UAV precision landing system and method

Abstract

The present invention discloses a system and method for precision landing of unmanned aerial vehicles (UAVs). The system includes a UAV and a landing platform. The landing platform is mounted on a horizontal motion device and can rotate horizontally. The horizontal motion device can drive the landing platform to move horizontally. Both the landing platform and the UAV are equipped with communication modules to enable communication between the two. The UAV precision landing system also includes an infrared recognition device, which includes an infrared transmitter disposed near the landing platform and an infrared receiver disposed on the UAV. Through two-way recognition between the landing platform and the UAV, the present invention improves the UAV's landing accuracy, ensures the UAV's landing safety, and increases the space utilization of the landing platform and the device.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicles (UAVs), and in particular to a system and method for precise landing of UAVs. Background Art

[0002] At present, drones are unable to complete missions multiple times due to mission distance and flight time, and require manual assistance to recharge. The emergence of automatic drone hangars solves this problem. The hangar can fully automatically complete the recharging process without human intervention. However, how to make the drone land accurately in the hangar is a step that cannot be ignored.

[0003] The existing drone landing method uses RTK positioning, combined with the drone's built-in binocular camera to perform feature recognition of the target below to achieve the purpose of landing at the target location. When the drone lands normally, this method itself has landing errors due to the accuracy of its own flight control system. Especially for vertical take-off and landing fixed-wing drones, once they are disturbed by strong winds, they can easily experience large landing deviations and even fail to land on the platform if they rely solely on the flight control system. To ensure that the drone lands on the designated platform, the platform must reserve sufficient safety margin, resulting in low hangar space utilization. Summary of the Invention

[0004] In view of this, the present invention provides a system and method for precise landing of a UAV, which utilizes two-way recognition between the UAV and the landing platform to achieve precise landing of the UAV on the landing platform.

[0005] To solve the above technical problems, the technical solution of the present invention is to adopt a UAV precision landing system, comprising a UAV and a landing platform, wherein the landing platform is mounted on a horizontal motion device and can rotate horizontally, and the horizontal motion device can drive the landing platform to move horizontally; the landing platform and the UAV are both provided with a communication module to enable communication between the two; the UAV precision landing system also includes an infrared recognition device, which includes an infrared emitting device arranged near the landing platform and an infrared receiving device arranged on the UAV;

[0006] As an improvement, there are two or more infrared emitting devices, which are evenly distributed along the circumference; the number of the infrared receiving devices is the same as that of the infrared emitting devices, which are evenly distributed along the circumference at the bottom of the drone.

[0007] As an improvement, the horizontal motion device includes a horizontally arranged X track, on which an X trolley capable of moving along the X track is provided; the X trolley is horizontally provided with a Y track perpendicular to the X track, on which a Y trolley capable of moving along the Y track is provided, and the landing platform is provided on the Y trolley.

[0008] As a further improvement, the X track and the Y track are lead screws, and the X trolley and the Y trolley are sliders respectively threadedly engaged with the X track and the Y track.

[0009] As an improvement, the infrared emitting devices are symmetrically arranged at the ends of the X track and the Y track.

[0010] As another further improvement, the landing platform is connected to the horizontal motion device by a turntable, and the turntable is driven by a motor to rotate.

[0011] As an improvement, the longitudinal emission angle of the infrared emitting device is adjustable.

[0012] As a further improvement, the infrared emitting device relies on an angle adjustment device to adjust the longitudinal emission angle. The angle adjustment device includes a horizontally arranged central axis driven by a motor, and the infrared emitting device is arranged on the cylindrical surface of the central axis.

[0013] As an improvement, a groove is provided on the landing platform, the bottom of the groove is wedge-shaped, and a protrusion corresponding to the groove is provided on the bottom of the drone.

