Reconfiguring propellers during aerial vehicle operation

Patent metadata

Field	Value
Publication number	US-10179646-B1
Application number	US-201715454785-A
Country	US
Kind code	B1
Filing date	Mar 9, 2017
Priority date	Dec 18, 2015
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

An aerial vehicle may be equipped with propellers having reconfigurable geometries. Such propellers may have blade tips or other features that may be adjusted or reconfigured while the aerial vehicle is operating, on any basis. Propellers having reconfigurable blade tips joined to blade roots may cause the blade tips to be aligned with the blade roots, or substantially perpendicular to the blade roots, e.g., in order to counter adverse effects of tip vortices, or at any intervening angle. The propellers may be reconfigured at predetermined times during operation of an aerial vehicle, or upon sensing one or more operational characteristics or environmental conditions, as may be desired or required.

First claim

What is claimed is:

1. An unmanned aerial vehicle (UAV) propulsion system comprising:
a first motor mounted to a UAV;
a first propeller comprising a first blade root, a first blade tip, and a first hub,
wherein the first blade root has a first proximal end mounted to the first hub and a first distal end pivotably joined to the first blade tip by a first hinge,
wherein the first motor is rotatably coupled to the first hub, and
wherein the first motor is configured to rotate the first propeller through a plurality of angular orientations about a first axis; and

at least one computer processor in communication with at least the first motor and the first propeller, wherein the at least one computer processor is configured to execute a method comprising:
causing the first motor to rotate the first propeller, wherein causing the first motor to rotate the first propeller comprises:
aligning the first blade tip at a first cant angle with respect to the first blade root when the first propeller is at a first angular orientation about the first axis; and
aligning the first blade tip at a second cant angle with respect to the first blade root when the first propeller is at a second angular orientation about the first axis.

2. The UAV propulsion system of claim 1 ,
wherein the first propeller further comprises a second blade root and a second blade tip,
wherein the second blade root has a second proximal end mounted to the first hub and a second distal end pivotably joined to the second blade tip by a second hinge, and
wherein causing the first motor to rotate the first propeller further comprises:
aligning the second blade tip at a third cant angle with respect to the second blade root when the second blade root is at a third angular orientation about the first axis; and
aligning the second blade tip at a fourth cant angle with respect to the second blade root when the second blade is at a fourth angular orientation about the first axis.

3. The UAV propulsion system of claim 1 , further comprising:
a second motor mounted to the UAV; and
a second propeller comprising a second blade root, a second blade tip, and a second hub,
wherein the second blade root has a second proximal end mounted to the second hub and a second distal end pivotably joined to the second blade tip by a second hinge,
wherein the second motor is rotatably coupled to the second hub,
wherein the second motor is configured to rotate the second propeller through a plurality of angular orientations about a second axis,
wherein the at least one computer processor is in communication with at least the second motor and the second propeller, and
wherein the method further comprises:
causing the second motor to rotate the second propeller, wherein causing the second motor to rotate the second propeller comprises:
aligning the second blade tip at a third cant angle with respect to the second blade root when the second propeller is at a third angular orientation about the second axis; and
aligning the second blade tip at a fourth cant angle with respect to the second blade root when the second propeller is at a fourth angular orientation about the second axis.

4. The UAV propulsion system of claim 3 , wherein each of the first cant angle and the third cant angle is approximately zero degrees, and
wherein each of the second cant angle and the fourth cant angle is approximately ninety degrees.

5. The UAV propulsion system of claim 1 ,
wherein the first blade root further comprises a first mechanical operator configured to vary a cant angle of the first blade tip within a first range comprising the first cant angle and the second cant angle, and
wherein the first mechanical operator is configured to operate under control of the at least one computer processor.

6. The UAV propulsion system of claim 1 ,
wherein aligning the first blade tip at the first cant angle comprises:
determining that the first propeller is at the first angular orientation about the first axis;
providing a first control signal to the first propeller;
in response to the first control signal,
causing the first blade tip to be aligned at the first cant angle with respect to the first blade root; and

wherein aligning the first blade tip at the second cant angle comprises:
determining that the first propeller is at the second angular orientation about the first axis;
providing a second control signal to the second propeller; and
in response to the second control signal,
causing the first blade tip to be aligned at the second cant angle with respect to the first blade root.

7. The UAV propulsion system of claim 1 , wherein the method further comprises:
predicting, prior to a first time, an attribute of the aerial vehicle at the first time according to at least one machine learning algorithm; and
selecting each of the first cant angle and the second cant angle based at least in part on the predicted attribute of the aerial vehicle at the first time,
wherein the predicted attribute of the unmanned aerial vehicle at the first time is at least one of:
a position, a speed, an acceleration, a rate of climb, a rate of descent, a turn rate, a temperature, a radiated sound, a barometric pressure, a weather event, a wind speed or a wind direction.

8. A method comprising:
initiating an operation of a first propeller, wherein the first propeller comprises a first blade root having a first proximal end coupled to a first hub and a first distal end pivotably coupled to a first blade tip by a first variable-cant connection, and wherein the first blade tip is at a first cant angle with respect to the first blade root at a first time;
determining a first attribute of the first propeller at a second time, wherein the first attribute of the first propeller is a first angular orientation of the first blade root about a first axis;
in response to determining the first attribute of the first propeller at the second time,
identifying a second cant angle with respect to the first blade root based at least in part on the first attribute of the first propeller, and
causing the first blade tip to pivot about the first variable-cant connection from the first cant angle with respect to the first blade root to the second cant angle with respect to the first blade root;

determining a second attribute of the first propeller at a third time, wherein the second attribute of the first propeller is a second angular orientation of the first blade root about the first axis; and
in response to determining the second attribute of the first propeller at the third time,
causing the first blade tip to pivot about the first variable-cant connection from the second cant angle with respect to the first blade root to the first cant angle with respect to the first blade root.

9. The method of claim 8 , wherein the first propeller is rotatably coupled to a first rotatable mast of a first motor,
wherein the first rotatable mast defines a first axis, and
wherein initiating the operation of the first propeller comprises:
causing, by the first motor, the first propeller to rotate about the first axis at a first predetermined speed.

10. The method of claim 8 , wherein the first propeller is rotatably mounted to an aerial vehicle,
wherein the aerial vehicle further comprises at least one sensor, and
wherein determining the first attribute of the first propeller at the second time comprises:
capturing, by the at least one sensor, information regarding the first attribute at the second time.

11. The method of claim 8 , wherein the first propeller is rotatably mounted to an aerial vehicle, and
wherein determining the first attribute of the first

Assignees

• Amazon Tech Inc

Inventors

• Beckman Brian C
• Ko Allan

Classifications

• B64C2201/108

  Operations & Transport · mapped topic

• B64C11/20 Primary

  Constructional features · CPC title

• B64C27/08

  with two or more rotors · CPC title

• B64C39/024

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

• B64C27/463 Primary

  Blade tips · CPC title