WO2017185651A1

WO2017185651A1 - Method and device for switching unmanned aerial vehicle image transmission modes, and unmanned aerial vehicle

Info

Publication number: WO2017185651A1
Application number: PCT/CN2016/101242
Authority: WO
Inventors: 杨震; 李大龙
Original assignee: 乐视控股（北京）有限公司; 乐视体育文化产业发展（北京）有限公司
Priority date: 2016-04-29
Filing date: 2016-09-30
Publication date: 2017-11-02
Also published as: CN105898099A

Abstract

The present application relates to a method and a device for switching unmanned aerial vehicle image transmission modes, and to an unmanned aerial vehicle. The method for switching unmanned aerial vehicle image transmission modes comprises: obtaining the distance between an unmanned aerial vehicle and a remote control, the remote control being used for receiving images sent by the unmanned aerial vehicle; determining the current image transmission mode of said unmanned aerial vehicle, the image transmission mode comprising a remote-control image transmission mode and a long-range image transmission mode; and, on the basis of the distance between the unmanned aerial vehicle and the remote control, switching unmanned aerial vehicle image transmission modes. In embodiments of the present application, switching image transmission modes on the basis of the distance between the unmanned aerial vehicle and the remote control allows for more flexible unmanned aerial vehicle image transmission, and improves unmanned aerial vehicle image transmission effectiveness. Moreover, the long-range image transmission mode utilizes a mobile cellular network, allowing for image transmission at distances even greater than, for example, the 10 kilometer-plus image transmission in the prior art.

Description

Method and device for switching image transmission mode of drone and its drone

This application claims the priority of the Chinese patent application filed on April 29, 2016, the Chinese Patent Office, the application number is 201610282362.3, and the application name is "an unmanned aerial vehicle image transmission mode switching method, device and its drone". The entire contents of this application are incorporated herein by reference.

Technical field

The present application relates to the field of flight control, and in particular, to a method and device for switching an image transmission mode of a drone, and a drone thereof.

Background technique

The drone is a non-manned aerial vehicle that is operated by a remote controller. There is no cockpit on the aircraft, but there are equipment such as autopilot and program control device. During the flight of the drone, in order to facilitate the control, the image taken by the drone needs to be transmitted to the remote control or ground control station.

In the process of implementing the present application, the inventors have found that in the prior art, the image transmission modes of the drone cannot be switched according to actual conditions, and thus the image transmission mode is not flexible enough.

Summary of the invention

The embodiment of the present application aims to provide a method and device for switching an image transmission mode of a drone and a drone thereof, and switch image transmission mode according to the distance between the drone and the remote controller, so that the image transmission of the drone is further improved. Flexible, it is beneficial to ensure the effectiveness of image transmission of drones.

In a first aspect, an embodiment of the present application provides a method for switching an image transmission mode of a drone, including:

Obtaining a distance between the drone and a remote controller, and the remote controller is configured to receive an image sent by the drone,

Determining a current image transmission mode of the drone, the image transmission mode including a remote image transmission mode and a remote image transmission mode,

According to the distance between the drone and the remote controller, the image transmission mode of the drone is switched.

Optionally, the obtaining the distance between the UAV and the remote controller includes:

Obtain the current position of the drone by satellite positioning or radar,

Calculate the distance between the drone and the remote control based on the current position of the drone.

Optionally, the determining the current image transmission mode of the drone includes:

Receiving an image transmission signal, the image transmission mode signal comprising a remote image transmission signal or a remote image transmission signal,

Determining a current image transmission mode of the drone based on the received image transmission signal.

Optionally, the switching the image transmission mode of the drone according to the distance between the drone and the remote controller comprises:

When the current image transmission mode of the drone is a remote image transmission mode, and the distance between the drone and the remote controller exceeds the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode, or

When the current control mode of the drone is remote image transmission mode, and the distance between the drone and the remote controller is less than the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode.

Optionally, the switching distance is less than a remote transmission distance of the remote controller.

