Abstract: In a method and a device for determining a reference position of a locking part moved by an electric motor, the locking part is moved in the direction of the closed state thereof, until the same reaches a stop position. At that location the meter reading of a position meter describing the stop position is detected and buffered. Subsequently a movement of the locking part is carried out in the direction of the opened state thereof. The locking part is then moved again in the direction of the closed state thereof, until it again reaches a stop position. At that location a meter reading describing the stop position is detected, and compared to the buffered meter reading. If both meter readings agree, the first stop position is determined as the reference position. The method and device can be utilized, for example, for power window lifts and sunroofs of motor vehicles.

Abstract: In order to determine a drive force (FAct) produced by an electric motor, the motor current (Ia) supplied to the electric motor (10) from a power supply source (32) is measured and a force is calculated from this; in addition, the motor voltage (UBat) applied to the electric motor (10) is measured, and drive force fluctuations which result from voltage fluctuations that occur during operation of the power supply source are compensated for, with at least one compensation force component being determined which is based on the measured motor voltage (UBat), including voltage fluctuations.

Abstract: In a method and a device for determining a reference position of a locking part moved by an electric motor, the locking part is moved in the direction of the closed state thereof, until the same reaches a stop position. At that location the meter reading of a position meter describing the stop position is detected and buffered. Subsequently a movement of the locking part is carried out in the direction of the opened state thereof. The locking part is then moved again in the direction of the closed state thereof, until it again reaches a stop position. At that location a meter reading describing the stop position is detected, and compared to the buffered meter reading. If both meter readings agree, the first stop position is determined as the reference position. The method and device can be utilized, for example, for power window lifts and sunroofs of motor vehicles.

Abstract: In order to determine a drive force (FAct) produced by an electric motor, the motor current (Ia) supplied to the electric motor (10) from a power supply source (32) is measured and a force is calculated from this; in addition, the motor voltage (UBat) applied to the electric motor (10) is measured, and drive force fluctuations which result from voltage fluctuations that occur during operation of the power supply source are compensated for, with at least one compensation force component being determined which is based on the measured motor voltage (UBat), including voltage fluctuations.