Moment limiting control laws for dual rigid rotor helicopters

Patent metadata

Field	Value
Publication number	US-10086932-B2
Application number	US-201213347316-A
Country	US
Kind code	B2
Filing date	Jan 10, 2012
Priority date	Jan 14, 2011
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A method of counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter includes sensing angular velocity and angular acceleration of a helicopter during a flight maneuver. The angular velocity and angular acceleration are compared to a set of control parameters and one or more control servos change the cyclic pitch of the one or more rotors to counteract the rotor moment. A control system for counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter includes one or more sensors configured to sense angular velocity and angular acceleration of a helicopter during a flight maneuver. A computer is operably connected to the one or more sensors and configured to compare sensor data to a set of control parameters. A plurality of control servos change the cyclic pitch of the one or more rotors to counteract the rotor moment.

First claim

The invention claimed is:

1. A method of counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter comprising:
sensing angular velocity and angular acceleration of a helicopter during a flight maneuver;
comparing the angular velocity and angular acceleration to a set of control parameters;
issuing a command to one or more control servos of a rotor swashplate according to the comparison; and
changing the cyclic pitch of the one or more rotors in response to the command via the control servos to counteract the rotor moment;
wherein the one or more rotors is two rotors, and the cyclic pitch change of a first rotor of the two rotors is in an opposite direction to the cyclic pitch change of a second rotor of the two rotors to increase a minimum blade tip clearance between the two rotors.

2. The method of claim 1 , further comprising utilizing pilot control inputs in comparison to the control parameters.

3. The method of claim 1 , wherein the control parameters further include helicopter airspeed.

4. The method of claim 1 , wherein the control parameters further include helicopter vertical acceleration.

5. The method of claim 1 , wherein the flight maneuver is a roll maneuver.

6. The method of claim 1 , wherein the flight maneuver is a pitch maneuver.

7. The method of claim 1 , wherein the comparing the angular velocity and angular acceleration to a set of control parameters and issuing a command to one or more control servos of a rotor swashplate is accomplished via a computer operably connected to the sensors and the control servos.

8. A control system for counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter comprising:
one or more sensors which sense angular velocity and angular acceleration of a helicopter during a flight maneuver;
a computer receiving the sensed angular velocity and angular acceleration from the one or more sensors to compare the sensed angular velocity and angular acceleration to a set of control parameters and produces a control signal according to the comparison; and
a plurality of control servos which receive the control signal and change the cyclic pitch of the one or more rotors in response to the control signal via the control servos to counteract the rotor moment;
wherein the one or more rotors is two rotors, and the cyclic pitch change of a first rotor of the two rotors is in an opposite direction to the cyclic pitch change of a second rotor of the two rotors to increase a minimum blade tip clearance between the two rotors.

9. The system of claim 8 , further comprising one or more pilot control inputs transmitted to the computer.

10. The system of claim 8 , wherein the control parameters further include helicopter airspeed.

11. The system of claim 8 , wherein the control parameters further include helicopter vertical acceleration.

12. The system of claim 8 , wherein the flight maneuver is a roll maneuver.

13. The system of claim 8 , wherein the flight maneuver is a pitch maneuver.

14. The system of claim 8 , wherein the plurality of control servos change the rotor cyclic pitch by changing a position of a swash plate.

15. A helicopter comprising:
an airframe;
two counterrotating rotors disposed concentrically at the airframe, each rotor including a plurality of rotor blades; and
a control system for counteracting a rotor moment of one or more rotors of the two rotors including:
one or more sensors configured to sense angular velocity and angular acceleration of the helicopter during a flight maneuver;
a computer operably connected to the one or more sensors and configured to compare sensor data to a set of control parameters; and
a plurality of control servos operably connected to the computer and to the plurality of rotor blades configured to change the cyclic pitch of each rotor of the two rotors via the control servos to counteract the rotor moment;
wherein the cyclic pitch change of a first rotor of the two rotors is in an opposite direction to the cyclic pitch change of a second rotor of the two rotors to increase a minimum blade tip clearance between the two rotors.

16. The helicopter of claim 15 , further comprising one or more pilot control inputs operably connected to the computer.

17. The helicopter of claim 15 , wherein the control parameters further include helicopter airspeed.

18. The helicopter of claim 15 , wherein the control parameters further include helicopter vertical acceleration.

19. The helicopter of claim 15 , wherein the flight maneuver is a roll maneuver.

20. The helicopter of claim 15 , wherein the flight maneuver is a pitch maneuver.

21. The helicopter of claim 15 , wherein the plurality of control servos are operably connected to the one or more rotors via a swash plate.

22. A method of counteracting a rotor moment of one or more rotors of a concentric dual-rotor helicopter comprising:
initiating a flight maneuver in the helicopter, the flight maneuver being about a first axis;
sensing angular velocity and angular acceleration of a helicopter during the flight maneuver;
comparing the angular velocity and angular acceleration to a set of control parameters;
issuing a command to one or more control servos of a rotor swashplate according to the comparison; and
changing the cyclic pitch of the one or more rotors along a second axis perpendicular to the first axis in response to the command via the control servos to counteract the rotor moment;
wherein the one or more rotors is two rotors, and the cyclic pitch change of a first rotor of the two rotors is in an opposite direction to the cyclic pitch change of a second rotor of the two rotors to increase a minimum blade tip clearance between the two rotors.

Assignees

• Eller Erez
• Knag John
• Sikorsky Aircraft Corp

Inventors

• Eller Erez
• Knag John

Classifications

• B64C27/04

  Helicopters · CPC title

• B64C27/10 Primary

  arranged coaxially · CPC title