Abstract: The invention relates to a process for adjusting a motor vehicle part between at least two positions, the motor vehicle part being driven by an electric motor, pulse signals being generated according to the rotary motion of the electric motor and being supplied to a control unit for controlling the electric motor, in the first computation (50) with a first parameter set the first value for the instantaneous force acting on the motor vehicle part is determined from the acquired pulse signals at certain first instants. Parallel to the first computation, in at least the second computation (52) with a second parameter set which differs from the first parameter set the second value for the instantaneous force acting on the motor vehicle part is determined from the acquired pulse signals at certain second instants, the two values being considered for the instantaneous action of the force in order to decide whether the electric motor is turned off or reversed or not.

Abstract: A process for adjusting a motor vehicle part between at least two positions and a drive device for executing this process. The motor vehicle part is driven by an electric motor. A pulse signal is generated according to the rotary motion of the electric motor (10) and is supplied to a control unit (24) for controlling the electric motor (10). The instant of input of each signal on the control unit (24) is acquired and between two such input instants at certain extrapolation instants from at least some of these measured instants the current force acting on the motor vehicle part is estimated, this estimate being used as the criterion in the decision whether the electric motor (10) is turned off or reversed or not.

Abstract: The invention relates to a process for adjusting a motor vehicle part between at least two positions and a drive device for executing this process. The motor vehicle part is driven by an electric motor, and a pulse signal is generated according to the rotary motion of the electric motor which is supplied to a control unit for controlling the electric motor, in which at certain instants the value for the current force acting on the motor vehicle part is determined from the pulse signal. This value of the force is used as the criteria in the decision whether the electric motor is to be turned off or reversed [or not]. Before connection of the electric motor to the motor vehicle part measurements are taken on the electric motor for determining the individual motor characteristics, the measured values determined in this way are used in the determination of the value of the action of force.

Abstract: A process for displacing a motor vehicle part between at least two positions and a drive device for executing this process in which the motor vehicle part is driven by an electric motor (10), a pulse signal is generated according to the rotary motion of the electric motor (10) and is supplied to a control unit (24) for controlling the electric motor (10), and the instant of input of each signal on the control unit (24) is acquired. Furthermore, at certain instants, a respective for the change of motor rpm is determined from at least some of these previously measured instants, from each value of the rpm change a force change value (&Dgr;F*[k]) is computed and at least some of the previously determined values of the force change are added up with weighting in order to determine the value for the instantaneous force acting on the moveable motor vehicle part. This value is used as the criterion in deciding whether or not the electric motor (10) is turned off or reversed.

Abstract: A top element of a convertible roof which is formed from a plastic component 2 and a sheet metal part 3 as a composite part and in which major areas of the plastic component 2 and the sheet metal part 3 are spaced apart from one another and form a stiff cavity structure.

Abstract: A motor vehicle roof structure with at least one openable roof part (3) which is movably guided in the area of the side members (11) has side members (11) which are detachably connected to vehicle-mounted parts, such as the A column (10) and the B column (28) of the vehicle body, by a plug-in/locking mechanism.