CN117836735A

CN117836735A - Unmanned aerial vehicle control method and device, unmanned aerial vehicle and storage medium

Info

Publication number: CN117836735A
Application number: CN202180101378.9A
Authority: CN
Inventors: 赵力尧; 吴宇豪
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2024-04-05
Also published as: WO2023044897A1

Abstract

Control method and device of unmanned aerial vehicle, unmanned aerial vehicle and storage medium, the method includes: responding to the return trigger of the unmanned aerial vehicle, and acquiring the current height of the unmanned aerial vehicle and the height of a return point; if the current height of the unmanned aerial vehicle is lower than the height of the return point, determining the return height of the unmanned aerial vehicle according to the height of the return point and a preset safety height difference; and controlling the unmanned aerial vehicle to ascend to the return altitude in the process of returning the unmanned aerial vehicle. The embodiment is favorable for reducing or avoiding the collision of the unmanned aerial vehicle to the obstacle, and improves the safety of the unmanned aerial vehicle returning.

Description

Unmanned aerial vehicle control method and device, unmanned aerial vehicle and storage medium

Technical Field

The application relates to the technical field of unmanned aerial vehicle control, in particular to a control method and device of an unmanned aerial vehicle, the unmanned aerial vehicle and a storage medium.

Background

When receiving a return control signal sent by the remote controller, the unmanned aerial vehicle is in disconnection with the remote controller, and the automatic return is triggered under the condition that the electric quantity is lower than a certain threshold value and the like. However, in the course of unmanned aerial vehicle returning, receive the influence of many factors such as environmental factor, electric quantity factor, still there is the potential safety hazard in some scenes, the problem that user experience is not good.

Disclosure of Invention

In view of the foregoing, it is an object of the present application to provide a control method and apparatus for a unmanned aerial vehicle, and a storage medium.

In the first aspect, in some return scenes, the unmanned aerial vehicle can adopt a strategy of returning at the current height, and the strategy can enable the unmanned aerial vehicle to collide with an obstacle or be blocked by the obstacle to be out of control during the return process, so that return failure is caused.

Therefore, the embodiment of the application provides a control method of an unmanned aerial vehicle, which comprises the following steps:

responding to the return trigger of the unmanned aerial vehicle, and acquiring the current height of the unmanned aerial vehicle and the height of a return point;

if the current height of the unmanned aerial vehicle is lower than the height of the return point, determining the return height of the unmanned aerial vehicle according to the height of the return point and a preset safety height difference;

and controlling the unmanned aerial vehicle to ascend to the return altitude in the process of returning the unmanned aerial vehicle.

In the embodiment of the application, the difference between the current height of the unmanned aerial vehicle and the height of the return point is considered, and in the case that the current height of the unmanned aerial vehicle is lower than the height of the return point, in order to avoid the unmanned aerial vehicle from bumping into an obstacle in the return process, a strategy of lifting the unmanned aerial vehicle can be adopted, so that the unmanned aerial vehicle is reduced or prevented from bumping into the obstacle; and can be according to the height of returning to the point and the safe altitude difference of predetermineeing decides unmanned aerial vehicle's returning to the altitude, the safe altitude difference of predetermineeing can provide error compensation, further reduces unmanned aerial vehicle and meets the probability of barrier, guarantees unmanned aerial vehicle and returns to the journey smoothly.

In a second aspect, in the related art, if the remaining power of the unmanned aerial vehicle is less than or equal to the safe power of the return journey, the return journey of the user is indicated, if the return journey is confirmed by the user, the unmanned aerial vehicle returns journey in response to the return journey instruction of the user, and in the return journey process, if the power of the unmanned aerial vehicle is less than or equal to the power threshold value of the low power landing, the unmanned aerial vehicle can be triggered to land. That is, a problem may occur in that the user is prompted to return to the journey but the drone falls during the return journey.

Therefore, the embodiment of the application provides a control method of a unmanned aerial vehicle, which comprises the following steps:

acquiring a first return electric quantity threshold value and a second return electric quantity threshold value, wherein the first return electric quantity threshold value represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold value represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold value is larger than the first return electric quantity threshold value;

and if the residual electric quantity of the unmanned aerial vehicle is larger than or equal to the first return electric quantity threshold value and smaller than the second return electric quantity threshold value, outputting low-electric quantity return prompt information to prompt a user to execute the return of the unmanned aerial vehicle.

In this embodiment of the application, set up first return electric quantity threshold value, this first return electric quantity threshold value characterization unmanned aerial vehicle is from the required minimum electric quantity of current position return journey unmanned aerial vehicle's residual electric quantity is less than under the circumstances of second return journey electric quantity threshold value, still need further satisfy unmanned aerial vehicle's residual electric quantity is greater than or equal first return journey electric quantity threshold value to be favorable to guaranteeing unmanned aerial vehicle's smooth return journey.

In a third aspect, an embodiment of the present application provides a control device of an unmanned aerial vehicle, including:

a memory for storing executable instructions;

one or more processors;

wherein the one or more processors, when executing the executable instructions, are individually or collectively configured to perform the method of the first aspect or the second aspect.

In a fourth aspect, embodiments of the present application provide a unmanned aerial vehicle, including:

a body;

the power system is arranged in the machine body and is used for providing power for the unmanned aerial vehicle;

and a control device according to the third aspect provided in the main body.

In a fifth aspect, embodiments of the present application provide a computer-readable storage medium storing executable instructions that when executed by a processor implement a method according to the first or second aspect.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.

Fig. 1 is a schematic structural diagram of an unmanned flying system according to an embodiment of the present application;

fig. 2 is a schematic flow chart of a control method of the unmanned aerial vehicle according to an embodiment of the present application;

fig. 3 is a schematic diagram of an application scenario provided in an embodiment of the present application;

fig. 4 is a schematic flow chart of a second control method of the unmanned aerial vehicle according to the embodiment of the present application;

fig. 5 is a schematic flow chart of a third control method of the unmanned aerial vehicle according to the embodiment of the present application;

FIGS. 6A and 6B are schematic illustrations of different return paths provided by embodiments of the present application;

fig. 7 is a schematic flow chart of a fourth method for controlling a unmanned aerial vehicle according to an embodiment of the present application;

fig. 8 is a schematic diagram of return prompt information provided in an embodiment of the present application;

fig. 9 is a schematic flow chart of a fifth method for controlling a unmanned aerial vehicle according to an embodiment of the present application;

Fig. 10 is a schematic structural diagram of a control device of an unmanned aerial vehicle according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The embodiment of the application provides a solution to the problem of potential safety hazards encountered by an Unmanned Aerial Vehicle (UAV) in the course of return voyage.

