A mobile nest and a flexible reset control method

Abstract

This invention provides a mobile drone housing and a flexible reset control method. The mobile housing includes a landing platform and a flexible reset component located on the landing platform. The flexible reset component is in a tensioned state when pushing the drone's landing gear. The flexible reset control method includes: obtaining the theoretical value of the friction force between the drone's landing gear and the landing platform; comparing the theoretical value of the friction force with the measured value of the friction force to obtain the drone's thrust threshold; when the tension of the flexible reset component is greater than the drone's thrust threshold, it is determined that the drone's reset is obstructed, and the thrust of the flexible reset component is reduced. When the thrust is reduced, the flexible material contracts and deforms. This invention increases the tension of the flexible reset component to give it a certain rigidity, which can effectively protect the drone when the thrust is excessive and avoid damage to the aircraft caused by excessive thrust locking.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to a mobile UAV nest and a flexible reset control method. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Currently, drones have become a reliable means of power line inspection, greatly improving the quality and efficiency of equipment inspection operations. With the rapid development of drones and communication technologies, drones have gradually evolved from independent operations to integrated applications of multiple products, among which the most representative is the drone nest product.

[0004] The inventors discovered that most existing drone nest products use rigid rod-type reset, which uses the rigidity of the reset rod to reset the drone back to center. This requires more precise monitoring and control of the movement of the reset rod to ensure reset accuracy. This not only presents the problem of difficult and costly fine control, but also easily leads to damage to the aircraft due to excessive thrust. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a mobile drone nest and a flexible reset control method. By increasing the tension of the flexible reset component to give it a certain rigidity, it can effectively protect the UAV when the thrust is excessive during reset, avoiding damage to the aircraft caused by excessive thrust locking.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a mobile nest.

[0008] A mobile aircraft nest includes: a landing platform and a flexible reset assembly located on the landing platform;

[0009] The flexible reset component is used to propel the drone's landing gear into a tensioned state.

[0010] As a further limitation of the first aspect of the present invention, the flexible reset assembly includes: a first rod and a second rod arranged parallel to each other along a first direction, and a third rod and a fourth rod arranged parallel to each other along a second direction, wherein the first direction is perpendicular to the second direction.

[0011] As a further limitation of the first aspect of the invention, the flexible reset component is made of rubber or hydrogel.

[0012] A second aspect of the present invention provides a flexible reset control method for a mobile nest.

[0013] A flexible reset control method for a mobile nest, utilizing the mobile nest described in the first aspect of the present invention, includes the following process:

[0014] Obtain the theoretical value of the friction force between the UAV's landing gear and the take-off and landing platform;

[0015] By comparing the theoretical value of friction with the measured value of friction, the thrust threshold of the UAV is obtained;

[0016] When the tension of the flexible reset component exceeds the thrust threshold of the UAV, it is determined that the UAV reset is obstructed. The thrust of the flexible reset component is reduced, and the flexible material contracts and deforms when the thrust is reduced.

[0017] As a further limitation of the second aspect of the present invention, the theoretical value of the friction force of the UAV's carrying legs is obtained based on the friction coefficient between the carrying legs and the take-off and landing platform.

[0018] As a further limitation of the second aspect of the present invention, the theoretical value of friction is compared with the measured value to obtain the thrust threshold of the UAV, including:

[0019] The thrust threshold of the UAV is the sum of the tension threshold and the friction force when the flexible reset component is not pushed.

[0020] When the actual value of friction is greater than the theoretical value of friction, the friction is the actual value of friction; otherwise, the friction is the theoretical value of friction.

[0021] As a further limitation of the second aspect of the present invention, the tension of the flexible reset component is determined by solving the time-domain solution of the flexible multibody dynamics according to the central difference scheme.

[0022] As a further limitation of the second aspect of the present invention, a variable resistance flexible sensor is used to detect the force on the flexible reset component.

[0023] As a further limitation of the second aspect of the invention, in the flexible reset assembly, the variable resistance sensors are distributed in a serpentine mesh pattern.

[0024] As a further limitation of the second aspect of the invention, the flexible reset component is moved by a drive mechanism located on the take-off and landing platform.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention innovatively proposes a mobile flexible reset control method for drone nests. When the flexible reset component is used to push the drone's carrying footrest, it is in a tensioned state, giving it a certain rigidity. This effectively protects the drone when excessive thrust is applied during reset, combining the reset motion provided by existing rigid materials with the drone's safety during the reset process through its material properties. When the tension of the flexible reset component exceeds the drone's thrust threshold, the drone's reset is deemed obstructed, and the thrust of the flexible reset component is reduced. As the thrust decreases, the flexible material contracts and deforms, achieving double-layer protection for the drone and avoiding crush damage caused by excessive thrust, thus improving the drone's safety.

