Method for damping vehicle drive train vibrations

1. A method of damping drive train vibrations in a motor vehicle, the method comprising the steps of:

continuously calculating a correction torque for the vibration damping;

determining, through a parallel signal path, whether the vibration damping shall be either activated or deactivated;

activation the vibration damping by overlaying the correction torque with the drive train vibration;

sensing a rotational speed signal in the drive train;

differentiating the rotational speed signal;

amplifying a derivation of the rotational speed signal with an amplification factor dependent on the drive train, and then continuously calculating the correction torque;

parallel hereto, determinating a frequency of the drive train vibrations from measured rotational speed signals;

detecting maxima and minima of the drive train vibrations with regard to established threshold values from the rotational speed signals;

starting a time counting device to count from a start value in a direction toward a zero value through a first determination of either a maximum or a minimum;

resetting the time counting device to the start value, during a next determination of either a maximum or a minimum of the drive train vibrations;

activating the vibration damping of the time counting device has been reset due to at least a new maximum or a new minimum, and the time counting device has reached the zero value; and

deactivating the vibration damping if the time counting device has been reset due to at least a new maximum or a new minimum but the time counting device has not reached the zero value.

2. The method according to claim 1 , further comprising the step of:

either activating or deactivating the vibration damping by either overlaying or deactivating the correction torque via a steady transition function.

3. The method according to claim 1 , further comprising the step of:

either activating or deactivating the vibration damping without an additional phase shift through the calculation of the correction torque.

4. The method according to claim 1 , further comprising the step of:

defining the amplification factor as being dependant on the differential rotational speed between an input element and an output element of a starting clutch which is positioned between a drive motor and a transmission.

5. A method of damping drive train vibrations in a motor vehicle, the method comprising the steps of:

sensing a rotational speed signal in the drive train;

differentiating, in a first signal path, the rotational speed signal;

amplifying, in the first signal path, a derivation of the rotational speed signal with an amplification factor that is dependant on a conditional parameter of the drive train;

continuously calculating, in the first signal path, a vibration damping correction torque;

determining, in a second signal path, a frequency of the drive train vibrations from the sensed rotational speed signals, and the second signal path being parallel to the first signal path;

detecting, in the second signal path, maxima and minima of the sensed drive train vibrations with regard to an established threshold value;

starting, in the second signal path, a time counting device to count from a start value in a direction toward a zero value during a first determination of either a maximum or a minimum of the sensed drive train vibrations;

resetting, in the second signal path, the time counting device to the start value, during a next determination of either a maximum or a minimum of the sensed drive train vibrations;

determining, in the second signal path, to either simultaneously activate or deactivate vibration damping with the continuous calculation of the vibration damping correction torque;

activating, in the second signal path, the vibration damping if the time counting device has been reset due to at least a new maximum or a new minimum of the sensed drive train vibrations, and the time counting device has reached the zero value;

deactivating, in the second signal path, the vibration damping if the time counting device has been reset due to at least a new maximum or a new minimum of the sensed drive train vibrations, and the time counting device has not reached the zero value; and

activating the vibration damping by overlaying the correction torque with the drive train vibrations.