Among them, it will be apparent to those skilled in the art that any type of unmanned aerial vehicle may be used without limitation, and embodiments of the present application may be applied to various types of unmanned aerial vehicles. For example, the drone may be a small or large drone. In some embodiments, the unmanned aerial vehicle may be a rotary-wing unmanned aerial vehicle (rotorcraft), for example, a multi-rotor unmanned aerial vehicle propelled by a plurality of propulsion devices through air, and embodiments of the present application are not limited thereto, as the unmanned aerial vehicle may be other types of unmanned aerial vehicles.

Fig. 1 is a schematic architectural diagram of an unmanned flight system according to an embodiment of the present application. In this embodiment, a rotor unmanned aerial vehicle is taken as an example for explanation.

Unmanned flight system 100 may include an unmanned aerial vehicle 110, a display device 130, and a remote control device 140. The drone 110 may include, among other things, a power system 150, a flight control system 160, a gantry, and a cradle head 120 carried on the gantry. Drone 110 may communicate wirelessly with remote control device 140 and display device 130. Unmanned aerial vehicle 110 may be an agricultural unmanned aerial vehicle or an industrial unmanned aerial vehicle, with the need for cyclic operation.

The frame may include a fuselage and a foot rest (also referred to as landing gear). The fuselage may include a center frame and one or more arms coupled to the center frame, the one or more arms extending radially from the center frame. The foot rest is connected to the fuselage for supporting the unmanned aerial vehicle 110 when landing.

The power system 150 may include one or more electronic speed governors (simply called electric governors) 151, one or more propellers 153, and one or more motors 152 corresponding to the one or more propellers 153, wherein the motors 152 are connected between the electronic speed governors 151 and the propellers 153, and the motors 152 and the propellers 153 are disposed on a horn of the unmanned aerial vehicle 110; the electronic governor 151 is configured to receive a driving signal generated by the flight control system 160 and provide a driving current to the motor 152 according to the driving signal, so as to control the rotation speed of the motor 152. The motor 152 is used to drive the propeller to rotate, thereby powering the flight of the drone 110, which enables one or more degrees of freedom of movement of the drone 110. In some embodiments, the drone 110 may rotate about one or more axes of rotation. For example, the rotation shaft may include a Roll shaft (Roll), a Yaw shaft (Yaw), and a pitch shaft (pitch). It should be appreciated that the motor 152 may be a DC motor or an AC motor. The motor 152 may be a brushless motor or a brushed motor.

Flight control system 160 may include a flight controller 161 and a sensing system 162. The sensing system 162 is used to measure pose information of the unmanned aerial vehicle, that is, position information and state information of the unmanned aerial vehicle 110 in space, for example, three-dimensional position, three-dimensional angle, three-dimensional speed, three-dimensional acceleration, three-dimensional angular speed, and the like. The sensing system 162 may include, for example, at least one of a gyroscope, an ultrasonic sensor, an electronic compass, an inertial measurement unit (Inertial Measurement Unit, IMU), a vision sensor, a global navigation satellite system, and a barometer. For example, the global navigation satellite system may be a global positioning system (Global Positioning System, GPS). The flight controller 161 is configured to control the flight of the unmanned aerial vehicle 110, and may control the flight of the unmanned aerial vehicle 110 based on attitude information measured by the sensing system 162, for example. It should be appreciated that the flight controller 161 may control the drone 110 in accordance with preprogrammed instructions or may control the drone 110 in response to one or more remote control signals from the remote control device 140.

Cradle head 120 may include a motor 122. The cradle head is used for carrying the photographing device 123. Flight controller 161 can control movement of pan-tilt 120 via motor 122. Alternatively, as another embodiment, the pan-tilt head 120 may further include a controller for controlling the movement of the pan-tilt head 120 by controlling the motor 122. It should be appreciated that the pan-tilt 120 may be independent of the drone 110 or may be part of the drone 110. It should be appreciated that the motor 122 may be a DC motor or an AC motor. The motor 122 may be a brushless motor or a brushed motor. It should also be appreciated that the pan-tilt may be located at the top of the drone or at the bottom of the drone.

The photographing device 123 may be, for example, a device for capturing an image, such as a camera or a video camera, and the photographing device 123 may communicate with and photograph under the control of the flight controller. The photographing Device 123 of the present embodiment at least includes a photosensitive element, which is, for example, a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) sensor or a Charge-coupled Device (CCD) sensor. It is understood that the camera 123 may be directly fixed to the unmanned aerial vehicle 110, so that the pan-tilt 120 may be omitted.

The display device 130 is located at the ground side of the unmanned aerial vehicle 100, can communicate with the unmanned aerial vehicle 110 in a wireless manner, and can be used to display attitude information of the unmanned aerial vehicle 110. In addition, an image captured by the capturing device 123 may also be displayed on the display apparatus 130. It should be appreciated that display device 130 may be a stand-alone device or may be integrated into remote control device 140.

The remote control device 140 is located at the ground side of the unmanned aerial vehicle system 100, and can communicate with the unmanned aerial vehicle 110 in a wireless manner, so as to remotely operate the unmanned aerial vehicle 110.

It should be understood that the above designations for the components of the unmanned air vehicle are for identification purposes only and should not be construed as limiting the embodiments of the present application.

In some return scenes, the unmanned aerial vehicle can adopt a strategy of returning at the current height, and the strategy can enable the unmanned aerial vehicle to collide with an obstacle or be blocked by the obstacle to be out of control in the return process, so that return failure is caused; or, the unmanned plane may use the obstacle avoidance strategy to bypass the obstacle to continue flying, and in the case of more obstacles, more electric quantity is required for executing the obstacle avoidance strategy for multiple times, so that the return flight fails.

In view of the above, the present application provides a control method of an unmanned aerial vehicle, which can be executed by a control device of the unmanned aerial vehicle. The control means may be, for example, a flight controller in the embodiment of fig. 1.

Referring to fig. 2, fig. 2 shows a flow chart of a control method of the unmanned aerial vehicle, where the method includes:

in step S101, in response to the unmanned aerial vehicle return trigger, the current altitude of the unmanned aerial vehicle and the altitude of the return point are obtained.

In step S102, if the current altitude of the unmanned aerial vehicle is lower than the altitude of the return point, determining the return altitude of the unmanned aerial vehicle according to the altitude of the return point and a preset safety altitude difference.

In step S103, during the course of the unmanned aerial vehicle returning, the unmanned aerial vehicle is controlled to rise to the returning altitude.

