Selectively thrusting propulsion units for aerial vehicles

Patent metadata

Field	Value
Publication number	US-9840324-B2
Application number	US-201615083151-A
Country	US
Kind code	B2
Filing date	Mar 28, 2016
Priority date	Mar 28, 2016
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

Aerial vehicles may include propulsion units having motors with drive shafts that may be aligned at a variety of orientations, propellers with variable pitch blades, and common operators for aligning the drive shafts at one or more orientations and for varying the pitch angles of the blades. The common operators may include plate elements to which a propeller hub is rotatably joined, and which may be supported by one or more linear actuators that may extend or retract to vary both the orientations of the drive shafts and the pitch angles of the blades. Operating the motors and propellers at varying speeds, gimbal angles or pitch angles enables the motors to generate forces in any number of directions and at any magnitudes. Attributes of the propulsion units may be selected in order to shape or control the noise generated thereby.

First claim

What is claimed is:

1. An unmanned aerial vehicle comprising:
a frame;
a first propulsion unit mounted to the frame, wherein the first propulsion unit comprises a first motor configured to operate at a plurality of speeds and a first propeller rotatably coupled to the first motor by a first drive shaft, wherein the first propeller has a first plurality of blades mounted to a first hub;
a second propulsion unit mounted to the frame, wherein the second propulsion unit comprises a second motor configured to operate at a plurality of speeds and a second propeller rotatably coupled to the second motor by a second drive shaft, wherein the second propeller has a second plurality of blades mounted to a second hub;
at least one acoustic sensor; and
a computing device having a memory and one or more computer processors,
wherein the computing device is configured to:
determine a first force to be supplied to the unmanned aerial vehicle by the first propulsion unit;
determine a second force to be supplied to the unmanned aerial vehicle by the second propulsion unit;
select a first set of attributes to operate the first propulsion unit to supply the first force, wherein the first set of attributes comprises a first motor speed of the first motor and a first gimbal angle of the first drive shaft;
select a second set of attributes to operate the second propulsion unit to supply the second force, wherein the second set of attributes comprises a second motor speed of the second motor and a second gimbal angle of the second drive shaft;
initiate a first operation of the first propulsion unit in accordance with the first set of attributes at a first time;
initiate a second operation of the second propulsion unit in accordance with the second set of attributes at the first time;
capture, by the at least one acoustic sensor, information regarding sound radiating from the unmanned aerial vehicle during the first operation or the second operation;
determine a third set of attributes to operate the first motor based at least in part on the information regarding the sound, wherein the third set of attributes comprises at least one of a third motor speed for the first motor or a third gimbal angle for the first drive shaft,
determine a fourth set of attributes to operate the second motor based at least in part on the information regarding the sound, wherein the fourth set of attributes comprises at least one of a fourth motor speed for the second motor or a fourth gimbal angle for the second drive shaft;
initiate a third operation of the first propulsion unit in accordance with the third set of attributes at a second time; and
initiate a fourth operation of the second propulsion unit in accordance with the fourth set of attributes at the second time,
wherein the second time is not earlier than the first time.

2. The unmanned aerial vehicle of claim 1 , wherein the information regarding the sound comprises a first sound pressure level of the sound and a first frequency spectrum of the sound, and
wherein the computing device is further configured to at least:
select the third motor speed based at least in part on the first sound pressure level or the first frequency spectrum of the sound.

3. The unmanned aerial vehicle of claim 1 ,
wherein the first set of attributes comprises a first pitch angle of at least one blade of the first propeller, and
wherein the third set of attributes comprises a second pitch angle of the at least one blade of the first propeller.

4. The unmanned aerial vehicle of claim 1 ,
wherein the first set of attributes comprises a first shape of at least one blade of the first propeller, and
wherein the third set of attributes comprises a second shape of the at least one blade of the first propeller.

5. A method to operate an aerial vehicle having a first propulsion unit comprising a first motor and a first propeller coupled to the first motor by a first drive shaft and a second propulsion unit comprising a second motor and a second propeller coupled to the second motor by a second drive shaft, the method comprising:
operating the first propulsion unit with the first drive shaft aligned at a first gimbal angle and the first motor rotating at a first motor speed at a first time;
operating the second propulsion unit with the second drive aligned at a second gimbal angle and the second motor rotating at a second motor speed at the first time; and
at least one of:
a first set of operations comprising:
selecting at least one of a third gimbal angle for the first drive shaft or a third motor speed for the first motor; and at least one of:
aligning the first drive shaft at the third gimbal angle at a second time; or
causing the first motor to rotate at the third motor speed at the second time; or

a second set of operations comprising:
selecting at least one of a fourth gimbal angle for the second drive shaft or a fourth motor speed for the second motor, and at least one of;
aligning the second drive shaft at the fourth gimbal angle at the second time; or
causing the second motor to rotate at the fourth motor speed at the second time.

6. The method of claim 5 , wherein the aerial vehicle further comprises at least one sensor, and wherein the method further comprises:
determining information regarding at least one sound emitted by the aerial vehicle at a third time using the at least one sensor, wherein the information regarding the at least one sound comprises at least one of a sound pressure level of the at least one sound or a frequency spectrum of the at least one sound; and
in response to determining the information regarding the at least one sound emitted by the aerial vehicle at the third time, at least one of:
selecting the at least one of the third gimbal angle for the first drive shaft or the third motor speed for the first motor based at least in part on the information regarding the at least one sound at the third time; or
selecting the at least one of the fourth gimbal angle for the second drive shaft or the fourth motor speed for the second motor based at least in part on the information regarding the at least one sound at the third time.

7. The method of claim 5 , further comprising:
determining information regarding at least one of a desired velocity or a desired acceleration of the aerial vehicle at the second time; and
in response to determining the information regarding the at least one of the desired velocity or the desired acceleration of the aerial vehicle at the second time, at least one of:
selecting the at least one of the third gimbal angle for the first drive shaft or the third motor speed for the first motor based at least in part on the information regarding the at least of the desired velocity or the desired acceleration of the aerial vehicle at the third time; or
selecting the at least one of the fourth gimbal angle for the second drive shaft or the fourth motor speed for the second motor based at least in part on the information regarding the at least of the desired velocity or the desired acceleration of the aerial vehicle at the third time.

8. The method of claim 5 ,
identifying information regarding a mission for the aerial vehicle;
determining a first attribute of the mission for the aerial vehicle; and at least one of:
selecting the at least one of the third gimbal angle or the third motor speed based at least in part on the first attribute of the mission for the aerial vehicle; or
selecting the at least one of the fourth gimbal angle or the fourth motor speed based at least in part on the first attribute of the mission for the aerial vehicle.

9. The method of claim 8 ,
wherein the first attribute of the mission for the aerial vehicle comprises

Assignees

• Amazon Tech Inc

Inventors

• Shiosaki Dominic Timothy
• Welsh Ricky Dean

Classifications

• B64C11/46

  Arrangements of, or constructional features peculiar to, multiple propellers {(B64C11/306 takes precedence)} · CPC title

• B64C39/024

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

• B64C27/14 Primary

  Direct drive between power plant and rotor hub · CPC title

• B64C27/57

  automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust · CPC title

• B64U50/19 Primary

  using electrically powered motors · CPC title