WO2020191666A1 - Return to home control method, flight control device, and unmanned aerial vehicle - Google Patents

Abstract

Provided are a return to home control method, a flight control device, and an unmanned aerial vehicle capable of enhancing return to home performance of an unmanned aerial vehicle. The unmanned aerial vehicle has a fixed wing flight mode and a rotary wing flight mode. The method comprises: if an unmanned aerial vehicle satisfies a return to home condition, acquiring a current flight mode of the unmanned aerial vehicle, a flight height of the unmanned aerial vehicle, and a horizontal distance between the unmanned aerial vehicle and a home location (S201); determining a return to home scheme according to the flight mode, the horizontal distance and the flight height (S202); and controlling the unmanned aerial vehicle to return to home according to the return to home scheme (S203).

Description

Return home control method, flight control device and drone Technical field

This application relates to the field of control technology, in particular to a return-to-home control method, a flight control device and an unmanned aerial vehicle.

Background technique

Automatic return to home is one of the common functions in the UAV flight control system. Its purpose is to control the UAV to automatically return from any position to the return position set by the user (that is, the home point). In practical applications, the existing automatic return-to-home functions of UAVs are individually designed for rotary-wing UAVs or fixed-wing UAVs. For UAVs that have both rotary-wing flight mode and fixed-wing flight mode, the advantages of the two flight modes are not fully utilized, so they cannot achieve better performance in terms of return time and energy consumption.

Summary of the invention

The application discloses a return-to-home control method, a flight control device and an unmanned aerial vehicle, which are beneficial to improving the return-to-home performance of the unmanned aerial vehicle.

In the first aspect, this application provides a method for controlling the return home of an unmanned aerial vehicle. The unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode. The method includes:

If the drone meets the conditions for returning home, acquiring the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position;

Determining a return home strategy according to the flight mode, the horizontal distance and the flight altitude;

According to the return-to-home strategy, control the drone to return to home.

In a second aspect, this application provides a flight control device, which is applied to an unmanned aerial vehicle. The unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode. The flight control device includes: a memory, a processing , Where:

The memory is used to store program instructions;

The processor calls the program instructions for:

If the drone meets the conditions for returning home, acquiring the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position;

Determining a return home strategy according to the flight mode, the horizontal distance and the flight altitude;

According to the return-to-home strategy, control the drone to return to home.

In the third aspect, this application provides a drone, which includes:

body;

The communication device is used to communicate with the control terminal;

The flight control device as described in the second aspect.

In the return home control method, flight control device, and drone provided in the embodiments of this application, if the drone meets the return home conditions, the current flight mode of the drone, the flight height of the drone, and The horizontal distance between the drone and the return position. Then, a return-to-home strategy is determined according to the flight mode, the horizontal distance, and the flight altitude, and the drone is controlled to return to the home based on the return-to-home strategy. In this way, considering the flight mode, flight altitude and horizontal distance of the drone, it is beneficial to improve the return performance of the drone, reduce the time required for the return of the drone, and reduce the energy consumption of the return of the drone.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings.

FIG. 1 is a schematic diagram of a system architecture provided by an embodiment of the present application;

FIG. 2 is a schematic flow chart of a method for controlling the return of a drone according to an embodiment of the present application;

FIG. 3 is a schematic flowchart of another drone return control method provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of a return-to-home strategy provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of another return-to-home strategy provided by an embodiment of the present application;

FIG. 6 is a schematic diagram of another return-to-home strategy provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of a first fixed wing circling ascent course provided by an embodiment of the present application;

FIG. 8 is a schematic diagram of a method for calculating the first track inclination angle and the first ascent circle provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a first fixed wing hovering and descending course provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of a return trajectory of a fixed wing provided by an embodiment of the application;

FIG. 11 is a schematic diagram of a method for calculating a third track inclination angle and a second ascent circle provided by an embodiment of the present application;

FIG. 12 is a schematic diagram of another fixed wing return trajectory provided by an embodiment of the present application;

FIG. 13 is a schematic structural diagram of a flight control device provided by an embodiment of the present application.

detailed description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be described below with reference to the accompanying drawings.

In order to clearly describe the solution of the embodiment of the present application, the following describes the possible application system architecture of the embodiment of the present application with reference to FIG. 1.

Please refer to FIG. 1 for details. FIG. 1 is a schematic structural diagram of an unmanned aerial vehicle's return home control system provided by an embodiment of the present application. The return control system of the UAV includes: the UAV 11 and the control terminal 12. The flight control device 110 is included in the drone 11. The flight control device 110 may be a flight controller. Wherein, the unmanned aerial vehicle 11 and the flight control device 110 may establish a communication connection through a wireless communication connection, and the unmanned aerial vehicle 11 and the flight control device 110 may also establish a communication connection through a wired communication connection.

In some embodiments, the drone 11 further includes a power system 111, and the power system 111 is used to provide power for the drone 11 to move. The drone 11 includes a rotor assembly and a fixed-wing assembly. Correspondingly, the drone 11 has a rotor flight mode and a fixed-wing flight mode. In the rotor flight mode, the rotor assembly provides the flight power of the drone. In the fixed-wing mode, the fixed-wing component provides the flying power of the drone.

In some embodiments, the drone 11 further includes a communication device for communicating with the control terminal 12. The control terminal 12 is used to control the drone 11. The control terminal 12 may be a mobile phone, a tablet computer, a remote control, or other wearable devices (watches or bracelets), etc., which is not limited in the embodiment of the present application. It should be noted that the flight control device 110 may also be included in the control terminal 12. In the figure, the flight control device 110 is included in the drone 11 as an example.

For drones with fixed-wing flight modes and rotor flight modes, during the return process, if the flight mode of the drone is considered, the return performance of the drone can be improved. For example, the fixed-wing flight mode consumes less energy than the rotor flight mode. If one section of the route is converted to fixed-wing flight mode, the energy consumption of the entire route can be saved.

Before describing specific embodiments, first introduce the preset parameters involved in the embodiments of this application, among which:

The fixed-wing safety altitude refers to the minimum flight altitude allowed in the fixed-wing flight mode to ensure flight safety.

The fixed-wing return altitude refers to the lowest altitude of the route when flying to the return position (ie home point) in the fixed-wing flight mode.

Rotor return altitude refers to the lowest altitude of the route when flying to the return position in the rotor flight mode.

The energy-saving threshold refers to the minimum value of the height difference between ascending or descending when switching from the rotor flight mode to the fixed wing flight mode. It can be understood that if the UAV's flight mode is switched from the rotor flight mode to the fixed wing flight mode and then rise or fall to save power consumption, the height difference of the rise or fall needs to be greater than the energy saving threshold.

The energy-saving descent height is equal to the sum of the target value and the energy-saving threshold, where the target value is the maximum value between the safe height of the fixed wing and the return height of the rotor.

The energy-saving ascent height is equal to the difference between the rotor return height and the energy-saving threshold.

Rotor return range refers to the area where the horizontal distance from the return position is less than the return distance of the rotor.

The fixed wing return range refers to the area where the horizontal distance from the return position is greater than the rotor return distance and less than the fixed wing return distance.

Exceeding the fixed-wing return range refers to the area where the horizontal distance from the return position is greater than the fixed-wing return distance. Optionally, the fixed-wing return range is greater than the rotor return range, and the fixed-wing return range is greater than the fixed-wing return range.

The preset circling radius refers to the radius of the circle corresponding to circling up or down in the fixed-wing flight mode.

The maximum track inclination angle refers to the maximum value of the attitude angle corresponding to hovering up or down in the fixed-wing flight mode.

It should be noted that those skilled in the art can set the aforementioned preset parameters according to actual application scenarios.

The specific process of the return-to-home control method of the drone provided by the embodiment of the application will be further described below.

Please refer to FIG. 2. FIG. 2 is a schematic flowchart of a method for controlling the return of a drone according to an embodiment of the application. As shown in Fig. 2, the method may include steps 201-203. The above-mentioned steps 201-203 may be executed by a drone or a control terminal. Optionally, it can be specifically executed by a drone or a flight control device of a control terminal. among them:

201. If the drone meets the conditions for returning home, obtain the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position.

Among them, the current flight mode of the UAV includes a fixed-wing flight mode or a rotary-wing flight mode.

Among them, the return home condition is the condition that triggers the drone to return home.

Optionally, the drone meets the conditions for returning home, including: the difference between the remaining battery power of the drone and the power required for the drone to return home is less than or equal to a preset power threshold.

Among them, the power required for the return of the drone can be calculated according to the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position.

It can be understood that when the difference between the remaining power of the drone’s battery and the power required for the drone to return to home is less than or equal to the preset power threshold, it is determined that the remaining power of the drone can support the drone to return to the return position. At this time, the UAV does not perform the return operation, which may result in the final return to the return position, so it is determined that the UAV meets the return conditions. For example, the preset power threshold may be 10% of the battery power. It should be noted that the embodiment of the present application does not limit the specific value of the preset power threshold, and those skilled in the art can set the preset power threshold according to actual conditions.

Optionally, the drone meets the conditions for returning home, including: the time for the drone to disconnect from the control terminal is greater than the time threshold; and the return instruction sent by the control terminal is acquired.