In this embodiment, considering the difference between the current height of the unmanned aerial vehicle and the height of the return point, in the case that the current height of the unmanned aerial vehicle is lower than the height of the return point, in order to avoid the unmanned aerial vehicle from bumping into an obstacle in the process of returning, a strategy of raising the unmanned aerial vehicle may be adopted, so as to reduce or avoid the unmanned aerial vehicle from bumping into the obstacle; and the return altitude of the unmanned aerial vehicle can be determined according to the altitude of the return point and a preset safety altitude difference, the preset safety altitude difference can provide altitude error compensation, the probability that the unmanned aerial vehicle encounters an obstacle is further reduced, the number of times of executing an obstacle avoidance strategy is reduced, the power consumption of the unmanned aerial vehicle is avoided, and the unmanned aerial vehicle is ensured to have enough electric quantity to return smoothly.

For step S101, if the unmanned aerial vehicle receives a return instruction generated by user operation, triggering a return flow of the unmanned aerial vehicle; or the unmanned aerial vehicle can automatically trigger the unmanned aerial vehicle return journey flow due to a set program or instruction. And responding to the unmanned aerial vehicle return trigger, and acquiring the current height of the unmanned aerial vehicle and the height of a return point by the unmanned aerial vehicle.

Wherein the current altitude of the unmanned aerial vehicle may be measured using an altitude measurement device in the unmanned aerial vehicle; illustratively, the height measuring device includes, but is not limited to, a barometer, a visual sensor, and/or ultrasonic waves, etc., and the present embodiment is not limited in any way to the specific type of height measuring device.

The return points comprise the flying spot of the unmanned aerial vehicle or return points set by a user. In the case where the return point is a flying spot of an unmanned aerial vehicle, the unmanned aerial vehicle may measure the height of the flying spot using the height measuring device at the time of the flying spot and store the height of the flying spot. If the return point is a return point set by a user and different from the departure point, the height of the return point can be input by the user or the unmanned aerial vehicle can be obtained from a server pre-stored with the height information of the return point.

For step S102, the current height of the unmanned aerial vehicle and the height of the return point are obtained, the current height of the unmanned aerial vehicle is compared with the height of the return point, and if the current height of the unmanned aerial vehicle is lower than the height of the return point, the return height of the unmanned aerial vehicle can be determined according to the height of the return point and the preset safety height difference, that is, the return height of the unmanned aerial vehicle has a certain safety height difference relative to the height of the return point. In this embodiment, a preset safety height difference is provided in consideration of possible height errors of the obtained current height of the unmanned aerial vehicle, which can provide height error compensation, further reduce the probability that the unmanned aerial vehicle encounters an obstacle and reduce the number of times of executing the obstacle avoidance strategy, avoid the power consumption of the unmanned aerial vehicle, and ensure that the unmanned aerial vehicle has enough electric quantity to return smoothly.

In some embodiments, the difference between the return altitude and the current altitude is greater than or equal to the sum of the difference between the altitude of the return point and the current altitude and the preset safety altitude difference, thereby enabling the unmanned aerial vehicle to return safely.

In some embodiments, the preset safety height difference is determined according to the size of the unmanned aerial vehicle and/or the measurement accuracy of a height measurement device in the unmanned aerial vehicle. The larger the size of the unmanned aerial vehicle is, the higher the risk of collision of the unmanned aerial vehicle is, the larger the preset safety height difference can be set to reduce the risk of collision of the unmanned aerial vehicle, otherwise, the smaller the size of the unmanned aerial vehicle is, the smaller the risk of collision of the unmanned aerial vehicle is, the smaller the preset safety height difference can be set to save electric quantity loss caused by the rising of the unmanned aerial vehicle, namely, the preset safety height and the size of the unmanned aerial vehicle form a positive correlation. The higher the measurement accuracy of the height measurement device is, the higher the current height accuracy of the unmanned aerial vehicle is, the smaller the preset safety height difference can be set, otherwise, the lower the measurement accuracy of the height measurement device is, the lower the current height accuracy of the unmanned aerial vehicle is, and in order to ensure safety, the larger the preset safety height difference can be set, namely, the preset safety height difference and the measurement accuracy of the height measurement device form a negative correlation.

For step S103, after determining the return altitude of the unmanned aerial vehicle, in the course of returning the unmanned aerial vehicle, controlling the unmanned aerial vehicle to rise to the return altitude, thereby improving the security of returning the unmanned aerial vehicle.

The number of the return paths of the unmanned aerial vehicle based on the return altitude can be multiple, the unmanned aerial vehicle can be specifically set according to actual application scenes, and the embodiment does not limit the return paths. For example, the unmanned aerial vehicle may first ascend to the return altitude, then fly straight above the return point according to the return altitude, and finally descend to the return point. For example, the unmanned aerial vehicle may first ascend to the return altitude and then fly a certain distance according to the return altitude, and then may fly obliquely to the return point or obliquely above the return point and land again in order to save power consumption. For example, the unmanned aerial vehicle may fly at the current altitude for a distance, and then ascend to the return altitude for return in case of encountering an obstacle.

In an exemplary application scenario, taking the return point as the take-off point of the unmanned aerial vehicle as an example, if the take-off point of the unmanned aerial vehicle is a mountain top, a user controls the unmanned aerial vehicle to fly downwards from the mountain top to shoot a landscape under the mountain, when the unmanned aerial vehicle finishes taking a return journey, please refer to fig. 3, the situation that the current height of the unmanned aerial vehicle is lower than the height of the return point can occur, and at this moment, if the return journey still occurs according to the current height, the risk of collision of the unmanned aerial vehicle can occur, so the control method provided by the embodiment of the application can be used, under the condition that the current height of the unmanned aerial vehicle is lower than the height of the return point, the return journey height of the unmanned aerial vehicle is determined according to the height of the return point and a preset safety height difference, the return journey height of the unmanned aerial vehicle has a certain safety height difference relative to the height of the return point, in the process of the unmanned aerial vehicle, the unmanned aerial vehicle is controlled to rise to the height according to the strategy of the return journey, and the return journey of the unmanned aerial vehicle can be further reduced according to the dashed line, for example, the probability of the return journey can be reduced, and the return journey of the unmanned aerial vehicle can be further carried out according to the dashed line.

It is contemplated that in some return scenarios, a return distance is typically preset, such as determined based on the visual distance of the human eye; when the distance between the current position of the unmanned aerial vehicle and the return point is larger than the preset return distance, controlling the unmanned aerial vehicle to ascend in the return process in order to avoid the risk of collision; in the case that the distance between the current position of the unmanned aerial vehicle and the return point is less than or equal to the preset return distance, the unmanned aerial vehicle returns at the current altitude, so that the problem occurs (i.e. the current altitude of the unmanned aerial vehicle is lower than the altitude of the return point, which causes the risk of collision).

