Unmanned aerial vehicle landing gear control method, apparatus, unmanned aerial vehicle, and system thereof

Patent metadata

Field	Value
Publication number	US-11834197-B2
Application number	US-201916515428-A
Country	US
Kind code	B2
Filing date	Jul 18, 2019
Priority date	Jan 19, 2017
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

A method for controlling a landing gear of an unmanned aerial vehicle (UAV) includes detecting whether a relative-to-ground height of the UAV is greater than a height threshold, where the relative-to-ground height is a vertical height of the UAV with respect to an object; and in response to the relative-to-ground height being not greater than the height threshold and the UAV having not lowered the landing gear, adjusting the relative-to-ground height to the height threshold or above, and lowering the landing gear.

First claim

What is claimed is:

1. A method for controlling a landing gear of an unmanned aerial vehicle (UAV), comprising:
determining whether the landing gear of the UAV has been released or not;
detecting a relative height of the UAV, the relative height being a vertical height of the UAV with respect to an object surface below the UAV;
obtaining a topography of a flight region of the UAV;
(1) keeping the landing gear of the UAV retracted in response to the relative height being greater than a height threshold and at least one of:
the topography not including contour lines that are denser than a preset density above an altitude threshold; or
a variation of the relative height obtained based on the topography being within a preset range when the UAV flies at a fixed altitude; and

(2) keeping the landing gear of the UAV released in response to at least one of:
the relative height being not greater than the height threshold;
the topography including contour lines that are denser than the preset density above the altitude threshold; or
the variation of the relative height obtained based on the topography being not within the preset range when the UAV flies at the fixed altitude.

2. The method according to claim 1 , wherein detecting the relative height of the UAV includes:
obtaining sensing data through one or more sensing elements at the UAV; and
calculating the relative height of the UAV according to the sensing data.

3. The method according to claim 2 , wherein:
obtaining the sensing data includes obtaining a time difference between a time at which the UAV emits a signal and a time at which the UAV receives a reflected signal of the emitted signal, the emitted signal including a wave signal or a light pulse signal; and
calculating the relative height of the UAV according to the sensing data includes calculating the relative height of the UAV according to the time difference and a transmission speed of the signal.

4. The method according to claim 2 , wherein:
obtaining the sensing data includes obtaining an image distance of a camera of the UAV focusing on the object, and
calculating the relative height of the UAV according to the sensing data includes calculating the relative height of the UAV according to a correspondence between the image distance and an object distance.

5. The method according to claim 4 , wherein the camera of the UAV camera includes a monocular camera or a binocular camera.

6. The method according to claim 1 , further comprising:
in response to the UAV receiving a descent instruction, the landing gear of the UAV having not been released, and the relative height of the UAV being less than the height threshold, releasing the landing gear after the UAV is controlled to move upward to cause the relative height to be equal to or greater than the height threshold, and controlling the UAV to move downward according to the descent instruction after the UAV has released the landing gear.

7. The method according to claim 1 ,
wherein the height threshold is a first height threshold;
the method further comprising:
in response to the UAV not receiving a descent instruction and the relative height being greater than a second height threshold, keeping the landing gear retracted.

8. A user device comprising:
a processor; and
a memory storing instructions that, when executed by the processor, cause the user device to:
determine whether a landing gear of an unmanned aerial vehicle (UAV) has been released or not;
detect a relative height of the UAV, the relative height being a vertical height of the UAV with respect to an object surface below the UAV;
obtain a topography of a flight region of the UAV;
(1) keep the landing gear of the UAV retracted in response to the relative height being greater than a height threshold and at least one of:
the topography not including contour lines that are denser than a preset density above an altitude threshold; or
a variation of the relative height obtained based on the topography being within a preset range when the UAV flies at a fixed altitude; and

(2) keep the landing gear of the UAV released in response to at least one of:
the relative height being not greater than the height threshold;
the topography including contour lines that are denser than the preset density above the altitude threshold; or
the variation of the relative height obtained based on the topography being not within the preset range when the UAV flies at the fixed altitude.

9. The user device according to claim 8 , wherein the instructions further cause the user device to:
obtain sensing data through one or more sensing elements at the UAV; and
calculate the relative height of the UAV according to the sensing data.

10. The user device according to claim 9 , wherein the instructions further cause the user device to:
obtain a time difference between a time at which the UAV emits a signal and a time at which the UAV receives a reflected signal of the emitted signal, the emitted signal including a wave signal or a light pulse signal; and
calculate the relative height of the UAV according to the time difference and a transmission speed of the signal.

11. The user device according to claim 9 , wherein the instructions further cause the user device to:
obtain an image distance of a camera of the UAV focusing on the object; and
calculate the relative height of the UAV according to a correspondence between the image distance and an object distance.

12. An unmanned aerial vehicle (UAV) comprising:
a fuselage;
a landing gear connected to the fuselage;
a sensing element arranged at the fuselage and configured to sense a relative height of the UAV; and
a controller arranged at the fuselage and configured to:
determine whether the landing gear of the UAV has been released or not;
detect the relative height of the UAV, the relative height being a vertical height of the UAV with respect to an object surface below the UAV;
obtain a topography of a flight region of the UAV;
(1) keep the landing gear of the UAV retracted in response to the relative height being greater than a height threshold and at least one of:
the topography not including contour lines that are denser than a preset density above an altitude threshold; or
a variation of the relative height obtained based on the topography being within a preset range when the UAV flies at a fixed altitude; and

(2) keep the landing gear of the UAV released in response to at least one of:
the relative height being not greater than the height threshold;
the topography including contour lines that are denser than the preset density above the altitude threshold; or
the variation of the relative height obtained based on the topography being not within the preset range when the UAV flies at the fixed altitude.

13. The UAV according to claim 12 , wherein:
the controller is further configured to control the landing gear according to a control instruction; and
a control terminal of a UAV system having the UAV is configured to communicate with the UAV and transmit the control instruction to the UAV.

14. The method according to claim 6 , wherein releasing the landing gear includes:
releasing the landing gear during a process of adjusting the relative height to the height threshold or above; or
releasing the landing gear when the relative height is maintained at the height threshold or above; or
after the relative height is adjusted to be above the height threshold, releasing the landing gear before the relative height drops back to the height threshold.

15. The user device according to claim 8

Assignees

• Sz Dji Technology Co Ltd

Inventors

• Lin Canlong
• Wang Li
• Shang Zhimeng

Classifications

• B64U2101/30

  for imaging, photography or videography · CPC title

• B64U60/40

  foldable or retractable · CPC title

• B64U70/80

  Vertical take-off or landing, e.g. using rockets (rotorcrafts B64U10/10; VTOL aircraft B64U10/20) · CPC title

• B64D45/04 Primary

  Landing aids; Safety measures to prevent collision with earth's surface · CPC title

• B64C25/24 Primary

  electric · CPC title