It can be understood that when the time for the drone to disconnect from the control terminal is greater than the time threshold, it means that the drone is disconnected from at least one device in the control terminal, and it can be determined that the drone meets the conditions for returning home, thereby avoiding The drone loses control to avoid losing it. In addition, when the drone receives the return instruction sent by the control terminal, it means that the user corresponding to the control terminal sends the return instruction to the drone through the control terminal. It can be determined that the drone meets the return conditions and respond to user operations.

Optionally, the drone meets the conditions for returning home, including: the drone's hardware equipment fails.

Among them, hardware devices include magnetic compasses, pan-tilts, cameras and other hardware that do not affect the basic flight of drones. The detection method of the hardware device can obtain the detection data periodically. If the acquisition fails, it is determined that the hardware device is faulty, or when the detection data is abnormal, it is determined that the hardware device is faulty.

It can be understood that when the above hardware equipment fails, it can be determined that the UAV meets the return-to-home condition to control the UAV to return to the return position, so as to avoid the UAV from causing a major failure.

Optionally, the drone meets the conditions for returning home, including: the current wind speed is greater than the preset wind speed threshold for safe flight of the drone.

Among them, the current wind speed can be detected by a wind speed detector. When the current wind speed is greater than the preset wind speed threshold for the safe flight of the drone, it indicates that the current drone flight has a certain safety hazard, and it is determined that the drone meets the conditions for returning home.

202. Determine a return home strategy according to the flight mode, the horizontal distance and the flight altitude.

Optionally, the return-to-home strategy includes: controlling the flight mode of the drone to switch between the fixed-wing flight mode and the rotary-wing flight mode.

In the process of returning home, if the flight mode of the drone is considered, for example, the fixed-wing flight mode consumes less energy than the rotor flight mode. If one section of the route is converted to the fixed-wing flight mode, the energy of the entire route can be saved Consumption; The rotor flight mode is more convenient to control than the fixed wing flight mode, and the rotor flight mode can achieve fixed-point hovering and vertical take-off and landing. If one of the routes is converted to the rotor flight mode, it can reduce the return of the drone The time required. The horizontal distance and flight height itself affect the planning of the route, and the horizontal distance and flight height also affect the choice of flight mode. In this application, the return strategy is determined according to the flight mode, horizontal distance and flight height, which is conducive to improving the drone’s performance. The return-to-home performance reduces the time required for the return of the drone and reduces the energy consumption of the return of the drone.

203. Control the UAV to return home according to the return home strategy.

Optionally, according to the return-to-home strategy, controlling the drone to return to home includes: invoking a return-to-home mode corresponding to the return-to-home strategy to control the drone to return to home. Among them, the return-to-home mode may include a forward transition mode, a backward transition mode, a fixed-wing strong-cut rotor mode, a fixed-wing return mode, a rotor return mode, and a rotor landing mode.

In some embodiments, the forward transition mode is used to indicate that the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, and the flight altitude of the drone does not change during the switching process. In some embodiments, the smooth switching of the drone from the rotor flight mode to the fixed wing flight mode means that the drone automatically turns off the rotor flight mode and turns on the fixed wing flight mode within a preset distance range, so as to achieve a smooth transition from the rotor flight mode. Switch to fixed-wing flight mode to ensure the stability of the drone during flight mode switching. For example, the preset distance range may be 50m.

In some embodiments, the backward transition mode is used to indicate that the flight mode of the drone is smoothly switched from the fixed-wing flight mode to the rotary-wing flight mode, and the flying height of the drone does not change during the switching process. In some embodiments, the smooth switching of the drone from the fixed-wing flight mode to the rotor-wing flight mode means that the drone automatically turns off the fixed-wing flight mode and turns on the rotor-wing flight mode within a preset distance range to realize the flight mode from the fixed-wing flight. Smooth transition to the rotor flight mode to ensure the stability of the drone during flight mode switching. For example, the preset distance range may be 50m.

In some embodiments, the fixed-wing strong-cut rotor mode is used to indicate that the flight mode of the drone is directly switched from the fixed-wing flight mode to the rotor flight mode, and the flight altitude of the drone does not change during the switching process. In some embodiments, the direct switching of the drone from the fixed-wing flight mode to the rotor-wing flight mode means that the fixed-wing flight mode of the drone is directly turned off at the current altitude of the drone, and the rotor-wing flight mode is turned on. There is no transition. Process to make the drone quickly switch flight modes.

In some embodiments, the fixed-wing return mode is used to instruct the drone to fly to the return position in the fixed-wing flight mode. Optionally, the process of flying to the return position in the fixed-wing flight mode may include the drone hovering up, hovering down, or hovering and flying at the same altitude. Among them, hovering level flight means that the UAV flies with a roll angle of 0 degrees in the fixed-wing flight mode, and the flying height of the UAV remains unchanged during the flight. Optionally, it may also include flying along a straight trajectory in a fixed-wing flight mode.

In some embodiments, the rotor return mode is used to instruct the drone to fly to the return position in the rotor flight mode and land on the return position. Optionally, the process of flying to the return position in the rotor flight mode may include ascending in the rotor flight mode, so as to avoid too low altitude and obstacles when returning home. Optionally, when an obstacle is encountered in front of the drone, an obstacle avoidance route is determined according to the position of the obstacle to bypass the obstacle. Optionally, it may also include adjusting the heading of the drone to a direction pointing to the return position or a preset direction. For example, the preset direction may be the heading of the drone when the drone takes off. Optionally, it may also include flying along a straight trajectory in the rotor flight mode.

In some embodiments, the rotor landing mode is used to instruct the drone to maintain the current horizontal position and to lower the altitude in the rotor flight mode until it hits the ground.

It should be noted that those skilled in the art can set the corresponding return home mode according to the return home strategy, so that when the drone is controlled to return home according to the return home strategy, the return home mode corresponding to the return home strategy can be invoked to control the return home strategy. The man-machine returns to the home, which improves the control efficiency of the drone.

By implementing the method described in Figure 2, if the drone meets the conditions for returning home, the flight mode used by the drone, the flying height of the drone, and the horizontal distance between the drone and the return position are obtained. Then, a return strategy is determined according to the flight mode, the horizontal distance and the flight altitude. Then, according to the return-to-home strategy and return-to-home parameters, control the UAV to return to home. In this way, considering the flight mode, flight altitude and horizontal distance of the drone, it is beneficial to improve the return performance of the drone, reduce the time required for the return of the drone, and reduce the energy consumption of the return of the drone.

Please refer to FIG. 3, which is a schematic flowchart of another drone return control method disclosed in an embodiment of the application. Among them, 302 and 303 are specific implementations of 202. As shown in Fig. 3, the method may include steps 301-304. The above steps 301 to 304 can be executed by a drone or a control terminal. Optionally, it can be specifically executed by a drone or a flight control device of a control terminal. among them:

301. If the drone meets the conditions for returning home, obtain the flight mode used by the drone, the flying height of the drone, and the horizontal distance between the drone and the return position.

Among them, the specific implementation manner of 301 is the same as the specific implementation manner of 201. For details, please refer to the corresponding description of 201, which is not repeated here.

302. Determine the return range corresponding to the horizontal distance.

Among them, the return range can include the return range of the rotor, the return range of the fixed wing, and the return range of the fixed wing. As before, it is optional to determine the return range corresponding to the horizontal distance, including: if the horizontal distance is less than the return distance of the rotor, it is determined The return range is the return range of the rotor; if the horizontal distance is greater than or equal to the return distance of the rotor and less than the return distance of the fixed wing, the return range is determined to be the return range of the fixed wing; if the horizontal distance is greater than or equal to the return distance of the fixed wing, then Determine that the return range is beyond the fixed-wing return range.

It can be understood that according to the comparison between the horizontal distance and the preset rotor return distance and fixed wing return distance, the corresponding return range of the drone can be obtained.

303. Determine a return strategy according to the return range, the flight mode, and the flight altitude.

Please refer to Figure 4, which describes the return strategy when the return range is the rotor return range.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes: unmanned The flight mode of the aircraft is directly switched from the fixed-wing flight mode to the rotor flight mode, the drone is controlled to rise to the rotor return height in the rotor flight mode, and the drone is controlled to return in the rotor flight mode.

In this optional method, when the return range is the rotor return range, the UAV needs to perform the rotor return. Since the current flight mode of the UAV is a fixed-wing flight mode, the flying height is less than the fixed-wing safety height. In order to ensure the safety of the drone, it is first necessary to directly switch the flight mode of the drone from the fixed-wing flight mode to the rotary-wing flight mode. Since the flying height is less than the rotor return height, in order to ensure the flight safety of the drone, after switching to the rotor flight mode, it is necessary to rise to the rotor return height in the rotor flight mode, and then return to the rotor flight mode.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return strategy includes: The flight mode of the drone is directly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return to home in the rotor flight mode.

In this optional way, since the current flight mode of the drone is the fixed-wing flight mode, the flight height is less than the fixed-wing safety height. In order to ensure the safety of the drone, the flight mode of the drone needs to be changed to the fixed-wing flight mode. The flight mode is directly switched to the rotor flight mode. Since the current flying altitude is greater than or equal to the rotor return altitude, after switching to the rotor flight mode, you can directly return to the rotor flight mode.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving rise altitude, the return strategy includes Control the drone to rise to the rotor return height in the fixed-wing flight mode, smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor flight mode, and control the drone to return in the rotor flight mode.