Optionally, the remote control mode is a cellular mobile communication transmission mode.

Optionally, the method further includes:

When the current image transmission mode of the drone is a remote image transmission mode, and the actual transmission image size is larger than the preset transmission image size, the image transmission mode of the drone is switched to the remote image transmission mode.

In a second aspect, an embodiment of the present application provides a UAV image transmission mode switching apparatus, including:

An acquiring unit, configured to acquire a distance between the drone and a remote controller, where the remote controller is configured to receive an image sent by the drone,

a determining unit, configured to determine a current image transmission mode of the drone, wherein the image transmission mode includes a remote image transmission mode and a remote image transmission mode,

The switching unit is configured to switch the image transmission mode of the drone according to the distance between the drone and the remote controller.

Optionally, the obtaining unit is specifically configured to:

Obtain the current position of the drone by satellite positioning or radar,

Optionally, the determining unit is specifically configured to:

Optionally, the switching unit is specifically configured to:

Optionally, the switching distance is smaller than a remote control distance of the remote controller.

Optionally, the switching unit is further configured to:

In a third aspect, an embodiment of the present application provides a drone, including:

Remote antenna for receiving remote image transmission signals,

RF antenna for receiving remote image transmission signals,

a central processor, configured to acquire a distance between the drone and the remote controller, and determine a current image transmission mode of the drone according to the received remote control image transmission signal or an image transmission control signal, where the image transmission mode includes a remote control The image transmission mode and the remote image transmission mode switch the image transmission mode of the drone according to the distance between the drone and the remote controller.

In a fourth aspect, an embodiment of the present application provides an electronic device, including:

At least one processor; and,

a memory communicatively coupled to the at least one processor; wherein

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method as described above.

In a fifth aspect, embodiments of the present application provide a non-transitory computer readable storage medium storing computer executable instructions for causing a computer to execute as described above Methods.

In a sixth aspect, an embodiment of the present application provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions, when the program When the instructions are executed by the computer, the computer is caused to perform the method as described above. In the embodiment of the present application, in the embodiment of the present application, by acquiring the distance between the drone and the remote controller, the remote controller is configured to receive an image sent by the drone, and determine a current image transmission mode of the drone. The image transmission mode includes a remote image transmission mode and a remote image transmission mode, and according to the distance between the drone and the remote controller, the image transmission mode of the drone is switched, and the flexible transmission mode of the image transmission mode of the drone is realized. It is beneficial to ensure the effectiveness of image transmission of drones.

DRAWINGS

The one or more embodiments are exemplified by the accompanying drawings in the accompanying drawings, and FIG. The figures in the drawings do not constitute a scale limitation unless otherwise stated.

1 is a schematic flowchart of a method for switching an image transmission mode of a drone according to an embodiment of the present application;

2 is a schematic structural diagram of an apparatus for switching an image transmission mode of a drone according to an embodiment of the present application;

3 is a schematic structural diagram of a drone provided by an embodiment of the present application;

FIG. 4 is a structural block diagram of an electronic device according to an embodiment of the present application.

detailed description

In order to make the objects, technical solutions, and advantages of the present application more comprehensible, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the application and are not intended to be limiting.

Further, the technical features involved in the various embodiments of the present application described below may be combined with each other as long as they do not constitute a conflict with each other.

In the embodiment of the present application, the drone transmits an image to the remote controller, and may also send an image to the ground control station, and the image is transmitted to the remote controller in a remote image transmission mode, and the image is transmitted to the ground control station as a remote image transmission mode. In the remote image transmission mode, image transmission can be performed by means of cellular mobile communication, and the cellular mobile communication method includes various wireless communication systems, for example, 2G, 3G or 4G communication methods, and in the remote image transmission mode, a ground control The device can receive images transmitted by multiple drones, and each drone is provided with a cellular mobile communication unit, such as a 2G, 3G or 4G communication unit. In order to realize that the ground controller receives images transmitted by multiple drones, the drone identification can be carried in the image transmitted by the drone.

