Method for operating a driver assistance system and driver assistance system

1. A method for operating a driver assistance system of a vehicle combination that comprises a tractor vehicle and at least one trailer, and the driver assistance system is designed to automatically actuate at least one element of the vehicle combination, the method comprising:

determining at least a first parameter characterizing a potentially unstable driving condition of the at least one trailer;

determining whether an unstable driving condition of the at least one trailer is imminent based on the at least one calculated first parameter; and

determining at least one second parameter characterizing a position of the at least one trailer, when it is determined that an unstable driving condition of the at least one trailer is imminent, and automatically actuating at least one element selected from the group comprising a braking device, a drive device and a warning device in such manner that a braking operation of the vehicle combination is initiated when the at least one trailer is positioned directly in line behind the tractor vehicle in the longitudinal direction of the tractor vehicle.

2. The method according to claim 1 , wherein the at least one first parameter characterizes at least one of a swinging motion and a tilting motion of the at least one trailer.

3. The method according to claim 1 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

calculating a distance between at least one point on a rear side of the tractor vehicle and at least one point on a front side of the at least one trailer.

4. The method according to claim 1 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter is made on the basis of data from at least one sensor selected from the group comprising: an electromagnetic sensor, an acoustic sensor and an optical camera.

5. The method according to claim 1 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining an inflation pressure of at least one tire of the at least one trailer.

6. The method according to claim 1 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining an angle of inclination of the at least one trailer.

7. The method according to claim 1 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining at least one of a frequency and an amplitude of a swinging motion of the at least one trailer.

8. The method according to claim 1 , further comprising:

calculating a speed of the vehicle combination,

wherein at least one of the at least one first parameter is determined and a determination is made as to whether an unstable driving condition of the at least one trailer is imminent if the calculated speed exceeds a predetermined threshold value.

9. The method according to claim 1 , wherein a radius of curvature of a carriageway currently being travelled by the vehicle combination is also determined, and wherein the determination as to whether an unstable driving condition of the at least one trailer is imminent is made on the basis of the at least one calculated first parameter and the determined radius of curvature.

10. The method according to claim 1 , further comprising:

automatically actuating a steering device of the vehicle combination if it is determined that an unstable driving condition of the at least one trailer is imminent.

11. A driver assistance system for a vehicle combination, comprising:

a first calculation device that determines at least a first parameter characterizing a potentially unstable driving condition of at least one trailer of the vehicle combination:

a second calculation device that determines whether an unstable driving condition of the at least one trailer is imminent, based on the at least one determined first parameter;

a third calculation device that determines at least a second parameter characterizing a position of the at least one trailer; and

an actuation device that automatically actuates at least one element of the vehicle combination, selected from the group comprising a braking device, a drive device and a warning device in such manner that a braking operation of the vehicle combination is initiated when the at least one trailer is positioned directly in line behind a tractor vehicle in the longitudinal direction of the tractor vehicle of the vehicle combination when it is determined that an unstable driving condition of the at least one trailer is imminent.

12. The driver assistance system according to claim 11 , wherein at least one of the first calculation device and the third calculation device is coupled with a sensor selected from the group comprising an electromagnetic sensor, an acoustic sensor, optical camera and a pressure sensor.

13. The driver assistance system according to claim 11 , wherein the actuation device automatically actuates a steering device of the vehicle combination, if it is determined that an unstable driving condition of the at least one trailer is imminent.

14. A computer software product, comprising:

a storage medium readable by a computing unit of a driver assistance system of a vehicle combination, the vehicle combination including a tractor vehicle and at least one trailer, and the driver assistance system is designed to automatically actuate at least one element of the vehicle combination selected from the group comprising a braking device, a drive device and a warning device, and the storage medium stores instructions for the computing unit to carry out a method comprising:

determining at least a first parameter characterizing a potentially unstable driving condition of the at least one trailer;

determining whether an unstable driving condition of the at least one trailer is imminent based on the at least one calculated first parameter and

determining at least one second parameter characterizing a position of the at least one trailer, when it is determined that an unstable driving condition of the at least one trailer is imminent, and automatically actuating the at least one element in such manner that a braking operation of the vehicle combination is initiated when the at least one trailer is positioned directly in line behind the tractor vehicle in the longitudinal direction of the tractor vehicle.

15. The computer software product according to claim 14 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining an inflation pressure of at least one tire of the at least one trailer.

16. The computer software product according to claim 14 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining an angle of inclination of the at least one trailer.

17. The computer software product according to claim 14 , wherein the determination of at least one of the at least one first parameter and the at least one second parameter further comprises:

determining at least one of a frequency and an amplitude of a singing motion of the at least one trailer.