Therefore, referring to fig. 4, fig. 4 is a flow chart of a control method of the unmanned aerial vehicle according to an embodiment of the present application, where the method includes:

in step S201, in response to the unmanned aerial vehicle return trigger, detecting whether the distance between the current position of the unmanned aerial vehicle and the return point is less than or equal to a preset return distance; if not, step S202 is executed, and if yes, step S203 is executed.

In step S202, during the course of the unmanned aerial vehicle returning, the unmanned aerial vehicle is controlled to rise to the second returning altitude.

In step S203, the current altitude of the unmanned aerial vehicle and the altitude of the return point are acquired.

In step S204, detecting whether the current altitude of the unmanned aerial vehicle is lower than the altitude of the return point; if not, step S205 is executed, and if yes, step S206 is executed.

In step S205, the unmanned aerial vehicle is controlled to return at the current altitude.

In step S206, determining a first return altitude of the unmanned aerial vehicle according to the altitude of the return point and a preset safety altitude difference; in the process of the unmanned aerial vehicle returning, controlling the unmanned aerial vehicle to ascend to the first returning height; wherein the first return altitude is different from the second return altitude.

And if the distance between the current position of the unmanned aerial vehicle and the return point is greater than the preset return distance, controlling the unmanned aerial vehicle to rise to a second return altitude in the return process of the unmanned aerial vehicle, wherein the second return altitude is usually set in advance by a user based on the judgment of the environment.

When the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance and the current height of the unmanned aerial vehicle is higher than the height of the return point, the probability that the unmanned aerial vehicle encounters an obstacle during return is lower, and the unmanned aerial vehicle can be controlled to return at the current height, so that the length of a return path is reduced as much as possible.

When the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance and the current height of the unmanned aerial vehicle is lower than the height of the return point, the unmanned aerial vehicle is controlled to rise to the first return height in the process of returning the unmanned aerial vehicle, so that the unmanned aerial vehicle is ensured to return safely.

In some embodiments, consider the return policy in the related art as: if the residual electric quantity of the unmanned aerial vehicle is smaller than or equal to the return safe electric quantity, prompting the user to return, if the user confirms the return, responding to the return instruction of the user to return, and in the return process, triggering the unmanned aerial vehicle to drop if the electric quantity of the unmanned aerial vehicle is smaller than or equal to the electric quantity threshold value of low electric quantity drop. That is, a problem may occur in that the user is prompted to return to the journey but the drone falls during the return journey. The inventor researches have found that this is because the return strategy in the related art only considers the return safe electric quantity with a certain margin, and does not consider the minimum electric quantity required for actual return. Therefore, when the electric quantity is smaller than the minimum electric quantity required for the return, the condition of prompting the user to execute the return operation still occurs.

Referring to fig. 5, fig. 5 shows a flow chart of a control method of an unmanned aerial vehicle, where the method includes:

in step S301, a first return electric quantity threshold value and a second return electric quantity threshold value are obtained, the first return electric quantity threshold value represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold value represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold value is greater than the first return electric quantity threshold value.

In step S302, if the remaining power of the unmanned aerial vehicle is greater than or equal to the first return power threshold and less than the second return power threshold, a low power return prompt message is output to prompt the user to execute the unmanned aerial vehicle return.

In this embodiment, in addition to setting the second return electric quantity threshold as in the related art, a first return electric quantity threshold is further set, where the first return electric quantity threshold characterizes the minimum electric quantity required for returning the unmanned aerial vehicle from the current position, and under the condition that the remaining electric quantity of the unmanned aerial vehicle is less than the second return electric quantity threshold, it is further required to satisfy that the remaining electric quantity of the unmanned aerial vehicle is greater than or equal to the first return electric quantity threshold, thereby being beneficial to ensuring smooth return of the unmanned aerial vehicle.

In some embodiments, in the flight process of the unmanned aerial vehicle, the first return electric quantity threshold value and the second return electric quantity threshold value corresponding to the current position of the unmanned aerial vehicle may be calculated in real time according to the current position of the unmanned aerial vehicle, or the first return electric quantity threshold value and the second return electric quantity threshold value corresponding to the current position of the unmanned aerial vehicle may also be calculated in response to the return trigger of the unmanned aerial vehicle. The unmanned aerial vehicle is located the different positions and has corresponding first return electric quantity threshold value and second return electric quantity threshold value, and the first return electric quantity threshold value and the second return electric quantity threshold value that different positions correspond are different.

The first return electric quantity threshold represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the first return electric quantity threshold is determined based on a return path of the unmanned aerial vehicle, and the return path of the unmanned aerial vehicle comprises at least one or more of the following: the unmanned aerial vehicle ascends to the route of the return altitude, the unmanned aerial vehicle flies to the position above the return point at the return altitude or the current altitude, the unmanned aerial vehicle descends to the position above the return point from the position above the return point, or the unmanned aerial vehicle flies to the position above the return point from the current altitude or the return altitude obliquely, and the like.

Illustratively, taking the return route as shown in fig. 6A as an example, the unmanned aerial vehicle returns at the current altitude, the first return power threshold may include a sum of a minimum power required for the unmanned aerial vehicle to fly at the current altitude to the route a above the return point and a minimum power required for the unmanned aerial vehicle to land from the above the return point to the route b of the return point.

Illustratively, taking the return path as shown in fig. 6B as an example, the unmanned aerial vehicle needs to ascend to a return altitude for return, and the first return power threshold may include a sum of a minimum power required for the unmanned aerial vehicle to ascend to a path c of the return altitude, a minimum power required for the unmanned aerial vehicle to fly to a path d of a certain distance at the return altitude, a minimum power required for the unmanned aerial vehicle to fly obliquely to a path e above the return point, and a minimum power required for the unmanned aerial vehicle to descend from above the return point to a path f of the return point.

Considering the environmental condition that unmanned aerial vehicle is located also has the influence to the electric quantity loss that unmanned aerial vehicle was returned to the journey, say the wind-force that unmanned aerial vehicle is located the environment is stronger, in order to offset wind-force influence, the electric quantity that unmanned aerial vehicle returned to the journey needs to consume is more, if the wind-force that unmanned aerial vehicle is located the environment is weaker, then need not consume too much electric power in addition and be used for resisting wind-force, the electric quantity that unmanned aerial vehicle returned to the journey needs to consume is less, consequently, in order to improve the accuracy of the first return electric quantity threshold value that determines, first return electric quantity threshold value can be based on unmanned aerial vehicle's return route and environmental wind sensing data are synthesized and are determined, thereby can be based on the return strategy of first return electric quantity threshold value guarantees unmanned aerial vehicle returns smoothly.

