Systems and methods for reliable relative navigation and autonomous following between unmanned aerial vehicle and a target object

• US 10,414,494 B2
• Filed: 08/24/2017
• Issued: 09/17/2019
• Est. Priority Date: 12/03/2014
• Status: Active Grant

• Current Assignee: Wing Aviation LLC (Alphabet Inc.)
• Original Assignee: Wing Aviation LLC (Alphabet Inc.)
• Inventors: Jourdan, Damien Bruno
• Primary Examiner(s): Odeh, Nadeem
• Application Number:
  US15/685,478
• Publication Number:
  US 20180002018A1
• Time in Patent Office: 754 Days
• Field of Search: 701 3, 701 11
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/10 Rotorcrafts
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: B64U 2101/31 for surveillance
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 30/20 Rotors; Rotor supports
• CPC Class Codes: G05D 1/0088 characterized by the autonomous decision making process, e.g. artificial intelligence, predefined behaviours using knowledge based models G06N5/00
• CPC Class Codes: G05D 1/042 specially adapted for aircraft
• CPC Class Codes: G05D 1/102 specially adapted for vertical take-off of aircraft
• CPC Class Codes: G08G 5/0069 specially adapted for an unmanned aircraft
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935
• CPC Class Codes: G08G 5/045 Navigation or guidance aids, e.g. determination of anti-collision manoeuvers radar or analogous systems specially adapted for anti-collision between aircraft G01S13/933

Abstract

A method for navigating an airborne device relative to a target comprises detecting, at an optical detector on the airborne device, an optical signal generated by one or more LEDs on the target; comparing the detected optical signal with a previously-detected optical signal; determining, based on the comparison, a change in location of at least one of the airborne device or the target; adjusting a position of the airborne device based on the determined change in location; predicting a movement of the target based on information indicative of at least one of a position, a rotation, an orientation, an acceleration, a velocity, or an altitude of the target, wherein the position of the airborne device is adjusted based on the predicted movement; detecting an obstacle in a flight path associated with the airborne device and adjusting a position of the airborne device based on detected obstacle information.

Claims

1. A method, comprising:

causing an aerial vehicle to follow a flight path that positions the aerial vehicle at a perch position relative to a ground-based mobile target;

detecting an obstacle in the flight path of the aerial vehicle;

in response to detecting the obstacle, adjusting the flight path of the aerial vehicle to cause the aerial vehicle to reduce altitude from the perch position to connect to an obstacle-free path traversed by the ground-based mobile target; and

causing the aerial vehicle to follow behind the ground-based mobile target on the obstacle-free path until the obstacle is no longer detected.

2. The method of claim 1, further comprising:

determining that the obstacle is no longer detected; and

in response to determining that the obstacle is no longer detected, adjusting the flight path of the aerial vehicle to cause the aerial vehicle to continue following the ground-based mobile target from the perch position.

3. The method of claim 1, wherein detecting the obstacle in the flight path of the aerial vehicle comprises monitoring a volume of space with a sensor on the aerial vehicle, wherein the volume of space has a height that corresponds to a height difference between the aerial vehicle and the ground-based mobile target.

4. The method of claim 1, further comprising before detecting the obstacle, causing the aerial vehicle to maintain a first following distance between the aerial vehicle and the ground-based mobile target.

5. The method of claim 4, further comprising after detecting the obstacle, causing the aerial vehicle to maintain a second following distance between the aerial vehicle and the ground-based mobile target along the obstacle-free path, wherein the second following distance is less than the first following distance.

6. The method of claim 4, wherein causing the aerial vehicle to maintain the first following distance comprises causing the aerial vehicle to maintain the first following distance to within a threshold range value.

7. The method of claim 1, wherein the ground-based mobile target includes a plurality of light emitting diodes (LEDs), and the method further includes detecting a plurality of optical signals from the plurality of LEDs to cause the aerial vehicle to follow the ground-based mobile target.

8. The method of claim 7, further comprising comparing a pattern defined by the plurality of detected optical signals from the plurality of LEDs with a previously-detected pattern to cause the aerial vehicle to follow the ground-based mobile target.

9. A system, comprising:

a processor; and

program instructions stored in a non-transitory computer readable medium and executable by the processor to;

cause an aerial vehicle to follow a flight path that positions the aerial vehicle at a perch position relative to a ground-based mobile target;

detect an obstacle in the flight path of the aerial vehicle;

in response to detection of the obstacle, adjust the flight path of the aerial vehicle to cause the aerial vehicle to reduce altitude from the perch position to connect to an obstacle-free path traversed by the ground-based mobile target; and

cause the aerial vehicle to follow behind the ground-based mobile target on the obstacle-free path until the obstacle is no longer detected.

10. The system of claim 9, further comprising a plurality of light emitting diodes (LEDs) coupled to the ground-based mobile target, wherein the plurality of LEDs are configured to emit a flashing pattern to assist the aerial vehicle in following the ground-based mobile target.

11. The system of claim 10, wherein the aerial vehicle comprises a monochrome camera configured to detect the flashing pattern from the plurality of LEDs.

12. The system of claim 10, wherein the flashing pattern is communicated wirelessly in real time to the aerial vehicle from a device on the ground-based mobile target.

13. The system of claim 10, wherein the ground-based mobile target comprises another vehicle.

14. The system of claim 10, wherein the processor and the non-transitory computer readable medium are part of a control system physically located on the aerial vehicle.

15. The system of claim 10, wherein the program instructions are further executable by the processor to:

determine that the obstacle is no longer detected; and

in response to the determination that the obstacle is no longer detected, adjust the flight path of the aerial vehicle to cause the aerial vehicle to continue following the ground-based mobile target from the perch position.

16. A non-transitory computer readable medium having stored therein instructions, that when executed by a processor, cause the processor to perform functions comprising:

causing an aerial vehicle to follow a flight path that positions the aerial vehicle at a perch position relative to a ground-based mobile target;

detecting an obstacle in the flight path of the aerial vehicle;

in response to detecting the obstacle, adjusting the flight path of the aerial vehicle to cause the aerial vehicle to reduce altitude from the perch position to connect to an obstacle-free path traversed by the ground-based mobile target; and

causing the aerial vehicle to follow behind the ground-based mobile target on the obstacle-free path until the obstacle is no longer detected.

17. The non-transitory computer readable medium of claim 16, the functions further comprising:

determining that the obstacle is no longer detected; and

in response to determining that the obstacle is no longer detected, adjusting the flight path of the aerial vehicle to cause the aerial vehicle to continue following the ground-based mobile target from the perch position.

18. The non-transitory computer readable medium of claim 16, wherein detecting the obstacle in the flight path of the aerial vehicle comprises monitoring a volume of space with a sensor on the aerial vehicle, wherein the volume of space has a height that corresponds to a height difference between the aerial vehicle and the ground-based mobile target.

19. The non-transitory computer readable medium of claim 16, the functions further comprising before detecting the obstacle, causing the aerial vehicle to maintain a first following distance between the aerial vehicle and the ground-based mobile target.

20. The non-transitory computer readable medium of claim 19, the functions further comprising after detecting the obstacle, causing the aerial vehicle to maintain a second following distance between the aerial vehicle and the ground-based mobile target along the obstacle-free path, wherein the second following distance is less than the first following distance.