Drone control methods and drones

Abstract

A control method for unmanned aerial vehicles (UAVs) (1a, 1b, 1c) and the UAVs (1a, 1b, 1c) are disclosed. The control method for the UAVs (1a, 1b, 1c) includes: generating a return-to-home command to cause the UAVs (1a, 1b, 1c) to perform a return-to-home action, the return-to-home action including at least a cruise phase; during the cruise phase, measuring the flight parameters of the UAVs (1a, 1b, 1c); when the flight parameters indicate that the UAVs (1a, 1b, 1c) are in a high-wind-impeded state, the UAVs (1a, 1b, 1c) enter a high-wind return-to-home phase; during the high-wind return-to-home phase, measuring the flight parameters; when the flight parameters indicate that the UAVs (1a, 1b, 1c) have exited the high-wind-impeded state, the UAVs (1a, 1b, 1c) return to the cruise phase.

Description

Technical Field

[0001] This disclosure relates to the field of unmanned aerial vehicles (UAVs), and more particularly to a control method for an UAV and the UAV itself. Background Technology

[0002] Drones may encounter strong winds during their return flight or normal operations. When the wind is strong, the forward force of the drone may not be sufficient to counteract the wind, which can reduce the drone's speed or even cause it to come to a standstill. Wind can also cause the drone's course to deviate significantly from its preset course. Current technology does not detect strong winds, and drones do not take precautions against them during flight, which can easily lead to the drone running out of power and failing to reach its target, thus compromising flight safety. Summary of the Invention

[0003] This disclosure provides a control method for an unmanned aerial vehicle (UAV), comprising: generating a return-to-home command to cause the UAV to perform a return-to-home action, the return-to-home action including at least a cruise phase; measuring the flight parameters of the UAV during the cruise phase, and when the flight parameters indicate that the UAV is in a wind-damped state, the UAV enters a wind-damped return-to-home phase; measuring the flight parameters during the wind-damped return-to-home phase, and when the flight parameters indicate that the UAV has exited the wind-damped state, the UAV returns to the cruise phase.

[0004] This disclosure also provides a drone, comprising: a fuselage, the fuselage being provided with a controller and at least one measuring device; the controller being used to generate a return-to-home command to cause the drone to perform a return-to-home action, the return-to-home action including at least a cruise phase; during the cruise phase, the at least one measuring device being used to measure the flight parameters of the drone; when the controller determines based on the flight parameters that the drone is in a high-wind-impeded state, the controller controls the drone to enter the high-wind return-to-home phase; during the high-wind return-to-home phase, the at least one measuring device being used to measure the flight parameters; when the controller determines based on the flight parameters that the drone has exited the high-wind-impeded state, the controller controls the drone to return to the cruise phase.

[0005] As can be seen from the above technical solutions, the embodiments disclosed herein have at least the following beneficial effects:

[0006] By detecting whether the drone is hindered by strong winds during the cruise phase and implementing corresponding return-to-home strategies to avoid the impact of strong winds on the return, the reliability and safety of the drone's return are improved. Attached Figure Description

[0007] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0008] Figure 1 This is a flowchart of a drone control method according to an embodiment of the present disclosure.

[0009] Figure 2 This is a flowchart of the drone's return-to-home action according to an embodiment of this disclosure.

[0010] Figure 3 This is a schematic diagram of the structure of a pitot tube for an unmanned aerial vehicle according to an embodiment of the present disclosure.

[0011] Figure 4 This is a schematic diagram of the structure of an unmanned aerial vehicle according to an embodiment of the present disclosure.

[0012] Figure 5 This is a top view of an embodiment of an unmanned aerial vehicle (UAV) disclosed herein.

[0013] Figure 6 This is a top view of a drone according to another embodiment of this disclosure.

[0014] Figure 7 This is a top view of another embodiment of the UAV disclosed herein.

[0015] [Symbol Explanation]

[0016] 1a, 1b, 1c - Unmanned aerial vehicles (UAVs);

[0017] 10a, 10b, 10c - Fuselage;

[0018] 11a, 11b, 11c - Controllers;

[0019] 12a, 12b, 12c - Positioning devices;

[0020] 13a, 13c - Airspeed gauges;

[0021] 131a, 131c - Pitot tubes;

[0022] 1311 - Total pressure hole; 1312 - Static pressure hole; 1313 - Total pressure outlet tube; 1314 - Static pressure outlet tube; 1315 - Alignment handle; D - Diameter of probe; d - Diameter of total pressure hole;

[0023] 132a, 132c - Pressure gauges;

[0024] 133a, 133c - Support tubes;

[0025] 14a, 14b, 14c - Obstacle detection devices;

[0026] 20a, 20b, 20c - Power unit;

[0027] θ - included angle; p1, p2 - positions of the pitot tubes; α - maximum flight tilt angle; R - area affected by airflow;

[0028] W - Wind direction; W1 - Component parallel to the cruise heading; W2 - Component perpendicular to the cruise heading;

[0029] C - Cruise heading; E - Actual heading. Detailed Implementation

[0030] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0031] One embodiment of this disclosure provides a control method for an unmanned aerial vehicle (UAV), such as... Figure 1 As shown, the control method includes the following steps:

[0032] Step S101: By sending a return-to-home command to the drone, the drone performs a return-to-home action, which includes at least one cruise phase.