[0027] Advantages of additional aspects of the invention 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 the invention. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0029] Figure 1 This is a simplified schematic diagram of the mobile nest provided in Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the sinusoidal distribution of the variable resistance sensor provided in Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the principle of the mobile nest flexible reset control method provided in Embodiment 2 of the present invention;

[0032] Among them, 1-left and right reset flexible body; 2-front and rear reset flexible body; 3-drive motor. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0037] Example 1:

[0038] like Figure 1 As shown, Embodiment 1 of the present invention provides a mobile aircraft nest, including: a take-off and landing platform and a flexible reset component located on the take-off and landing platform;

[0039] The flexible reset component is used to propel the drone's landing gear into a tensioned state.

[0040] The flexible reset assembly includes left and right reset flexible bodies 1 and front and rear reset flexible bodies 2. The left and right reset flexible bodies 1 include a first rod and a second rod arranged parallel to each other along a first direction. The front and rear reset flexible bodies 2 include a third rod and a fourth rod arranged parallel to each other along a second direction. The first direction is perpendicular to the second direction.

[0041] In this embodiment, the left and right reset flexible bodies 1 and the front and rear reset flexible bodies 2 are driven by a drive mechanism on the lifting platform. Preferably, in this embodiment, a motor drive is used, for example... Figure 1 In the middle, the left and right reset flexible bodies 1 are driven by motor 3, and similarly, the front and rear reset flexible bodies 2 can also be driven by motor.

[0042] In this embodiment, the flexible reset component is made of rubber or hydrogel. It is understood that in other implementations, other flexible materials can also be selected, such as polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), and polyethylene naphthalate (PEN). Those skilled in the art can select according to specific working conditions, which will not be elaborated here.

[0043] In this embodiment, a variable resistance flexible sensor is used for tension detection, such as... Figure 2 As shown, the variable resistance sensor in the flexible body is distributed in a serpentine mesh. From the final result, the present invention has the reset motion provided by existing rigid materials, while ensuring the safety of the UAV during the reset process through its material properties.

[0044] Example 2:

[0045] Embodiment 2 of the present invention provides a mobile pod flexible reset control method, which applies the physical properties of flexible materials (rubber, hydrogel, etc.) to increase the tension of the flexible material during the UAV reset process, so that it has a certain rigidity. At the same time, it can effectively protect the UAV in case of excessive reset and avoid damage to the aircraft caused by excessive thrust.

[0046] In this embodiment, a mechanical hybridization method is used to disperse graphene nanosheets into a flexible material to create a strain and pressure-sensitive flexible piezoresistive sensor. The tensile force calculated by the mechanical hybridization method is then used to set a thrust threshold according to a pre-defined flexible multibody system dynamics algorithm. When the force exceeds the threshold, it is determined that the UAV reset is obstructed, and the thrust of the power system is reduced to avoid crush damage to the aircraft caused by excessive thrust. At the same time, due to the reduction of the thrust of the power system, the flexible material contracts and deforms, further reducing the thrust on the UAV, thus achieving a double layer of protection for the UAV reset.

[0047] Dynamic equations of flexible multibody systems:

[0048]

[0049] Where X, M, D, K, Q, and F are the system variables, mass matrix, stiffness matrix, damping matrix, inertial coupling force term, and external force term, respectively, and they are composed of corresponding terms for each individual component. C, λ represents the end terms of the system constraint equation, the matrix of the constraint equation, and the Laplace multiplier, respectively.

[0050] The system dynamics equations are discretized in the time domain using a central difference scheme to obtain the tension value of the flexible body. Since the effect is to push the UAV back to its original position through the rigidity after the rope is tensioned, the actual measurement process is similar to the calculation of the traction force of a fully constrained rope. The specific solution method for tension T is as follows:

[0051]

[0052] Where M is the mass correlation matrix of the dynamic equations, N is the velocity correlation matrix of the dynamic equations, and W... e End effector external force spinor vector, W g For the generalized gravity vector of the end effector, The velocity vector of the end effector. Let T be the actuator acceleration vector. S The particular solution term of the tension, determined by the Moore-Penrose generalized inverse of the structure matrix, is defined as the external tension. Its solution is unique and can be obtained by combining it with the dynamic equations of the flexible multibody system; T H Let N(J) be the general solution term for tension, which does no work externally but only changes the tension distribution within the system; J is the structure matrix. N(J)∈R m×1Let J be a one-dimensional null basis for the structure matrix J, and let λ be an arbitrary scalar.

[0053] By combining the tension algorithm with the dynamic equations of flexible multibody systems, we can obtain T. S =F (F represents the external force terms in the summary of the dynamic equations of the flexible multibody system), the force after the flexible body is tensioned is set as Fz. The characteristic of the application of the flexible body (rope) is that when Fz is tensioned, its effect is equivalent to the pushing of a rod. The key to protecting UAVs is that the forces they experience in all directions are below the threshold F. max When the system is functioning normally, the drone is in a normal state.