In this optional manner, when the flying height is less than or equal to the energy-saving rising height, controlling the drone to rise to the rotor return height in the fixed-wing flight mode can achieve the effect of energy saving.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude is greater than the energy-saving ascent altitude , The return-to-home strategy includes: smoothly switching the drone's flight mode from fixed-wing flight mode to rotor-wing flight mode, and controlling the drone to return home in the rotor-wing flight mode.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, the return strategy includes : Control the drone to drop to the target value in the fixed-wing flight mode, smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor flight mode, and control the drone to return home in the rotor flight mode.

In this optional manner, when the flying height is greater than or equal to the energy-saving descent height, controlling the drone to descend to the target value in the fixed-wing flight mode can achieve the effect of energy saving.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes: controlling the drone In the rotor flight mode, ascend to the rotor return height, and control the drone to return in the rotor flight mode.

In this optional way, since the flight mode is rotor flight mode, and the flying height of the drone is less than the rotor return height, you can control the drone to rise to the rotor return height in the rotor flight mode, and then control the drone The aircraft returns to home in the rotor flight mode, so that the drone returns to the return position.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return strategy includes: Control None The man-machine returns home in rotor flight mode.

In this optional manner, since the flight mode is the rotor flight mode, and the flying height is greater than or equal to the rotor return height, the drone can be controlled to return to the rotor flight mode to make the drone return to the return position.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent altitude, the return strategy includes: Align the drone's heading to the return position, smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, control the drone to rise to the rotor return height in the fixed-wing flight mode, and move the drone The flight mode is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return to home in the rotor flight mode.

In this optional manner, first align the heading of the drone to the return position, which can reduce the distance to the return position. After the heading is aligned to the return position, the flight mode of the controllable drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, and then the drone is controlled to rise to the rotor return height in the fixed-wing flight mode, so that the drone meets The flying altitude of the rotor flight mode. After performing the ascent to the rotor return height, the drone's flight mode is switched from the fixed-wing flight mode to the rotor flight mode, and finally the drone is controlled to return to the rotor flight mode to make the drone return to the return position. In this optional way, when the flying height is less than or equal to the energy-saving ascent height, controlling the drone to rise to the rotor return height in the fixed-wing flight mode can achieve the effect of energy saving.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude is greater than the energy-saving ascent altitude, The return-to-home strategy includes: controlling the drone to return to home in the rotor flight mode.

Optionally, as shown in Figure 4, if the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then the return strategy includes: Align the drone's heading to the return position, smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, control the drone to descend to the target value in the fixed-wing flight mode, and reduce the drone's flight mode. The flight mode is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode.

In this optional manner, first align the heading of the drone to the return position, which can reduce the distance to the return position. After the heading is aligned to the return position, the flight mode of the drone can be smoothly switched from the rotor flight mode to the fixed-wing flight mode, and then the drone can be controlled to drop to the target value in the fixed-wing flight mode, and then to the target value. After the target value, the drone's flight mode is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and finally the drone is controlled to return to the rotor flight mode to make the drone return to the return position. This optional method controls the drone to descend to the target value in the fixed-wing flight mode when the flying height is greater than the energy-saving descent height, which can achieve the effect of energy saving.

Please refer to Figure 5, which describes the return steps when the return range is the fixed-wing return range.

Optionally, as shown in Figure 5, if the return range is the fixed-wing return range, the flight mode is fixed-wing flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: changing the drone's flight mode from fixed The wing flight mode is directly switched to the rotor flight mode, the drone is controlled to rise to the fixed-wing safety height in the rotor flight mode, the heading of the drone is controlled to align to the return position, and the flight mode of the drone is smoothly switched from the rotor flight mode It is a fixed-wing flight mode, controlling the drone to return home in the fixed-wing flight mode, smoothly switching the flight mode of the drone from fixed-wing flight mode to rotor flight mode, and controlling the drone to return home in the rotor flight mode.

In this optional method, when the return range is the fixed-wing return range, the fixed-wing flight mode can be used to return to the home first, and then the rotor flight mode can be used to return. Since the flight mode is fixed-wing flight mode, and the flight height is less than the safety height of the fixed-wing flight, in order to ensure the safety of the drone, it is necessary to switch the fixed-wing flight mode to the rotor flight mode in time. Therefore, the flight mode of the drone needs to be changed from The fixed-wing flight mode is directly switched to the rotary-wing flight mode. After switching from fixed wing to rotor, control the drone to rise to the fixed wing safety height in the rotor flight mode, and then control the drone's heading to align with the return position, which can reduce the distance to the return position. Then smoothly switch the flight mode of the drone from the rotor flight mode to the fixed wing flight mode. Then control the drone to return in the fixed-wing flight mode, and then smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor flight mode, and finally control the drone to return in the rotor flight mode to make the drone return home To return position. Returning to the return position via the rotor reduces the requirements for the return position field.

Optionally, as shown in Figure 5, if the return range is the fixed-wing return range, the flight mode is fixed-wing flight mode, and the flying height is greater than or equal to the fixed-wing safety height, the return strategy includes: controlling the drone on the fixed-wing Return to home in flight mode, smoothly switch the flight mode of the drone from fixed-wing flight mode to rotor flight mode, and control the drone to return to home in rotor flight mode.

In this optional manner, since the flight mode is a fixed-wing flight mode, and the flying height is greater than or equal to the fixed-wing safety height. Therefore, the drone can be directly controlled to return to home in the fixed-wing flight mode, and then the flight mode of the drone can be smoothly switched from the fixed-wing flight mode to the rotor flight mode. Finally, control the drone to return home in the rotor flight mode to make the drone return to the return position.

Optionally, as shown in Figure 5, if the return range is the fixed-wing return range, the flight mode is rotor flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: controlling the drone to rise in the rotor flight mode To the fixed-wing safety height, align the drone's heading to the return position, smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, and control the drone to return to the fixed-wing flight mode. The flight mode of the man-machine is smoothly switched from the fixed-wing flight mode to the rotary-wing flight mode, and the drone is controlled to return home in the rotary-wing flight mode.

In this optional manner, since the flight mode is the rotor flight mode, and the flight height is less than the fixed wing safety height. In order to ensure the safety of the drone, it is necessary to control the drone to rise to the safe height of the fixed wing in the rotor flight mode. After rising to the safe height of the fixed wing, align the drone's heading to the return position to reduce the flying direction. The distance to return to the position. After the heading is aligned to the return position, the drone's flight mode is smoothly switched from the rotor flight mode to the fixed-wing flight mode, and the drone is controlled to return to the fixed-wing flight mode, and the flight mode of the drone is changed from the fixed-wing flight mode. The flight mode is smoothly switched to the rotor flight mode, which makes the drone switch from the fixed wing flight mode to the rotor flight mode. Finally, control the drone to return home in the rotor flight mode to make the drone return to the return position.

Optionally, as shown in Figure 5, if the return range is the fixed-wing return range, the flight mode is rotor flight mode, and the flying height is greater than or equal to the fixed-wing safety height, the return strategy includes: aligning the drone's heading Return to the position, smoothly switch the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, control the drone to return home in the fixed-wing flight mode, and smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor Flight mode, control the drone to return home in the rotor flight mode.

In this optional manner, first align the heading of the drone to the return position, which can reduce the distance to the return position. Then smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, then control the drone to return to the fixed-wing flight mode, and then smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor flight mode. Flight mode. Finally, control the drone to return to home in the rotor flight mode, so that the drone returns to the return position.

Please refer to Figure 6. Figure 6 describes the return steps when the return range exceeds the fixed-wing return range.

Optionally, as shown in Figure 6, if the return range is beyond the fixed-wing return range, the flight mode is fixed-wing flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: changing the drone's flight mode from The fixed-wing flight mode is directly switched to the rotor flight mode, and the drone is controlled to land in the rotor flight mode.

In this optional manner, since the flying height is less than the fixed-wing safety height, in order to ensure the safety of the drone, the flying mode of the drone can be directly switched from the fixed-wing flying mode to the rotary-wing flying mode. When the return range is beyond the fixed-wing return range, it may be that the drone is too far away from the return position, and the remaining power of the drone is not enough to support the return of the drone to the return position. Therefore, after switching to the rotor flight mode, the drone can be controlled to land in the rotor flight mode to achieve a nearby landing.

Optionally, as shown in Figure 6, if the return range exceeds the fixed-wing return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than the energy-saving descending altitude, the return strategy includes : Smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to land in the rotor flight mode.

Optionally, as shown in Figure 6, if the return range exceeds the fixed-wing return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then return The strategy includes: controlling the drone to descend to the target value in the fixed-wing flight mode, smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling the drone to land in the rotor flight mode.

In this optional manner, when the flying height is greater than or equal to the energy-saving descent height, controlling the drone to descend to the target value in the fixed-wing flight mode can achieve the effect of energy saving.

Optionally, as shown in Figure 6, if the return range is beyond the fixed-wing return range, the flight mode is rotor flight mode, and the flight altitude is less than the energy-saving descending height, the return strategy includes: controlling the drone to land in the rotor flight mode.