[0033] like Figure 2 As shown, the return maneuver includes: climb phase S1, cruise phase S2, and descent phase S3. Cruise phase S2 includes a high-wind return phase S21.

[0034] The climb phase includes stages such as return preparation, forced climb, course alignment, and automatic climb.

[0035] The drone first performs a braking and hovering maneuver to prepare for its return. When the drone is hovering, or its speed is lower than the preset speed, or the braking and hovering maneuver has lasted for more than the preset time, the drone enters the forced ascent phase.

[0036] During the forced ascent phase, the drone ascends at a preset speed. When the drone reaches the preset altitude, or when the forced ascent time has exceeded the preset time, the drone enters the heading alignment phase.

[0037] During the heading alignment phase, the drone hovers at a preset altitude and adjusts its heading to align with the cruise heading. The drone can point either nose-to-home or tail-to-home. When the difference between the drone's actual heading and the cruise heading is less than a preset angle, or when the heading adjustment time has exceeded a preset time, the drone enters the automatic ascent phase.

[0038] During the automatic ascent phase, the drone ascends to its cruising altitude at a preset speed. The cruising altitude is the lesser of the preset return-to-home altitude and the drone's altitude limit. The drone enters the cruise phase when it reaches its cruising altitude, when the automatic ascent time has exceeded the preset time, or when the drone receives a throttle control command.

[0039] During the cruise phase, the drone flies towards the return point at a preset speed. When the drone reaches directly above the return point, the cruise phase ends, and the drone enters the landing phase.

[0040] During the landing phase, the drone descends at a preset speed until it lands at the target point, completing the return flight.

[0041] In addition, during the cruise phase, the drone will detect the distance between its current position and surrounding objects. When the distance is less than the preset distance, the surrounding object is considered an obstacle. At this time, the cruise phase may also include an obstacle avoidance phase.

[0042] During the obstacle avoidance phase, the drone first performs a braking and hovering maneuver and calculates its retraction position. Then, the drone reverses towards the retraction position. When the distance between the drone's current position and the retraction position is less than a preset distance, or the retraction time exceeds a preset time, the drone begins obstacle avoidance ascent. During the obstacle avoidance ascent, the drone continuously monitors its distance to obstacles. When the distance to an obstacle exceeds a preset distance, or the obstacle avoidance ascent time exceeds a preset time, the drone continues cruising to the return point at the altitude reached after obstacle avoidance ascent.

[0043] Step S102: During the cruise phase, the flight parameters of the UAV are measured. When the flight parameters indicate that the UAV is in a state of high wind obstruction, the UAV enters the high wind return phase.

[0044] In this embodiment, the flight parameters include the airspeed and ground speed of the UAV. The UAV is equipped with a positioning device and an airspeed meter, used to measure the ground speed and airspeed of the UAV during flight, respectively. Ground speed refers to the speed of the UAV relative to the ground, and airspeed refers to the speed of the UAV relative to the air. The positioning device is, for example, a GPS receiver and / or an inertial measurement unit. The airspeed meter includes a pitot tube mounted on the outside of the UAV fuselage. When the UAV is flying in the air, the incoming airflow faces the total pressure orifice of the pitot tube, generating hysteresis pressure. The static pressure orifice of the pitot tube measures the static pressure, and the airspeed meter can calculate the dynamic pressure according to Bernoulli's equation, thereby obtaining the airspeed of the UAV.

[0045] In this embodiment, the wind-induced stalling state refers to the speed stalling state. For the return maneuver, when the wind direction W is as follows... Figure 5As shown, when the drone's airspeed is higher than its cruising trajectory, it indicates two possible scenarios. One is that the drone is in a windless, low-wind, or light-wind environment, flying at a high ground speed. The other is a speed stagnation state, where the wind speed is high, but the drone's ground speed is very low or even zero. In this case, although the airspeed meter measures a high airspeed, the wind force makes it almost impossible for the drone to fly back to its return point. If the drone continues cruising, it will be very difficult to complete the return maneuver.

[0046] Therefore, during the cruise phase, the airspeed and ground speed of the UAV are first measured using an airspeed meter and a positioning device, and the difference between the airspeed and ground speed is calculated. Then, it is determined whether the difference is greater than a first threshold. If it is less than the first threshold, it indicates that the wind speed is not high enough to affect the UAV's cruise. If it is greater than the first threshold, it indicates that the wind speed is high, and due to the wind force, the UAV is finding it difficult to fly back to the return point, resulting in a speed stagnation state, requiring the UAV to enter the high-wind return phase.

[0047] When a drone is cruising, regardless of whether its nose or tail is facing the return point, its fuselage has a certain angle relative to the horizontal plane. When the wind speed is high, in order to resist the effect of the wind, the drone will continuously increase this angle of tilt and fly at the maximum angle of tilt.

[0048] In this embodiment, the airspeed of the UAV is measured during the cruise phase when it is cruising at its maximum flight tilt angle. That is, when the UAV is cruising at its maximum flight tilt angle, the axis of the pitot tube is parallel to the cruise heading, thereby improving the accuracy of airspeed measurement and allowing for a more accurate determination of the airspeed stall state.

[0049] Meanwhile, the air entering the pitot tube is air outside the airflow influence area of ​​the drone's fuselage, such as around the rotor, especially below the rotor. The airspeed meter uses air outside the airflow influence area to measure airspeed, which can avoid the airflow of the fuselage affecting the pitot tube and further improve the accuracy of airspeed measurement.