[0054] The calculation of the drone thrust F1 is based on the drone weight M1 (including the landing gear), the landing gear material A1, the platform material A2, and the friction coefficient between the two materials f1. The maximum push-pull force F2 = f1M1G of the system is obtained. Since the theoretical value may have a certain amount of calculation deviation, simply using this number as a threshold may easily cause the system to misjudge. Therefore, it is necessary to conduct experimental measurement of the force F3 for comparison. At the same time, it is considered that when there is a slight drop on the plane, the flexible reset can operate normally.

[0055]

[0056] F max =F1+F z

[0057] The dynamic thrust value of the flexible body is calculated by combining the central difference method, and the thrust threshold F of the UAV is calculated accordingly. max The output force is corrected to achieve closed-loop protection for the drone.

[0058] like Figure 3 As shown, firstly, the time-domain solution of the flexible multibody dynamics is obtained using the central difference scheme to determine the tension of the flexible body (rope). Then, the tension threshold Fz under no-push conditions is determined. Next, the theoretical friction value F2 is obtained using the friction force calculation formula. Finally, the actual resistance threshold F3 on the measured plane is used. By comparing F2 and F3, the final threshold F is confirmed. max， The measured value is compared with a threshold value. When the threshold value is exceeded, the system reduces the power output to avoid mechanical damage.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A flexible repositionable nest, characterized in that, include: The take-off and landing platform and the flexible reset assembly located on the take-off and landing platform; The flexible reset component is used to keep the drone in a tensioned state when pushing the drone's carrying tripod; By using the central difference scheme to obtain the time-domain solution of the flexible multibody dynamics, the tension of the flexible body is determined. Then, the tension threshold Fz under no-push conditions is determined. Next, the theoretical value of friction F2 is obtained through the friction force calculation formula. Finally, F2 and F3 are compared and calculated using the measured actual resistance threshold F3 on the plane to confirm the final threshold F. max The system compares the measured value with a threshold. When the threshold is exceeded, the system reduces the power output to avoid mechanical damage. At the same time, due to the reduction in thrust of the power system, the flexible material shrinks and deforms, reducing the thrust on the drone and achieving dual protection for drone reset. The F1 thrust calculation for drones is based on the weight of the drone. tripod materials Platform material A2. Based on the friction coefficient f1 between the two materials, the maximum push-pull force F2=f1M1G of the system is obtained. The force is tested and measured F3 for comparison. At the same time, considering that there is a slight drop in the plane, the flexible reset can operate normally. 。 2. The flexible repositionable nest as described in claim 1, characterized in that, The flexible reset assembly includes: a first rod and a second rod arranged parallel to each other along a first direction, and a third rod and a fourth rod arranged parallel to each other along a second direction, wherein the first direction is perpendicular to the second direction.

3. The flexible repositioning nest as described in claim 1 or 2, characterized in that, The flexible reset component is made of rubber or hydrogel.

4. A flexible reset method, characterized in that, The flexible repositionable cell according to any one of claims 1-3 includes the following process: Obtain the theoretical value of the friction force between the UAV's landing gear and the take-off and landing platform; By comparing the theoretical value of friction with the measured value of friction, the thrust threshold of the UAV is obtained; When the tension of the flexible reset component exceeds the thrust threshold of the UAV, it is determined that the UAV reset is obstructed. The thrust of the flexible reset component is reduced, and the flexible material contracts and deforms when the thrust is reduced.

5. The flexible reset method as described in claim 4, characterized in that, Based on the friction coefficient between the support landing gear and the take-off and landing platform, the theoretical value of the friction force of the UAV support landing gear is obtained.

6. The flexible reset method as described in claim 4, characterized in that, By comparing the theoretical and measured values ​​of friction, the thrust threshold of the UAV is obtained, including: The thrust threshold of the UAV is the sum of the tension threshold and the friction force when the flexible reset component is not pushed. When the actual value of friction is greater than the theoretical value of friction, the friction is the actual value of friction; otherwise, the friction is the theoretical value of friction.

7. The flexible reset method as described in claim 4, characterized in that, The tension of the flexible reset component is determined by solving the time-domain solution of the flexible multibody dynamics using the central difference scheme.

8. The flexible reset method as described in claim 4, characterized in that, A variable resistance flexible sensor is used to detect the force on the flexible reset component.

9. The flexible reset method as described in claim 8, characterized in that, In the flexible reset assembly, the variable resistance sensors are distributed in a serpentine mesh pattern.

10. The flexible reset method as described in claim 8, characterized in that, The flexible reset assembly is moved by a drive mechanism located on the take-off and landing platform.

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