Optionally, as shown in Figure 6, if the return range exceeds the fixed-wing return range, the flight mode is rotor flight mode, and the flying altitude is greater than or equal to the energy-saving descent altitude, the return strategy includes: align the drone's heading and return Position, smoothly switch the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, control the drone to drop to the target value in the fixed-wing flight mode, and smoothly switch the flight mode of the drone from the fixed-wing flight mode For the rotor flight mode, control the drone to land in the rotor flight mode.

In this optional manner, first align the heading of the drone to the return position, which can reduce the distance the drone flies to the return position. Then smoothly switch the flight mode of the drone from the rotor flight mode to the fixed wing flight mode. When the flying height is greater than or equal to the energy-saving descent height, controlling the drone to descend to the target value in the fixed-wing flight mode can achieve the effect of energy saving. Then smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and finally control the drone to land in the rotor flight mode.

This application does not limit the return path corresponding to the return strategy. Optionally, when the return strategy includes controlling the drone to rise to the rotor return height in the fixed-wing flight mode, control the drone Circling the ascent route along the first fixed wing to rise to the return height of the rotor.

For example, FIG. 7 is a schematic diagram of a first fixed wing hovering ascent course disclosed in an embodiment of the application. As shown in Figure 7, the drone hovered from point A along the first fixed wing hovering ascent route L1 to point B, where the height of point B is the return height of the rotor.

In a possible example, the first fixed-wing hovering ascent route is determined according to the first track inclination angle, the first ascent circle, and the preset hovering radius; the first flight path inclination angle and the first ascent circle It is determined based on the difference between the rotor return altitude and the flight altitude, the preset circling radius and the maximum track inclination.

Among them, the first ascent lap is the number of laps to ascend to the return height of the rotor when hovering in the fixed-wing flight mode. The first trajectory inclination angle is the attitude angle of the UAV in each circle.

It can be understood that the UAV can hover according to the first track inclination, the first ascent circle and the preset hovering radius, so that the UAV can rise to the rotor return height. In this way, after the drone rises to the rotor return height, the safety of returning to the return position in the rotor flight mode can be improved.

This application does not limit the method for determining the first track inclination angle and the first ascent circle. For example, FIG. 8 is a schematic diagram of calculating the first track inclination angle and the first ascent circle disclosed in an embodiment of this application. As shown in Figure 8, the length of the first right-angle side H1 is the vertical height of the spiral ascending. Since the preset spiral radius R is fixed, the horizontal distance will increase by 2πR for each turn, and the first turn can be A first vertical triangle formed by the first right-angled side H1, the second right-angled side H2 and the first hypotenuse T1 is obtained, and the length of the second right-angled side H2 is 2πR. Circling the second circle to obtain a second vertical triangle composed of the first right-angled side H1, the third right-angled side H3 and the second hypotenuse T2, the length of the third right-angled side H3 is 4πR, and so on. In the first vertical triangle, the first angle θ1 is calculated based on the first right-angle side H1 and the second right-angle side H2. If the first included angle is less than or equal to the maximum trajectory inclination angle, the first trajectory inclination angle is determined to be the first included angle θ1, and the first ascent circle is 1; otherwise, according to the first right angle side H1 and the third right angle side H3 calculates the second included angle θ2. If the second included angle θ2 is less than or equal to the maximum track inclination angle, the first track inclination angle is determined to be the second included angle, and the first ascent circle is 2, and so on, so that the final included angle is less than or equal to the maximum The track inclination angle is calculated based on the vertical height of the circling ascent, the preset circling radius R and the maximum track inclination to obtain the first track inclination and the first ascent lap. In this embodiment, the vertical height of the hovering rise is the difference between the return height of the rotor and the flying height. In this way, according to the difference between the return altitude and the flight altitude of the rotor, the preset circling radius and the maximum track inclination are used to determine the first track inclination and the first ascent lap.

Optionally, when the return-to-home strategy includes controlling the UAV to descend to a target value in the fixed-wing flight mode, controlling the UAV to descend to the target value along the first fixed-wing hovering descent route.

For example, FIG. 9 is a schematic diagram of a spiral descent route of a first fixed wing disclosed in an embodiment of the application. As shown in Figure 9, the UAV descends from point C along the first fixed wing hovering descent route L2 to point D, where the height of point D is the target value, that is, the distance between the fixed wing safety height and the rotor return height Maximum value.

In a possible example, the first fixed-wing hovering descent route is determined based on the second track inclination angle and the first descent circle, and the preset hovering radius, the second flight path inclination and the first descent circle It is determined based on the difference between the flight altitude and the target value, the preset circling radius and the maximum track inclination.

Among them, the first descending circle is the number of circle descending to the target value when hovering in the fixed-wing flight mode. The second trajectory inclination angle is the attitude angle of the UAV in each circle. It can be understood that the drone can hover according to the second track inclination, the first descending circle and the preset hovering radius, so that the drone can descend to the target value of circle. In this way, after the drone drops to the target value, the power consumption can be saved on the basis of ensuring the safety of flying in the rotor flight mode.

The specific method for determining the second flight path inclination angle and the first descent number can refer to the description of FIG. 8, which will not be repeated here. That is, according to the vertical height of the hovering descent, the preset hovering radius and the maximum track inclination are calculated to obtain the second track inclination and the first descent lap. In this embodiment, the vertical height of the hovering descent is the difference between the flying height and the target value. In this way, according to the difference between the flight altitude and the target value, the preset circling radius and the maximum track inclination are used to determine the second track inclination and the first descent lap.

Optionally, when the return strategy includes controlling the UAV to return in the fixed-wing flight mode, controlling the UAV to ascend along the second fixed-wing hovering ascent course and fly along the fixed-wing horizontal course, Descend along the descent path of the second fixed wing circling.

Optionally, the fixed-wing horizontal course may be determined through the dubins curve planning algorithm, or other algorithms may be used to determine the fixed-wing horizontal course, which is not limited in the embodiment of the present application.

Optionally, the fixed-wing horizontal route includes an initial circle, an end circle, and a target tangent. The target tangent and the initial circle are tangent to the first tangent point, and the target tangent and the end circle are tangent to the second tangent point. The circle is the end point of smoothly switching from the rotor flight mode to the fixed-wing flight mode according to the flight mode of the drone. The preset circling radius and the flight mode of the drone are smoothly switched from the rotor flight mode to the starting point of the fixed-wing flight mode. The end circle is determined by the line between the return positions. The end circle is determined by the starting point, the preset circling radius and the line of the UAV's flight mode from the fixed-wing flight mode to the rotor flight mode. The center of the circle is on the line.

Please refer to FIG. 10, which is a schematic diagram of the trajectory of the fixed wing returning home. As shown in Figure 10, the fixed-wing horizontal course includes an initial circle C1, an end circle C2, and a target tangent line IJ. Among them, the target tangent IJ and the initial circle C1 are tangent to the first tangent point I, and the target tangent IJ and the end circle C2 are tangent to the second tangent point J. Point O is the return position, point E is the starting point of the drone's flight mode smoothly switching from the rotor flight mode to the fixed wing flight mode. Point F is the end point of the drone's flight mode smoothly switching from rotor flight mode to fixed-wing flight mode, and point F is the point where the initial circle C1 is tangent to the line EO. Point G is the starting point of the drone's flight mode smoothly switching from fixed-wing flight mode to rotor flight mode, and point G is the point where the end circle C2 is tangent to the line GO. Point Q is the center of the ending circle C2, and point Q is on the line EO.

In an alternative embodiment, after the positions of the E point and the O point are known, the line EO can be determined. And the point F is on the line EO, the distance (that is, the distance between the lines EF) for the drone's flight mode to smoothly switch from the rotor flight mode to the fixed-wing flight mode is fixed, so the position of the point F can be determined . Since the initial circle C1 is tangent to the line EO at point F, the initial circle C1 is determined according to the point F, the preset spiral radius R and the line EO.

In an alternative embodiment, the radius of the end circle C2 is the preset circling radius R, and the distance (that is, the distance between the connecting GO points) of the drone's flight mode from fixed-wing flight mode to rotary-wing flight mode smoothly is Fixed, the center Q of the end circle C2 is on the line EO. Therefore, after knowing the position of the O point and the distance of the line GO, and the preset circling radius R, the position of the circle center Q can be determined. According to the position of the center Q and the preset spiral radius R, the ending circle C2 can be determined. Therefore, the end circle C2 is determined according to the G point, the preset spiral radius R and the line EO.

Optionally, the second fixed wing hovering ascent path is determined according to the second ascent circle and the third track inclination angle and the preset hovering radius, and the second ascent circle and the third track inclination angle are determined according to the first projection The arc length between the point and the end point when the drone is smoothly switched from rotor flight mode to fixed-wing flight mode, the difference between the fixed-wing return height and the fixed-wing safety height, the preset circling radius and the maximum track inclination are determined Yes, the first projection point is the point where the projection of the first tangent point to the plane where the end point of the drone is smoothly switched from the rotor flight mode to the fixed wing flight mode.

