsion axis is shown as dashed line 3202.

In summary, the surface reason for the vibration of the horn 32 is that the rotation speed of the blade 50 is higher than the critical rotation speed, i.e., higher than the critical destabilization frequency ω, so that the blade 50 is destabilized and the horn 32 vibrates. The internal cause of the vibration of the horn 32 is the large length of the horn 32 and the large mass and inertia introduced by the motor 34 and the foot 40, resulting in a low torsional frequency ω x of the horn 32. The critical rotating speed of the blade 50 instability is reduced, and the horn vibration easily occurs when the unmanned aerial vehicle 100 performs the maneuvering action with high rotating speed.

According to the vibration mode optimization method, the vibration mode optimization device 200 and the unmanned aerial vehicle 100, by optimizing the structures of the horn 32, the foot rest 40, the motor 34, the blade 50, the rotating shaft 3201 of the horn 32 and the like, the torsional frequency ω x of the horn 32 can be improved with the least cost, the actual paddle frequency of the blade is lower than the requirement of the critical instability paddle frequency ω of the blade 50, and the risk of horn vibration is eliminated. Like this, can promote unmanned aerial vehicle 100's mobility ability and working range, can promote unmanned aerial vehicle 100's structural reliability, avoid the fried machine that the vibration leads to. Moreover, the reliability of the unmanned aerial vehicle 100 in use in a complex environment is greatly improved.

In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and the scope of the preferred embodiments of the present application includes additional implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

The logic and/or steps represented in the flowcharts or otherwise described herein, such as an ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, various steps or methods may be performed by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for performing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried out in the method of implementing the above embodiments may be implemented by hardware associated with instructions of a program, which may be stored in a computer-readable storage medium, and which, when executed, includes one or a combination of the steps of the method embodiments.

In addition, each functional unit in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be executed in the form of hardware or in the form of a software functional module. The integrated module, if executed in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are exemplary and not to be construed as limiting the present application, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. A vibration mode optimization method is used for an unmanned aerial vehicle and is characterized in that the unmanned aerial vehicle comprises a body and a horn assembly, the horn assembly comprises a horn and a motor, one end of the horn is rotatably connected with the body, the motor is connected to the top of the other end of the horn, a foot rest is connected to the bottom of the other end of the horn, and an output shaft of the motor is connected with a paddle;

the vibration mode optimization method comprises the following steps:

acquiring critical instability paddle frequency of the paddle;

2. A vibrational mode optimization method according to claim 1, characterized in that,

the critical destabilizing paddle frequency is positively correlated with the torsional frequency of the horn;

the critical destabilizing pitch frequency is inversely related to the square of the distance from the blade plane to the horn torsion axis;

the critical destabilizing pitch frequency is inversely related to a moment of inertia of the horn assembly about the horn twist axis.

3. The vibrational mode optimization method according to claim 1, wherein the vibrational mode optimization method comprises:

adjusting at least one of a radius of the horn, a wall thickness of the horn, a length of the horn, a shear modulus of the horn, a moment of inertia of the horn torsion to adjust a torsional frequency of the horn.

4. A vibrational mode optimization method according to claim 3, wherein a shear modulus of said horn is related to a material of said horn.

5. The vibrational mode optimization method of claim 4, wherein the material of said horn comprises polyamide or a mixture of polyamide and glass fiber.

6. A vibrational mode optimization method according to claim 3, characterized in that,

the torsional frequency of the horn is positively correlated with the radius of the horn;

the torsional frequency of the horn is positively correlated with the wall thickness of the horn;

the torsional frequency of the horn is inversely related to the length of the horn;

the torsion frequency of the horn is positively correlated with the shear modulus of the horn;

the torsional frequency of the horn is inversely related to the torsional moment of inertia of the horn.

7. The vibrational mode optimization method according to claim 3, wherein the vibrational mode optimization method comprises:

determining the critical instability torsion frequency of a horn according to the critical instability paddle frequency of the paddle, the distance from a paddle plane of the paddle to a horn torsion shaft and the moment of inertia of the horn assembly about the horn torsion shaft;

determining the critical instability radius of the horn according to the critical instability torsion frequency of the horn, the wall thickness of the horn, the length of the horn, the shear modulus of the horn and the torsional moment inertia of the horn;

and determining the value range of the radius of the horn corresponding to the wall thickness of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn according to the critical instability radius of the horn.

