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: 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: A controlling device with a sensor for the detection of a position of a window pane of the window lifter depending on a driving motion of an actuation is provided. The position signals generated by the sensor, for example by a path sensor or rotary pulse sensor, concern thereby the position of the window pane. Position signals are for example gained from a waviness of a driving power of a mechanically commuted electromotor. The sensor signals can thereby be evaluated by the controlling device. The controlling device includes an analogue or a digital computer unit which provides a function for the combined evaluation of the current position of the window pane and a condition of a roof of the motor vehicle. The evaluation can thereby occur for example by a respective logical circuit as computer unit, by a hard-wired program logic as computer unit or by a programmable computer unit.