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 is disclosed 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. The friction clutch is positioned in a drivetrain between an internal combustion engine and a transmission, having a present actual clutch torque which is marked by vibrations as a result of vibrations (M(i)). 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, and a phase-selective disturbance torque is ascertained. From the phase-selective disturbance torque, a phase-correct correction torque (M(k)) is determined, and the target clutch torque (M(s)) is corrected by the regulator. 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.

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.

An automatic disconnect coupling includes a retainer and a biasing member. The biasing member is coupled to the retainer and is arranged to communicate excitation from a generator input member to the retainer. The retainer and the biasing member have a fundamental frequency tuned to the rotational speed of the generator input member to automatically disconnect the input member from a drive member when rotating unbalance of the input member exceeds a predetermined level.

A method of controlling a clutch for vehicle may include determining, by a controller, raised offset engine torque, when engine torque is raised to a reference torque or more in an engine idle state, and controlling, by the controller, the clutch based on the determined offset engine torque.

The present disclosure provides a clutch control method, including: a variation setting step of setting, by a controller, a current torque variation depending on a difference between a just previous clutch control torque and a clutch target torque; a limit determining step of determining whether a jerk of a clutch control torque need not be limited when the clutch control torque is reduced and then is increased or when the clutch control torque is continuously reduced by using the current torque variation and a just previous torque variation; a direction setting step and a limit setting step to determine a final torque variation based on the outcome of the limit determining step; and a control torque calculating step of calculating the clutch control torque to control a clutch.

An automatic disconnect coupling includes a retainer and a biasing member. The biasing member is coupled to the retainer and is arranged to communicate excitation from a generator input member to the retainer. The retainer and the biasing member have a fundamental frequency tuned to the rotational speed of the generator input member to automatically disconnect the input member from a drive member when rotating unbalance of the input member exceeds a predetermined level.

A method for automatic detection of need for clutch calibration includes registering and storing in a data memory, before or in connection with engine shut down, a value of a clutch operating parameter, registering a corresponding value of the clutch operating parameter in connection with subsequent engine start up, and determining need for clutch calibration if the difference between the stored value of the clutch operating parameter and the corresponding value of the clutch operating parameter exceeds a predetermined threshold value.

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.