[0014] The present invention also provides a UAV precision landing method, which is applied to the UAV in the above-mentioned UAV precision landing system, comprising:

[0015] Return steps: When returning, send a return signal to the landing platform;

[0016] Initial landing steps: fly above the landing platform and begin landing;

[0017] Hovering step: hover when landing to a height where the infrared ray emitted by the infrared ray transmitter can be received;

[0018] Infrared recognition step: if one or more infrared receiving devices receive the infrared light emitted by the infrared emitting device, the recognition is considered successful;

[0019] Position information sending step: after successful recognition, the position information of the vehicle is sent to the landing platform;

[0020] When the landing platform is adjusted to the position according to the position information, it starts to descend. After descending to a preset height, the infrared recognition step and the position information sending step are repeated until it lands on the landing platform.

[0021] As an improvement, if the recognition is unsuccessful during the infrared recognition step, the infrared emitting device is waited for to perform longitudinal scanning; if the infrared ray emitted by the infrared emitting device is still not received, a go-around is performed and the aircraft lands again.

[0022] The present invention also provides a method for precise landing of a UAV, which is applied to the landing platform in the above-mentioned precise landing system of the UAV, comprising:

[0023] Angle adjustment steps: After receiving the return signal sent by the drone, adjust the infrared transmitter to the preset angle;

[0024] Infrared recognition steps: If one or more infrared transmitters transmit infrared rays and the infrared receiver on the drone receives them, the recognition is considered successful;

[0025] Horizontal position adjustment step: after successful recognition, the position information sent by the drone is received, and the horizontal position is adjusted to be directly below the drone according to the position information;

[0026] After the drone descends to the preset height, repeat the infrared recognition steps and horizontal position adjustment steps until the drone lands on the landing platform;

[0027] Direction adjustment steps: Adjust the horizontal angle until the infrared rays emitted by each infrared transmitter are received by the infrared receiver on the drone one by one.

[0028] As an improvement, if the recognition is unsuccessful during the infrared recognition step, the infrared emitting device performs a longitudinal scan; if the infrared ray emitted by the infrared emitting device is still not received by the infrared receiving device on the drone, the drone is waited for to take off and land again.

[0029] The benefits of the present invention are that: through the two-way identification between the landing platform and the UAV, the present invention improves the landing accuracy of the UAV, ensures the landing safety of the UAV, and improves the space utilization of the landing platform and the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the present invention.

[0031] Figure 2 Schematic diagram of the angle adjustment device.

[0032] Figure 3 This is a cross-sectional view of the landing platform.

[0033] Figure 4 Flowchart of the UAV in the present invention.

[0034] Figure 5 It is a flow chart of the landing platform in the present invention.

[0035] Markings in the figure: 1 landing platform, 2X track, 3X trolley, 4Y track, 5Y trolley, 6 turntable, 7 infrared emitting device, 8 center axis, 9 groove, 100 infrared. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0037] like Figure 1 、 Figure 2 、 Figure 3 As shown, the present invention provides a UAV precision landing system, comprising a UAV (not shown) and a landing platform 1, wherein the landing platform 1 is arranged on a horizontal motion device and can rotate horizontally, and the horizontal motion device can drive the landing platform 1 to move horizontally; the landing platform 1 and the UAV 2 are both provided with a communication module so that the two can communicate; and an infrared recognition device is also included, wherein the infrared recognition device includes an infrared emitting device 7 arranged near the landing platform and an infrared receiving device arranged on the UAV; the longitudinal emission angle of the infrared emitting device 7 is adjustable;

[0038] There are two or more infrared emitting devices 7, preferably four in this embodiment, which are evenly distributed along the circumference of a circle with the landing platform 1 as the center; the number of the infrared receiving devices is the same as that of the infrared emitting devices, and they are evenly distributed along the circumference at the bottom of the drone.

