VARIABLE DAMPING OF HAPTIC FEEDBACK FOR A FLIGHT-ATTITUDE CHANGING LINKAGE OF AN AIRCRAFT

• US 20110024551A1
• Filed: 07/15/2010
• Published: 02/03/2011
• Est. Priority Date: 07/28/2009
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Gemmati, Bernard, Pruss, Julien, Biest, Romuald
• Granted Patent: US 8,240,617 B2
• Time in Patent Office: Days
• US Class Current: 244/6
• CPC Class Codes: B64C 13/345 with artificial feel
• CPC Class Codes: B64C 27/26 characterised by provision of fixed wings

Abstract

The present invention relates to haptic feedback for operating at least one manual flight control device (21) for controlling the cyclic pitch of the blades (5) of a rotary wing (4) of a hybrid helicopter (1) via power assistance (27). Said operations of said control device (21) are defined according to a predetermined damping force relationship (A) that is a function of an instantaneous load factor of the hybrid helicopter (1) in such a manner that the instantaneous load factor is maintained between its minimum and maximum limit values in proportion to a position of a thrust control member (20) between its minimum and maximum thrust values (23, 22).

Claims

1. A method of providing haptic feedback for operating at least one manual flight control device suitable for giving rise to adjustments of at least one airfoil surface of a hybrid helicopter via a flight-attitude changing linkage that is provided with power assistance, the hybrid helicopter comprising at least a fuselage, a rotary wing and a fixed wing having anti-torque differential thrust propulsion arrangements distributed symmetrically thereon on either side of the fuselage, said arrangements being controlled between minimum and maximum thrust values by a manual thrust control member, the hybrid helicopter further including an autopilot suitable for acting on the power assistance for adjusting said cyclic pitch of the blades of the rotary wing, said operations of said control device being damped by haptic feedback defined according to a predetermined damping force relationship, wherein said damping force relationship for operating the manual flight control device is predetermined as a function of an instantaneous load factor of the hybrid helicopter in such a manner that this instantaneous load factor is maintained between its minimum and maximum limit values in proportion to a position of said thrust control member between its minimum and maximum thrust values.

2. A method according to claim 1, wherein said manual control device with damping of its operation acts on the pitch attitude of the hybrid helicopter, said airfoil surfaces comprising blades of a rotary wing, with the cyclic pitch thereof being adjusted.

3. A method according to claim 1, wherein said manual control device with damping of its operation acts on the roll attitude of the hybrid helicopter, said airfoil surfaces comprising blades of a rotary wing (4), with the cyclic pitch thereof being adjusted.

4. A method according to claim 1, wherein manual control device with damping of its operation acts on the yaw attitude of the hybrid helicopter, said airfoil surfaces forming parts of the thrust arrangements and/or of a set of stabilizer and rudder control surfaces.

5. A method according to claim 1, wherein said predetermined damping force relationship for operating said manual control device is obtained by applying an opposing torque exerted by a damper on said attitude changing linkage using a damping coefficient of said damper that is variable in application of another predetermined damping coefficient variation relationship as a function of the stroke of the mean collective pitch of blades of propellers of said thrust arrangements.

6. A method according to claim 5, wherein when said manual control member is ordering thrust at said minimum value or even zero thrust, the collective pitch of said propellers of the propulsion arrangements is at a minimum and said damping coefficient applied by the damper defined according to the predetermined damping coefficient variation relationship lies substantially in the range 2.5 Nm/rd/s to 3.5 Nm/rd/s, while the damping coefficient applied by the damper when said control member is ordering thrust at said maximum value is itself at a maximum, said damping coefficient applied by the damper lying substantially in the range 13.5 Nm/rd/s to 14.5 Nm/rd/s.

7. A method according to claim 2, wherein said adjustments of the cyclic pitch of the blades of the rotary wing of the hybrid helicopter are obtained via said power assistance, said assistance being defined at least in part by said autopilot independently of said predetermined damping force relationship for operating the manual flight control device;

operations applied to said manual control thrust member acting directly and/or via power assistance on the adjustment of the thrust, this adjustment being delivered to an autopilot which then responds by adapting at least one flight parameter such as an engine speed for the propulsion arrangements, which adaptation gives rise in return to a new assistance setpoint being defined for adjusting the cyclic pitch of the blades of the rotary wing, in a manner that is indirect, and thus independent.