This application does not limit the method for determining the third flight path inclination and the second ascending circle. For example, as shown in Fig. 11, the vertical distance of hovering ascent is the length of the fourth right angle side H4, and the first circle of hovering can be obtained by The fourth right-angled side H4, the fifth right-angled side H5 and the third hypotenuse T3 form a third vertical triangle, and the length of the fifth right-angled side H5 is the sum of the initial horizontal distance W and 2πR. Circling the second circle can get a fourth vertical triangle formed by the fourth right-angled side H4, the sixth right-angled side H6 and the fourth hypotenuse T4. The length of the sixth right-angled side H6 is the sum between the initial horizontal distance W and 4πR Value, and so on. In the third vertical triangle, the third angle θ3 can be calculated based on the fourth right-angle side H4 and the fifth right-angle side H5. If the third inclination angle θ3 is less than or equal to the maximum track inclination angle, the third inclination angle is determined to be the third inclination angle θ3, and the second ascent circle is 1; otherwise, in the fourth vertical triangle, according to the fourth The right angle side H4 and the sixth right angle side H6 can calculate the fourth included angle θ4. If the fourth inclination angle θ4 is less than or equal to the maximum track inclination angle, the third inclination angle is determined to be the fourth inclination angle θ4, the second ascent circle is 2, and so on, so that the final inclination angle is less than or equal to The maximum track inclination angle is calculated based on the vertical height of the circling ascent, the initial horizontal distance W, the preset circling radius R and the maximum track inclination to obtain the third track inclination and the second ascent circle.

Based on this, in this embodiment, the initial horizontal distance W is the arc length between the first tangential point and the point on the plane where the drone is smoothly switched from the rotor flight mode to the fixed wing flight mode. The vertical height of the hovering rise is the difference between the fixed-wing return height and the fixed-wing safety height. Thus, according to the difference between the fixed-wing return height and the fixed-wing safety height, the first projection point and the drone fly by the rotor The mode is smoothly switched to the arc length between the end points of the fixed-wing flight mode. The preset circling radius R and the maximum track inclination determine the third track inclination and the second ascent circle, and then according to the second ascent circle and the third The track inclination and the preset circling radius R determine the circling ascent course of the second fixed wing.

Optionally, the second fixed-wing hovering descent route is determined according to the second descent circle and the fourth track inclination angle, and the preset hovering radius, the second descent circle and the fourth track inclination angle are determined according to the second It is determined by the arc length between the projection point and the starting point where the drone is smoothly switched from the fixed-wing flight mode to the rotor flight mode, the difference between the fixed-wing return height and the target value, the preset circling radius and the maximum track inclination angle , The target value is the maximum value between the fixed-wing safety height and the rotor return height, and the second projection point is the second tangent point projected to the plane where the drone is smoothly switched from fixed-wing flight mode to rotor flight mode. Point.

In the same way, for the method of planning the second fixed-wing hovering descent route, refer to the description in Fig. 11. In this embodiment, according to the vertical height of hovering descent (the difference between the target value and the fixed-wing return height), the second The arc length, preset circling radius and maximum track inclination between the projection point and the starting point when the drone is smoothly switched from fixed-wing flight mode to rotary-wing flight mode to determine the fourth track inclination angle and the second descent circle number, and then according to The second descent circle, the fourth track inclination, and the preset circling radius determine the second fixed wing circling descent course.

For example, FIG. 12 is a schematic diagram of another fixed-wing return trajectory provided by an embodiment of the application. In Fig. 12, point F is the end point of the drone flight mode smoothly switching from the rotor flight mode to the fixed wing flight mode. Point G is the starting point for the UAV's flight mode to smoothly switch from fixed-wing flight mode to rotary-wing flight mode. Point I is the first tangent point, and point J is the second tangent point. The height of points I and J is the fixed-wing return height, and the height of point G is the target value. As shown in Figure 8, the UAV hovered from point F to point I along the second fixed wing hovering ascent route L3. Then fly straight horizontally from the first tangential point I to the second tangent point J, and then descend from the point J to the starting point G along the second fixed-wing hovering descent route L4. Optionally, in order to further improve flight stability, after reaching point I, the drone can hover and level along the plane determined by straight line IJ, and fly along the route determined by IJ after hovering and level flight. Optionally, after reaching point J, the drone can hover and level along the plane determined by the straight line IJ, and hover and descend to the starting point G along the second fixed wing hovering descent route L4 after hovering and leveling.

It should be noted that if the previous step of controlling the drone to return in the fixed-wing flight mode is not the step of smoothly switching the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, then the second The number of ascent laps and the third track inclination are determined based on the difference between the fixed wing's return altitude and the fixed wing's safe altitude, the preset circling radius and the maximum track inclination.

304. Control the UAV to return home according to the return-to-home strategy.

Optionally, according to the return-to-home strategy, controlling the drone to return to home includes: invoking a return-to-home mode corresponding to the return-to-home strategy to control the drone to return to home.

It should be noted that those skilled in the art can set the corresponding return home mode according to the return home strategy, so that when the drone is controlled to return home according to the return home strategy, the return home mode corresponding to the return home strategy can be invoked to control the return home strategy. The man-machine returns to the home, which improves the control efficiency of the drone.

The specific implementation manner of 304 is the same as the specific implementation manner of 203. For details, please refer to the corresponding description of 203, which is not repeated here.

By implementing the method described in Figure 3, if the drone meets the conditions for returning home, the flight mode used by the drone, the flying height of the drone, and the horizontal distance between the drone and the return position are obtained. Then, determine the return range corresponding to the horizontal distance, and determine the return strategy based on the return range, the flight mode, and the flight altitude. Then, according to the return-to-home strategy, control the drone to return to home. In this way, the flight mode, flight altitude and horizontal distance of the UAV are considered, which is beneficial to improve the return performance of the UAV.

Please refer to FIG. 13, which is a schematic structural diagram of a flight control device provided in an embodiment of the application. The flight control device is applied to an unmanned aerial vehicle. The unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode. The device includes a memory 1301 and a processor 1302. Optionally, the memory 1301 and the processor 1302 may be connected through a bus system 1303.

The memory 1301 is used to store program instructions. The memory 1301 may include a volatile memory (volatile memory), such as a random-access memory (random-access memory, RAM); the memory 1301 may also include a non-volatile memory (non-volatile memory), such as a flash memory (flash memory). memory), solid-state drive (SSD), etc.; the memory 1301 may also include a combination of the foregoing types of memories.

The processor 1302 may include a central processing unit (CPU). The processor 1302 may further include a hardware chip. The aforementioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), etc. The above-mentioned PLD may be a field-programmable gate array (FPGA), a generic array logic (GAL), etc. Wherein, the processor 1302 calls the program instructions in the memory 1301 to execute the following steps:

If the drone meets the conditions for returning home, get the current flight mode of the drone, the drone's flying height, and the horizontal distance between the drone and the return position;

Determine the return strategy according to the flight mode, horizontal distance and flight altitude;

According to the return-to-home strategy, control the drone to return to home.

Optionally, the return-to-home strategy includes: controlling the flight mode of the drone to switch between the fixed-wing flight mode and the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-to-home strategy according to the flight mode, horizontal distance and flight altitude is specifically as follows:

Determine the return range corresponding to the horizontal distance;

Determine the return strategy based on the return range, flight mode and flight altitude.

Optionally, the specific method for the processor 1302 to determine the return range corresponding to the horizontal distance is as follows:

If the horizontal distance is less than the return distance of the rotor, the return range is determined to be the return range of the rotor;

If the horizontal distance is greater than or equal to the return distance of the rotor and less than the return distance of the fixed wing, the return range is determined to be the return range of the fixed wing;

