Operating multirotor aircraft with enhanced yaw control

Patent metadata

Field	Value
Publication number	US-11111009-B1
Application number	US-201715592866-A
Country	US
Kind code	B1
Filing date	May 11, 2017
Priority date	Jun 9, 2015
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

This disclosure describes a configuration of a multirotor aircraft that will facilitate enhanced yaw control. The multirotor aircraft includes one or more adjustable members that will twist the frame of the multirotor aircraft, thereby adjusting the orientation of the motors and propellers and enhance the yaw control of the multirotor aircraft. In some implementations, the adjustable member(s) are passive and twist in response to differential thrusts generated by the propellers. In other implementations, the adjustable members are active and twist in response to a yaw command from the multirotor aircraft control system.

First claim

What is claimed is:

1. A method of operating a multirotor aircraft, comprising:
generating a first differential thrust between a first motor and a second motor, the first motor coupled to a first end of a first motor arm and the second motor coupled to a second end of the first motor arm, the first motor arm coupled to a front frame of the multirotor aircraft;
generating a second differential thrust between a third motor and a fourth motor, the third motor coupled to a first end of a second motor arm and the fourth motor coupled to a second end of the second motor arm, the second motor arm coupled to a rear frame of the multirotor aircraft, the front frame coupled to the rear frame via an adjustable member, and the front frame, the adjustable member, and the rear frame extending along an axis;
generating a first rotation of the front frame in a first direction about the axis in response to the first differential thrust; and
generating a second rotation of the rear frame in a second direction about the axis in response to the second differential thrust;
wherein the axis is transverse to axes of rotation of the first, second, third, and fourth motors.

2. The method of claim 1 , further comprising:
altering a first orientation of the first motor and a second orientation of the second motor due to the first rotation; and
altering a third orientation of the third motor and a fourth orientation of the fourth motor due to the second rotation.

3. The method of claim 1 , further comprising generating a yaw moment of the multirotor aircraft in response to the first rotation and the second rotation.

4. The method of claim 1 , wherein the adjustable member comprises at least one of a spring, a leadscrew, a gear, a bearing, a swivel, a joint, metal, fiberglass, carbon fiber, plastic, or an elastomeric material.

5. The method of claim 1 , further comprising:
twisting the adjustable member about the axis via a motor coupled to the adjustable member in response to a yaw command.

6. A method of operating a multirotor aircraft, comprising:
generating a first differential thrust between a first motor and a second motor, the first motor coupled to a first portion of a frame of the multirotor aircraft, the frame extending along an axis and comprising the first portion and a second portion connected by an adjustable member; and
causing the multirotor aircraft to yaw by altering an orientation of the first portion of the frame with respect to the second portion of the frame about the axis via the adjustable member, the axis being transverse to axes of rotation of the first and second motors.

7. The method of claim 6 , wherein the first differential thrust is generated by rotating the first motor at a different speed than the second motor.

8. The method of claim 6 , wherein the orientation is altered in response to the first differential thrust generated between the first motor and the second motor of the first portion of the frame relative to a second differential thrust generated between a third motor and a fourth motor of the second portion of the frame.

9. The method of claim 8 , further comprising:
rotating the first motor and the third motor in a first direction; and
rotating the second motor and the fourth motor in a second direction.

10. The method of claim 8 , further comprising:
rotating each of the first motor, the second motor, the third motor, and the fourth motor in a first direction.

11. The method of claim 8 , wherein the orientation is altered by:
causing the first portion of the frame to rotate in a first direction about the axis; and
causing the second portion of the frame to rotate in a second direction about the axis.

12. The method of claim 6 , wherein the orientation of the first portion of the frame with respect to the second portion of the frame is altered via an actuator associated with the adjustable member.

13. The method of claim 12 , wherein the orientation is altered via the actuator in response to a yaw command.

14. The method of claim 6 , further comprising varying a stiffness of the adjustable member via a controller.

15. The method of claim 6 , wherein the orientation is altered by causing a wing of the multirotor aircraft to rotate with respect to the frame.

16. A method of operating an aircraft, comprising:
generating a first differential thrust between a first motor and a second motor of the aircraft;
causing a first rotation of a first portion of a frame of the aircraft in a first direction about an axis via an adjustable member at least partially in response to the first differential thrust; and
causing a second rotation of a second portion of the frame of the aircraft in a second direction about the axis via the adjustable member;
wherein the first portion of the frame, the adjustable member, and the second portion of the frame extend along the axis;
wherein the first portion is coupled to the second portion via the adjustable member; and
wherein the axis is transverse to axes of rotation of the first and second motors.

17. The method of claim 16 , further comprising:
generating a second differential thrust between a third motor and a fourth motor of the aircraft;
wherein the second rotation is caused at least partially in response to the second differential thrust.

18. The method of claim 17 , wherein the first motor and the second motor are coupled to opposing ends of a first motor arm coupled to the first portion of the frame; and
wherein the third motor and the fourth motor are coupled to opposing ends of a second motor arm coupled to the second portion of the frame.

19. The method of claim 16 , wherein the adjustable member comprises at least one of a spring, a leadscrew, a gear, a bearing, a swivel, a joint, metal, fiberglass, carbon fiber, plastic, an elastomeric material, or an actuator.

20. The method of claim 16 , further comprising:
twisting the adjustable member about the axis via an actuator coupled to the adjustable member in response to a yaw command.

Assignees

• Amazon Tech Inc

Inventors

• Beckman Brian C
• Elzinga Michael John
• Harris Scott Raymond
• Legrand Iii Louis Leroi
• Schaffalitzky Frederik

Classifications

• B64U2201/10

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

• B64C15/14

  the jets being other than main propulsion jets (jet flaps B64C9/38) · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• B64U40/20

  for in-flight adjustment of the base configuration · CPC title

• B64U30/29

  Constructional aspects of rotors or rotor supports; Arrangements thereof · CPC title