Drive train having clutch activation for overcoming the backlash of the drive train before start-up

1. A drive train for a motor vehicle, comprising a drive unit having:

a drive shaft; and,

a transmission having a transmission input shaft and a plurality of gears, of which at least one is used as a starting gear for the motor vehicle, and having a friction clutch, which is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner, wherein a rotation clearance present in the transmission is compensated by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up.

2. The drive train according to claim 1 , wherein the compensation torque is smaller than a startup torque required for moving the motor vehicle.

3. The drive train according to claim 1 , wherein the compensation torque required for compensating the rotation clearance is learned during operations of the drive train.

4. The drive train according to claim 1 , wherein:

the transmission includes an output shaft; and

the rotation clearance is determined by comparing a speed of the transmission input shaft with a speed of the transmission output shaft.

5. The drive train according to claim 4 , wherein a respective compensation torque is associated with the determined rotation clearance.

6. The drive train according to claim 1 , the compensation torque is configured as a function of the startup gear used.

7. The drive train according to claim 1 , wherein the rotation clearance is compensated when the motor vehicle is standing still and a brake of the motor vehicle is actuated.

8. A method for actuating a drive train for a motor vehicle including a drive unit having a drive shaft and a transmission having a transmission input shaft and a plurality of gears, of which at least one is used as a starting gear for the motor vehicle, and having a friction clutch, which is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner, the method comprising:

compensating a rotation clearance present in the transmission by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up, wherein:

compensating the rotation clearance includes compensating the rotation clearance when the motor vehicle is standing still and a brake of the motor vehicle is actuated.

9. A drive train for a motor vehicle, comprising a drive unit having:

a drive shaft; and,

a transmission including an input shaft, an output shaft, a plurality of gears, and a friction clutch, wherein:

a gear from the plurality of gears is used as a starting gear for the motor vehicle;

the friction clutch is arranged between the crankshaft and the transmission input shaft and is actuated in an automated manner;

a rotation clearance is present in the transmission;

the rotation clearance is determined by comparing a speed of the transmission input shaft with a speed of the transmission output shaft; and

the rotation clearance is compensated by applying a small compensating torque set at the friction clutch to the transmission input shaft while the starting gear is engaged before start up.