8. The vibrational mode optimization method according to claim 3, wherein the vibrational mode optimization method comprises:

determining the critical instability wall thickness of the horn according to the critical instability torsion frequency of the horn, the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment inertia of the horn;

and determining the value range of the wall thickness of the horn corresponding to the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn according to the critical unstable wall thickness of the horn.

9. The vibrational mode optimization method according to claim 3, wherein the vibrational mode optimization method comprises:

determining the critical instability length of the horn according to the critical instability torsion frequency of the horn, the wall thickness of the horn, the radius of the horn, the shear modulus of the horn and the torsional moment inertia of the horn;

and determining the value range of the length of the horn corresponding to the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn according to the critical instability length of the horn.

10. The vibrational mode optimization method according to claim 1, wherein the vibrational mode optimization method comprises:

dividing the horn into a plurality of horn portions along the length direction of the horn;

carrying out sensitivity analysis on the plurality of horn parts respectively to obtain the influence strength of each horn part on the torsion frequency of the horn;

and carrying out structural optimization on the plurality of horn parts according to the influence intensity from large to small.

11. The vibrational mode optimization method according to claim 10, wherein structurally optimizing the plurality of horn portions from large to small in the influence strength comprises:

increasing the radius of the horn section, and/or increasing a tendon section at the horn section.

12. The vibrational mode optimization method according to claim 1, wherein the vibrational mode optimization method comprises at least one of:

adjusting the rigidity of a structure at the joint of the foot stand and the horn to adjust the torsional frequency of the horn;

adjusting the length of the foot rest to adjust the torsional frequency of the horn;

and adjusting the mass of the lower end part of the foot rest so as to adjust the torsional frequency of the horn.

13. The vibrational mode optimization method according to claim 12, wherein a torsional frequency of said horn is positively correlated with a rigidity of a structure at a junction of said foot stand and said horn;

the torsion frequency of the horn is inversely related to the length of the foot rest;

the torsional frequency of the horn is inversely related to the mass of the lower end of the spider.

14. A method of vibrational mode optimization according to claim 1, characterized in that the material of said foot rest is related to the torsional frequency of said horn.

15. A vibrational mode optimization method according to claim 1, characterized in that the lower end face of said foot rest is provided with a spacer, the material and mass of said spacer being related to the torsional frequency of said horn.

16. A method of vibrational mode optimization according to claim 15, wherein said gasket material comprises thermoplastic polyurethane elastomer rubber.

17. The vibrational mode optimization method of claim 1, wherein the horn is rotatably coupled to the body by a shaft, the vibrational mode optimization method comprising:

and adjusting the structural rigidity of the rotating shaft to adjust the torsional frequency of the horn.

18. The vibrational mode optimization method of claim 17, wherein a torsional frequency of the horn is positively correlated with a structural stiffness at the shaft.

19. A vibration mode optimization device is used for an unmanned aerial vehicle and is characterized in that the unmanned aerial vehicle comprises a machine body and a machine arm assembly, the machine arm assembly comprises a machine arm and a motor, one end of the machine arm is rotatably connected with the machine body, the top of the other end of the machine arm is connected with the motor, the bottom of the other end of the machine arm is connected with a foot rest, an output shaft of the motor is connected with a blade, the vibration mode optimization device comprises a processor, and the processor is used for acquiring critical destabilization blade frequency of the blade; and the controller is used for adjusting at least one of the torsion frequency of the horn, the distance from the blade plane of the blade to the horn torsion shaft and the inertia moment of the horn assembly about the horn torsion shaft according to the critical instability blade frequency of the blade.

20. A vibrational mode optimization device according to claim 19,

21. A vibrational mode optimization device according to claim 19, wherein said processor is configured to adjust at least one of a radius of said horn, a wall thickness of said horn, a length of said horn, a shear modulus of said horn, a moment of inertia of said horn torsion to adjust a torsional frequency of said horn.