[0050] Step S103: During the high wind return phase, measure the flight parameters. When it is determined from the flight parameters that the UAV has exited the high wind obstruction state, the UAV returns to the cruise phase.

[0051] Wind is formed by the large-scale movement of air. As wind flows across the Earth's surface, it creates friction with objects on the surface, causing wind speed to decrease. As altitude decreases, the effect of air-to-surface friction gradually increases, and airflow slows down. Therefore, for drones flying near the Earth's surface, wind speed decreases as altitude decreases.

[0052] Therefore, to overcome the speed lag, during the high-wind return phase, the drone enters a descent phase, maintaining cruise power and descending at a preset speed. As the wind speed gradually decreases during descent, the drone is continuously monitored to determine if it has exited the speed lag state. If it has, the drone stops descent and returns to the cruise phase to continue flying towards the return point.

[0053] During descent, the airspeed and ground speed of the UAV are measured using an airspeed meter and a positioning device, and the difference between the airspeed and ground speed is calculated. Then, it is determined whether the difference is greater than a first threshold. If it is still greater than the first threshold, it indicates that the UAV is still in a speed-stalled state. If it is less than the first threshold, it is considered that the UAV has exited the speed-stalled state, and the UAV returns to the cruise phase, continuing to cruise to the return point at the altitude it reached after descent.

[0054] In this embodiment, the drone can also perform obstacle avoidance maneuvers during the return-to-home phase in strong winds. During the descent phase, if there is an obstacle below the drone, the drone stops descending and maintains its cruise power. When the obstacle is no longer below the drone, the drone continues its descent. This avoids damage to the drone from obstacles and improves cruise safety.

[0055] As can be seen, this embodiment detects whether the drone is in a state of speed stagnation during the cruise phase and executes the corresponding return-to-home strategy to avoid the impact of strong winds on the return-to-home, thereby ensuring that the drone can return safely. This solves the problem of slow or even stalled return-to-home speed in strong winds, which leads to the drone running out of power and being unable to return, thus improving the reliability and safety of drone return-to-home.

[0056] If a drone encounters strong winds and becomes stuck in a wind-damped state, it will be difficult for it to continue flying normally. When the drone is in flight, the control method in this embodiment measures flight parameters, and when it is determined from the flight parameters that the drone is stuck in a wind-damped state, a return-to-home command is generated.

[0057] First, the airspeed and ground speed of the drone are measured using an airspeed meter and a positioning device, respectively, and the difference between the airspeed and ground speed is calculated. Then, it is determined whether the difference is greater than a first threshold. If it is less than the first threshold, it means that the wind speed is not high enough to affect the normal flight of the drone. If it is greater than the first threshold, it means that the wind speed is high, and due to the wind force, the drone can hardly fly normally and is in a state of airspeed stagnation. At this time, a return-to-home command is generated, causing the drone to perform the return-to-home action as described above.

[0058] Therefore, this embodiment improves the reliability and safety of UAV flight by determining whether the UAV is in a speed stagnation state during normal flight and generating a return-to-home command to avoid the impact of strong winds on normal flight.

[0059] The control method for a drone according to another embodiment of this disclosure is described in a brief manner. Its features that are the same as or similar to those in the previous embodiment will not be repeated. Only its features that are different from those in the previous embodiment will be described below.

[0060] In the control method of this embodiment, during the cruise phase, when the UAV is in a state of high wind obstruction, it enters the high wind return phase. The state of high wind obstruction refers to the state of deviation from the flight path. The flight parameters include the actual flight path of the UAV.

[0061] During the cruise phase, when the wind direction is W... Figure 6 As shown, when the drone's cruising heading C is perpendicular to its actual heading E, the wind will cause the drone's actual heading E to deviate from the cruising heading C, forming an angle θ between them. The magnitude of this angle θ reflects the difference between the actual heading E and the cruising heading C. This angle θ increases with increasing wind force. When the angle θ becomes too large, the actual heading E will deviate significantly from the cruising heading C, and the drone will be unable to successfully reach its return point.

[0062] Therefore, during the cruise phase, the actual heading E of the UAV is measured using a positioning device, and the difference between the actual heading E and the cruise heading C is calculated. Then, it is determined whether the difference is greater than a second threshold. If it is less than the second threshold, it indicates that the wind force is not strong enough to affect the UAV's cruise. If it is greater than the second threshold, it indicates that the wind force is strong, and due to the wind, the UAV is flying in a direction deviating from the return-to-home point, resulting in a heading deviation, requiring the UAV to enter the high-wind return-to-home phase.

[0063] Similar to the previous embodiment, to overcome the course deviation, the UAV enters the descent phase during the high-wind return phase. As the descent progresses, the wind speed gradually decreases, and the system continuously monitors whether the UAV has exited the course deviation state. If it has, the UAV stops its descent and returns to the cruise phase to continue flying towards the return point.

[0064] During descent, the actual heading E of the drone is measured using a positioning device, and the difference between the actual heading E and the cruise heading C is calculated. Then, it is determined whether the difference is greater than a second threshold. If it is still greater than the second threshold, it indicates that the drone is still in a heading deviation state. If it is less than the second threshold, it is considered that the drone has exited the heading deviation state, and the drone returns to the cruise phase, continuing to cruise to the return point at the altitude after descent.

