Method and device for operating drivetrain

A method for operating a drive train of a vehicle, wherein the drive train has at least a transmission housing, and a clutch unit situated therein with a clutch that acts in a form-fitting manner, as well as an actuating unit for actuating the clutch, and a sensor for determining the coupling status;

• wherein the clutch includes at least a first clutch component and a second clutch component that are connected to one another in a form-fitting manner when the clutch is actuated;
• wherein the actuating unit includes an electromagnetic actuator having a piston;
• wherein for actuating the clutch the piston is moved from a starting position into an end position;
• wherein at least the piston and the clutch are acted on at least partially by a transmission fluid;
• wherein a torque is transmitted via the clutch components only after a fully engaged first state of the clutch components is determined in which the piston is in the end position;
• wherein a position of the piston may be determined with the sensor;
• and wherein the method includes at least the following steps:
• a) actuating the actuator and moving the piston from the starting position;
• b) ascertaining a measured sensor value;
• c) ascertaining a temperature of the transmission fluid;
• d) determining an actual position of the piston based on the measured sensor value and the temperature;
• and
• e) moving the piston, starting from the determined actual position, into the end position;
• wherein the temperature of the transmission fluid is ascertained at least by
• i. measuring an electrical resistance of the actuator, or
• ii. measuring a first time interval between actuation of the actuator according to step a) and the detection by the sensor of an intermediate position that is reached by the piston.

A drive train of a vehicle, including at least a transmission housing, and a clutch unit situated therein with a clutch that acts in a form-fitting manner, as well as an actuating unit for actuating the clutch, and a sensor for determining the coupling status;

• wherein the clutch includes at least a first clutch component and a second clutch component that are connectable to one another in a form-fitting manner when the clutch is actuated;
• wherein the actuating unit includes an electromagnetic actuator having a piston;
• wherein the piston is movable from a starting position into an end position in order to actuate the clutch;
• wherein at least the piston and the clutch are acted on at least partially by a transmission fluid;
• wherein transmission of a torque via the clutch components does not occur until a fully engaged first state of the clutch components is determined for which the piston is in the end position;
• wherein a position of the piston may be determined with the sensor;
• wherein the drive train is configured for carrying out a method including at least the following steps:
• f) actuating the actuator and moving the piston from the starting position;
• g) ascertaining a measured sensor value;
• h) ascertaining a temperature of the transmission fluid;
• i) determining an actual position of the piston based on the measured sensor value and the temperature;
• and
• j) moving the piston, starting from the determined actual position, into the end position;
• wherein the temperature of the transmission fluid is ascertained at least by
• iii. measuring an electrical resistance of the actuator, or
• iv. measuring a first time interval between actuation of the actuator according to step a) and the detection by the sensor of an intermediate position that is reached by the piston.