Ground effect based surface sensing using multiple propellers in automated aerial vehicles

• US 9,934,694 B2
• Filed: 05/26/2017
• Issued: 04/03/2018
• Est. Priority Date: 06/26/2014
• Status: Active Grant

• Current Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Original Assignee: Amazon Technologies, Inc. (Amazon.com, Inc.)
• Inventors: Navot, Amir, Beckman, Brian C., Buchmueller, Daniel, Kimchi, Gur, Hensel, Fabian, Green, Scott A., Porter, Brandon William, Rault, Severan Sylvain Jean-Michel
• Primary Examiner(s): ANTONUCCI, ANNE MARIE
• Application Number:
  US15/606,807
• Publication Number:
  US 20170263136A1
• Time in Patent Office: 312 Days
• CPC Class Codes: B64D 45/04 Landing aids; Safety measures to prevent collision with earth's surface
• 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: G01S 2007/4975 of sensor obstruction by, e.g. dirt- or ice-coating, e.g. by reflection measurement on front-screen
• 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 1/0676 specially adapted for landing
• CPC Class Codes: G05D 1/0858 specially adapted for vertical take-off of aircraft
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005
• CPC Class Codes: G08G 5/0086 for monitoring terrain radar or analogous systems specially adapted for terrain avoidance G01S13/935

Abstract

A system and method for operating an automated aerial vehicle are provided wherein influences of ground effects (e.g., which may increase the effective thrusts of propellers by interfering with the respective airflows) are utilized for sensing the ground or other surfaces. In various implementations, operating parameters of the automated aerial vehicle are monitored to determine when ground effects are influencing the parameters associated with each of the propellers, which correspondingly indicate proximities to a surface (e.g., the ground). Utilizing such techniques, different propellers of an automated aerial vehicle may provide different sensing data (e.g., for detecting issues with an uneven landing area, a sloped ground, determining an automated aerial vehicle'"'"'s location based on a unique ground surface profile, etc.)

Claims

1. An automated aerial vehicle, comprising:

first and second propellers;

first and second propeller motors that rotate the first and second propellers, respectively;

a power supply connected to the first and second propeller motors that provides power to the first and second propeller motors; and

a control system, comprising;

one or more processors; and

a memory coupled to the one or more processors and storing program instructions that when executed by the one or more processors cause the one or more processors to at least;

determine a first distance to a surface based at least in part on a level of a first parameter that is associated with the first propeller and that is influenced by a first ground effect, wherein the first ground effect corresponds to a condition in which an airflow of the first propeller is directed against the surface which increases an effective thrust of the first propeller and which influences the first parameter; and

determine a second distance to the surface based at least in part on a level of a second parameter that is associated with the second propeller and that is influenced by a second ground effect, wherein the second distance is different than the first distance and the second ground effect corresponds to a condition in which an airflow of the second propeller is directed against the surface which increases an effective thrust of the second propeller and which influences the second parameter.

2. The automated aerial vehicle of claim 1, wherein the first and second distances are determined at least in part by referencing data that is stored in the memory for correlating levels of the parameters to distances from the surface.

3. The automated aerial vehicle of claim 1, wherein:

the level of the first parameter corresponds to a level of at least one of a voltage, current or power supplied from the power supply for rotating the first propeller; and

the level of the second parameter corresponds to a level of at least one of a voltage, current or power supplied from the power supply for rotating the second propeller.

4. The automated aerial vehicle of claim 1, wherein the program instructions when executed by the one or more processors further cause the one or more processors to utilize the determined first and second distances to determine a profile of the surface.

5. The automated aerial vehicle of claim 1, wherein the program instructions when executed by the one or more processors further cause the one or more processors to fly the automated aerial vehicle along a flight path and the first ground effect reduces the amount of power required to be supplied to at least the first propeller motor for flying the automated aerial vehicle while the automated aerial vehicle is proximate to the surface.

6. The automated aerial vehicle of claim 5, wherein the control system further comprises an autopilot system that is utilized to control the amount of power supplied by the power supply to at least the first propeller motor and that automatically reduces the amount of power supplied when the automated aerial vehicle is proximate to the surface.

7. A system for determining a proximity to a surface, the system comprising:

an automated aerial vehicle, comprising;

a first propeller;

a second propeller;

a computing system, comprising;

one or more processors; and

a memory coupled to the one or more processors and storing program instructions that when executed by the one or more processors cause the one or more processors to at least;

monitor first and second operating parameters that are associated with the first and second propellers, respectively;

detect a change in the first operating parameter as caused by a first ground effect, the first ground effect corresponding to a condition in which an airflow of the first propeller is directed against a surface which increases an effective thrust of the first propeller; and

determine that a proximity of the first propeller to the surface is different than a proximity of the second propeller to the surface based at least in part on the detected change in the first operating parameter as caused by the first ground effect.

