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.

A T-S curve correction method for a clutch system may include: detecting differences between actual positions of a clutch in first and second torque regions and a position on a T-S curve; determining whether the difference between the actual position in the first torque region and the position on the T-S curve is equal to or more than a first reference value; determining whether the difference between the actual position in the second torque region and the position on the T-S curve is equal to or less than a third reference value, when the difference of the actual position in the first torque region is equal to or more than the first reference value; and correcting the slope of the T-S curve in the increasing direction, when the difference of the actual position in the second torque region is equal to or less than the third reference value.

A method for operating a drive train of a vehicle having a clutch assembly, in particular for distributing torque to a primary axle and a secondary axle of the vehicle and/or for distributing torque between two wheels of one axle of the vehicle, comprises at least the following steps:

a) determining temperature data at least from an electronic control unit which is assigned to the clutch assembly, or from an actuation unit of the clutch assembly;
b) evaluating the temperature data determined in step a); and
c) reducing an effective value of a control current at least of the electronic control unit or of the actuation unit by pulsing the control current if the evaluation in step b) reveals that a temperature at least of the electronic control unit or of the actuation unit exceeds a threshold value.

A control device includes a deceleration flex-torque calculation unit that calculates a target torque capacity of a lock-up clutch when a state of the lock-up clutch is controlled to a deceleration flex control state, an acceleration flex-torque calculation unit that calculates a target torque capacity of the lock-up clutch when the state of the lock-up clutch is controlled to an acceleration flex control state, and a control unit that controls a torque capacity of the lock-up clutch to a target torque capacity calculated by the acceleration flex-torque calculation unit, during a period until a target torque capacity calculated by the acceleration flex-torque calculation unit falls below a target torque capacity calculated by the deceleration flex-torque calculation unit, when the state of the lock-up clutch is shifted from the acceleration flex control state to the deceleration flex control state.

A method of preventing a vehicle clutch from sticking includes a wear compensation actuation step of actuating a wear compensation device in conjunction with engagement actuation of a clutch actuator after an ignition is turned off when an actuation condition of the wear compensation device is satisfied, and a clutch control step of controlling a clutch position so that the clutch position returns to a disengaged state of the clutch actuator by reactuating the wear compensation device, when a clutch position based on an amount of variation in an actuation length of the actuation rod fails to return to the disengaged state of the clutch actuator during returning of the engaged clutch actuator.

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.

In one aspect, a computer-implemented method for preventing centrifugal clutch lock-ups within a work vehicle transmission may generally include transmitting a signal associated with disengaging a clutch of the transmission, wherein the clutch includes a hydraulic actuator having a pressure relief valve. The method may also include monitoring a pressure of the hydraulic fluid supplied to the actuator relative to a predetermined pressure threshold and monitoring a rotational speed of a clutch can associated with the clutch relative to a predetermined speed threshold, wherein the speed threshold is defined relative to a lock-up speed associated with the clutch can. In addition, the method may include transmitting a lock-up signal associated with limiting the rotational speed of the clutch can and/or providing an indication that a clutch lock-up is likely to occur when the pressure exceeds the pressure threshold and the rotational speed exceeds the speed threshold.

The present invention provides a method for searching a touch point of a clutch in a dual clutch transmission, including: (a) a step of checking whether a touch point searching condition for a non-driving clutch and a driving clutch is met or not; (b) when the search condition of the step (a) is met, a step of detecting a searching point at which an absolute value of a difference between an acceleration value of an engine and an acceleration value of the driving clutch is larger than a threshold value after applying a position value of the non-driving clutch to the engine; and (c) a step of determining a position of the non-driving clutch corresponding to the searching point as the touch point.

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.