Method for operating a torque-transmitting system and torque-transmitting system

A method of operating a torque-transmitting system, wherein the torque-transmitting system has an input side coupled to an output shaft of a drive unit and an output side coupled to an input shaft of a transmission and a torque flux runs from the drive unit via the torque-transmitting system to the transmission,

• the torque-transmitting system including:
• a hydrodynamic torque converter via which a hydraulic path of the torque flux runs;
• a lockup clutch disposed functionally in parallel with the torque converter and via which a mechanical path of the torque flux runs;
• and
• a control unit configured to control a distribution of the torque flux between the hydraulic path and the mechanical path for setting a predetermined overall torque profile at the input shaft of the transmission;
• the method which comprises the following method steps, to be carried out by the control unit:
• determining a torque currently being transmitted by the lockup clutch;
• comparing the torque thus determined with a predetermined setpoint overall torque and calculating a corresponding difference torque;
• determining a current output speed of the torque converter;
• calculating a setpoint input speed of the torque converter that would be necessary at the output speed thus determined to transmit the difference torque via the hydraulic path;
• and
• setting the output speed of the drive unit to the calculated input speed or a value corresponding thereto.