[0039] Specifically, the horizontal motion device includes a horizontally arranged X-track 2, on which is mounted an X-trolley 3 capable of moving along the X-track 2; a Y-track 4 disposed horizontally and perpendicular to the X-track 2, on which is mounted a Y-trolley 5 capable of moving along the Y-track 4; and the landing platform 1 is mounted on the Y-trolley 5. In this embodiment, the X-track 2 and Y-track 4 are lead screws, and the X-trolley 3 and Y-trolley 5 are sliders threadedly engaged with the X-track 2 and Y-track 4, respectively. The lead screws are controlled by a motor to rotate, thereby driving the trolley along them, providing precise control and a simple structure. Of course, other mechanical structures can also be used to achieve horizontal motion of the landing platform, and this is not a limitation in the present invention.

[0040] The landing platform 1 is connected to the horizontal motion device via a turntable 6, which is driven by a motor to rotate. Specifically, the turntable 6 is fixed to the Y-trolley 5, and the landing platform 1 is set on the turntable 6. The motor drives the turntable 6 to rotate and drives the landing platform 1 to rotate on the horizontal plane.

[0041] In addition, the infrared emitting devices 7 of the present invention are symmetrically arranged at the ends of the X track 2 and the Y track 4, which can ensure that the landing platforms can be adjusted into place when the drone is identified.

[0042] The infrared emitting device 7 adjusts its longitudinal emission angle via an angle adjustment mechanism. The angle adjustment mechanism includes a horizontally disposed central shaft 8 driven by a motor, and the infrared emitting device 7 is mounted on the cylindrical surface of the central shaft 8. When the motor rotates the central shaft 8, the infrared emitting device 7 also rotates with the central shaft, achieving scanning and adjustment functions.

[0043] In this embodiment, landing platform 1 is a circular flat plate with a central groove 9. The bottom of this groove 9 is wedge-shaped, and the bottom of the drone is equipped with a bump that corresponds to this groove 9. After the drone lands on landing platform 1, its bump slides into groove 9, effectively correcting the drone's orientation. The wedge-shaped bottom of groove 9 serves as a guide, making it easier for the bump on the drone to slide into place.

[0044] like Figure 4 As shown, the present invention also provides a UAV precision landing method, which is applied to the UAV in the above-mentioned UAV precision landing system, comprising:

[0045] S11 Return step: When returning, send a return signal to the landing platform.

[0046] When returning home, the drone communicates with the landing platform through its wireless communication module, sending a release signal to it. After receiving the drone's return signal, the landing platform adjusts the inclination of the infrared transmitter to the agreed angle according to the drone's established route.

[0047] S12 Initial landing steps: Fly above the landing platform and start landing.

[0048] The drone performed preliminary landing steps using existing RTK positioning methods and combining the drone's built-in binocular camera with feature recognition of the target below. RTK positioning technology is based on the close proximity of the rover and base station errors and utilizes GPS carrier phase observations for real-time dynamic positioning. Because positioning accuracy decreases with increasing distance between the base and rover stations, RTK positioning technology is ideally suited for a range of 10-15 km. Therefore, RTK positioning is not particularly precise. Even with camera-based target recognition, its accuracy is far from sufficient for a drone, and is even worse in windy weather. Therefore, a landing using RTK positioning can only be a preliminary landing to determine a general direction.

[0049] S13 Hovering step: Hovering when the vehicle lands at a height where the vehicle can receive the infrared rays emitted by the infrared ray emitting device.

[0050] After the landing platform is adjusted to the agreed angle, it determines the hovering height of the drone. At this height, if the drone is directly above the platform, it will receive infrared light from the infrared transmitter. Therefore, the drone hovers at this height and waits for infrared recognition.

[0051] S14 Infrared recognition step: if one or more infrared receiving devices receive the infrared rays emitted by the infrared emitting device, it is considered that the recognition is successful.

[0052] There are multiple infrared emitting devices and multiple infrared receiving devices. As long as any infrared receiving device receives the infrared ray emitted by any infrared emitting device, it is considered that the recognition is successful.

