Aircraft attitude control methods

Patent metadata

Field	Value
Publication number	US-9958874-B2
Application number	US-201414390004-A
Country	US
Kind code	B2
Filing date	May 30, 2014
Priority date	May 30, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Systems and methods are provided for aircraft attitude control. The aircraft attitude control may take physical parameters of the aircraft into account. For example, one or more aircraft configuration parameters, such as moment of inertia, motor lift curve, and/or axial distance may be calculated and/or taken into account based on the aircraft physical parameters. The aircraft configuration parameters may include non-linear parameters. The control systems may include feedback control systems, and may optionally use a feedforward and feedback control for angular acceleration.

First claim

What is claimed is:

1. A method for controlling aircraft attitude, said method comprising:
(a) calculating one or more aircraft configuration parameters based on one or more physical characteristics of an aircraft;
(b) receiving, at a processor, a signal indicative of a target attitude of the aircraft;
(c) generating, with aid of the processor, a command signal to be delivered to at least one actuator of the aircraft operably coupled to one or more propulsion units of the aircraft, wherein said generation is based on (1) the signal indicative of the target attitude of (b), and (2) the one or more aircraft configuration parameters of (a), and where said generation further uses a feedback control scheme that includes an angular acceleration loop with angular acceleration feedback;
(d) measuring, with aid of one or more sensors operably coupled to the aircraft, dynamics of the aircraft resulting from actuation of the one or more propulsion units; and
(e) feeding the dynamics to the processor to yield the feedback control scheme that adjusts or confirms the command signal of (c).

2. The method of claim 1 , wherein the aircraft is an unmanned aerial vehicle.

3. The method of claim 1 , wherein the aircraft includes a plurality of actuators operably coupled to a plurality of propulsion units, wherein the propulsion units include rotors that generate lift for the aircraft.

4. The method of claim 1 , wherein the signal indicative of a target attitude of the aircraft is received from a remote controller over a wireless connection.

5. The method of claim 1 , wherein the one or more physical characteristics are input by a user.

6. The method of claim 1 , wherein the one or more physical characteristics of the aircraft include a physical dimension and weight.

7. The method of claim 6 , further comprising calculating an aerodynamic center and center of gravity of the aircraft.

8. The method of claim 6 , further comprising calculating a moment of inertia for the aircraft.

9. The method of claim 8 , wherein the calculation using the feedback controls system includes a feedforward calculation using the moment of inertia of the aircraft.

10. The method of claim 1 , wherein the calculation using the feedback control scheme is performed for aircraft attitude about a pitch axis, roll axis, and yaw axis.

11. The method of claim 10 , further comprising combining, using a mixer, results of the calculations about the pitch axis, roll axis, and yaw axis, and an aircraft configuration parameter to calculate the command signal to be delivered to the at least one actuator.

12. The method of claim 11 , wherein the aircraft configuration parameter is a distance from the actuator to an aerodynamic center of the aircraft.

13. The method of claim 1 , wherein the one or more sensors are inertial sensors.

14. The method of claim 1 , wherein the dynamics of the aircraft include the attitude of the aircraft with respect to at least one axis, the angular velocity with respect to at least one axis, and the angular acceleration with respect to the at least one axis.

15. A method for controlling aircraft attitude, said method comprising:
(a) assessing, with aid of a processor, a non-linear relationship between thrust of an actuator and actuator output;
(b) receiving, at the processor, a signal indicative of a target attitude of an aircraft;
(c) generating, with aid of the processor, a command signal to be delivered to at least one actuator of the aircraft operably coupled to one or more propulsion units of the aircraft, wherein said generation is based on (1) the signal indicative of the target attitude of (b), and (2) the non-linear relationship of (a), and wherein said generation uses a feedback control scheme that includes an angular acceleration loop with angular acceleration feedback;
(d) measuring, with aid of one or more sensors operably coupled to the aircraft, dynamics of the aircraft resulting from actuation of the one or more propulsion units; and
(e) feeding the dynamics to the processor to yield the feedback control scheme that adjusts or confirms the command signal of (c).

16. The method of claim 15 , wherein the aircraft is an unmanned aerial vehicle.

17. The method of claim 15 , wherein the aircraft includes a plurality of actuators operably coupled to a plurality of propulsion units, wherein the propulsion units include rotors that generate lift for the aircraft.

18. The method of claim 15 , wherein the signal indicative of a target attitude of the aircraft is received from a remote controller over a wireless connection.

19. The method of claim 15 , wherein the non-linear relationship is input by a user.

20. The method of claim 15 , wherein the non-linear relationship is calculated during a calibration of one or more actuator of the aircraft.

21. The method of claim 15 , further comprising calculating an aerodynamic center and center of gravity of the aircraft based on one or more physical characteristics of the aircraft.

22. The method of claim 21 , further comprising calculating a moment of inertia for the aircraft based on the physical characteristics of the aircraft.

23. The method of claim 22 , wherein the calculation using the feedback controls system includes a feedforward calculation using the moment of inertia of the aircraft.

24. The method of claim 15 , wherein the one or more sensors are inertial sensors.

25. A method for controlling aircraft attitude, said method comprising:
(a) receiving, at the processor, a signal indicative of a target attitude of an aircraft;
(b) generating, with aid of the processor, a command signal to be delivered to at least one actuator of the aircraft operably coupled to one or more propulsion units of the aircraft, wherein said generation is based on the signal indicative of the target attitude of (a), and wherein said generation uses a feedback control scheme that includes (1) an angular acceleration loop with angular acceleration feedback and (2) direct feedforward calculation based on a target acceleration;
(c) measuring, with aid of one or more sensors operably coupled to the aircraft, dynamics of the aircraft resulting from actuation of the one or more propulsion units; and
(d) feeding the dynamics to the processor to yield the feedback control scheme that adjusts or confirms the command signal of (b).

26. The method of claim 25 , wherein the aircraft is an unmanned aerial vehicle and includes a plurality of actuators operably coupled to a plurality of propulsion units, wherein the propulsion units include rotors that generate lift for the aircraft.

27. The method of claim 25 , further comprising calculating an aerodynamic center and center of gravity of the aircraft based on one or more physical characteristics of the aircraft.

28. The method of claim 27 , further comprising calculating a moment of inertia for the aircraft based on the physical characteristics of the aircraft, wherein the feedforward calculation uses the moment of inertia of the aircraft.

29. The method of claim 25 , wherein the calculation using the feedback control scheme is performed for aircraft attitude about a pitch axis, roll axis, and yaw axis; and further comprising combining, using a mixer, results of the calculations about the pitch axis, roll axis, and yaw axis, and an aircraft configuration parameter to calculate the command sig

Assignees

• Sz Dji Technology Co Ltd
• Sz Dji Technology Co Ltd

Inventors

• Yu Yun

Classifications

• G05D1/0858 Primary

  specially adapted for vertical take-off of aircraft · CPC title

• B64C29/0025

  the propellers being fixed relative to the fuselage · CPC title

• B64C15/00

  Attitude, flight direction, or altitude control by jet reaction · CPC title