The second return electric quantity threshold represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold can be a preset electric quantity difference value superimposed on the basis of the first return electric quantity threshold, namely the difference value between the second return electric quantity threshold and the first return electric quantity is the preset electric quantity difference value. The preset electric quantity difference value is used for providing a space for a user to manually control in the process of returning the unmanned aerial vehicle. The magnitude of the preset electric quantity difference value can be specifically set according to an actual application scene, and the implementation is not limited in any way, for example, the preset electric quantity difference value can be one third of the first return electric quantity threshold value.

In some embodiments, referring to fig. 7, fig. 7 shows a schematic flow chart of another method for controlling a drone, where the method includes:

in step S401, a first return electric quantity threshold and a second return electric quantity threshold are obtained, the first return electric quantity threshold represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold is greater than the first return electric quantity threshold.

In step S402, it is determined whether the remaining power of the unmanned aerial vehicle is less than a second return power threshold; if yes, go to step S403, if no, go to step S401;

in step S403, it is determined whether the remaining power of the unmanned aerial vehicle is greater than or equal to the first return power threshold; if yes, go to step S404, if no, go to step S405;

in step S404, outputting a low-power return prompt message to prompt the user to execute the return of the unmanned aerial vehicle;

in step S405, it is determined whether the remaining power of the unmanned aerial vehicle is greater than or equal to a landing power threshold; if yes, go to step S406, if no, go to step S407;

in step S406, outputting a warning message that the unmanned aerial vehicle cannot return to the navigation system, and prompting the user to operate the unmanned aerial vehicle to land as soon as possible;

in step S407, the unmanned aerial vehicle is controlled to land.

The magnitude relation among the first return electric quantity threshold value, the second return electric quantity threshold value and the landing electric quantity threshold value is as follows: the threshold value of the descending electric quantity is smaller than the threshold value of the first returning electric quantity and smaller than the threshold value of the second returning electric quantity.

In this embodiment, for step S404, if the remaining power of the unmanned aerial vehicle is greater than or equal to the first return power threshold and less than the second return power threshold, a low power return prompt message is output to prompt the user to execute the return of the unmanned aerial vehicle; the user can trigger unmanned aerial vehicle to return to the journey according to low electric quantity warning information that returns to the journey, say that the user clicks the control that returns to the journey that control equipment provided to make control equipment generate and send for unmanned aerial vehicle's command that returns to the journey, unmanned aerial vehicle response return to the command, according to unmanned aerial vehicle's return to the journey route execution returns to the journey and returns to the journey to operate, thereby guarantee unmanned aerial vehicle's smooth return to the journey.

If the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value, the residual electric quantity of the unmanned aerial vehicle is insufficient for returning, and if a return instruction triggered by a user is received at the moment, the unmanned aerial vehicle can not respond to the return instruction, namely the unmanned aerial vehicle does not execute return action.

If the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value and is larger than or equal to the landing electric quantity threshold value, outputting a warning message that the unmanned aerial vehicle cannot return to the air, prompting a user to operate the unmanned aerial vehicle to land as soon as possible, for example, the user can trigger the unmanned aerial vehicle to land according to the warning message, for example, the user clicks a landing control provided by the control device, so that the control device generates a landing instruction sent to the unmanned aerial vehicle, and the unmanned aerial vehicle responds to the landing instruction to land on a landing surface (such as the ground or other planes), thereby ensuring the smooth landing of the unmanned aerial vehicle. And if the residual electric quantity of the unmanned aerial vehicle is smaller than the landing electric quantity threshold value, directly controlling the unmanned aerial vehicle to land.

In some embodiments, in the unmanned aerial vehicle return course, if the manual control instruction sent by the control device is acquired within the preset duration, considering that controlling the unmanned aerial vehicle to fly based on the manual control instruction may cause the path of the unmanned aerial vehicle return to be long, so that the residual electric quantity of the unmanned aerial vehicle is insufficient for return, the unmanned aerial vehicle may output prompt information that may not reach the return point through the control device. It can be appreciated that the preset duration may be specifically set according to an actual application scenario, and in this implementation, for example, the control device is a device with a rocker component, and a user may perform flight control on the unmanned aerial vehicle through the rocker component, for example, the preset duration is 3s, when the user continuously operates the remote control component for 3s, the unmanned aerial vehicle continuously receives a manual control instruction within 3s, and may output prompt information that may not reach a return trip point.

In one example, if the unmanned aerial vehicle is to return when the remaining power is greater than or equal to the first return power threshold and less than the second return power threshold, the remaining power of the unmanned aerial vehicle is relatively low, and insufficient power is available to support the unmanned aerial vehicle to execute other flight tasks, if a manual control instruction sent by the control device is obtained within a preset duration, a prompt message that a return point may not be reached is output, and the manual control instruction may not be responded.

In some embodiments, if a manual control instruction sent by a control device is acquired in the course of the unmanned aerial vehicle returning, in a possible implementation manner, during the period of continuously receiving the manual control instruction, the manual control instruction and an automatic returning control instruction of the unmanned aerial vehicle can be overlapped, and the unmanned aerial vehicle is controlled based on the overlapped control instruction, namely, the unmanned aerial vehicle flies according to the manual control instruction on the premise of not completely deviating from a returning path; in another possible implementation manner, during the period of continuously receiving the manual control instruction, the unmanned aerial vehicle may also be controlled based on the manual control instruction only, and the automatic return control instruction of the unmanned aerial vehicle is not executed. And after the manual control instruction is released, controlling the unmanned aerial vehicle to return to a return route. For example, in order to enable the user to know the current electric quantity condition of the unmanned aerial vehicle, after the manual control instruction is released, the unmanned aerial vehicle may output a return prompt message, where the return prompt message is used to prompt the user that the unmanned aerial vehicle will return automatically, and the user needs to confirm to continue returning, for example, the return prompt message shown in fig. 8 may be displayed on the control device.

In some embodiments, to ensure the safety of the unmanned aerial vehicle during landing, if a sensor in the unmanned aerial vehicle for detecting the safety of a landing surface fails or detects that the landing surface is not suitable for landing during the landing of the unmanned aerial vehicle, the unmanned aerial vehicle is controlled to hover at a specified height, and the specified height is greater than 2 meters. In this embodiment, will unmanned aerial vehicle hovers at the height that is greater than 2 meters, can effectively prevent that the screw from rotating the injury to crowd or other animals, reduced the space and the possibility that go up aircraft and people contact in time, increased people's security.