In the embodiment of the present application, a satellite positioning system can be installed on the drone, for example, a GPS satellite positioning system, and the current position of the drone can be obtained through the satellite positioning system, thereby obtaining the drone and the remote controller and the ground controller. The distance between the remote control image transmission mode and the remote image transmission mode is realized according to the distance between the drone and the remote controller.

In the embodiment of the present application, the unmanned aerial vehicle may include: an unmanned fixed wing aircraft, an unmanned vertical take-off and landing machine, an unmanned airship, an unmanned helicopter, an unmanned multi-rotor aircraft, an unmanned wing aircraft, and the like.

The embodiments of the present application are specifically described below with the unmanned multi-rotor aircraft in conjunction with specific drawings.

FIG. 1 is a schematic flowchart of a method for switching an image transmission mode of a drone according to an embodiment of the present application. As shown in Figure 1, the method includes the following steps:

S11. Obtain a distance between the drone and a remote controller, and the remote controller is configured to receive an image sent by the drone.

In the embodiment of the present application, the image transmitted by the drone is mainly received by the remote controller, and during the flight, the current position of the drone can be obtained by satellite positioning or radar on the drone. Set and calculate the distance between the drone and the remote control based on the current position. When the drone receives image transmission through the remote control, it has a certain remote transmission distance. For example, the remote transmission distance is 10KM. If the distance is exceeded, it needs to be switched to the remote image transmission mode. In the remote image mode, the drone can pass the ground. The satellite positioning or radar system of the control station monitors the current position of the drone and obtains the distance between the drone and the remote control. For example, the ground control station can separately locate the position of the drone and the remote controller through the GPS positioning system, thereby obtaining the distance between the drone and the remote controller, and transmitting the distance to the drone.

S13. Determine a current image transmission mode of the drone, and the image transmission mode includes a remote image transmission mode and a remote image transmission mode.

In the embodiment of the present application, during the image transmission process of the drone, the drone can respectively receive the remote image transmission signal and the remote image transmission signal through the remote control system and the cellular mobile communication unit, and transmit the signal according to the received image. Determine the current image transfer mode of the drone. When the drone receives the remote image transmission signal, the current image transmission mode of the drone is the remote image transmission mode. When the drone receives the remote image transmission signal, the current image transmission mode of the drone is the remote image transmission mode.

S15. Switch the image transmission mode of the drone according to the distance between the drone and the remote controller.

In the embodiment of the present application, in order to realize the switching of the image transmission mode of the drone, especially when the flight distance of the drone is about to exceed the remote control transmission distance of the remote controller, in order to effectively transmit the image, the drone needs to be transmitted by the remote control image. The mode is switched to the remote image transmission mode. Therefore, according to the distance between the drone and the remote controller, in the process of switching the image transmission mode of the drone, the switching distance of the switching image transmission mode needs to be set in advance, and the switching distance should be smaller than the remote control transmission distance of the remote controller, so as to facilitate The image transmission mode is switched before the drone exceeds the remote control transmission range of the remote controller to ensure effective image transmission.

In the embodiment of the present application, the switching the image transmission mode of the drone according to the distance between the drone and the remote controller includes:

When the drone is currently controlled by remote image transmission, and the drone and remote control When the distance between them is less than the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode.

In the embodiment of the present application, after the UAV switches to the remote image transmission mode, the image transmitted by the UAV carries the identity of the UAV, and the identity identifier can be used by the ground control station for its image transmission range. The drone is distributed and sent to the drone, or it can be the device identifier of the drone. By transmitting the identity of the drone carried in the image, the ground control station can distinguish the images transmitted by different drones.

In the embodiment of the present application, in order to realize remote image transmission of the drone, the cellular mobile communication system is used for communication between the drone and the ground control station. Therefore, the cellular mobile communication unit needs to be installed on the drone, for example, 2G, 3G or 4G communication unit.