[0065] Therefore, this embodiment detects whether the drone is deviating from its course during the cruise phase and executes the corresponding return-to-home strategy to avoid the impact of strong winds on the return-to-home process, thereby ensuring the drone can return safely. This solves the problem of course deviation in strong winds causing the drone to run out of power and be unable to return, thus improving the reliability and safety of the drone's return-to-home process.

[0066] Similar to the previous embodiment, when the drone is in flight, the control method of this embodiment measures the flight parameters. When it is determined from the flight parameters that the drone is in a state of strong wind obstruction, a return-to-home command is generated.

[0067] First, the actual heading E of the drone is measured using a positioning device, and the difference between the actual heading E and the set flight heading is calculated. Then, it is determined whether the difference is greater than a second threshold. If it is less than the second threshold, it means that the wind speed is insufficient to affect the normal flight of the drone. If it is greater than the second threshold, it means that the wind speed is very high, and due to the wind force, the drone has seriously deviated from the set flight heading and is in a heading deviation state. At this time, a return-to-home command is generated, causing the drone to perform the return-to-home action as described above.

[0068] Therefore, this embodiment improves the reliability and safety of drone flight by determining whether the drone is deviating from its course during normal flight and generating a return-to-home command to avoid the impact of strong winds on normal flight.

[0069] Another embodiment of the drone control method disclosed herein is described briefly, and its features that are the same as or similar to those in the above embodiments will not be repeated. Only its features that are different from those in the above embodiments will be described below.

[0070] In the control method of this embodiment, during the cruise phase, when the UAV is in a state of high wind obstruction, it enters the high wind return phase. The high wind obstruction state includes a speed obstruction state and a heading deviation state. The flight parameters include the UAV's ground speed, airspeed, and actual heading.

[0071] During the cruise phase, when the wind direction is W... Figure 7 When the wind direction W is neither parallel nor perpendicular to the cruise heading C, it can be decomposed into a component W1 parallel to the cruise heading and a component W2 perpendicular to the cruise heading. In the W1 direction, the wind component in that direction may cause the UAV to experience speed stagnation. In the W2 direction, the wind component in that direction may cause the UAV to experience heading deviation.

[0072] Therefore, during the cruise phase, the airspeed of the UAV is measured using an airspeed meter, the ground speed and actual heading E of the UAV are measured using a positioning device, and the difference between the airspeed and ground speed of the UAV, as well as the difference between the actual heading E and the cruise heading C, are calculated.

[0073] Then, determine whether the difference between the drone's airspeed and ground speed exceeds a first threshold, and whether the difference between the actual heading E and the cruising heading C exceeds a second threshold. If either of these conditions is met, it indicates that under the influence of wind, the drone is finding it difficult to fly back to the return point, or is flying in a direction deviating from the return point. If both conditions are met, it indicates that both situations are occurring simultaneously. The drone is in a state of airspeed stagnation and / or heading deviation, requiring it to enter the high-wind return phase.

[0074] Therefore, to overcome the wind resistance, during the high-wind return phase, the drone enters a descent phase, maintaining cruise power and descending at a preset speed. As the wind speed gradually decreases during descent, the drone is continuously monitored to determine if it has exited the speed resistance and heading deviation states. If it has exited these states, the drone stops descent and returns to the cruise phase to continue flying towards the return point.

[0075] During the descent, the airspeed of the UAV is measured using an airspeed meter, and the ground speed and actual heading E of the UAV are measured using a positioning device. The difference between the airspeed and ground speed of the UAV, as well as the difference between the actual heading E and the cruising heading C, are calculated.

[0076] Then, it is determined whether the difference between the drone's airspeed and ground speed is greater than the first threshold, and whether the difference between the actual heading E and the cruising heading C is greater than the second difference. If neither of the above two conditions is met, it is considered that the drone has exited the high wind jamming state, and the drone returns to the cruising phase, continuing to cruise to the return point at the descending altitude.

[0077] Therefore, this embodiment detects whether the UAV is in a state of speed stagnation and heading deviation during the cruise phase and executes the corresponding return-to-home strategy to avoid the impact of strong winds on the return-to-home, thereby ensuring that the UAV can return safely. This solves the problem of speed stagnation and heading deviation in strong winds in the prior art, which causes the UAV to run out of power and be unable to return, thus improving the reliability and safety of the UAV's return-to-home.

[0078] Similar to the above embodiments, when the UAV is in flight, the control method of this embodiment measures the flight parameters. When it is determined from the flight parameters that the UAV is in a state of strong wind obstruction, a return-to-home command is generated.

[0079] First, the airspeed of the UAV is measured using an airspeed meter. Then, the ground speed and actual heading E of the UAV are measured using a positioning device. Finally, the difference between the airspeed and ground speed, as well as the difference between the actual heading E and the cruising heading C, are calculated.

[0080] Then, it is determined whether the difference between the drone's airspeed and ground speed is greater than a first threshold, and whether the difference between the actual heading E and the cruising heading C is greater than a second difference. When at least one of the two conditions is met, a return-to-home command is generated, causing the drone to perform the return-to-home action as described above.

[0081] Therefore, this embodiment improves the reliability and safety of drone flight by determining whether the drone is in a wind-damped state during normal flight and generating a return-to-home command to avoid the impact of strong winds on normal flight.