If the horizontal distance is greater than or equal to the fixed-wing return distance, the return range is determined to exceed the fixed-wing return range.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flying height is less than the fixed-wing safety height, and the flying height is less than the rotor return height, then the return-to-home strategy includes: changing the drone's flight mode directly from the fixed-wing flight mode Switch to the rotor flight mode, control the drone to rise to the rotor return height in the rotor flight mode, and control the drone to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flying height is less than the fixed-wing safety height, and the flying height is greater than or equal to the rotor return height, then the return strategy includes: changing the drone's flight mode to fixed-wing flight The mode is directly switched to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flying altitude is greater than or equal to the fixed-wing safety altitude, and the flying altitude is less than or equal to the energy-saving ascent height, the return strategy includes: controlling the drone in fixed-wing flight mode Ascend to the rotor return height, smoothly switch the drone's flight mode from fixed-wing flight mode to rotor flight mode, and control the drone to return to home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flying altitude is greater than or equal to the fixed-wing safety altitude, the flying altitude is less than the energy-saving descent altitude, and the flying altitude is greater than the energy-saving ascent altitude, then the return strategy includes: The flight mode is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return to home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, the return strategy includes: controlling the drone in the fixed-wing flight mode Descend to the target value, smoothly switch the drone's flight mode from fixed-wing flight mode to rotary-wing flight mode, control the drone to return to home in the rotary-wing flight mode, the target value is between the fixed-wing safety altitude and the rotor return altitude Maximum value.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is the rotor flight mode, the flying height is less than the fixed wing safety height, and the flying height is less than the rotor return height, then the return strategy includes: controlling the drone to rise to the rotor return height in the rotor flight mode , Control the drone to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return strategy includes: controlling the drone to return in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent height, the return strategy includes: align the drone's heading to the return position , Smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, control the drone to rise to the rotor return height in the fixed-wing flight mode, and smoothly switch the drone's flight mode from the fixed-wing flight mode In the rotor flight mode, control the drone to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude is greater than the energy-saving ascent altitude, then the return strategy includes: controlling the drone at Return home in rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the rotor return range, the flight mode is the rotor flight mode, the flying altitude is greater than or equal to the fixed-wing safety altitude, and the flying altitude is greater than or equal to the energy-saving descent altitude, the return strategy includes: align the drone's heading to the return position, Smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, control the drone to drop to the target value in the fixed-wing flight mode, and smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor Flight mode, control the drone to return home in the rotor flight mode, the target value is the maximum value between the fixed wing safety altitude and the rotor return home altitude.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the fixed-wing return range, the flight mode is fixed-wing flight mode, and the flying height is less than the fixed-wing safety altitude, the return strategy includes: switching the drone's flight mode from fixed-wing flight mode to rotor flight mode directly, Control the drone to rise to the fixed-wing safety height in the rotor flight mode, control the drone's heading to align to the return position, smoothly switch the drone's flight mode from the rotor flight mode to the fixed-wing flight mode, and control the drone Return to home in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to return to home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the fixed-wing return range, the flight mode is fixed-wing flight mode, and the flying altitude is greater than or equal to the fixed-wing safety height, the return strategy includes: controlling the drone to return to home in the fixed-wing flight mode and turning the drone into The flight mode is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the fixed-wing return range, the flight mode is rotor flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: controlling the drone to rise to the fixed-wing safety height in the rotor flight mode, and moving the drone The heading of the drone is aligned with the return position, the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, the drone is controlled to return to the fixed-wing flight mode, and the flight mode of the drone is changed from the fixed-wing flight mode Smoothly switch to the rotor flight mode, and control the drone to return home in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is the fixed-wing return range, the flight mode is rotor flight mode, and the flying altitude is greater than or equal to the fixed-wing safety height, the return strategy includes: align the drone's heading to the return position, and adjust the drone's flight mode Smoothly switch from the rotor flight mode to the fixed-wing flight mode, control the drone to return home in the fixed-wing flight mode, smoothly switch the drone's flight mode from the fixed-wing flight mode to the rotor flight mode, and control the drone to fly on the rotor Return home in mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range exceeds the fixed-wing return range, the flight mode is fixed-wing flight mode, the flying altitude is greater than or equal to the fixed-wing safety altitude, and the flying altitude is less than the energy-saving descending altitude, the return strategy includes: changing the drone's flight mode from fixed The wing flight mode is smoothly switched to the rotor flight mode, and the drone is controlled to land in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is beyond the fixed-wing return range, the flight mode is fixed-wing flight mode, the flying altitude is greater than or equal to the fixed-wing safety altitude, and the flying altitude is greater than or equal to the energy-saving descent altitude, then the return strategy includes: controlling the drone on the fixed-wing Drop to the target value in flight mode, smoothly switch the drone's flight mode from fixed-wing flight mode to rotary-wing flight mode, control the drone to fall in the rotary-wing flight mode, and the target value is between the fixed-wing safety height and the rotor return height The maximum value.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range exceeds the fixed-wing return range, the flight mode is rotor flight mode, and the flight altitude is less than the energy-saving descent height, the return strategy includes: controlling the drone to land in the rotor flight mode.

Optionally, the method for the processor 1302 to determine the return-home strategy according to the return-home range, flight mode, and flight altitude is specifically as follows:

If the return range is beyond the fixed-wing return range, the flight mode is rotor flight mode, and the flying altitude is greater than or equal to the energy-saving descending altitude, the return strategy includes: align the drone's heading to the return position, and change the drone's flight mode The rotor flight mode is smoothly switched to the fixed-wing flight mode, the drone is controlled to drop to the target value in the fixed-wing flight mode, the flight mode of the drone is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled in In the rotor flight mode, the target value is the maximum value between the safe height of the fixed wing and the return height of the rotor.

Optionally, when the return-to-home strategy includes controlling the drone to ascend to the return height of the rotor in the fixed-wing flight mode, control the drone to rise to the return height of the rotor along the first fixed-wing hovering route.

Optionally, the first fixed-wing hovering ascent route is determined based on the first track inclination angle and the first ascent circle, and the preset hovering radius; the first flight path inclination and the first ascent circle are determined based on the return height of the rotor The difference between the flight altitudes is determined by the preset circling radius and the maximum track inclination.

Optionally, when the return-to-home strategy includes controlling the drone to descend to the target value in the fixed-wing flight mode, controlling the drone to descend to the target value along the first fixed-wing hovering route, the target value is the fixed-wing safety altitude and the rotor The maximum value between the return altitudes.

Optionally, the first fixed-wing hovering descent route is determined based on the second track inclination angle and the first descent circle, and the preset hovering radius. The second flight path inclination and the first descent circle are determined based on the flight altitude and the target The difference between the values is determined by the preset circling radius and the maximum track inclination.

Optionally, when the return strategy includes controlling the drone to return in the fixed-wing flight mode, controlling the drone to ascend along the second fixed-wing hovering ascent route, fly along the fixed-wing horizontal route, and hover along the second fixed-wing descending route decline.

Optionally, the fixed-wing horizontal route includes the initial circle, the end circle and the target tangent. The target tangent and the initial circle are tangent to the first tangent point, and the target tangent and the end circle are tangent to the second tangent point. The flight mode of the aircraft is smoothly switched from the rotor flight mode to the end point of the fixed-wing flight mode. The preset circling radius and the flight mode of the drone are smoothly switched from the rotor flight mode to the fixed-wing flight mode between the starting point and the return position. The connection is determined, and the end circle is determined by the starting point, the preset circling radius and the connection line when the UAV's flight mode is smoothly switched from fixed-wing flight mode to rotary-wing flight mode. The center of the end circle is on the connection line.

Optionally, the second fixed-wing hovering ascent path is determined according to the second ascent circle and the third track inclination angle and the preset hovering radius, and the second ascent circle and the third track inclination angle are determined according to the first projection point and The UAV is determined by the arc length between the end point of the smooth switch from the rotor flight mode to the fixed-wing flight mode, the difference between the fixed-wing return height and the fixed-wing safety height, the preset hovering radius and the maximum track inclination, The first projection point is the point where the projection of the first all point to the plane where the end point of the UAV smoothly switches from the rotor flight mode to the fixed wing flight mode.

Optionally, the second fixed-wing hovering descent route is determined according to the second descent circle and the fourth track inclination angle, and the preset hovering radius, and the second descent circle and the fourth track inclination angle are determined according to the second projection point The target is determined by the arc length between the starting point when the drone is smoothly switched from the fixed-wing flight mode to the rotary-wing flight mode, the difference between the fixed-wing return altitude and the target value, the preset circling radius and the maximum track inclination. The value is the maximum value between the fixed-wing safety height and the rotor return height. The second projection point is the point where the second tangent point is projected to the plane where the UAV smoothly switches from the fixed-wing flight mode to the rotor flight mode.

Optionally, the drone meets the conditions for returning home, including one or more of the following:

The difference between the remaining battery power of the drone and the power required for the drone to return is less than or equal to the preset power threshold;

The disconnection time between the drone and the control terminal is greater than the time threshold;

The hardware equipment of the drone fails;

The current wind speed is greater than the preset wind speed threshold for safe flight of the drone;

Get the return home instruction sent by the control terminal.

Based on the same application concept, the principle of the flight control device provided in the embodiment of this application to solve the problem is similar to that of the method embodiment of this application. Therefore, the implementation of the device can refer to the implementation of the method, and its beneficial effects can be referred to the beneficial effects of the method. Description, I won’t repeat it here.

The embodiments of the present application also provide an unmanned aerial vehicle, wherein the unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode, and includes a fuselage, a communication device, and a flight control device as shown in FIG. 13. The communication device uses To communicate with the control terminal.

In the above-mentioned embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in an embodiment, reference may be made to related descriptions of other embodiments.

Those skilled in the art should be aware that in one or more of the above examples, the functions described in this application can be implemented by hardware, software, firmware or any combination thereof. When implemented by software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on the computer-readable medium. The computer-readable medium includes a computer storage medium and a communication medium, where the communication medium includes any medium that facilitates the transfer of a computer program from one place to another. The storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

The specific implementations described above further describe the purpose, technical solutions and beneficial effects of this application in detail. It should be understood that the above are only specific implementations of this application and are not intended to limit the scope of this application. The protection scope, any modification, equivalent replacement, improvement, etc. made on the basis of the technical solution of this application shall be included in the protection scope of this application.