The sensor for detecting the safety of the landing surface may be one or more sensors installed on the bottom surface of the unmanned aerial vehicle, and the sensors may detect the safety of the landing surface during the landing of the unmanned aerial vehicle, for example, if it is detected that a sharp object exists on the landing surface or the landing surface is a water surface, it is determined that the landing surface is not suitable for landing. The sensor for detecting the safety of the landing surface comprises, but is not limited to, a visual sensor, a thermal infrared imager or a laser radar, and the like, and can be specifically set according to actual application scenes. Such sensor failures for detecting fall safety include, but are not limited to, sensor surface fouling or breakage, damage to sensor internal components, or current ambient light being too dark to be detected by a sensor (e.g., a visual sensor), and the like.

In addition, the function of hovering of unmanned aerial vehicle needs to be in unmanned aerial vehicle's horizontal positioning function can only realize under the available condition, if unmanned aerial vehicle's horizontal positioning function is unavailable, then the direct control unmanned aerial vehicle descends, avoids the crash risk. The horizontal positioning function of the unmanned aerial vehicle can be realized based on a GPS receiver or a visual sensor and the like, and when the position of the unmanned aerial vehicle on the horizontal plane cannot be determined, the horizontal positioning function can be considered to be unavailable.

As shown in fig. 9, the embodiment of the application provides a flow diagram of a control method of a unmanned aerial vehicle, and fig. 9 shows operation logic of the unmanned aerial vehicle in a landing process:

in step S501, the drone is controlled to make a landing in response to a drone landing trigger.

After receiving a landing instruction triggered by a user, triggering a landing flow of the unmanned aerial vehicle; or the unmanned aerial vehicle can automatically trigger the unmanned aerial vehicle landing process due to a set program or instruction, for example, the unmanned aerial vehicle can land in the automatic return course.

In step S502, during the landing of the unmanned aerial vehicle, it is determined whether a sensor for detecting the safety of the landing surface is disabled. If yes, go to step S503, if no, go to step S504.

Wherein, can judge when unmanned aerial vehicle approaches the landing face whether the sensor that is used for detecting landing face security is inefficacy. Illustratively, the drone initiates a sensor failure determination procedure for detecting landing surface safety, such as at 10 meters from the landing surface.

In step S503, it is determined whether the horizontal positioning function of the unmanned aerial vehicle is available; if yes, go to step S505, if no, go to step S506.

In step S504, whether the landing surface is suitable for landing is detected using a sensor for detecting the safety of the landing surface; if yes, go to step S506; if not, step S505 is executed.

In step S505, the drone is controlled to hover at a specified altitude, the specified altitude being greater than 2 meters.

In step S506, the unmanned aerial vehicle is controlled to land directly.

In the embodiment, various possible situations of the unmanned aerial vehicle in the landing process are comprehensively considered, a hovering or landing mode is adopted based on different situations, and safety of people or animals on the unmanned aerial vehicle or a landing surface is guaranteed.

In an exemplary embodiment, the unmanned aerial vehicle determines a return path of the unmanned aerial vehicle to a return point at a current position during flight or in response to a return trigger of the unmanned aerial vehicle, and calculates a first return electric quantity threshold and a second return electric quantity threshold according to the return path.

When determining the return path, if the distance between the current position of the unmanned aerial vehicle and the return point is greater than a preset return distance, the unmanned aerial vehicle needs to ascend to a second return altitude in the return process, for example, the return path may include a path in which the unmanned aerial vehicle ascends to the second return altitude from the current position, a path in which the unmanned aerial vehicle flies above the return point at the second return altitude, and a path in which the unmanned aerial vehicle descends to the return point from above the return point.

And if the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to a preset return distance, acquiring the current height of the unmanned aerial vehicle and the height of the return point, and if the current height of the unmanned aerial vehicle is higher than the height of the return point, returning the unmanned aerial vehicle with the current height in the return process, for example, the return path can comprise a path of the unmanned aerial vehicle flying from the current position to the position above the return point and a path of the unmanned aerial vehicle falling from the position above the return point to the return point.

If the current height of the unmanned aerial vehicle is lower than the height of the return point, determining a first return altitude of the unmanned aerial vehicle according to the height of the return point and a preset safety altitude difference, wherein the unmanned aerial vehicle needs to rise to the first return altitude in the return process to avoid the risk of collision, for example, the return route can comprise a route from the current position to the first return altitude, a route from the first return altitude to the position above the return point and a route from the position above the return point to the return point; wherein the first return altitude is different from the second return altitude.

After determining the return path, the unmanned aerial vehicle may determine a first return electrical quantity threshold and a second return electrical quantity threshold according to the return path and environmental wind sensing data; the first return electric quantity threshold represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold represents the safety electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold is larger than the first return electric quantity threshold.

If the residual electric quantity of the unmanned aerial vehicle is larger than or equal to the first return electric quantity threshold value and smaller than the second return electric quantity threshold value, outputting low-electric quantity return prompt information to prompt a user to execute unmanned aerial vehicle return, or controlling the unmanned aerial vehicle to return in response to unmanned aerial vehicle return triggering.

If the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value and larger than or equal to the landing electric quantity threshold value, outputting a return failure prompting message and prompting a user to operate the unmanned aerial vehicle to land as soon as possible; or under the condition that a return instruction triggered by a user is received, the return instruction is not responded, namely, the return action is not executed.

And if the residual electric quantity of the unmanned aerial vehicle is smaller than the landing electric quantity threshold value, directly controlling the unmanned aerial vehicle to land so as to prevent the risk of falling.

In order to guarantee unmanned aerial vehicle's security in the process of falling the in-process that unmanned aerial vehicle falls unmanned aerial vehicle is when unmanned aerial vehicle is close to the plane of falling, unmanned aerial vehicle can inspect whether the sensor that is used for detecting plane of falling security is inefficacy, if be used for detecting in the unmanned aerial vehicle the sensor that is used for detecting plane of falling security is inefficacy or detect the plane of falling is unsuitable for the descending, control unmanned aerial vehicle hovers at the height of being greater than 2 meters, waits for user's manual control operation. If a sensor for detecting the safety of a landing surface in the unmanned aerial vehicle fails and the horizontal positioning function of the unmanned aerial vehicle is not available, or the landing surface is detected to be suitable for landing, the unmanned aerial vehicle is directly controlled to land, and the risk of falling is avoided.

Accordingly, referring to fig. 10, the embodiment of the present application further provides a control device 60 of an unmanned aerial vehicle, including:

a memory for storing executable instructions;

one or more processors;

wherein the one or more processors, when executing the executable instructions, are individually or collectively configured to perform the method of any one of the preceding claims.