In the embodiment of the present application, the image size that can be transmitted by the remote image transmission mode and the remote image transmission mode is different, and since the remote image transmission mode adopts the wireless transmission mode, the transmission bandwidth is larger than the remote control transmission bandwidth, and therefore, when the image is transmitted When it is large, the remote image transmission method is preferred. In the embodiment of the present application, when the current image transmission mode of the drone is a remote image transmission mode, and the actual transmission image size is larger than the preset transmission image size, the image transmission mode of the drone can be switched to the remote image transmission mode.

In the embodiment of the present application, the remote controller is configured to receive an image sent by the drone to determine a current image transmission mode of the drone by acquiring a distance between the drone and the remote controller, where the image transmission mode includes The remote control image transmission mode and the remote image transmission mode switch the image transmission mode of the drone according to the distance between the drone and the remote controller, thereby realizing the flexible switching of the image transmission mode of the drone, which is beneficial to guarantee the drone The effectiveness of image transmission, at the same time, the remote image transmission method using mobile cellular networks, can achieve longer distances, for example, beyond the existing distance of more than 10 kilometers of image transmission.

2 is a schematic structural diagram of an apparatus for switching an image transmission mode of a drone according to an embodiment of the present application. As shown in FIG. 2, the apparatus 2 includes:

An acquiring unit 21, configured to acquire a distance between the drone and a remote controller, where the remote controller is configured to receive an image sent by the drone,

The determining unit 22 is configured to determine a current image transmission mode of the drone, and the image transmission mode includes a remote image transmission mode and a remote image transmission mode.

a switching unit 23, configured to switch according to a distance between the drone and the remote controller UAV image transmission method.

In the embodiment of the present application, the obtaining unit 21 is specifically configured to:

Obtain the current position of the drone by satellite positioning or radar,

In the embodiment of the present application, the determining unit 22 is specifically configured to:

In the embodiment of the present application, the switching unit 23 is specifically configured to:

In the embodiment of the present application, the drone obtains the current position of the drone through the satellite positioning or radar through the acquiring unit 21, thereby acquiring the distance between the drone and the remote controller, and the receiving unit 22 according to the received The image transmission signal determines the current image transmission mode of the drone, and then the switching unit 23 switches the image transmission mode of the drone according to the distance between the drone and the remote controller. During the switching process, the switching unit 23 connects the drone with The distance between the remote controller and the switching distance are compared. If the distance between the drone and the remote controller is greater than the switching distance, and the current image transmission of the drone is the remote image transmission mode, the image of the drone is transmitted. The mode is switched to the remote image transmission mode. If the distance between the drone and the remote controller is less than the switching distance, and the current image transmission mode of the drone is the remote image transmission mode, the image transmission mode of the drone is switched to the remote image. The transmission mode, wherein the switching distance is smaller than the remote control transmission distance of the remote controller in order to realize the effectiveness of the image transmission of the drone.

In the embodiment of the present application, the remote image transmission mode is a cellular mobile communication transmission mode. In order to realize remote image transmission to the drone, the mobile communication system is used for communication between the drone and the ground control station. Therefore, cellular movement is required on the drone. A communication unit, such as a 2G, 3G or 4G communication unit.

In the embodiment of the present application, the switching unit 23 is further configured to:

It should be noted that, since the UAV image transmission mode switching method and the UAV image transmission mode switching device are based on the same application concept, the corresponding technical contents in the method embodiment and the device embodiment may be mutually applicable, and the details are not described herein. Said.

FIG. 3 is a schematic structural diagram of a drone provided by an embodiment of the present application. As shown in FIG. 3, the drone 3 includes:

a remote control antenna 31 for receiving a remote image transmission signal,

An RF antenna 32 for receiving a remote image transmission signal,

The central processing unit 33 is configured to acquire a distance between the drone and the remote controller, and determine a current image transmission mode of the drone according to the received remote control image transmission signal or an image transmission control signal, according to the drone The distance between the remote control and the remote control is switched.