[0082] This disclosure provides an embodiment of an unmanned aerial vehicle (UAV) 1a. For example... Figure 5 As shown, the UAV 1a includes a fuselage 10a and a power unit 20a. The power unit 20a includes four arms extending from the fuselage 10a and rotors mounted on the arms for generating power.

[0083] The fuselage 10a is equipped with: a controller 11a, an airspeed measuring device, and a ground speed measuring device. Flight parameters include: the airspeed and ground speed of the UAV 1a.

[0084] A ground speed measuring device, such as a GPS receiver or an inertial measurement unit, is a positioning device 12a installed inside the fuselage 10a and electrically connected to the controller 11a, used to measure the ground speed of the UAV 1a during flight.

[0085] An airspeed measuring device, such as an airspeed meter 13a, is electrically connected to a controller 11a and is used to measure the airspeed of the UAV 1a during flight.

[0086] The controller 11a, located inside the fuselage 10a, is used to receive the measurement values ​​from the airspeed measuring device and the ground speed measuring device, and to control the action of the power unit 20a to control the flight of the UAV 1a.

[0087] In this embodiment, the controller 11a is used to generate a return-to-home command, causing the drone 1a to perform a return-to-home action, which includes at least a cruise phase.

[0088] During the cruise phase, airspeed meter 13a measures the airspeed of UAV 1a, and positioning device 12a measures the ground speed of UAV 1a. When controller 11a determines that UAV 1a is in a speed-impaired state, it initiates the high-wind return-to-home phase. Specifically, controller 11a calculates the difference between UAV 1a's airspeed and ground speed, and then determines whether the difference is greater than a first threshold. If it is less than the first threshold, it indicates that the wind speed is not high enough to affect UAV 1a's cruise. If it is greater than the first threshold, it indicates that the wind speed is high, and due to the wind force, UAV 1a has difficulty flying back to the return point, is in a speed-impaired state, and initiates the high-wind return-to-home phase.

[0089] The airspeed indicator 13a includes a pitot tube 131a mounted on the outside of the drone fuselage 10a and a pressure gauge 132a mounted inside the fuselage 10a.

[0090] The Pitot tube 131a, also known as an airspeed tube or pitot tube, is a device for measuring the point velocity of fluids. For example... Figure 3 As shown, this embodiment uses an L-shaped Pitot tube, which is a metal tube bent at a right angle, comprising two sleeves: a total pressure tube and a static pressure tube, which are not connected to each other. One section of the L-shaped Pitot tube is a probe, where D is the diameter of the probe. The top of the probe has a total pressure hole 1311 communicating with the total pressure tube, where d is the diameter of the total pressure hole 1311. The side of the probe has a static pressure hole 1312 communicating with the static pressure tube. The other section of the L-shaped Pitot tube is a support rod, the bottom of which has a total pressure outlet tube 1313, a static pressure outlet tube 1314, and an alignment handle 1315.

[0091] The pressure gauge 132a includes a piezoelectric sensor and processing circuitry. The pressure sensor converts a pressure signal into an electrical signal. The processing circuitry includes an amplifier, a filter, and an A / D converter, which process the electrical signal output from the piezoelectric sensor to obtain the measured pressure value.

[0092] like Figure 4 As shown, the pitot tube 131a is mounted on the back of the body 10a (pito tube position p1) or the front or rear of the body 10a (pito tube position p2) via a support tube 133a. The support tube 133a includes two sleeves: an inner tube and an outer tube that are not connected to each other. One end of the inner tube is connected to the total pressure outlet tube 1313, and one end of the outer tube is connected to the static pressure outlet tube 1314. The other ends of both the inner and outer tubes are connected to the piezoelectric sensor of the pressure gauge 132a.

[0093] During the cruise phase, air enters the pitot tube 131a through the total pressure port 1311, and then flows through the inner tubes of the total pressure tube, total pressure outlet tube 1313, and support tube 133a into the pressure gauge 132a. The piezoelectric sensor of the pressure gauge 132a converts the air pressure into an electrical signal. This electrical signal is amplified, filtered, and converted by an A / D converter to obtain the total pressure measurement value. Air enters the pitot tube 131a through the static pressure port 1312, and then flows through the outer tubes of the static pressure tube, static pressure outlet tube 1314, and support tube 133a into the pressure gauge 132a. The piezoelectric sensor of the pressure gauge 132a converts the air pressure into an electrical signal. This electrical signal is amplified, filtered, and converted by an A / D converter to obtain the static pressure measurement value. The controller 11a receives the total pressure and static pressure measurements from the airspeed indicator 13a and calculates the dynamic pressure and the airspeed of the UAV 1a according to Bernoulli's equation.

[0094] In this embodiment, the UAV 1a has a pitot tube 131a mounted on the outside of the fuselage 10a via a support tube 133a. The pitot tube 131a is spaced a certain distance from the fuselage 10a and is located outside the airflow influence area R of the fuselage 10a, such as around the rotor, especially below the rotor. This can prevent the airflow of the fuselage from affecting the pitot tube 131a and further improve the accuracy of airspeed measurement.

