Patent ID: 8170728

Claim:
A system for controlling a rotorcraft having a rotor, at least one variable-pitch propulsion propeller, and a motor for driving the rotor and the at least one variable-pitch propulsion propeller, the system comprising: a member ( 101 , 101 A, 102 , 103 , 104 ) configured to generate a propeller pitch setpoint (θ p *+θ d *, θ p *−θ d *) as a function at least of a variation thrust command (TCL); a member ( 105 , 105 A) configured to generate a drive speed setpoint (RPM*) for a drive speed (RPM) of the rotor and the at least one variable-pitch propulsion propeller, as a function at least of a travel speed (VTAS) of the rotorcraft and where appropriate as a function of ambient temperature; and a member ( 106 ) configured to generate an engine speed setpoint (NG*) for an engine speed as a function at least of the variation thrust command (TCL), of the drive speed setpoint (RPM*), and of a rotor collective pitch command (θ 0 ); wherein the member ( 106 ) configured to generate the engine speed setpoint (NG*) includes: a member ( 109 ) configured to generate a first anticipated command for varying engine speed as a function of the rotor collective pitch command (θ 0 ); a member ( 110 ) configured to generate a second anticipated command for varying engine speed as a function of the variation thrust command (TCL); a first summing circuit ( 111 ) for adding together the first and second anticipated commands for varying engine speed, and for outputting a first component (NG 1 *) of the engine speed setpoint (NG*); and a unit ( 112 , 113 , 114 ) configured to generate the engine speed setpoint (NG*) as a function of the first component (NG 1 *), of the drive speed setpoint (RPM*), and of a measurement of the drive speed (RPM).