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

Patent metadata

Field	Value
Publication number	US-9896202-B2
Application number	US-201414559365-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 3, 2014
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

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. The method also comprises comparing, by a processor on the airborne device, the detected optical signal with a previously-detected optical signal. The method further comprises determining, by the processor based on the comparison, a change in location of at least one of the airborne device or the target. The method also comprises adjusting a position of the airborne device based on the determined change in location. The method also comprises predicting, by the processor, 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 of the target. The method also comprises detecting an obstacle in a flight path associated with the airborne device and adjusting a position of the airborne device is further based, at least in part, on detected obstacle information.

First claim

What is claimed is:

1. A method for navigating an airborne vehicle relative to a target, comprising:
detecting, at a signal detector associated with the airborne vehicle, a signal generated by a signal emitter associated with the target;
correlating, by a processor associated with the airborne vehicle, the detected signal with a previously-detected signal;
determining, by the processor based on the correlating, a change in location of the target;
adjusting a position of the airborne vehicle based, at least in part, on the determined change in location in order to cause the airborne vehicle to follow a flight path that maintains a first following distance between the airborne vehicle and the target;
detecting an obstacle in the flight path of the airborne vehicle;
responsively adjusting the flight path of the airborne vehicle to cause the airborne vehicle to connect to an obstacle-free path traversed by the target; and
causing the airborne vehicle to follow behind the target on the obstacle-free path at a second following distance that is less than the first following distance until the obstacle is no longer detected.

2. The method of claim 1 , wherein adjusting the position of the airborne vehicle includes adjusting the position of the airborne vehicle to maintain the first following distance between the airborne vehicle and the target to within a threshold range value.

3. The method of claim 1 , where relative motion of the airborne vehicle relative to the target is used to estimate relative distance between the target and the airborne vehicle.

4. The method of claim 1 , further comprising receiving, at the processor associated with the airborne vehicle from at least one sensor located on-board the target, information indicative of at least one of a position, a rotation, an orientation, an acceleration, a velocity, or an altitude associated with the target.

5. The method of claim 4 , further comprising:
predicting, by the processor associated with the airborne vehicle based on the received information, a movement of the target; and
wherein adjusting the position of the airborne vehicle is further based, at least in part, on the predicted movement of the target.

6. The method of claim 4 , wherein receiving the information includes receiving orientation information from at least one orientation sensor located onboard the target.

7. The method of claim 4 , wherein receiving the information includes receiving acceleration and rotational information from at least one inertial measurement unit located on-board the target.

8. The method of claim 4 , wherein receiving the information includes receiving barometric pressure information from at least one barometric sensor located on-board the target.

9. The method of claim 8 , where a difference in static barometric pressure between the target and the airborne vehicle is used to estimate relative distance between the target and the airborne vehicle.

10. The method of claim 4 , wherein receiving the information includes receiving directional information from at least magnetometer located on-board the target.

11. The method of claim 4 , wherein receiving the information includes receiving GPS coordinates and velocities from at least one GPS module located onboard the target.

12. The method of claim 1 , wherein the signal emitter includes a plurality of light emitting diodes (LEDs), and the method further includes detecting a plurality of optical signals, each of the plurality of optical signals generated by a respective one of the plurality of LEDs.

13. The method of claim 12 , further comprising comparing a pattern defined by the plurality of detected optical signals with a previously-detected pattern.

14. The method of claim 13 , wherein determining the change in location is based on the comparison between the pattern defined by the plurality of detected optical signals with the previously-detected pattern.

15. The method of claim 12 , wherein the plurality of LEDs are placed on the target, the method further comprising estimating one or more of relative distance, relative velocity, a relative pitch, a relative roll, a relative heading, and relative inertial biases.

16. The method of claim 1 , further comprising:
determining that the obstacle is no longer detected; and
responsively adjusting the flight path of the airborne vehicle to cause the airborne vehicle to follow behind the target at the first following distance.

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

18. A system for aerial monitoring of a target, comprising:
a target device coupled to the target, the target device comprising:
at least one light emitting diode (LED) configured to generate an optical signal;

an airborne device coupled to an airborne vehicle and in data communication with the target device, the airborne device comprising:
an optical detector configured to detect the optical signal generated by the target device; and
a processor communicatively coupled to the optical detector and configured to:
compare the detected optical signal with a previously-detected optical signal;
determine a change in location the target;
generate a control signal for adjusting a position of the airborne vehicle based, at least in part, on the determined change in location in order to cause the airborne vehicle to follow a flight path that maintains a first following distance between the airborne vehicle and the target;
detect an obstacle in the flight path of the airborne vehicle;
responsively adjust the flight path of the airborne vehicle to cause the airborne vehicle to connect to an obstacle-free path traversed by the target; and
cause the airborne vehicle to follow behind the target on the obstacle-free path at a second following distance that is less than the first following distance until the obstacle is no longer detected.

19. The system of claim 18 , wherein the airborne vehicle comprises at least one motor that is communicatively coupled to the processor of the airborne device and configured to operate in response to the control signal generated by the processor.

20. The system of claim 19 , wherein the processor is configured to generate the control signal for adjusting the position of the airborne vehicle to maintain the first following distance between the airborne vehicle and the target to within a threshold range value.

21. The system of claim 18 , wherein the target device further comprises at least one sensor configured to measure information indicative of at least one of a position, a rotation, an orientation, an acceleration, a velocity, or an altitude associated with the target.

22. The system of claim 21 , wherein the processor is further configured to:
receive, from the target device, the information indicative of the at least one of a position, an orientation, an acceleration, a velocity, or an altitude associated with the target;
predict, based on the received information, a movement of the target; and
wherein the control signal for adjusting the position of the airborne vehicle is further based, at least in part, on the predicted movement of the target.

23. The system of claim 21 , wherein the at least one sensor is an orientation sensor configured to

Assignees

• X Dev Llc

Inventors

• Jourdan Damien Bruno

Classifications

• B64U2201/10

  autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS] · CPC title

• B64C2201/024

  Operations & Transport · mapped topic

• B64C39/024 Primary

  of the remote controlled vehicle type, i.e. RPV · CPC title

• G05D1/101

  specially adapted for aircraft · CPC title

• G08G5/0069

  Physics · mapped topic