An engine clutch control system of a hybrid vehicle includes a driving information detector for detecting vehicle information and road environment information according to operation of the hybrid vehicle. An engine clutch is disposed between an engine and a motor. A hybrid controller provides an EV (electric vehicle) mode or an HEV (hybrid electric vehicle) mode by controlling engagement or disengagement of the engine clutch. The hybrid controller sets a slip estimation region of the engine clutch from an accumulated value of an APS (Accelerator Pedal position Sensor), an engine clutch temperature, or a road inclination when engagement of the engine clutch is required, and extracts a speed variation of the engine and the motor in the slip estimation region. The hybrid controller compares the speed variation of the engine and the motor with each other, and determines the engine clutch is engaged when a maximal peak is detected.

A method for operating a drive train for a motor vehicle, with at least one primary drive axle and at least one secondary drive axle, which are operatively connected to each other via a clutch to an adjustable transmission torque. At the same time it is provided that a vibration amplitude of a vibration of the drive train is determined and in a damping operation type of the drive train, the transmission torque is determined from the vibration amplitude and adjusted on the clutch.

A method and an apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch are disclosed. An apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch may include: a gear stage sensor detecting a gear stage that is currently engaged; a controller executed by a predetermined program to learn the linearity error of the hydraulic pressure sensor based on signals of the gear stage sensor and the hydraulic pressure sensor; and a solenoid valve applying hydraulic pressure for learning the linearity error of the hydraulic pressure sensor to the hydraulic clutch based on a learning command of the controller.

A method is provided for reducing chatter vibrations in a motor vehicle drivetrain having a drive unit, a vehicle transmission and an automated friction clutch, wherein a vibration absorber is emulated by an appropriate operation of the friction clutch in order to improve the method.

A method and an apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch are disclosed. An apparatus for learning linearity error of a hydraulic pressure sensor for a hydraulic clutch may include: a gear stage sensor detecting a gear stage that is currently engaged; a controller executed by a predetermined program to learn the linearity error of the hydraulic pressure sensor based on signals of the gear stage sensor and the hydraulic pressure sensor; and a solenoid valve applying hydraulic pressure for learning the linearity error of the hydraulic pressure sensor to the hydraulic clutch based on a learning command of the controller.

The invention relates to a method for increasing the availability of a hybrid separating clutch in a hybrid drive train of a motor vehicle, wherein the hybrid separating clutch is disposed between an internal combustion engine and an electric traction drive. In the method where even in the event of a fault the motor vehicle continues to be driven, the hybrid separating clutch is controlled by a hydrostatic actuator, and when a malfunction of the hydrostatic actuator is detected, for actuation of the hybrid separating clutch which is engaged in the non-actuated state, the last state of the hydrostatic actuator detected by a control mechanism is used for estimation of a minimum clutch torque which can be transmitted.

A method actively changes the frictional value of a hybrid disconnect clutch installed in a powertrain of a vehicle in which a first electric motor (18) is connected to a clutch input (21) and an internal combustion engine (17), and a second electric motor (19) is connected to a clutch output (22) and a vehicle output (23). The frictional value of the hybrid disconnect clutch is actively changed, in order to roughen a surface of the friction linings on the hybrid disconnect clutch (20). A slip situation is established at the hybrid disconnect clutch (20), and during this slip situation energy is introduced into the hybrid disconnect clutch (20) in a controlled manner.

The present invention is directed to a method for determining a force transmission contact point of an actuating element (6) of an electric clutch actuator which comprises a linear drive assembly configured to linearly move the actuating element (6) towards a preload plunger (10) which is linked by a pushrod (12) to a clutch lever (14) and to move the pushrod (12) to turn the clutch lever, characterized by including the steps: monitoring an oscillation of the pushrod (12) by monitoring the position of the pushrod (12) and determining in consecutive time periods at least one of a maximum, minimum and centre value of the pushrod position, deriving a measure of non-oscillatory movement of the pushrod (12) based on a difference between at least one of the respective maximum, minimum and centre values of the pushrod position in a current and at least one of the preceding time periods or based on a difference between a combination of the respective positions in the current and at least one of the preceding time periods; and determining that the actuating element (6) has reached the force transmission contact point if the measure of non-oscillatory movement of the pushrod exceeds a predetermined threshold value.