The processor 61 executes executable instructions included in the memory 62. The processor 61 may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 62 stores executable instructions for a control method of the drone, and the memory 62 may include at least one type of storage medium including flash memory, hard disk, multimedia card, card memory (e.g., SD or DX memory, etc.), random Access Memory (RAM), static Random Access Memory (SRAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), programmable Read Only Memory (PROM), magnetic memory, magnetic disk, optical disk, etc. Moreover, the apparatus may cooperate with a network storage device that performs the storage function of the memory via a network connection. The memory 62 may be an internal storage unit of the device 60, such as a hard disk or a memory of the device 60. The memory 62 may also be an external storage device of the apparatus 60, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the apparatus 60. Further, the memory 62 may also include both internal storage units of the apparatus 60 and external storage devices. The memory 62 may also be used to temporarily store data that has been output or is to be output.

In some embodiments, the processor 61, when executing the executable instructions, is configured, individually or collectively, to:

Illustratively, the processor 61 is further configured to: and if the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance, acquiring the current height of the unmanned aerial vehicle and the height of the return point.

Illustratively, the return altitude is a first return altitude, and the processor 61 is further configured to: and if the distance between the current position of the unmanned aerial vehicle and the return point is greater than the preset return distance, controlling the unmanned aerial vehicle to rise to a second return altitude in the return process of the unmanned aerial vehicle, wherein the second return altitude is different from the first return altitude.

Illustratively, the processor 61 is further configured to: and if the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance, and the current height of the unmanned aerial vehicle is higher than the height of the return point, controlling the unmanned aerial vehicle to return at the current height.

Illustratively, the return points include a departure point of the unmanned aerial vehicle or a return point set by a user.

Illustratively, the difference between the return altitude and the current altitude is greater than or equal to the sum of the difference between the altitude of the return point and the current altitude and the preset safety altitude difference.

The predetermined safety height difference is determined, for example, as a function of the dimensions of the unmanned aerial vehicle and/or the measurement accuracy of the height measuring device in the unmanned aerial vehicle.

Illustratively, the preset safety height difference has a negative correlation with the measurement accuracy of the height measurement device, and/or the preset safety height has a positive correlation with the size of the unmanned aerial vehicle.

Illustratively, the processor 61 is further configured to:

if the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value and larger than or equal to the landing electric quantity threshold value, outputting a return failure prompting message and prompting a user to operate the unmanned aerial vehicle to land as soon as possible;

and if the residual electric quantity of the unmanned aerial vehicle is smaller than the landing electric quantity threshold value, controlling the unmanned aerial vehicle to land.

The first return electric quantity threshold value is determined based on a return path of the unmanned aerial vehicle, and a difference value between the second return electric quantity threshold value and the first return electric quantity threshold value is a preset electric quantity difference value.

The first return power threshold is determined based on a return path of the drone and ambient wind sensing data.

Illustratively, the processor 61 is further configured to: in the unmanned aerial vehicle landing process, if a sensor for detecting landing surface safety in the unmanned aerial vehicle fails or detects that a landing surface is unsuitable for landing, the unmanned aerial vehicle is controlled to hover at a specified height, and the specified height is greater than 2 meters.

Illustratively, the processor 61 is further configured to: in the unmanned aerial vehicle landing process, if the unmanned aerial vehicle is out of control and the horizontal positioning function of the unmanned aerial vehicle is not available, the unmanned aerial vehicle is controlled to directly land.

Illustratively, the processor 61 is further configured to: in the course of the unmanned aerial vehicle returning, if the manual control instruction sent by the control equipment is obtained within the preset duration, the prompt information that the returning point can not be reached is output.

Illustratively, the processor 61 is further configured to: in the course of the unmanned aerial vehicle returning, if a manual control instruction sent by a control device is obtained, superposing the manual control instruction and an automatic returning control instruction of the unmanned aerial vehicle in the period of continuously receiving the manual control instruction, and controlling the unmanned aerial vehicle based on the superposed control instruction; or controlling the unmanned aerial vehicle based on the manual control instruction;

and after the manual control instruction is released, controlling the unmanned aerial vehicle to return to a return route.

The various embodiments described herein may be implemented using a computer readable medium, such as computer software, hardware, or any combination thereof. For hardware implementation, the embodiments described herein may be implemented through the use of at least one of Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic units designed to perform the functions described herein. For a software implementation, an embodiment such as a process or function may be implemented with a separate software module that allows for performing at least one function or operation. The software codes may be implemented by a software application (or program) written in any suitable programming language, which may be stored in memory and executed by a controller.

The implementation process of the functions and roles of each unit in the above-mentioned device is specifically detailed in the implementation process of the corresponding steps in the above-mentioned method, and will not be described herein again.

In an exemplary embodiment, a non-transitory computer readable storage medium is also provided, such as a memory, comprising instructions executable by a processor of an apparatus to perform the above-described method. For example, the non-transitory computer readable storage medium may be ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

A non-transitory computer readable storage medium, which when executed by a processor of a terminal, enables the terminal to perform the above-described method.

In some embodiments, embodiments of the present application further provide a unmanned aerial vehicle, including:

a body;

and the control device is arranged in the machine body.

For example, referring to fig. 1, the control device may be a flight controller in an unmanned aerial vehicle.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing has outlined the detailed description of the method and apparatus provided in the embodiments of the present application, wherein specific examples are provided herein to illustrate the principles and embodiments of the present application, the above examples being provided solely to assist in the understanding of the method and core ideas of the present application; meanwhile, as those skilled in the art will have modifications in the specific embodiments and application scope in accordance with the ideas of the present application, the present description should not be construed as limiting the present application in view of the above.

