The disclosure relates to a method for calibrating a drive system for an axle of a motor vehicle; wherein the drive system includes at least one electric machine as the drive unit, a drive shaft driven by the drive unit, a first output shaft and a second output shaft, as well as a first clutch connecting the drive shaft to the first output shaft and a second clutch connecting the drive shaft to the second output shaft.

Methods and systems for operating a clutch of an axle are provided. In one example, the clutch may be characterized in static or dynamic conditions. The clutch characterization may be a basis for subsequently operating the clutch during gearbox shifting. In particular, an amount of torque that is transferred via the clutch may be controlled or adjusted according to the clutch characterization.

Methods and systems for operating a clutch of an axle are provided. In one example, the clutch may be characterized in static or dynamic conditions. The clutch characterization may be a basis for subsequently operating the clutch during gearbox shifting. In particular, an amount of torque that is transferred via the clutch may be controlled or adjusted according to the clutch characterization.

A calibration method for a slip control arrangement of a driveline including a continuously variable transmission is described herein. The driveline includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling. A calibration method to link a valve command value and a torque allowed to pass through the clutch includes preventing the vehicle from moving and increasing the pressure applied in the clutch while noting the torque % value developed by the prime mover.

The invention relates to a method for determining a characteristic curve of a hybrid separating clutch of a hybrid vehicle without a test stand, wherein the hybrid separating clutch separates or connects an internal combustion engine and an electric motor and the hybrid separating clutch is slowly actuated on the basis of a position which the hybrid separating clutch assumes in an unactuated state, and a clutch characteristic curve is determined as a function of a clutch torque over a path of the hybrid separating clutch. In a method by which a characteristic curve of the hybrid separating clutch can be reliably defined without a test stand, a clutch torque which underlies the characteristic curve of the hybrid separating clutch is determined from the torque of the internal combustion engine in the case of a running internal combustion engine and a motion state of the electric motor which brakes the internal combustion engine while the hybrid separating clutch is moving.

The invention relates to a method for determining an engagement point of a hybrid clutch in a hybrid vehicle; which hybrid clutch is actuated by a hydrostatic clutch actuator and disconnects or connects an internal combustion engine and an electric traction drive; the engagement point is determined by slowly actuating the clutch starting from a position in which the hybrid clutch is in the non-actuated state, and monitoring a moment of the electric traction drive when a defined increase in the momentum is detected. In a method in which engagement point adaptation is optimized, a current engagement point (tp) is adapted during operation of the hybrid vehicle using a start-up routine, by which a first engagement point is determined when the hybrid vehicle is started; the hybrid clutch is moved close to a previously determined engagement point, and starting from said last determined engagement point, the hybrid clutch is displaced further until the defined increase in the moment is detected.

The invention relates to a method for determining a bite point of a hybrid clutch in a hybrid vehicle. The hybrid clutch is actuated by a hydrostatic clutch actuator (12) and disconnects or connects an internal combustion engine (2) and an electric motor (3); the bite point is determined by slowly actuating the hybrid clutch (4) starting from a separating position of the hybrid clutch (4), this position being in the non-actuated state, with a defined torque reaction of the electric motor (3) being detected. The invention also relates to a method in which the quality of the bite point is improved, the duration of the bite point adaptation is essentially shortened, the bite point being adapted during the running of the internal combustion engine (2) and when the electric motor (3) is immobile and a torque reaction of the electric motor (3) is validated by the torque reaction of the internal combustion engine (2).

A method and device for controlling an engine clutch of a hybrid vehicle are provided. The method includes setting a target speed of an engine to change a driving mode of the hybrid vehicle from an EV mode to an HEV mode and operating a HSG to adjust an engine speed to reach the target speed. An engine clutch that connects the engine with a driving motor or disconnects the engine from the driving motor is engaged to start when the speed of the engine is maintained at the target speed. A kiss point generated when the engine clutch is in a slip state is detected to learn the kiss point of the engine clutch and an output of the engine is increased based on a driver required torque when the speed of the engine and a speed of the driving motor are synchronized after the kiss point is learned.

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.

A method for learning a touch point of an engine clutch of a hybrid electric vehicle including a motor connected to a transmission and an engine selectively connected to the motor through the engine clutch includes determining whether a learning condition of the touch point of the engine clutch is satisfied, releasing a transmission clutch and controlling a motor speed when the learning condition is satisfied, increasing a coupling pressure of the engine clutch when a change amount of the motor speed is less than a first predetermined value, comparing a change amount of a motor torque according to the increased coupling pressure of the engine clutch with a second predetermined value, and learning the touch point of the engine clutch when the change amount of the motor torque is greater than or equal to the second predetermined value.