In order to reduce torsional vibrations in a drive including a torque converter with a turbine and impeller, clutch slip speed of the drive is adjusted by manipulation of clutch pressure. This may be done in either closed loop mode or open loop mode by setting the clutch pressure to a predetermined value or continuously adjusting clutch pressure. Pressure is adjusted to produce a positively sloped function of sensed total torque of the clutch and turbine over the clutch slip speed. This produces extended service life of the drive train components, greater efficiency of the torque converter, and smoother operation of the drive.

The invention relates to a method for reducing chatter vibrations of a friction clutch controlled automatically by a clutch actuator on the basis of a target clutch torque (M(s)) assigned to a clutch torque which is to be transmitted, which friction clutch is positioned in a drivetrain of a motor vehicle between an internal combustion engine and a transmission, having a present actual clutch torque which is marked by vibrations as a result of vibrations which occur occasionally (M(i)), wherein from a transmission behavior of the present actual clutch torque (M(i)) an absolute amplitude and a phase of an input signal detected at the output of the friction clutch and conveyed to a regulator are ascertained, from these a phase-selective disturbance torque is ascertained, from the latter a phase-correct correction torque (M(k)) is determined, and with this the target clutch torque (M(s)) is corrected by means of the regulator. In order to be able to design the method robustly, the correction torque (M(k)) is weighted with a specifiable intensification factor.

The invention relates to a method for reducing occasionally occurring vibrations, in particular chatter vibrations of a unit controlled automatically by an actuator, in particular a clutch actuator, on the basis of a target torque assigned to a clutch torque that is to be transmitted, in particular a target clutch torque, in particular a unit located in a drivetrain of a motor vehicle between a combustion engine and a transmission, in particular a friction clutch having an actual present clutch torque which is marked by vibrations as a result of occasionally occurring vibrations, wherein from an input signal which is representative of the vibration-marked torque on the basis of a known transfer behavior of the actual present torque vibration components of known form with unknown prefactors are continuously ascertained, a phase-correct correction torque is determined from these, and the target torque is corrected using the latter. In order to be able to separate a plurality of vibration components from one another and resolve them, an estimation model is made the basis of the input signal, and by means of the estimation model the prefactors are determined on the basis of a recursive method of the smallest square errors.

The invention relates to a software damper and to a method for configuring a software damper connected to a clutch control system for damping chatter vibrations of a clutch torque being transferred by means of an automated friction clutch positioned between a combustion engine and a transmission and controlled by the clutch control system, wherein a transmission input speed (r(g)) is captured at the output of the friction clutch by means of the software damper, and the target clutch torque (m(k)) encumbered by chatter vibrations is corrected by means of negative feedback. To design the software damper, a transfer behavior is ascertained over a control link of the clutch control system while the target clutch torque is excited in a frequency range which is relevant for chatter vibrations, under this transfer behavior an undamped first frequency response of the transmission input speed (r(g)) and a second frequency response at the output of the software damper are ascertained, and the negative feedback of the software damper is determined by comparing the two frequency responses.

A method is provided for reducing chatter vibrations in a motor vehicle drivetrain having a drive unit, a vehicle transmission and an automated friction clutch, wherein a vibration absorber is emulated by an appropriate operation of the friction clutch in order to improve the method.

The invention relates to a method for parameterizing a software damper connected to a clutch control system for damping chatter vibrations of a clutch torque being transferred by means of an automated friction clutch which is controlled by the clutch control system by means of a target clutch torque and which is positioned between a combustion engine and a drivetrain of a motor vehicle, wherein the target clutch torque affected in specified operating states by chatter vibrations is corrected by means of the software damper, wherein a transfer behavior of a clutch torque transferred via the friction clutch on the basis of the target clutch torque is ascertained during a modulation of the target clutch torque and the software damper is parameterized with the help of the ascertained transfer behavior. In order to be able to parameterize the software damper quickly and comprehensively, the target clutch torque is modulated by means of a broadband excitation in a frequency range of the chatter vibrations, and the transfer behavior is ascertained depending on operating parameters of the drivetrain.