8. The system of claim 7, wherein the program instructions when executed by the one or more processors further cause the one or more processors to determine that the surface is at least one of sloped or uneven based at least in part on the determination that the proximity of the first propeller to the surface is different than the proximity of the second propeller to the surface.

9. The system of claim 8, wherein the surface corresponds to a first potential landing location and the program instructions when executed by the one or more processors further cause the one or more processors to fly the automated aerial vehicle to a second potential landing location based at least in part on the determination that the surface is at least one of sloped or uneven.

10. The system of claim 7, wherein the program instructions when executed by the one or more processors further cause the one or more processors to determine that the automated aerial vehicle is in danger of colliding with the surface based at least in part on the determination that the proximity of the first propeller to the surface is different than the proximity of the second propeller to the surface.

11. The system of claim 7, wherein the program instructions when executed by the one or more processors further cause the one or more processors to:

detect a change in the second operating parameter as caused by a second ground effect, the second ground effect corresponding to a condition in which an airflow of the second propeller is directed against the surface which increases an effective thrust of the second propeller; and

wherein the determination that the proximity of the first propeller to the surface is different than the proximity of the second propeller to the surface is further based at least in part on the detected change in the second operating parameter.

12. A system, comprising:

an automated aerial vehicle, comprising;

a first propeller;

a second propeller;

a computing system, comprising;

one or more processors; and

a memory coupled to the one or more processors and storing program instructions that when executed by the one or more processors cause the one or more processors to at least;

determine a proximity to a first surface portion based at least in part on a level of a first parameter that is related to the operation of the first propeller of the automated aerial vehicle, wherein a first ground effect that influences the airflow of the first propeller also influences the first parameter, the first ground effect corresponding to a condition in which the airflow of the first propeller is directed against the first surface portion which increases an effective thrust of the first propeller; and

determine a proximity to a second surface portion based at least in part on a level of a second parameter that is related to the operation of the second propeller of the automated aerial vehicle, wherein a second ground effect that influences the airflow of the second propeller also influences the second parameter, the second ground effect corresponding to a condition in which the airflow of the second propeller is directed against the second surface portion which increases an effective thrust of the second propeller.

13. The system of claim 12, wherein the program instructions when executed by the one or more processors further cause the one or more processors to determine a profile of a surface that includes the first and second surface portions based at least in part on the determined proximities to the first and second surface portions.

14. The system of claim 13, wherein the profile of the surface is determined to be at least one of sloped or uneven based at least in part on a difference between the determined proximities to the first and second surface portions.

15. The system of claim 13, wherein the program instructions when executed by the one or more processors further cause the one or more processors to:

determine a proximity to a third surface portion based at least in part on a level of a third parameter that is related to the operation of a third propeller of the automated aerial vehicle, wherein a third ground effect that influences the airflow of the third propeller also influences the third parameter, the third ground effect corresponding to a condition in which the airflow of the third propeller is directed against the third surface portion which increases an effective thrust of the third propeller; and

wherein the profile of the surface is also determined based at least in part on the determined proximity to the third surface portion.

16. The system of claim 13, wherein the program instructions when executed by the one or more processors further cause the one or more processors to identify a current location of the automated aerial vehicle as corresponding to a known location based at least in part on a determination that the profile of the surface corresponds to a known profile at the known location.

17. The system of claim 12, wherein the program instructions when executed by the one or more processors further cause the one or more processors to:

determine that the automated aerial vehicle is in danger of colliding with a surface that includes the first and second surface portions based at least in part on the determined proximities to the first and second surface portions; and

based on the determination that the automated aerial vehicle is in danger of colliding with the surface, control the first and second propellers to perform an evasive aerial maneuver to prevent the automated aerial vehicle from colliding with the surface.

18. The system of claim 12, wherein the program instructions when executed by the one or more processors further cause the one or more processors to compare the determined proximities to expected proximities during at least one of a landing process, a takeoff process or a flying process.

19. The system of claim 12, wherein the program instructions when executed by the one or more processors further cause the one or more processors to determine that there is an issue with a sensor system of the automated aerial vehicle based at least in part on the sensor system indicating at least one of:

a distance to the first surface portion that is different than the determined proximity to the first surface portion;

or

a distance to the second surface portion that is different than the determined proximity to the second surface portion.

20. The system of claim 12, wherein the program instructions when executed by the one or more processors further cause the one or more processors to utilize at least one of machine learning or modeling to determine levels of the parameters that correspond to proximities to surface portions.