In the embodiment of the present application, the unmanned aerial vehicle may be an unmanned fixed wing aircraft, an unmanned vertical take-off and landing machine, an unmanned airship, an unmanned helicopter, an unmanned multi-rotor aircraft, an unmanned wing aircraft, and the like.

In the embodiment of the present application, the central processing unit is a control center of the drone, and connects various parts of the entire electronic device by using various interfaces and lines, by running or executing software programs and/or modules stored in the storage unit. And invoking data stored in the storage unit to perform various functions of the electronic device and/or process data. The processor may be composed of an integrated circuit, or may be composed of a plurality of sealed integrated chips that connect the same function or different functions. That is, the processor can be a combination of a GPU, a digital signal processor, and a control chip in the communication unit.

A person skilled in the art should further appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, in order to clearly illustrate hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application. The computer software can be stored in a computer readable storage medium, which, when executed, can include the flow of an embodiment of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only storage memory, or a random storage memory.

In the embodiment of the present application, the remote controller is configured to receive an image sent by the drone to determine a current image transmission mode of the drone by acquiring a distance between the drone and the remote controller, where the image transmission mode includes The remote control image transmission mode and the remote image transmission mode switch the image transmission mode of the drone according to the distance between the drone and the remote controller, thereby realizing the flexible switching of the image transmission mode of the drone, which is beneficial to guarantee the drone The effectiveness of the image transmission.

4 is a structural block diagram of an electronic device according to an embodiment of the present application. As shown in FIG. 4, the electronic device 4 includes:

One or more processors 41 and a memory 42 are exemplified by a processor 41 in FIG.

The processor 41 and the memory 42 may be connected by a bus or other means, and the connection by a bus is taken as an example in FIG.

The memory 42 is a non-volatile computer readable storage medium, and is applicable to a non-volatile software program, a non-volatile computer-executable program, and a module, such as an image acquisition method of a terminal in the embodiment of the present application. Program instructions/modules (for example, the acquisition unit 21 of the UAV image transmission mode switching device 2 shown in FIG. 2, the determination unit 22, the switching unit 23). The processor 41 executes various functional applications and data processing of the electronic device 4 by executing non-volatile software programs, instructions, and modules stored in the memory 42, that is, the UAV image transmission mode switching of the foregoing method embodiment is implemented. The method and the functions of the respective modules of the above-described UAV image transmission mode switching device embodiment.

Memory 42 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, memory 42 may optionally include memory remotely located relative to processor 41, which may be coupled to processor 41 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The program instructions/modules are stored in the memory 42 and, when executed by the one or more processors 41, the UAV image transmission mode switching method in any of the above method embodiments may be performed, for example, performing the above The method steps S11 to S15 in Fig. 1 are described; the functions of the modules 21-23 in Fig. 2 can also be implemented.

The electronic device 4 of the embodiment of the present application may exist in various forms, including but not limited to:

Unmanned fixed-wing aircraft, unmanned vertical take-off and landing aircraft, unmanned airships, unmanned helicopters, unmanned multi-rotor aircraft, unmanned parachute aircraft.

The embodiment of the present application further provides a non-volatile computer storage medium storing computer-executable instructions executed by one or more processors, such as one of the processes in FIG. The above-mentioned one or more processors may perform the unmanned image transmission mode switching method in any of the above method embodiments, for example, perform the method steps S11 to S15 in FIG. 1 described above; The function of module 21-23 in 2.

The apparatus or device embodiments described above are merely illustrative in which The units described by the separate components may or may not be physically separate, and the components displayed as the units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

Through the description of the above embodiments, those skilled in the art can clearly understand that the various embodiments can be implemented by means of software plus a general hardware platform, and of course, by hardware. Based on such understanding, the above technical solutions may be embodied in the form of software products in essence or in the form of software products, which may be stored in a computer readable storage medium such as a ROM/RAM or a disk. , an optical disk, etc., includes instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments or portions of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; in the idea of the present application, the technical features in the above embodiments or different embodiments may also be combined. The steps may be carried out in any order, and there are many other variations of the various aspects of the present application as described above, which are not provided in the details for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, The skilled person should understand that the technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the embodiments of the present application. The scope of the technical solution.

