Method for adapting an engagement point of a vehicle clutch

A method for adapting an engagement point of a disconnect clutch that can be moved between at least one engaged state, in which an output shaft of an internal combustion engine for propelling a vehicle is coupled by way of the disconnect clutch to a rotor of an electric machine for propelling the vehicle, and at least one disengaged state, in which the output shaft is decoupled from the rotor, comprising:

• a) deactivating the initially activated internal combustion engine and disengaging the initially engaged disconnect clutch;
• b) while the disconnect clutch is disengaged and the internal combustion engine is deactivated:
• recording a first curve of the rotational speed of the output shaft;
• c) calculating a friction torque of the internal combustion engine as a function of at least one predetermined moment of inertia of the internal combustion engine and a first rotational speed gradient, which is determined from the recorded first curve;
• d) moving the disconnect clutch in the direction of its engaged state;
• e) while the disconnect clutch is being moved in the direction of its engaged state and the internal combustion engine is still deactivated:
• recording of a second curve of the rotational speed of the output shaft coming after the first curve;
• f) determining a second rotational speed gradient from the recorded second curve;
• g) determining a reaction moment of the disconnect clutch as a function of the calculated friction torque, the second rotational speed gradient and the predetermined moment of inertia of the internal combustion engine;
• and
• h) adapting the engagement point as a function of the determined reaction moment.