[0095] like Figure 4 As shown, the angle between the axis of the pitot tube 131a and the fuselage 10a is equal to the maximum flight tilt angle α of the UAV 1a. That is, when the UAV 1a cruises at the maximum flight tilt angle α, the axis of the pitot tube 131a is parallel to the cruise heading. In this way, the pitot tube 131a measures the airspeed of the UAV 1a when it cruises at the maximum flight tilt angle α, thereby improving the accuracy of airspeed measurement and allowing for a more accurate determination of the airspeed stall state.

[0096] The above is merely an illustrative example, and this embodiment is not limited thereto. For example, two pitot tubes 131a can be installed on the back of the fuselage 10a, facing the nose and tail respectively; or, pitot tubes 131a can be installed simultaneously on the front and rear of the fuselage 10a, so that airspeed can be measured regardless of whether the nose or tail of the drone 1a faces the return point. The pitot tubes 131a can also be directly installed on the back, front, or rear surface of the fuselage 10a, which can reduce the overall volume and size of the drone 1a without affecting its appearance.

[0097] During the high-wind return phase, airspeed meter 13a measures the airspeed of UAV 1a during flight, and positioning device 12a measures the ground speed of UAV 1a during flight. Controller 11a determines whether the difference between airspeed and ground speed is greater than a first threshold. If not, UAV 1a exits the airspeed stagnation state, and controller 11a causes UAV 1a to return to the cruise phase.

[0098] To overcome the speed lag, during the high-wind return phase, controller 11a issues a command to initiate the descent phase of UAV 1a. During descent, UAV 1a maintains cruise power and descends at a preset speed. As the wind speed gradually decreases during descent, controller 11a continuously monitors whether UAV 1a has exited the speed lag state. If it has, UAV 1a stops its descent and returns to the cruise phase to continue flying towards the return point.

[0099] During descent, the airspeed meter 13a and the positioning device 12a measure the airspeed and ground speed of the UAV 1a, respectively. The controller 11a calculates the difference between the airspeed and ground speed of the UAV 1a and determines whether the difference is greater than a first threshold. If it is still greater than the first threshold, it indicates that the UAV 1a is still in a speed stagnation state. If it is less than the first threshold, it is considered that the UAV 1a has exited the speed stagnation state, and the UAV 1a returns to the cruise phase to continue cruise to the return point at the altitude after descent.

[0100] The fuselage 10a of the drone 1a is also equipped with an obstacle detection device 14a for detecting obstacles below the fuselage 10a. During the descent phase, when the obstacle detection device 14a detects an obstacle below the drone 1a, the controller 11a stops the drone 1a from descending and maintains cruise power. When the obstacle detection device 14a detects that the obstacle is no longer below the drone 1a, the controller 11a allows the drone 1a to continue descending. This avoids damage to the drone 1a from obstacles and improves cruise safety.

[0101] During normal flight of UAV 1a, positioning device 12a measures the ground speed of UAV 1a, and airspeed meter 13a measures the airspeed of UAV 1a. Controller 11a calculates the difference between the airspeed and ground speed of UAV 1a and determines whether the difference is greater than a first threshold. If it is less than the first threshold, it indicates that the wind speed is not high enough to affect the normal flight of UAV 1a. If it is greater than the first threshold, it indicates that the wind speed is high, and due to the wind force, UAV 1a can hardly continue normal flight and is in a state of airspeed stagnation. Controller 11a generates a return-to-home command, causing UAV 1a to perform the aforementioned return-to-home action.

[0102] Therefore, this embodiment utilizes an airspeed meter and positioning device to detect whether the drone is in a state of speed stagnation during the cruise phase and executes corresponding return-to-home strategies to avoid the impact of strong winds on the return journey. This ensures the drone can return safely, solving the problem of slow or even stalled return speeds in strong winds, which can lead to the drone running out of power and being unable to return. This improves the reliability and safety of the drone's return journey. By using an airspeed meter and positioning device to detect whether the drone is in a state of wind stagnation during the normal flight phase, and generating a return-to-home command when such a state is detected, the reliability and safety of the drone's flight are further improved to avoid the impact of strong winds on normal flight.

[0103] Another embodiment of this disclosure provides a drone 1b. For the sake of brevity, its features that are the same as or similar to those in the previous embodiment will not be repeated. Only its features that are different from those in the previous embodiment will be described below.

[0104] like Figure 6As shown, the fuselage 10b is equipped with a controller 11b and a heading measurement device. Flight parameters include the actual heading E of the UAV 1b.

[0105] A heading measurement device, such as a GPS receiver or an inertial measurement unit, is a positioning device 12b located inside the fuselage 10b and electrically connected to the controller 11b, used to measure the actual heading E of the UAV 1b during flight.

[0106] The controller 11b, located inside the fuselage 10b, is used to receive the measurement values ​​from the heading measurement device and control the action of the power unit 20b to control the flight of the UAV 1b.

[0107] In this embodiment, the controller 11b is used to generate a return-to-home command, causing the drone 1b to perform a return-to-home action, which includes at least a cruise phase.

[0108] During the cruise phase, positioning device 12b measures the actual heading E of UAV 1b. Controller 11b calculates the difference between the actual heading E and the cruise heading C of UAV 1b, and then determines whether the difference is greater than a second threshold. If it is less than the second threshold, it indicates that the wind force is not strong enough to affect the cruise of UAV 1b. If it is greater than the second threshold, it indicates that the wind force is strong, and due to the wind force, UAV 1b is flying in a direction deviating from the return point, and is in a heading deviation state. Controller 11b then initiates the high-wind return phase for UAV 1b.