[0053] If the recognition fails, there are two possibilities: one is the drone's height deviation, and the other is the drone's horizontal position deviation.

[0054] The problem of height deviation is relatively easy to solve. Therefore, if the recognition is unsuccessful, wait for the infrared transmitter to perform a longitudinal scan; the problem of height deviation of the drone can be solved by adjusting the inclination angle of the infrared generator.

[0055] If infrared recognition is still not possible after scanning, it is considered that the drone has deviated in the horizontal direction and the deviation is too large to be resolved by moving the landing platform. Therefore, if the infrared light emitted by the infrared transmitter still cannot be received at this time, the drone will fly around and land again to eliminate the deviation in the horizontal position.

[0056] S15 Position information sending step: After successful recognition, the vehicle sends its own position information to the landing platform.

[0057] Successful recognition indicates that the drone is at a horizontal position that the platform can adjust to. Therefore, based on the position information sent by the drone, the platform adjusts to the position directly below the drone and waits for the drone to land.

[0058] S16: When the landing platform is adjusted to the position according to the position information, it starts to descend. After descending to a preset height, the infrared recognition step and the position information sending step are repeated until the vehicle lands on the landing platform.

[0059] Every time the drone descends a preset height, such as 10 cm, it will perform infrared recognition to avoid deviation from the horizontal position during the descent.

[0060] like Figure 5 As shown, the present invention also provides a UAV precision landing method, which is applied to the landing platform in the above-mentioned UAV precision landing system, comprising:

[0061] S21 Angle adjustment steps: After receiving the return signal sent by the drone, adjust the infrared transmitter to the preset angle.

[0062] When returning home, the drone communicates with the landing platform through its wireless communication module, sending a release signal to it. After receiving the drone's return signal, the landing platform adjusts the inclination of the infrared transmitter to the agreed angle according to the drone's established route.

[0063] S22 Infrared recognition step: If one or more infrared emitting devices emit infrared rays and the infrared receiving device on the drone receives them, the recognition is considered successful.

[0064] After the infrared transmitter is adjusted to the agreed angle, it effectively determines the drone's hovering altitude. At this altitude, if the drone is directly above the platform, it will receive infrared light from the infrared transmitter. Therefore, the drone hovers at this altitude awaiting infrared recognition. There are multiple infrared transmitters and receivers; recognition is considered successful when any infrared receiver receives infrared light from any infrared transmitter.

[0065] If the recognition is unsuccessful, the infrared emitting device performs a longitudinal scan; if the infrared ray emitted by the infrared emitting device is still not received by the infrared receiving device on the drone, the drone waits for a go-around and lands again.

[0066] S23 Horizontal position adjustment step: After successful recognition, the position information sent by the drone is received, and the horizontal position is adjusted to be directly below the drone according to the position information.

[0067] The landing platform uses a horizontal motion device to adjust its horizontal position according to the position information sent by the drone, so that it is located directly below the drone.

[0068] After the S24 drone descends to the preset height, the infrared recognition steps and horizontal position adjustment steps are repeated until the drone lands on the landing platform.

[0069] By repeating the two-way recognition process, the drone can avoid excessive deviation in the horizontal position. The landing platform can be translated to always be directly below the drone, making it easier for the drone to land on the landing platform.

[0070] S25 Direction adjustment step: adjust the horizontal angle until the infrared rays emitted by each infrared emitting device are received one by one by the infrared receiving device on the drone.

[0071] After landing, although the drone's orientation is theoretically fixed, in practice, there will be some deviation. However, once the bumps on the drone slide into the grooves on the landing platform, the platform knows the drone's orientation. Therefore, by rotating the landing platform, the drone's four infrared receivers can be aligned with the four infrared transmitters on the platform, ensuring the drone's nose is facing the desired direction.

