A method for controlling a polyphase actuator includes supplying each phase with a periodically varying voltage having a periodic sequence of steps Pi that have a constant duration and an amplitude An,i, where n corresponds to the rank of the phase and i to the rank of the step. The method further includes determining a target position PCi of a rotor of the actuator, in order to define a sinusoidal voltage envelope. The actuator further includes a movable member, a stator equipped with electrical coils and a sensor detecting the mechanical position of the movable member with respect to the stator, as well as a microcontroller. The microcontroller determines, at times Tcapteur, a mechanical position of a mechanical member, the microcontroller calculates, at each of the times Tcapteur, a difference between the mechanical position and a target position PCi corresponding to the step Pi and the microcontroller calculates a coefficient k as a function of the difference. The microcontroller also weights the amplitude of a power supply applied to the phases by a coefficient k in order to supply the phases with weighted amplitude voltages An,i*k.