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.

A method for parameterizing a software damper is disclosed. A target clutch torque affected in specified operating states by chatter vibrations is corrected by a software damper, wherein a transfer behavior of a clutch torque transferred via a friction clutch based on the target clutch torque is ascertained during a modulation of the target clutch torque. The software damper is parameterized with the help of the ascertained transfer behavior. To parameterize the software damper quickly and comprehensively, the target clutch torque is modulated by a broadband excitation in a frequency range of the chatter vibrations, and the transfer behavior is ascertained depending on operating parameters of the drivetrain.

A vehicle propulsion system that includes a prime mover having an output shaft, a torque converter including a compressor coupled to the output shaft of the prime mover, a turbine fluidly coupled to the compressor, and a torque converter clutch for selectively mechanically coupling the compressor to the turbine, a continuously variable transmission (CVT) coupled to the turbine of the torque converter, and a controller that is programmed to receive signals indicating operating conditions of the vehicle propulsion system, determine whether the received signals indicate a reduction in ratio in the CVT is impending, determine whether to open the torque converter clutch based upon a determination that a reduction in ratio is impending, and open the torque converter clutch in response to a determination to open the torque converter clutch.

A clutch torque control method for a dual clutch transmission (DCT) vehicle may include a shift initiation determining step of determining whether power-on downshift in which a driver steps on an accelerator pedal to change a current shift stage to a lower shift stage is initiated, and a torque correcting step of correcting basic control torque according to torque-stroke (TS) curve characteristics for controlling a disengagement-side clutch within a real shift range in which a number of rotations of an engine is changed with observer torque calculated by a torque observer when the power-on downshift is initiated, and determining the corrected basic control torque into control torque of the disengagement-side clutch.

A method of selectively controlling a power take-off (PTO) assembly includes positioning a clutch assembly radially between a shaft and a PTO gear, operably controlling the clutch assembly with a controller, and selectively engaging the clutch assembly with the controller. The controller monitors signals received from a plurality of sensors and compares the monitored signals with respective signal thresholds. The clutch assembly is engaged when the compared monitored signals are within the signal thresholds.

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 system for controlling transmission shifting includes a controller that receives a shift request signal and determines if a clutch has been unapplied for more than a predetermined time. With a yes determination, a maximum fill time value for hydraulic fluid to be applied to a clutch control circuit is determined, the maximum fill time value being a function of time the clutch has been unapplied and temperature. A signal indicative of an amount of engine RPM flare after the transmission executes the requested shift is received and a modified maximum fill time value is determined as a function of this flare. The modified maximum fill time value is stored as a replacement for the maximum fill time value for use with a subsequent transmission shifts using this clutch, and reduces an amount of air in the control circuit and an amount of flare with subsequent transmission shifts.

A method for operating a dual-clutch transmission with two clutches. During realization of a ratio, a first clutch is closed and a second clutch is open. During a ratio change, the first clutch is opened and the second clutch is closed. During a ratio change within short operating times, a target actuating pressure of the clutch for engagement is set to a fast-charging pressure level and subsequently adjusted to a closing pressure level, while a target actuating pressure of the clutch for disengagement is adjusted to an opening pressure level before setting the closing pressure level of the clutch for engagement. At least during a ratio change, an actual actuating pressure of the clutch for engagement is monitored and the target actuating pressure of the clutch for disengagement is adjusted to the opening pressure level if the actual actuating pressure of the clutch for engagement exceeds a pressure threshold.

The present disclosure provides a clutch control method of a hybrid vehicle of the including an entering condition determining step in which a controller determines whether shifting is being performed during regenerative braking; an error calculating step in which the controller calculates a torque error by subtracting observer torque, which is clutch transfer torque calculated by a clutch torque estimator receiving transmission input torque and motor speed, from map torque, which is clutch transfer torque calculated based on a clutch transfer torque map for clutch actuator strokes learned in advance, when shifting is being performed during regenerative braking; a correcting step in which the controller corrects the clutch transfer torque map for the clutch actuator strokes using the torque error calculated in the error calculating step; and a clutch control step in which the controller controls a clutch using the map corrected in the correcting step.

A power take-off (PTO) drive assembly for a transmission includes a shaft defining a shaft axis, a PTO gear defined radially about the shaft axis, and a clutch assembly positioned between the shaft and the PTO gear and having an engaged position and a disengaged position. When the clutch assembly is in the engaged position, torque is transferred from the shaft to the PTO gear. When the clutch assembly is in the disengaged position, torque is not transferred from the shaft to the PTO gear.