The present disclosure relates to a method for defining a clutch slipping point position (X.sub.sp) of a clutch in a gearbox comprising an input shaft arranged to be braked by a braking means. The method includes determining if the clutch is dragging when the clutch is fully disengaged. The method includes when it is determined that the clutch is dragging, applying the braking means with a predetermined brake torque (T.sub.b) and so that the input shaft is not rotating; and thereafter: moving the clutch from the fully disengaged position towards an engaged position; determining when the input shaft starts to rotate with a predetermined rotation value indicative of a rotational speed of the input shaft; registering a clutch position (X.sub.b) in which the clutch is positioned when the predetermined rotation value is reached; using a clutch transfer characteristics of the clutch, T.sub.b, and X.sub.b to define the clutch slipping point position (X.sub.sp).

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the engagement and disengagement of the dog clutch and the friction clutch. In this clutch control device, when there is a request to engage the dog clutch from a disengaged state, the controller, during the engagement control of the friction clutch, first controls the engagement of the friction clutch, monitors the change gradient of the clutch rotational speed difference of the dog clutch and starts engagement of the dog clutch upon determining that the gradient of the clutch rotational speed difference is no longer decreasing.

An apparatus and method of using the apparatus for learning a clutch torque of a Dual Clutch Transmission (DCT) includes judging whether shifting begins, controlling torque transmission of a coupling-side clutch and a release-side clutch to cross each other while following a coupling-side target clutch torque when shifting begins, and calculating and storing a learning value, after the controlling has begun, using a function determined by the relationship between an average value of an engine angular acceleration and a coupling-side shifter input-shaft angular acceleration, engine rotation inertia, and a torque compensated to the torque transmission of the coupling-side clutch for reducing a slippage of the release-side clutch by feedback control during a torque handover interval.

A drive train arrangement for a motor vehicle includes at least one drive device, a start-up element arrangement, a gear drive arrangement, at least one driveshaft configured to drive drive wheels, an electronic operator control member configured to be operated, a torque control member, and a controller. The controller is configured to store torque regions for a change in load and to transmit a torque default value to the torque control member depending on an actuation of the electronic operator control member. The stored torque regions are zero transition regions with a zero transition starting point and a zero transition end point for covering all zero-load clearance regions. The controller is configured to adapt at least one respective zero transition region of at least one respective stored torque region.

The present disclosure relates to a method for defining a clutch slipping point position (X.sub.sp) of a clutch in a gearbox comprising an input shaft arranged to be braked by a braking means. The method includes determining if the clutch is dragging when the clutch is fully disengaged. The method includes when it is determined that the clutch is dragging, applying the braking means with a predetermined brake torque (T.sub.b) and so that the input shaft is not rotating; and thereafter: moving the clutch from the fully disengaged position towards an engaged position; determining when the input shaft starts to rotate with a predetermined rotation value indicative of a rotational speed of the input shaft; registering a clutch position (X.sub.b) in which the clutch is positioned when the predetermined rotation value is reached; using a clutch transfer characteristics of the clutch, T.sub.b, and X.sub.b to define the clutch slipping point position (X.sub.sp).

A drive train arrangement for a motor vehicle includes at least one drive device, a start-up element arrangement, a gear drive arrangement, at least one driveshaft configured to drive drive wheels, an electronic operator control member configured to be operated, a torque control member, and a controller. The controller is configured to store torque regions for a change in load and to transmit a torque default value to the torque control member depending on an actuation of the electronic operator control member. The stored torque regions are zero transition regions with a zero transition starting point and a zero transition end point for covering all zero-load clearance regions. The controller is configured to adapt at least one respective zero transition region of at least one respective stored torque region.

A method for operating a motor vehicle includes, when a target differential speed is set for a separating clutch (4), determining a power transmission factor depending on the target differential speed and an internal combustion engine-driven torque to be transmitted by the separating clutch (4). The method also includes determining an actuating pressure for the separating clutch (4) depending on the power transmission factor, controlling the separating clutch (4) with the actuating pressure, ascertaining an actual differential speed forming at the separating clutch (4) depending on the actuating pressure, determining a corrected power transmission factor with a controller (10) depending on a deviation between the target differential speed and the actual differential speed, determining a corrected actuating pressure for the separating clutch (4) depending on the corrected power transmission factor and the internal combustion engine-driven torque to be transmitted, and controlling the separating clutch (4) with the corrected actuating pressure.

A clutch disengagement position is detectable with high precision even during speed change. A vehicle transmission device can include a transmission including a main shaft to which rotational power from an engine is inputted via a clutch, and a countershaft, a clutch operation member that is driven by an actuator and performs disengaging and engaging operations of the clutch, and a driving wheel to which rotational power of the countershaft is transmitted via a driving force transmitting device. A damper member deformed by a driving force is provided in the countershaft, the driving force transmitting device or the driving wheel, or among the countershaft, the driving force transmitting device and the driving wheel. A control device learns a clutch disengagement operation amount when the control device detects deceleration of a predetermined value of the rotational frequency of the main shaft.

A method for operating a motor vehicle includes, when a target differential speed is set for a separating clutch (4), determining a power transmission factor depending on the target differential speed and an internal combustion engine-driven torque to be transmitted by the separating clutch (4). The method also includes determining an actuating pressure for the separating clutch (4) depending on the power transmission factor, controlling the separating clutch (4) with the actuating pressure, ascertaining an actual differential speed forming at the separating clutch (4) depending on the actuating pressure, determining a corrected power transmission factor with a controller (10) depending on a deviation between the target differential speed and the actual differential speed, determining a corrected actuating pressure for the separating clutch (4) depending on the corrected power transmission factor and the internal combustion engine-driven torque to be transmitted, and controlling the separating clutch (4) with the corrected actuating pressure.

Disclosed are a method and an apparatus for detecting a touch point of a clutch and the method includes: maintaining a touch point of the clutch; correcting a setting value for determining a lowest value by calculating drag torque using a speed and an acceleration of a input shaft to change a detection range of the touch point; setting the lowest value of the speed of the input shaft within the changed detection range of the touch point to a reference value of the input shaft after actuating the clutch; releasing the clutch when the speed of the input shaft is more than a value acquired by adding the reference value of the input shaft and the corrected setting value for determining the lowest value; and updating the touch point as a clutch position matched to the reference value.