Claims

A method for switching an image transmission mode of a drone, characterized in that it comprises:

Obtaining a distance between the drone and a remote controller, and the remote controller is configured to receive an image sent by the drone,

Determining a current image transmission mode of the drone, the image transmission mode including a remote image transmission mode and a remote image transmission mode,

According to the distance between the drone and the remote controller, the image transmission mode of the drone is switched.
The method according to claim 1, wherein the obtaining the distance between the drone and the remote controller comprises:

Obtain the current position of the drone by satellite positioning or radar,

Calculate the distance between the drone and the remote control based on the current position of the drone.
The method according to claim 1, wherein the determining the current image transmission mode of the drone comprises:

Receiving an image transmission signal, the image transmission mode signal comprising a remote image transmission signal or a remote image transmission signal,

Determining a current image transmission mode of the drone based on the received image transmission signal.
The method according to any one of claims 1 to 3, wherein the switching the image transmission mode of the drone according to the distance between the drone and the remote controller comprises:

When the current image transmission mode of the drone is a remote image transmission mode, and the distance between the drone and the remote controller exceeds the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode, or

When the current control mode of the drone is remote image transmission mode, and the distance between the drone and the remote controller is less than the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode.
The method of claim 4 wherein said switching distance is less than a remote transmission distance of the remote control.
The method of claim 4 wherein said remote control party The formula is a cellular mobile communication transmission method.
The method of claim 4, wherein the method further comprises:

When the current image transmission mode of the drone is a remote image transmission mode, and the actual transmission image size is larger than the preset transmission image size, the image transmission mode of the drone is switched to the remote image transmission mode.
A UAV image transmission mode switching device, comprising:

An acquiring unit, configured to acquire a distance between the drone and a remote controller, where the remote controller is configured to receive an image sent by the drone,

a determining unit, configured to determine a current image transmission mode of the drone, wherein the image transmission mode includes a remote image transmission mode and a remote image transmission mode,

The switching unit is configured to switch the image transmission mode of the drone according to the distance between the drone and the remote controller.
The device according to claim 8, wherein the obtaining unit is specifically configured to:

Obtain the current position of the drone by satellite positioning or radar,

Calculate the distance between the drone and the remote control based on the current position of the drone.
The device according to claim 8, wherein the determining unit is specifically configured to:

Receiving an image transmission signal, the image transmission mode signal comprising a remote image transmission signal or a remote image transmission signal,

Determining a current image transmission mode of the drone based on the received image transmission signal.
The device according to any one of claims 8 to 10, wherein the switching unit is specifically configured to:

When the current image transmission mode of the drone is a remote image transmission mode, and the distance between the drone and the remote controller exceeds the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode, or

When the current control mode of the drone is remote image transmission mode, and the distance between the drone and the remote controller is less than the switching distance, the image transmission mode of the drone is switched to the remote image transmission mode.
The apparatus of claim 11 wherein said switching distance is less than a remote control distance of the remote control.
The apparatus according to claim 11, wherein said remote control mode is a cellular mobile communication transmission mode.
The device according to claim 11, wherein the switching unit is further configured to:

When the current image transmission mode of the drone is a remote image transmission mode, and the actual transmission image size is larger than the preset transmission image size, the image transmission mode of the drone is switched to the remote image transmission mode.
A drone, characterized in that it comprises:

Remote antenna for receiving remote image transmission signals,

RF antenna for receiving remote image transmission signals,

a central processor, configured to acquire a distance between the drone and the remote controller, and determine a current image transmission mode of the drone according to the received remote control image transmission signal or an image transmission control signal, where the image transmission mode includes a remote control The image transmission mode and the remote image transmission mode switch the image transmission mode of the drone according to the distance between the drone and the remote controller.