High-authority yaw control for a tandem vehicle with rigid rotors
A method for executing yaw control of an aircraft including two rotors is provided. The method includes inducing helicopter yaw by creating a differential torque between the two rotors, wherein the creating of the differential torque comprises inducing a differential collective pitch to generate a differential thrust, and maintaining helicopter roll equilibrium during the inducing of the helicopter yaw by inducing a differential cyclic pitch to generate a differential lift offset.
1. A method for executing yaw control of an aircraft including two rotors, the method comprising:
inducing helicopter yaw by creating a differential torque between the two rotors in a flight state with tandem rotor configuration,
wherein the creating of the differential torque comprises inducing a differential collective pitch to generate a differential thrust, and
maintaining helicopter roll equilibrium during the inducing of the helicopter yaw by inducing a differential cyclic pitch to generate a differential lift offset, wherein the lift offset applied to each rotor is proportional to the variation in thrust applied to the rotors.
2. The method according to claim 1 , wherein each of the two rotors comprises a rigid rotor.
3. The method according to claim 1 , further comprising inducing the differential collective pitch and the differential cyclic pitch at each of the two rotors.
4. The method according to claim 1 , wherein the aircraft comprises a fuselage having leading and trailing ends at which the two rotors are respectively disposed.
5. The method according to claim 4 , wherein the helicopter yaw is defined about a vertical axis.
6. The method according to claim 4 , wherein the helicopter roll equilibrium is defined along a longitudinal axis of the fuselage.
7. The method according to claim 1 , wherein the aircraft comprises a fuselage with wings extending outwardly from opposite sides of the fuselage, the two rotors being respectively disposed at the wings.
8. The method according to claim 7 , wherein the helicopter yaw is defined about a vertical axis.
9. The method according to claim 7 , wherein the helicopter roll equilibrium is defined transversely relative to a longitudinal axis of the fuselage.
10. An aircraft, comprising:
a fuselage;
first and second rotors disposed to rotate with respect to the fuselage to generate lift and thrust;
a control system coupled to the first and second rotors and configured to induce helicopter yaw by creating a differential torque between the two rotors in a flight state with tandem rotor configuration,
wherein the creating of the differential torque by the control system comprises inducing at the control system a differential collective pitch to generate a differential thrust, the control system being further configured to maintain helicopter roll equilibrium during the inducing of the helicopter yaw by inducement of a differential cyclic pitch to generate a differential lift offset wherein the lift offset applied to each rotor is proportional to the variation in thrust applied to the rotors.
11. The aircraft according to claim 10 , wherein each of the two rotors comprises a rigid rotor.
12. The aircraft according to claim 10 , wherein the first and second rotors are respectively disposed at leading and trailing ends of the fuselage.
13. The aircraft according to claim 12 , wherein the helicopter yaw is defined about a vertical axis and the helicopter roll equilibrium is defined along a longitudinal axis of the fuselage.
14. The aircraft according to claim 10 , wherein the first and second rotors are respectively disposed at wings extending outwardly from opposite sides of the fuselage.
15. The aircraft according to claim 14 , wherein the helicopter yaw is defined about a vertical axis and the helicopter roll equilibrium is defined transversely relative to a longitudinal axis of the fuselage.