8. A method according to claim 1, wherein said minimum and maximum limit values of the load factor and/or said minimum and maximum thrust values are calibrated as a function of limit states for the hybrid helicopter tending automatically to pitch up.

9. A hybrid helicopter including at least one damper for implementing the method according to claim 1, wherein the helicopter includes at least one damper motor;

a haptic feedback system for operating at least one manual flight control device being suitable for giving rise to adjustments of a cyclic pitch of the blades of a rotary wing of the hybrid helicopter via power assistance, said hybrid helicopter comprising at least a fuselage, said rotary wing, and a fixed wing having anti-torque differential thrust propulsion arrangements distributed symmetrically thereon on either side of the fuselage, a manual thrust control member being provided so that operating it controls said thrust arrangements between maximum and minimum thrust positions, said hybrid helicopter further including an autopilot functionally connected to the power assistance so as to participate in said cyclic pitch adjustment of said blades of the rotary wing, and said manual control device being arranged in such a manner that operating it is damped by haptic feedback defined according to a predetermined damping force relationship; and

in order to predetermine said predetermined damping force relationship in proportion to a position of said thrust control member between the minimum and maximum thrust values, a flight-attitude changing linkage to which said damping force relationship is to be applied is incorporated in said hybrid helicopter in parallel with another flight-attitude changing linkage for changing thrust and provided with said control member.

10. A hybrid helicopter according to claim 9, wherein the operation haptic feedback system includes assistance dedicated to said flight-attitude changing linkage and in parallel, assistance dedicated to said other flight-attitude changing linkage that acts on thrust, the flight direction control assistance being functionally connected firstly to a manual control device such as a lever and secondly to at least one airfoil surface of the rotary wing via swashplates for controlling the cyclic pitch of the blades of said rotary wing, while in parallel, said thrust control assistance is functionally connected firstly to said control member and secondly to mechanisms for adjusting the pitch of the blades of propellers of said thrust arrangements.

11. A hybrid helicopter according to claim 10, wherein it implements the method according to claim 1.

12. A hybrid helicopter according to claim 9, wherein said other flight-attitude changing linkage for controlling thrust includes at least two pivoting crank hinges and a position sensor at one of said hinges that is functionally connected to said control member in such a manner as to produce an electric signal representative of the control of said member between said minimum and maximum thrust values;

for example the position sensor is a rotary variable differential transformer sensor.

13. A hybrid helicopter according to claim 9, wherein said flight-attitude changing linkage includes at least two pivoting crank hinges and at one said hinges at least one damper of operations of said manual flight control device, the damper being in the form of an alternator or motor connected in such a manner as to deliver electricity to an opposing electronic circuit connected to the terminals of said damper in order to produce a back emf proportional to the speed of rotation of said hinge receiving the damper.

14. A hybrid helicopter according to claim 9, wherein said manual flight control device is functionally coupled to an operation speed sensor adapted to produce an operation speed signal proportional to the instantaneous speed at which said manual flight control device is being actuated, said speed signal then being incorporated as a parameter in the predetermined damper relationship.

15. A hybrid helicopter according to claim 14, wherein said feedback system includes at least one sensor for sensing the position of said manual control member, a damper for damping operation of said manual control device, and a speed sensor, which sensors and damper are functionally connected to define the damping directly as a function of the predetermined damping force relationship.

16. A hybrid helicopter according to claim 9, wherein the system includes a computer having connected thereto at least one position sensor for sensing the position of said control member, and a damper for damping operations of said manual flight control device, and optionally a speed sensor for sensing the speed of said control member.

17. A hybrid helicopter according to claim 9, wherein the hybrid helicopter is suitable for implementing the haptic feedback method according to claim 1, and wherein it is a drone having a piloting station that is remote and not on board, and that includes at least one manual flight control device with haptic feedback and a manual thrust control member of instantaneous position that is taken into consideration to determine the force relationship.