Method and device for reducing the effect of the vibration generated by the driveline of a helicopter

A device for reducing the effect of vibration generated by the driveline (2, 3, 4, 5) of a helicopter (H), the said helicopter (H) including at least one rotor (2, 3), the collective pitch of the blades (6, 26) of which can be controlled by a control system (7, 27), comprising:

• (a) at least one sensor (14, 15, 16, 23, 24) capable of measuring the values of at least one parameter representing the effect of the vibration generated by the said driveline (2, 3, 4, 5);
• and
• (b) computation means (17) capable:
• (i) of determining, directly from the values measured by the said sensor (14, 15, 16, 23, 24), a signal for controlling the collective pitch of the blades (6, 26) of the said rotor (2, 3), the said control being such that applying the said control signal to the system (7, 27) for controlling the collective pitch of the blades (6, 26) of the said rotor (2, 3) generates a set of forces and of moments which oppose the said effect of the vibration generated by the driveline (2, 3, 4, 5);
• and
• (ii) of transmitting the control signal thus formed to the said system (7, 27) for controlling solely the collective pitch of the blades (6, 26) of the rotor (2, 3).