Method and control device for operating a drive train of a motor vehicle

A method for operating a drive train (1) of a motor vehicle, the drive train (1) comprising a propulsion unit (2) and an automatic or automated transmission (4) connected between the propulsion unit (2) and a driven end (3), the method comprising:

• for a reversing operation for changing from a forward gear to a reverse gear or from the reverse gear to the forward gear, the reversing operation being carried out when the motor vehicle is rolling at a rolling speed less than a limit value, a first friction-locking shift element (5) of the transmission (4) being disengaged during the reversing operation and a second friction-locking shift element (6) of the transmission (4) being engaged during the reversing operation, the first friction-locking shift element (5) being a first shift element which is engaged in the forward gear and the second friction-locking shift element (6) being a second shift element which is disengaged in the forward gear for changing from the forward gear to the reverse gear, or the first friction-locking shift element (5) being one shift element which is engaged in the reverse gear and the second friction-locking shift element (6) being another shift element which is disengaged in the reverse gear for changing from the reverse gear to the forward gear:
• receiving a target torque profile for a transmission output shaft (9) of the transmission (4) for the reversing operation;
• determining, in accordance with the target torque profile for the transmission output shaft (9), a target torque profile for the first friction-locking shift element (5), a target torque profile for the second friction-locking shift element (6), and a target torque profile for the propulsion unit (2);
• and
• activating the first friction-locking shift element (5) in accordance with the target torque profile for the first friction-locking shift element (5), the second friction-locking shift element (6) in accordance with the target torque profile for the second friction-locking shift element (6), and the propulsion unit (2) in accordance with the target torque profile for the propulsion unit (2) such that an actual torque profile for the transmission output shaft (9) follows the target torque profile for the transmission output shaft (9).