[0109] To overcome the course deviation, during the high-wind return phase, controller 11b initiates the descent phase for UAV 1b. During the descent, controller 11b continuously monitors whether UAV 1b has exited the course deviation state. If it has, controller 11b halts the descent and returns to the cruise phase to continue flying towards the return point.

[0110] During descent, positioning device 12b measures the actual heading E of UAV 1b. Controller 11b calculates the difference between the actual heading E and the cruise heading C of UAV 1b, and then determines whether the difference is greater than a second threshold. If it is still greater than the second threshold, it indicates that UAV 1b is still in a heading deviation state. If it is less than the second threshold, it is considered that UAV 1b has exited the heading deviation state, and controller 11b causes UAV 1b to return to the cruise phase, continuing to cruise to the return point at the altitude after descent.

[0111] Similar to the previous embodiment, the fuselage 10b of the drone 1b is also equipped with an obstacle detection device 14b for detecting obstacles below the fuselage 10b.

[0112] During normal flight of UAV 1b, positioning device 12b measures the actual heading E of UAV 1b. Controller 11b calculates the difference between the actual heading E of UAV 1b and the set flight heading, and determines whether the difference is greater than a second threshold. If it is less than the second threshold, it indicates that the wind speed is insufficient to affect the normal flight of UAV 1b. If it is greater than the second threshold, it indicates that the wind speed is high, and due to the wind force, UAV 1b has significantly deviated from the set flight heading and is in a heading deviation state. Controller 11b also generates a return-to-home command, causing UAV 1b to perform the return-to-home action as described above.

[0113] Therefore, this embodiment utilizes a positioning device to detect whether the drone is deviating from its course during the cruise phase and executes corresponding return-to-home strategies to avoid the impact of strong winds on the return, thus ensuring the drone's safe return. This solves the problem in existing technologies where course deviation in strong winds leads to the drone running out of power and being unable to return, improving the reliability and safety of the drone's return. Simultaneously, during normal flight, the positioning device detects whether the drone is deviating from its course and generates a return-to-home command to avoid the impact of strong winds on normal flight, further improving the reliability and safety of the drone's flight.

[0114] Another embodiment of this disclosure provides a drone 1c. For the sake of brevity, its features that are the same as or similar to those in the above embodiments will not be repeated. Only its features that are different from those in the above embodiments will be described below.

[0115] like Figure 7 As shown, the fuselage 10c is equipped with: a controller 11c, an airspeed measuring device, and a ground speed and heading measuring device. Flight parameters include: the airspeed, ground speed, and actual heading E of the UAV 1c.

[0116] A ground speed and heading measurement device, such as a GPS receiver or an inertial measurement unit, is a positioning device 12c, which is located inside the fuselage 10c and electrically connected to the controller 11c, and is used to measure the ground speed and actual heading E of the UAV 1c during flight.

[0117] An airspeed measuring device, such as an airspeed meter 13c, is electrically connected to the controller 11c and is used to measure the airspeed of the UAV 1c during flight. The airspeed meter 13c includes a pitot tube 131c mounted on the outside of the fuselage 10c via a support tube 133c, and a pressure gauge 132c mounted inside the fuselage 10c.

[0118] The controller 11c, located inside the fuselage 10c, is used to receive the measurement values ​​from the airspeed measuring device and the ground speed and heading measuring device, and to control the action of the power unit 20c to control the flight of the UAV 1c.

[0119] In this embodiment, the controller 11c is used to generate a return-to-home command, causing the UAV 1c to perform a return-to-home action, which includes at least a cruise phase.

[0120] During the cruise phase, airspeed meter 13c measures the airspeed of UAV 1c, and positioning device 12c measures the ground speed and actual heading E of UAV 1c. Controller 11c calculates the difference between the airspeed and ground speed of UAV 1c, as well as the difference between the actual heading E and the cruise heading C, and determines whether the difference between the airspeed and ground speed of UAV 1c is greater than a first threshold, and whether the difference between the actual heading E and the cruise heading C is greater than a second threshold. If either of these conditions is met, it indicates that under the influence of wind, UAV 1c is finding it difficult to fly back to the return point, or is flying in a direction deviating from the return point. If both conditions are met, it indicates that both situations occur simultaneously, and UAV 1c is in a state of airspeed stagnation and / or heading deviation. Controller 11c then initiates the high-wind return phase for UAV 1c.

[0121] To overcome the wind resistance, during the high-wind return phase, controller 11c initiates the descent phase for UAV 1c. During descent, UAV 1c maintains cruise power and descends at a preset speed. As the wind speed gradually decreases during descent, controller 11c continuously monitors whether UAV 1c has exited the speed resistance and heading deviation states. If it has, UAV 1c stops its descent and returns to the cruise phase to continue flying towards the return point.

[0122] During descent, airspeed meter 13c measures the airspeed of UAV 1c, and positioning device 12c measures the ground speed and actual heading E of UAV 1c. Controller 11c calculates the difference between the airspeed and ground speed of UAV 1c, as well as the difference between the actual heading E and the cruising heading C, and determines whether the difference between the airspeed and ground speed of UAV 1c is greater than a first threshold, and whether the difference between the actual heading E and the cruising heading C is greater than a second threshold. When neither of the above conditions is met, it is considered that UAV 1c has exited the high wind jamming state, and UAV 1c returns to the cruising phase, continuing to cruise to the return point at the altitude after descent.

