Abstract: For the purpose of realizing an operationally reliable window lifter (opener) for a vehicle, there is provision to ascertain from an operating variable of a servomotor in each case a measure of a regulated position of the window pane in the course of a plurality of operating cycles of the window lifter in which a window pane of the vehicle is opened and closed again, in each case entirely or partly. In each operating cycle, or at least in selected operating cycles, the measure is normalized to a reference value if at the end of the respective operating cycle the window pane is driven by the servomotor for at least a predetermined blocked time beyond a blocked position. The blocked time is shortened if the normalization was not carried out for a predetermined number of consecutive operating cycles.

Abstract: In order to ascertain the actuating position of a vehicle part that is moved by an electric actuating motor via an actuating mechanism, an angle of rotation correlating with the number of motor shaft rotations during the actuation process or a motor signal correlated therewith are ascertained during an actuation process. An actuating position measure for the actuating position of the vehicle part is derived from the angle of rotation or the motor signal correlating therewith. During this process, an unloaded angle of rotation, through which the motor shaft rotates during an initial no-load phase of the actuation process without motion of the vehicle part is compensated by a predetermined correction term. The correction term is changed according to a stored dependency on a characteristic quantity for the age of the actuating mechanism.

Abstract: For the purpose of realizing an operationally reliable window lifter (opener) for a vehicle, there is provision to ascertain from an operating variable of a servomotor in each case a measure of a regulated position of the window pane in the course of a plurality of operating cycles of the window lifter in which a window pane of the vehicle is opened and closed again, in each case entirely or partly. In each operating cycle, or at least in selected operating cycles, the measure is normalized to a reference value if at the end of the respective operating cycle the window pane is driven by the servomotor for at least a predetermined blocked time beyond a blocked position. The blocked time is shortened if the normalization was not carried out for a predetermined number of consecutive operating cycles.

Abstract: In order to ascertain the actuating position of a vehicle part that is moved by an electric actuating motor via an actuating mechanism, an angle of rotation correlating with the number of motor shaft rotations during the actuation process or a motor signal correlated therewith are ascertained during an actuation process. An actuating position measure for the actuating position of the vehicle part is derived from the angle of rotation or the motor signal correlating therewith. During this process, an unloaded angle of rotation, through which the motor shaft rotates during an initial no-load phase of the actuation process without motion of the vehicle part is compensated by a predetermined correction term. The correction term is changed according to a stored dependency on a characteristic quantity for the age of the actuating mechanism.