Claims (65)

A return control method of an unmanned aerial vehicle, characterized in that the unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode, and the method includes: If the drone meets the conditions for returning home, acquiring the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position; Determining a return home strategy according to the flight mode, the horizontal distance and the flight altitude; According to the return-to-home strategy, control the drone to return to home. The method according to claim 1, wherein the return-to-home strategy comprises: controlling the flight mode of the drone to switch between the fixed-wing flight mode and the rotor flight mode. The method according to claim 1, wherein the determining a return strategy according to the flight mode, the horizontal distance and the flight altitude comprises: Determine the return range corresponding to the horizontal distance; The return home strategy is determined according to the return home range, the flight mode, and the flight altitude. The method according to claim 3, wherein the determining the return range corresponding to the horizontal distance comprises: If the horizontal distance is less than the return distance of the rotor, it is determined that the return range is the return range of the rotor; If the horizontal distance is greater than or equal to the return distance of the rotor and less than the return distance of the fixed wing, the return range is determined to be the return range of the fixed wing; If the horizontal distance is greater than or equal to the fixed-wing return distance, it is determined that the return range is beyond the fixed-wing return range. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes : Switch the flight mode of the drone directly from the fixed-wing flight mode to the rotor flight mode, control the drone to rise to the rotor return height in the rotor flight mode, and control the The drone returns home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return The strategy includes: directly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling the drone to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent altitude, then The return strategy includes: controlling the drone to rise to the rotor return height in the fixed-wing flight mode, smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, Control the drone to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude Is greater than the energy-saving ascent height, the return strategy includes: smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling the drone in the rotor flight mode Return home. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then The return-to-home strategy includes: controlling the drone to descend to a target value in the fixed-wing flight mode, smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling The UAV returns home in the rotor flight mode, and the target value is the maximum value between the fixed wing safety height and the rotor return home height. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes: Control the drone to rise to the rotor return height in the rotor flight mode, and control the drone to return to home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return strategy Including: controlling the drone to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent altitude, then The return strategy includes: aligning the heading of the drone to the return position, smoothly switching the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and controlling the drone Ascend to the rotor return height in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to fly on the rotor Return home in mode. The method of claim 4, wherein the determining the return-to-home strategy according to the return-to-home range, the flight mode, and the flight height comprises: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude is greater than For energy-saving ascent, the return-to-home strategy includes: controlling the UAV to return to the home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then the return The strategy includes: aligning the heading of the drone to the return position, smoothly switching the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and controlling the drone to fly Decrease to a target value in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to be in the rotor flight mode Return home, the target value is the maximum value between the fixed wing safety height and the rotor return home height. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: The flight mode is directly switched from the fixed-wing flight mode to the rotor flight mode, the drone is controlled to rise to the fixed-wing safe height in the rotor flight mode, and the heading alignment of the drone is controlled In the return position, the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, the drone is controlled to return home in the fixed-wing flight mode, and the drone is controlled The flight mode of the man-machine is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying altitude is greater than or equal to the fixed-wing safety altitude, the return strategy includes: controlling the unmanned aircraft The aircraft returns to home in the fixed-wing flight mode, smoothly switches the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controls the drone to return to home in the rotor flight mode . The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the fixed-wing return range, the flight mode is the rotor flight mode, and the flying height is less than the fixed-wing safety height, then the return strategy includes: controlling the UAV to travel there. In the rotor flight mode, ascending to the safe height of the fixed wing, aligning the heading of the drone to the return position, and smoothly switching the flight mode of the drone from the rotor flight mode to the fixed wing flight mode, Control the drone to return home in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the fixed-wing return range, the flight mode is the rotor flight mode, and the flying altitude is greater than or equal to the fixed-wing safety altitude, the return strategy includes: turning the drone The heading of the drone is aligned with the return position, the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, the drone is controlled to return in the fixed-wing flight mode, The flight mode of the drone is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying altitude is less than the fixed-wing safety altitude, then the return strategy includes: turning the drone The flight mode is directly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to land in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than the energy-saving descent altitude. The return-to-home strategy includes: smoothly switching the flight mode of the drone from a fixed-wing flight mode to a rotor flight mode, and controlling the drone to land in the rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, Then the return-to-home strategy includes: controlling the drone to drop to a target value in the fixed-wing flight mode, and smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode , Controlling the drone to land in the rotor flight mode, and the target value is the maximum value between the safe height of the fixed wing and the return height of the rotor. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the range beyond the fixed-wing return range, the flight mode is the rotor flight mode, and the flight altitude is less than the energy-saving descending altitude, the return strategy includes: controlling the UAV in the Landing in rotor flight mode. The method according to claim 4, wherein the determining the return strategy according to the return range, the flight mode, and the flight altitude comprises: If the return range is the beyond the fixed-wing return range, the flight mode is the rotor flight mode, and the flight altitude is greater than or equal to the energy-saving descent altitude, then the return strategy includes: Align the heading to the return position, smoothly switch the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and control the drone to descend to the target in the fixed-wing flight mode Value, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, control the drone to land in the rotor flight mode, and the target value is fixed-wing safety The maximum value between the altitude and the return altitude of the rotor. The method of claim 1, wherein when the return strategy includes controlling the drone to rise to the rotor return height in the fixed-wing flight mode, controlling the drone to move along a first fixed The ascent course of the wing circling rises to the return altitude of the rotor. The method according to claim 24, wherein the first fixed-wing hovering ascent course is determined according to a first track inclination angle, a first ascent number, and a preset hovering radius; the first track The inclination angle and the first ascent circle are determined according to the difference between the return height of the rotor and the flying height, the preset circling radius and the maximum track inclination angle. The method of claim 1, wherein when the return strategy includes controlling the drone to descend to a target value in the fixed-wing flight mode, controlling the drone to move along the first fixed-wing The hovering descent course descends to a target value, and the target value is the maximum value between the fixed wing safety height and the rotor return height. The method according to claim 26, wherein the first fixed-wing hovering descent route is determined according to the second track inclination angle, the first descent number, and a preset hovering radius, and the second track The inclination angle and the first descent circle number are determined according to the difference between the flying height and the target value, the preset circling radius, and the maximum track inclination angle. The method of claim 1, wherein when the return strategy includes controlling the drone to return in the fixed-wing flight mode, controlling the drone to hover along the second fixed-wing flight path Ascend, fly along the fixed-wing horizontal course, descend along the second fixed-wing hovering course. The method according to claim 28, wherein the fixed-wing horizontal course includes an initial circle, an end circle, and a target tangent line, the target tangent line is tangent to the initial circle at a first tangent point, and the target tangent line It is tangent to the end circle at the second tangent point, the initial circle is the end point of smoothly switching from the rotor flight mode to the fixed wing flight mode according to the flight mode of the UAV, the preset circling radius and the no The flight mode of the man-machine is determined by the line between the starting point and the return position when the rotor flight mode is smoothly switched to the fixed-wing flight mode. The end circle is determined by the fixed-wing flight according to the flight mode of the drone. The smooth mode switching is determined by the starting point of the rotor flight mode, the preset circling radius and the connecting line, and the center of the ending circle is on the connecting line. The method according to claim 29, wherein the second fixed-wing circling ascent course is determined according to the second ascending circle, the third track inclination and the preset circling radius, the second ascending circle And the third trajectory inclination is based on the arc length between the first projection point and the end point of the UAV smoothly switching from the rotor flight mode to the fixed wing flight mode, the return height of the fixed wing and the fixed wing The difference between the safety height of the wing, the preset circling radius and the maximum track inclination are determined, the first projection point is the projection of the first tangent point to the drone, and the flight mode of the rotor is smoothly switched to The point on the plane where the end point of the fixed-wing flight mode lies. The method according to claim 29, wherein the second fixed-wing hovering descent course is determined according to the second descent circle number and the fourth track inclination angle, and a preset hovering radius, the second descent circle The number and the fourth track inclination are based on the arc length between the second projection point and the starting point of the UAV smoothly switching from the fixed-wing flight mode to the rotary-wing flight mode, the fixed-wing return height and the target value The target value is the maximum value between the fixed wing safety height and the rotor return height, and the second projection point is the The second tangent point is projected to the point on the plane where the starting point of the drone is smoothly switched from the fixed-wing flight mode to the rotor-wing flight mode. The method according to any one of claims 1-31, wherein the drone meets the conditions for returning home, including one or more of the following: The difference between the remaining power of the drone's battery and the power required for the drone to return home is less than or equal to a preset power threshold; The disconnection time of the drone from the control terminal is greater than the time threshold; The hardware equipment of the drone is malfunctioning; The current wind speed is greater than the preset wind speed threshold for safe flight of the drone; Acquire the return home instruction sent by the control terminal. A flight control device, characterized in that the flight control device is applied to an unmanned aerial vehicle, the unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode, and the flight control device includes: a memory and a processor, wherein: The memory is used to store program instructions; The processor calls the program instructions for: If the drone meets the conditions for returning home, acquiring the current flight mode of the drone, the flying height of the drone, and the horizontal distance between the drone and the return position; Determining a return home strategy according to the flight mode, the horizontal distance and the flight altitude; According to the return-to-home strategy, control the drone to return to home. The device according to claim 33, wherein the return-to-home strategy comprises: controlling the flight mode of the drone to switch between the fixed-wing flight mode and the rotor flight mode. The device according to claim 33, wherein when the processor determines a return strategy according to the flight mode, the horizontal distance and the flight altitude, it is specifically configured to: Determine the return range corresponding to the horizontal distance; The return home strategy is determined according to the return home range, the flight mode, and the flight altitude. The device according to claim 35, wherein when the processor determines the return range corresponding to the horizontal distance, it is specifically configured to: If the horizontal distance is less than the return distance of the rotor, it is determined that the return range is the return range of the rotor; If the horizontal distance is greater than or equal to the return distance of the rotor and less than the return distance of the fixed wing, the return range is determined to be the return range of the fixed wing; If the horizontal distance is greater than or equal to the fixed-wing return distance, it is determined that the return range is beyond the fixed-wing return range. