Three-dimensional representations of objects detected by an unmanned aerial vehicle

Patent metadata

Field	Value
Publication number	US-10854096-B1
Application number	US-201816039469-A
Country	US
Kind code	B1
Filing date	Jul 19, 2018
Priority date	May 20, 2016
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

Described are systems, methods, and apparatus for detecting objects within a distance of an aerial vehicle, and developing a three-dimensional model or representation of those objects. Rather than attempting to use stereo imagery to determine distances and/or depth of objects, the described implementations utilize range-gating, or time-gating, and the known position of the aerial vehicle to develop a three-dimensional representation of objects. For example, when the aerial vehicle is at a first position it may use range-gating to detect an object at a defined distance from the vehicle. The aerial vehicle may then alter its position and use range-gating to detect an object that is the defined distance from the vehicle at the new position. This may be done at several different positions and the resulting information and aerial vehicle position information combined to form a three-dimensional representation of those objects.

First claim

What is claimed is:

1. A method to establish a three-dimensional model of an object, the method comprising:
emitting, at a first time and from a laser positioned on an unmanned aerial vehicle (“UAV”), a first laser pulse from a first position of the UAV;
determining a first time duration following the first time;
activating, at a second time responsive to expiration of the first time duration following the first time, a sensor positioned on the UAV to collect at least a portion of the first laser pulse reflected from a first portion of the object at a distance from the UAV, wherein the sensor is activated at the second time such that reflected portions of the first laser pulse arriving at the sensor between the first time and the second time will not be collected by the sensor;
generating, with the collected at least a portion of the first laser pulse, a first representation that includes at least the first portion of the object;
navigating, at a third time that is subsequent to the second time, the UAV from the first position to a second position;
emitting, at a fourth time that is subsequent to the third time and from the laser positioned on the UAV, a second laser pulse from the second position of the UAV;
determining a second time duration following the fourth time;
activating, at a fifth time responsive to expiration of the second time duration following the fourth time, the sensor positioned on the UAV to collect at least a portion of the second laser pulse reflected from a second portion of the object at the distance from the UAV, wherein the sensor is activated at the fifth time such that reflected portions of the second laser pulse arriving at the sensor between the fourth time and the fifth time will not be collected by the sensor;
generating, with the collected at least a portion of the second laser pulse, a second representation that includes at least the second portion of the object; and
combining the first representation and the second representation to form a three-dimensional representation of the object, wherein the first representation and the second representation are combined to form the three-dimensional representation of the object based at least in part on the first position, the second position, and the distance.

2. The method of claim 1 , further comprising:
correlating first position information representative of the first position of the UAV at the first time with the first representation; and
correlating second position information representative of the second position of the UAV at the fourth time with the second representation;
wherein correlating the first position information with the first representation includes associating different location information with each of a plurality of pixels of the first representation.

3. The method of claim 1 , wherein the collected at least a portion of the first laser pulse and the collected at least a portion of the second laser pulse are obtained at different times and at different positions of the UAV.

4. The method of claim 1 , further comprising:
navigating, at a sixth time that is subsequent to the fifth time, the UAV to a third position;
emitting, at a seventh time that is subsequent to the sixth time and from the laser positioned on the UAV, a third laser pulse from the third position of the UAV;
determining a third time duration following the seventh time;
activating, at an eighth time responsive to expiration of the third time duration following the seventh time, the sensor positioned on the UAV to collect at least a portion of the third laser pulse reflected from a third portion of the object at the distance from the UAV;
generating, with the collected at least a portion of the third laser pulse, a third representation that includes at least the third portion of the object; and
updating the three-dimensional representation of the object based at least in part on the third representation and the third position.

5. A method, comprising:
causing a light emitter of an aerial vehicle to emit light at a first time from a first position;
determining a time duration following the first time;
causing a sensor of the aerial vehicle to, at a second time responsive to expiration of the time duration following the first time, activate and collect light from the light emitter that has reflected from at least a first portion of an object, wherein the at least a first portion of the object is at a distance from the first position of the aerial vehicle at the first time, and wherein the sensor is activated at the second time such that reflected light arriving at the sensor prior to the second time will not be collected by the sensor;
forming, from the reflected light collected by the sensor at the second time, a first representation of the at least a first portion of the object; and
forming a three-dimensional representation of the object based at least in part on the first representation, the first position, and the distance.

6. The method of claim 5 , further comprising:
causing the light emitter of the aerial vehicle to emit light at a third time;
determining a second time duration following the third time;
causing the sensor of the aerial vehicle to, at a fourth time responsive to expiration of the second time duration following the third time, activate and collect light from the light emitter that has reflected from at least a second portion of the object, wherein the at least a second portion of the object is at the distance from a second position of the aerial vehicle at the third time;
forming, from the reflected light collected by the sensor at the fourth time, a second representation of the at least a second portion of the object; and
forming the three-dimensional representation of the object further based at least in part on the second representation and the second position.

7. The method of claim 6 , further comprising:
receiving, from a navigation system of the aerial vehicle, first position information and second position information indicative of the first position and the second position of the aerial vehicle at the first time and the third time, respectively.

8. The method of claim 7 , further comprising:
correlating the first position information with the reflected light collected at the second time.

9. The method of claim 7 , further comprising:
correlating the second position information with the reflected light collected at the fourth time.

10. The method of claim 5 , wherein the light emitter is a pulsed laser.

11. The method of claim 5 , wherein causing the sensor to activate comprises opening a shutter that is adjacent the sensor such that reflected light is allowed to pass to the sensor through the shutter when opened.

12. The method of claim 5 , wherein the distance is dependent upon a speed of light and the time duration between the first time and the second time.

13. The method of claim 5 , wherein the light emitted at the first time is a pulse of laser light.

14. A method, comprising:
determining a distance at which an object is to be detected by an aerial vehicle;
determining a time duration between a light emission and a light capture such that reflected light of the light emission from the object at the distance will arrive at a sensor of the aerial vehicle;
causing a light emitter of the aerial vehicle to emit first light at a first time from a first position of the aerial vehicle;
causing the sensor of the aerial vehicle to activate upon an expiration of the time duration following the first time such that at least a portion of the emitted first light that is reflected by the object is collected

Assignees

• Amazon Tech Inc

Inventors

• Harris Scott Raymond
• Novak Benjamin Griffin
• Watson Joshua John

Classifications

• G06V20/17 Primary

  taken from planes or by drones · CPC title

• G06T17/00

  Three-dimensional [3D] modelling for computer graphics · CPC title

• B64U2201/10

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

• B64U2101/60

  for transporting passengers; for transporting goods other than weapons · CPC title

• B64U30/20

  Rotors; Rotor supports · CPC title