[0072] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A UAV precision landing system, comprising a UAV and a landing platform, characterized by: The landing platform is mounted on a horizontal motion device and can rotate horizontally, and the horizontal motion device can drive the landing platform to move horizontally; the landing platform and the drone are both provided with a communication module so that the two can communicate; The UAV precision landing system further includes an infrared recognition device, which includes an infrared emitting device arranged near the landing platform and an infrared receiving device arranged on the UAV; Precision landing methods for drones include: Return steps: When returning, send a return signal to the landing platform; Initial landing steps: fly above the landing platform and begin landing; Hovering step: hover when landing to a height where the infrared ray emitted by the infrared ray transmitter can be received; Infrared recognition step: if one or more infrared receiving devices receive the infrared light emitted by the infrared emitting device, the recognition is considered successful; Position information sending step: after successful recognition, the position information of the vehicle is sent to the landing platform; When the landing platform is adjusted to the position according to the position information, it begins to descend. After descending to a preset height, the infrared recognition step and the position information sending step are repeated until the vehicle lands on the landing platform. Precision landing methods for drones applied to landing platforms include: Angle adjustment steps: After receiving the return signal sent by the drone, adjust the infrared transmitter to the preset angle; Infrared recognition steps: If one or more infrared transmitters transmit infrared rays and the infrared receiver on the drone receives them, the recognition is considered successful; Horizontal position adjustment step: after successful recognition, the position information sent by the drone is received, and the horizontal position is adjusted to be directly below the drone according to the position information; After the drone descends to the preset height, repeat the infrared recognition steps and horizontal position adjustment steps until the drone lands on the landing platform; Direction adjustment steps: Adjust the horizontal angle until the infrared rays emitted by each infrared transmitter are received by the infrared receiver on the drone one by one.

2. The UAV precision landing system according to claim 1, characterized in that: The horizontal motion device includes a horizontally arranged X track, on which an X trolley capable of moving along the X track is provided; the X trolley is horizontally provided with a Y track perpendicular to the X track, on which a Y trolley capable of moving along the Y track is provided, and the landing platform is provided on the Y trolley.

3. The UAV precision landing system according to claim 2, characterized in that: The X track and the Y track are lead screws, and the X trolley and the Y trolley are sliders respectively threadedly matched with the X track and the Y track.

4. The UAV precision landing system according to claim 2, characterized in that: The infrared emitting devices are symmetrically arranged at the ends of the X track and the Y track.

5. The UAV precision landing system according to claim 1, characterized in that: The landing platform is connected to the horizontal motion device by a turntable, and the turntable is driven by a motor to rotate.

6. The UAV precision landing system according to claim 1, characterized in that: There are two or more infrared emitting devices, which are evenly distributed along the circumference; the number of the infrared receiving devices is the same as that of the infrared emitting devices, and they are evenly distributed along the circumference on the bottom of the drone.

7. The UAV precision landing system according to claim 1, characterized in that: The longitudinal emission angle of the infrared emitting device is adjustable.

8. The UAV precision landing system according to claim 7, characterized in that: The infrared emitting device relies on an angle adjustment device to adjust the longitudinal emitting angle. The angle adjustment device includes a horizontally arranged central axis driven by a motor. The infrared emitting device is arranged on the cylindrical surface of the central axis.

9. The UAV precision landing system according to claim 1, characterized in that: The landing platform is provided with a groove, the bottom of the groove is wedge-shaped, and the bottom of the UAV is provided with a convex block corresponding to the groove.

10. The UAV precision landing system according to claim 1, characterized in that: If the recognition is unsuccessful during the infrared recognition step, the aircraft waits for the infrared emitting device to perform longitudinal scanning; if the infrared ray emitted by the infrared emitting device is still not received, the aircraft will make a go-around and land again.

11. The UAV precision landing system according to claim 1, characterized in that: If the recognition is unsuccessful during the infrared recognition step, the infrared emitting device performs a longitudinal scan; if the infrared ray emitted by the infrared emitting device is still not received by the infrared receiving device on the drone, the drone is waited for to take off and land again.

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