22. A vibrational mode optimization device according to claim 21, wherein a shear modulus of said horn is related to a material of said horn.

23. A vibrational mode optimising apparatus according to claim 22 wherein the material of said horn comprises polyamide or a mixture of polyamide and glass fibre.

24. A vibrational mode optimization device according to claim 21,

25. The vibrational mode optimization device of claim 21, wherein the processor is configured to determine a critical destabilizing torsional frequency of the horn based on the critical destabilizing paddle frequency of the blade, a distance from a paddle plane of the blade to a horn torsion axis, and a moment of inertia of the horn assembly about the horn torsion axis; the method comprises the steps of determining the critical instability radius of the horn according to the critical instability torsion frequency of the horn, the wall thickness of the horn, the length of the horn, the shear modulus of the horn and the torsional moment inertia of the horn; and the numerical range of the radius of the horn corresponding to the wall thickness of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn is determined according to the critical instability radius of the horn.

26. The vibrational mode optimization device of claim 21, wherein the processor is configured to determine a critical destabilizing torsional frequency of the horn based on the critical destabilizing paddle frequency of the blade, a distance from a paddle plane of the blade to a horn torsion axis, and a moment of inertia of the horn assembly about the horn torsion axis; the method comprises the steps of determining the critical instability wall thickness of a horn according to the critical instability torsion frequency of the horn, the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment inertia of the horn; and the value range of the wall thickness of the horn corresponding to the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn is determined according to the critical unstable wall thickness of the horn.

27. The vibrational mode optimization device of claim 21, wherein the processor is configured to determine a critical destabilizing torsional frequency of the horn based on the critical destabilizing paddle frequency of the blade, a distance from a paddle plane of the blade to a horn torsion axis, and a moment of inertia of the horn assembly about the horn torsion axis; the method comprises the steps of determining the critical instability length of the horn according to the critical instability torsion frequency of the horn, the wall thickness of the horn, the radius of the horn, the shear modulus of the horn and the torsional moment inertia of the horn; and the numerical range of the length of the horn corresponding to the radius of the horn, the length of the horn, the shear modulus of the horn and the torsional moment of inertia of the horn is determined according to the critical instability length of the horn.

28. A vibrational mode optimization device according to claim 19, wherein said processor is configured to divide said horn into a plurality of horn regions along a length of said horn; the sensitivity analysis is carried out on the plurality of horn parts respectively to obtain the influence strength of each horn part on the torsion frequency of the horn; and the structure optimization is carried out on the plurality of horn parts according to the influence intensity from large to small.

29. A vibrational mode optimization device according to claim 28, wherein said processor is configured to increase a radius of said horn section; and/or the processor is used for adding rib positions at the horn positions.

30. A vibrational mode optimization apparatus according to claim 19, wherein said processor is configured to perform at least one of the following methods:

31. The vibrational mode optimization device of claim 30, wherein a torsional frequency of the horn is positively correlated with a stiffness of a structure at a junction of the foot rest and the horn;

32. A vibrational mode optimization device according to claim 19, wherein said foot rest is made of a material that is related to a torsional frequency of said horn.

33. A vibrational mode optimising apparatus according to claim 19 wherein the lower end face of said foot rest is provided with a spacer, the material and mass of said spacer being related to the torsional frequency of said horn.

34. A vibrational mode optimization device according to claim 30, wherein said material of said spacer comprises thermoplastic polyurethane elastomer rubber.

35. A vibrational mode optimization device according to claim 19, wherein said horn is pivotally connected to said fuselage by a pivot, and said processor is configured to adjust structural stiffness at said pivot to adjust torsional frequency of said horn.

36. A vibrational mode optimization device according to claim 35, wherein the torsional frequency of said horn is positively correlated to the structural stiffness at said shaft.

37. A drone, characterised in that it is optimised by the vibration modality optimisation method of any of claims 1 to 18.

38. An unmanned aerial vehicle as claimed in claim 37, wherein the unmanned aerial vehicle comprises a cradle head, the cradle head is mounted on the fuselage, and a camera device is disposed on the cradle head.