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes : Switch the flight mode of the drone from the fixed-wing flight mode directly to the rotor flight mode, control the drone to rise to the rotor return height in the rotor flight mode, and control the drone The aircraft returns to home in rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is less than the fixed-wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return The strategy includes: directly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling the drone to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent altitude, then The return strategy includes: controlling the drone to rise to the rotor return height in the fixed-wing flight mode, smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, Control the drone to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude Is greater than the energy-saving ascent height, the return strategy includes: smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling the drone in the rotor flight mode Return home. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then The return-to-home strategy includes: controlling the drone to descend to a target value in the fixed-wing flight mode, smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controlling The UAV returns home in the rotor flight mode, and the target value is the maximum value between the fixed wing safety height and the rotor return home height. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is less than the rotor return altitude, then the return strategy includes: Control the drone to rise to the rotor return height in the rotor flight mode, and control the drone to return to home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is less than the fixed wing safety altitude, and the flight altitude is greater than or equal to the rotor return altitude, then the return strategy Including: controlling the drone to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than or equal to the energy-saving ascent altitude, then The return strategy includes: aligning the heading of the drone to the return position, smoothly switching the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and controlling the drone Ascend to the rotor return height in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to fly on the rotor Return home in mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, the flight altitude is less than the energy-saving descent altitude, and the flight altitude is greater than For energy-saving ascent, the return-to-home strategy includes: controlling the UAV to return to the home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the rotor return range, the flight mode is the rotor flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, then the return The strategy includes: aligning the heading of the drone to the return position, smoothly switching the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and controlling the drone to fly Decrease to a target value in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to be in the rotor flight mode Return home, the target value is the maximum value between the fixed wing safety height and the rotor return home height. The device according to claim 36, wherein when the processor determines the return home strategy according to the return home range, the flight mode, and the flight altitude, it is specifically configured to: If the return range is the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying height is less than the fixed-wing safety height, the return strategy includes: The flight mode is directly switched from the fixed-wing flight mode to the rotor flight mode, the drone is controlled to rise to the fixed-wing safe height in the rotor flight mode, and the heading alignment of the drone is controlled In the return position, the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, the drone is controlled to return home in the fixed-wing flight mode, and the drone is controlled The flight mode of the man-machine is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying altitude is greater than or equal to the fixed-wing safety altitude, the return strategy includes: controlling the unmanned aircraft The aircraft returns to home in the fixed-wing flight mode, smoothly switches the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and controls the drone to return to home in the rotor flight mode . The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the fixed-wing return range, the flight mode is the rotor flight mode, and the flying height is less than the fixed-wing safety height, then the return strategy includes: controlling the UAV to travel there. In the rotor flight mode, ascending to the safe height of the fixed wing, aligning the heading of the drone to the return position, and smoothly switching the flight mode of the drone from the rotor flight mode to the fixed wing flight mode, Control the drone to return home in the fixed-wing flight mode, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, and control the drone to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the fixed-wing return range, the flight mode is the rotor flight mode, and the flying altitude is greater than or equal to the fixed-wing safety altitude, the return strategy includes: turning the drone The heading of the drone is aligned with the return position, the flight mode of the drone is smoothly switched from the rotor flight mode to the fixed-wing flight mode, the drone is controlled to return in the fixed-wing flight mode, The flight mode of the drone is smoothly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to return home in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, and the flying altitude is less than the fixed-wing safety altitude, then the return strategy includes: turning the drone The flight mode is directly switched from the fixed-wing flight mode to the rotor flight mode, and the drone is controlled to land in the rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is less than the energy-saving descent altitude. The return-to-home strategy includes: smoothly switching the flight mode of the drone from a fixed-wing flight mode to a rotor-wing flight mode and controlling the drone to land in the rotor-wing flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the beyond the fixed-wing return range, the flight mode is the fixed-wing flight mode, the flight altitude is greater than or equal to the fixed-wing safety altitude, and the flight altitude is greater than or equal to the energy-saving descent altitude, Then the return-to-home strategy includes: controlling the drone to drop to a target value in the fixed-wing flight mode, and smoothly switching the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode , Controlling the drone to land in the rotor flight mode, and the target value is the maximum value between the safe height of the fixed wing and the return height of the rotor. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the range beyond the fixed-wing return range, the flight mode is the rotor flight mode, and the flight altitude is less than the energy-saving descending altitude, the return strategy includes: controlling the UAV in the Landing in rotor flight mode. The device according to claim 36, wherein the processor is specifically configured to: when determining the return strategy according to the return range, the flight mode, and the flight altitude: If the return range is the beyond the fixed-wing return range, the flight mode is the rotor flight mode, and the flight altitude is greater than or equal to the energy-saving descent altitude, then the return strategy includes: Align the heading to the return position, smoothly switch the flight mode of the drone from the rotor flight mode to the fixed-wing flight mode, and control the drone to descend to the target in the fixed-wing flight mode Value, smoothly switch the flight mode of the drone from the fixed-wing flight mode to the rotor flight mode, control the drone to land in the rotor flight mode, and the target value is fixed-wing safety The maximum value between the altitude and the return altitude of the rotor. The device according to claim 33, wherein when the return strategy includes controlling the drone to rise to the rotor return height in the fixed-wing flight mode, controlling the drone to move along the first fixed wing The ascent course of the wing circling rises to the return altitude of the rotor. The device according to claim 56, wherein the first fixed-wing hovering ascent course is determined according to a first track inclination angle, a first ascent number, and a preset hovering radius; the first track The inclination angle and the first ascent circle are determined according to the difference between the return height of the rotor and the flying height, the preset circling radius and the maximum track inclination angle. The device according to claim 33, wherein when the return strategy includes controlling the drone to descend to a target value in the fixed-wing flight mode, controlling the drone to move along the first fixed-wing The hovering descent course descends to a target value, and the target value is the maximum value between the fixed wing safety height and the rotor return height. The device according to claim 58, wherein the first fixed-wing hovering descent course is determined according to the second track inclination angle, the first descent number, and a preset hovering radius, and the second track The inclination angle and the first descent circle number are determined according to the difference between the flying height and the target value, the preset circling radius, and the maximum track inclination angle. The device according to claim 33, wherein when the return strategy includes controlling the drone to return in the fixed-wing flight mode, controlling the drone to hover along the second fixed-wing flight path Ascend, fly along the fixed-wing horizontal course, descend along the second fixed-wing hovering course. The device according to claim 60, wherein the horizontal course of the fixed wing comprises an initial circle, an end circle and a target tangent line, the target tangent line is tangent to the initial circle at a first tangent point, and the target tangent line It is tangent to the end circle at the second tangent point, the initial circle is the end point of smoothly switching from the rotor flight mode to the fixed wing flight mode according to the flight mode of the UAV, the preset circling radius and the no The flight mode of the man-machine is determined by the line between the starting point and the return position when the rotor flight mode is smoothly switched to the fixed-wing flight mode. The end circle is determined by the fixed-wing flight according to the flight mode of the drone. The mode smooth switching is determined by the starting point of the rotor flight mode, the preset circling radius and the connecting line, and the center of the ending circle is on the connecting line. The device according to claim 61, wherein the circling ascent course of the second fixed wing is determined according to the second ascending circle and the third track inclination angle and a preset circling radius, the second ascending circle And the third trajectory inclination is based on the arc length between the first projection point and the end point of the UAV smoothly switching from the rotor flight mode to the fixed wing flight mode, the return height of the fixed wing and the fixed wing The difference between the safety height of the wing, the preset circling radius and the maximum track inclination are determined, the first projection point is the projection of the first tangent point to the drone, and the flight mode of the rotor is smoothly switched to The point on the plane where the end point of the fixed-wing flight mode lies. The device according to claim 61, wherein the spiral descent course of the second fixed wing is determined according to the second number of descent laps, the fourth track inclination angle, and a preset circling radius, and the second descent circle The number and the fourth track inclination are based on the arc length between the second projection point and the starting point of the UAV smoothly switching from the fixed-wing flight mode to the rotary-wing flight mode, the fixed-wing return height and the target value The target value is the maximum value between the fixed wing safety height and the rotor return height, and the second projection point is the The second tangent point is projected to the point on the plane where the starting point of the drone is smoothly switched from the fixed-wing flight mode to the rotor-wing flight mode. The device according to any one of claims 33-63, wherein the drone meets the conditions for returning home, including one or more of the following: The difference between the remaining power of the drone's battery and the power required for the drone to return home is less than or equal to a preset power threshold; The disconnection time of the drone from the control terminal is greater than the time threshold; The hardware equipment of the drone is malfunctioning; The current wind speed is greater than the preset wind speed threshold for safe flight of the drone; Acquire the return home instruction sent by the control terminal. An unmanned aerial vehicle, characterized in that the unmanned aerial vehicle has a fixed-wing flight mode and a rotary-wing flight mode, and the unmanned aerial vehicle includes: body; The communication device is used to communicate with the control terminal; The flight control device according to any one of claims 33-63.

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