Claims

A method of controlling an unmanned aerial vehicle, comprising:

responding to the return trigger of the unmanned aerial vehicle, and acquiring the current height of the unmanned aerial vehicle and the height of a return point;

if the current height of the unmanned aerial vehicle is lower than the height of the return point, determining the return height of the unmanned aerial vehicle according to the height of the return point and a preset safety height difference;

and controlling the unmanned aerial vehicle to ascend to the return altitude in the process of returning the unmanned aerial vehicle.
The method of claim 1, wherein the obtaining the current altitude of the drone and the altitude of the return trip point comprises:

and if the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance, acquiring the current height of the unmanned aerial vehicle and the height of the return point.
The method of claim 2, wherein the return altitude is a first return altitude, the method further comprising:

and if the distance between the current position of the unmanned aerial vehicle and the return point is greater than the preset return distance, controlling the unmanned aerial vehicle to rise to a second return altitude in the return process of the unmanned aerial vehicle, wherein the second return altitude is different from the first return altitude.
The method according to claim 2, wherein the method further comprises:

and if the distance between the current position of the unmanned aerial vehicle and the return point is smaller than or equal to the preset return distance, and the current height of the unmanned aerial vehicle is higher than the height of the return point, controlling the unmanned aerial vehicle to return at the current height.
The method of claim 1, wherein the return points comprise departure points of the drone or user-set return points.
The method of claim 1, wherein a difference between the return altitude and the current altitude is greater than or equal to a sum of a difference between the altitude of the return point and the current altitude and the preset safety altitude difference.
Method according to claim 1, characterized in that the preset safety height difference is determined depending on the size of the unmanned aerial vehicle and/or the measurement accuracy of the height measuring device in the unmanned aerial vehicle.
The method according to claim 7, wherein the preset safety height difference is inversely related to the measurement accuracy of the height measurement device and/or the preset safety height is positively related to the size of the unmanned aerial vehicle.
The method according to any one of claims 1-8, further comprising:

acquiring a first return electric quantity threshold value and a second return electric quantity threshold value, wherein the first return electric quantity threshold value represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold value represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold value is larger than the first return electric quantity threshold value;

and if the residual electric quantity of the unmanned aerial vehicle is larger than or equal to the first return electric quantity threshold value and smaller than the second return electric quantity threshold value, outputting low-electric quantity return prompt information to prompt a user to execute the return of the unmanned aerial vehicle.
The method according to claim 9, wherein the method further comprises:

if the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value and larger than or equal to the landing electric quantity threshold value, outputting a return failure prompting message and prompting a user to operate the unmanned aerial vehicle to land as soon as possible;

And if the residual electric quantity of the unmanned aerial vehicle is smaller than the landing electric quantity threshold value, controlling the unmanned aerial vehicle to land.
The method of claim 9, wherein the first return charge threshold is determined based on a return path of the drone, and wherein a difference between the second return charge threshold and the first return charge threshold is a preset charge difference.
The method of claim 11, wherein the first return charge threshold is determined based on a return path of the drone and ambient wind sensing data.
The method according to any one of claims 1-8, further comprising:

in the course of the unmanned aerial vehicle returning, if the manual control instruction sent by the control equipment is obtained within the preset duration, the prompt information that the returning point can not be reached is output.
The method as recited in claim 13, further comprising:

in the course of the unmanned aerial vehicle returning, if a manual control instruction sent by a control device is obtained, superposing the manual control instruction and an automatic returning control instruction of the unmanned aerial vehicle in the period of continuously receiving the manual control instruction, and controlling the unmanned aerial vehicle based on the superposed control instruction; or controlling the unmanned aerial vehicle based on the manual control instruction;

And after the manual control instruction is released, controlling the unmanned aerial vehicle to return to a return route.
The method according to any one of claims 1-8, further comprising:

in the unmanned aerial vehicle landing process, if a sensor for detecting landing surface safety in the unmanned aerial vehicle fails or detects that a landing surface is unsuitable for landing, the unmanned aerial vehicle is controlled to hover at a specified height, and the specified height is greater than 2 meters.
The method of claim 15, wherein the method further comprises:

in the unmanned aerial vehicle landing process, if the unmanned aerial vehicle is out of control and the horizontal positioning function of the unmanned aerial vehicle is not available, the unmanned aerial vehicle is controlled to directly land.
A method of controlling a drone, the method comprising:

acquiring a first return electric quantity threshold value and a second return electric quantity threshold value, wherein the first return electric quantity threshold value represents the minimum electric quantity required by the unmanned aerial vehicle to return from the current position, the second return electric quantity threshold value represents the safe electric quantity required by the unmanned aerial vehicle to return from the current position, and the second return electric quantity threshold value is larger than the first return electric quantity threshold value;

And if the residual electric quantity of the unmanned aerial vehicle is larger than or equal to the first return electric quantity threshold value and smaller than the second return electric quantity threshold value, outputting low-electric quantity return prompt information to prompt a user to execute the return of the unmanned aerial vehicle.
The method as recited in claim 17, further comprising:

if the residual electric quantity of the unmanned aerial vehicle is smaller than the first return electric quantity threshold value and larger than or equal to the landing electric quantity threshold value, outputting a return failure prompting message and prompting a user to operate the unmanned aerial vehicle to land as soon as possible;

and if the residual electric quantity of the unmanned aerial vehicle is smaller than the landing electric quantity threshold value, controlling the unmanned aerial vehicle to land.
The method of claim 17, wherein the first return charge threshold is determined based on a return path of the drone, and wherein a difference between the second return charge threshold and the first return charge threshold is a preset charge difference.
The method of claim 19, wherein the first return charge threshold is determined based on a return path of the drone and ambient wind sensing data.
The method according to any one of claims 17 to 20, further comprising:

In the unmanned aerial vehicle landing process, if a sensor for detecting landing surface safety in the unmanned aerial vehicle fails or detects that a landing surface is unsuitable for landing, the unmanned aerial vehicle is controlled to hover at a specified height, and the specified height is greater than 2 meters.
The method of claim 21, wherein the method further comprises:

in the unmanned aerial vehicle landing process, if the unmanned aerial vehicle is out of control and the horizontal positioning function of the unmanned aerial vehicle is not available, the unmanned aerial vehicle is controlled to directly land.
The method according to any one of claims 17 to 20, further comprising:

in the course of the unmanned aerial vehicle returning, if the manual control instruction sent by the control equipment is obtained within the preset duration, the prompt information that the returning point can not be reached is output.
The method as recited in claim 23, further comprising:

in the course of the unmanned aerial vehicle returning, if a manual control instruction sent by a control device is obtained, superposing the manual control instruction and an automatic returning control instruction of the unmanned aerial vehicle in the period of continuously receiving the manual control instruction, and controlling the unmanned aerial vehicle based on the superposed control instruction; or controlling the unmanned aerial vehicle based on the manual control instruction;

And after the manual control instruction is released, controlling the unmanned aerial vehicle to return to a return route.
A control device for an unmanned aerial vehicle, comprising:

a memory for storing executable instructions;

one or more processors;

wherein the one or more processors, when executing the executable instructions, are individually or collectively configured to perform the method of any one of claims 1 to 24.
An unmanned aerial vehicle, comprising:

a body;

the power system is arranged in the machine body and is used for providing power for the unmanned aerial vehicle;

and the control device according to claim 25 provided in the body.
A computer readable storage medium storing executable instructions which when executed by a processor implement the method of any one of claims 1 to 24.