[0123] Similar to the above embodiments, the fuselage 10c of the drone 1c is also equipped with an obstacle detection device 14c for detecting obstacles below the fuselage 10c.

[0124] During normal flight of UAV 1c, airspeed meter 13c measures the airspeed of UAV 1c, and positioning device 12c measures the ground speed and actual heading E of UAV 1c. Controller 11c calculates the difference between the airspeed and ground speed of UAV 1c, and the difference between the actual heading E and the cruising heading C, and determines whether the difference between the airspeed and ground speed of UAV 1c is greater than a first threshold, and whether the difference between the actual heading E and the cruising heading C is greater than a second difference. When at least one of the two conditions is met, controller 11c generates a return-to-home command, causing UAV 1c to perform the return-to-home action as described above.

[0125] Therefore, this embodiment detects whether the UAV is in a state of strong wind obstruction during the cruise and normal flight phases and executes corresponding strategies to avoid the impact of strong winds on the return and normal flight, thereby ensuring that the UAV can return safely and fly normally, and improving the reliability and safety of UAV flight.

[0126] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is merely an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and not to limit them; although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; in the absence of conflict, the features in the embodiments of this disclosure can be arbitrarily combined; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A control method for an unmanned aerial vehicle (UAV), wherein, include: During the cruise phase, the flight parameters of the UAV are measured, including the UAV's airspeed, ground speed, and / or actual heading. Based on the flight parameters, it is determined that the UAV is in a high-wind-damped state. The high-wind-damped state includes a speed-damped state and / or a heading deviation state. If the difference between the airspeed and the ground speed is greater than a first threshold, the UAV is in the speed-damped state. If the difference between the actual heading and the UAV's cruise heading is greater than a second threshold, the UAV is in the heading deviation state. When the flight parameters indicate that the UAV is in a state of strong wind obstruction, the UAV enters the descent phase, maintaining cruise power and descending at a preset speed.

2. The control method as described in claim 1, wherein, During the descent phase, the flight parameters are measured. When it is determined from the flight parameters that the UAV has exited the high wind jamming state, the UAV returns to the cruise phase.

3. The control method as described in claim 2, wherein, The flight parameters include: the airspeed, ground speed and / or actual heading of the UAV; The step of determining whether the UAV exits the high wind jamming state based on the flight parameters includes: Determine whether the difference between the airspeed and the ground speed is greater than a first threshold, and whether the difference between the actual heading and the cruise heading is greater than a second threshold; If neither of these conditions is met, the drone exits the wind-damped state.

4. The control method as described in claim 1, wherein, The flight parameters are related to the speed and / or heading of the UAV.

5. The control method as described in claim 4, wherein, The speed includes the airspeed and ground speed of the UAV.

6. The control method as described in claim 1, wherein, The wind-induced obstruction state includes at least one of the following: speed obstruction state and course deviation state; Alternatively, during the descent phase, the drone stops descending when there is an obstacle below it; and continues descending when the obstacle is no longer below it.

7. The control method as described in claim 1, 3, or 5, wherein, The airspeed is the airspeed of the UAV when it cruises at its maximum flight tilt angle.

8. A control method for an unmanned aerial vehicle (UAV), wherein, include: During the cruise phase, flight parameters of the UAV are measured, including the UAV's airspeed, ground speed, and / or actual heading. Based on the flight parameters, it is determined that the UAV is in a high-wind-damped state. The high-wind-damped state includes a speed-damped state and / or a heading deviation state. If the difference between the airspeed and the ground speed is greater than a first threshold, the UAV is in the speed-damped state. If the difference between the actual heading and the UAV's cruise heading is greater than a second threshold, the UAV is in the heading deviation state. When the flight parameters indicate that the UAV is in a state of high wind resistance, the UAV enters the descent phase. During the descent phase, the flight parameters are measured. When it is determined from the flight parameters that the UAV has exited the high wind jamming state, the UAV returns to the cruise phase.

9. The control method as described in claim 7, wherein, During the descent phase, the flight parameters are measured. When it is determined from the flight parameters that the UAV has exited the high wind jamming state, the UAV returns to the cruise phase.

10. The control method as described in claim 9, wherein, The flight parameters include: the airspeed, ground speed and / or actual heading of the UAV; The step of determining whether the UAV exits the high wind obstruction state based on the flight parameters includes determining whether the difference between the airspeed and the ground speed is greater than a first threshold and whether the difference between the actual heading and the cruise heading is greater than a second threshold. If neither of these conditions is met, the UAV exits the high wind obstruction state.

11. The control method as described in claim 8, wherein, The flight parameters are related to the speed and / or heading of the UAV.

12. The control method as described in claim 11, wherein, The speed includes the airspeed and ground speed of the UAV.

13. The control method as described in claim 8, wherein, The wind-induced obstruction state includes at least one of the following: speed obstruction state and course deviation state; Alternatively, during the descent phase, the drone stops descending when there is an obstacle below it; and continues descending when the obstacle is no longer below it.

14. The control method as described in claim 8, 10, or 12, wherein, The airspeed is the airspeed of the UAV when it cruises at its maximum flight tilt angle.

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