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.

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.