A method for determining reference values of a sensor is provided. The reference values correspond to a disengaged operating condition or to an engaged operating condition of a form-locking shift element (A, F). With the aid of the sensor, at least one operating parameter of the shift element (A, F) determinable during a disengagement and during an engagement of the shift element (A, F). A torque, an actuation force of the shift element (A, F), and a differential speed between shift-element halves of the shift element (A, F) are varied during the determination of the reference values of the sensor in such that the form-locking shift element (A, F) is transferred into the disengaged operating condition or into the engaged operating condition.

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 of detecting a ball loss condition in a ball and ramp assembly. The method includes providing a drive unit having one or more clutch pack assemblies, one or more motors with a motor output shaft and one or more ball and ramp assemblies. One or more actuation profiles are ran by the motors and an amount of motor current used and a position of the output shaft of the motor is measured during the running of actuation profiles. One or more motor current vs. motor output shaft position plots are generated having one or more characteristic curves based on the amount of current measured and the position of the output shaft measured. The amount of motor current is compared to the motor current of characteristic curve at a given output shaft position and based on that comparison a ball loss condition is identified.

This clutch control device is provided with: a supply valve and a supply valve control unit, which control the supply of an operating fluid to a pressure chamber; a first discharge valve and a first discharge valve control unit, which control the discharge of the operating fluid in the pressure chamber; and a second discharge valve and a second discharge valve control unit, which control the discharge of the operating fluid in the pressure chamber. When it is determined that the engagement and disengagement switching of a clutch device 2, which is necessitated by the discharge of the operating fluid in the pressure chamber, is required, the first discharge valve is controlled to be opened and then the second discharge valve is controlled to be opened.

A method controls a clutch actuator, comprising a clutch cylinder piston of a clutch cylinder, which clutch cylinder piston moves an actuation element of a friction clutch along an actuation path, and comprising a hydraulic pump, which actuates the clutch cylinder piston by means of a pressure medium pumped along a hydrostatic path and which is operated by means of an electric motor. In order to determine an actuation state of the friction clutch, the operating state along the actuation path is estimated by means of a pressure medium volumetric flow rate produced by the pump and by means of a leakage volumetric flow rate of the pump.

A clutch control device and a clutch control method are capable of preventing progress of wear and damage of a pneumatic clutch actuator. The clutch control device that controls the operation of a pneumatic clutch actuator to disconnect a clutch is characterized by setting a stroke amount of a piston corresponding to a disconnection position of the clutch as a final target stroke amount, setting other stroke amounts different from the final target stroke amount as intermediate target stroke amounts, and controlling the operation of the piston in a stepwise manner such that an actual stroke amount of the piston is matched with the intermediate target stroke amounts and is thereafter matched with the final target stroke amount, thereby disconnecting the clutch.

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 invention relates to a method for disconnecting a valve unit (302) from a pneumatically controlled actuator arrangement (208, 210) of a vehicle transmission (100), said transmission comprising at least one clutch arrangement (202, 204), a pneumatically controlled actuator arrangement (208, 210) arranged to controllably position the at least one clutch arrangement between a closed position and an opened position, and a valve unit (302) mechanically connected to the pneumatically controlled actuator arrangement (208, 210), the method comprising the steps of positioning (S1) the valve unit (302) in an opened state for providing compressed air to the pneumatically controlled actuator arrangement (208, 210); and subsequently disconnecting (S4) the valve unit (304) from the pneumatically controlled actuator arrangement (208, 210).

The disclosure relates to a method for operating a motor vehicle that includes a drive unit, an output unit, and a clutch arranged between the drive unit and the output unit and configured to transmit a torque. A detection unit detects an operating state of the drive unit. When the operating state of the drive unit is in an overrun mode, a control unit controls a clutch slip, which results in adjustment of the torque that can be transmitted as a function of a speed of the motor vehicle. The disclosure further relates to a device for operating a motor vehicle, and to a motor vehicle that includes such a device.

A gear-position learning device for an automatic clutch transmission includes a transmission configured to be shifted by an operation of a driver of a vehicle, a clutch device disposed in a transmission path between the transmission and an engine and configured to be connected and disconnected by actuation of a clutch actuator, a controller configured to control connection and disconnection of the clutch device performed by the clutch actuator, a shift drum configured to rotate according to a shift operation that the driver performs on a shift operator and switch the shift stage of the transmission, and a rotational position defining mechanism configured to define a rotational position of the shift drum, wherein the controller has a learning mode for learning a rotation angle of the shift drum and is configured to control connection and disconnection of the clutch device during the learning mode such that the shift drum is at a rotational position determined by the rotational position defining mechanism.