Method and driver assistance system for assisted reversing with a vehicle-trailer combination and motor vehicle

A method for assisted reversing with a trailer having a towing vehicle and a coupled trailer vehicle as well as a driver assistance system, wherein the trailer is initially driven forwards, comprising:

• storing a corresponding forward trajectory in the driver assistance system;
• detecting, using a sensor system of the towing vehicle, at least one object arranged laterally next to the forward trajectory;
• planning the following:
• a) a reversing trajectory, which deviates no more than a permissible limit deviation from the driven forward trajectory;
• and
• b) for each vehicle of the trailer, a vehicle-specific reversing corridor corresponding to the planned reversing trajectory;
• classifying the detected at least one object as collision object if the at least one corresponding object lies in one or in both of the planned reversing corridors;
• selectively generating, if one or more of the at least one detected object has been classified as a collision object, a new reversing trajectory and, as a result, for each vehicle a new vehicle-specific reversing corridor, which deviates no more than a permissible limit deviation from the reversing corridor planned, such that the collision object does not lie in either of the new vehicle-specific reversing corridors;
• reversing the trailer with the aid of the driver assistance system, wherein the driver assistance system intervenes in transverse guidance of the towing vehicle at least such that the trailer is driven along the reversing trajectory or the new reversing trajectory, respectively, and, as a result, through the vehicle-specific reversing corridors or the new vehicle-specific reversing corridors, respectively, wherein
• a three-stage warning system is implemented, by means of which it is possible to more clearly inform a driver about potential risks, the three-stage warning system comprising:
• defining, for each vehicle of the trailer, an imaginary collision rectangle, which rectangle completely encloses the corresponding vehicle and moves along with the vehicle:
• defining, for each vehicle of the trailer, on which circle the vertices of the associated collision rectangle always lie;
• the at least one detected object is classified as a critical object if the corresponding object has been intersected by one or both circles when driving forwards;
• during classifying, only a critical object of the at least one detected object is classified, if applicable, as a collision object when the corresponding object would be intersected by the collision rectangle during reversing assisted by means of the driver assistance system;
• wherein
• for each vehicle, a second imaginary collision rectangle, which lies completely within the first collision rectangle, and t urd imaginary collision rectangle, which lies completely within the second collision rectangle, are defined, wherein, during reversing assisted by means of the driver assistance system, the collision object in each case;
• is classified as a notice object as long as the corresponding collision object is intersected by the first collision rectangle but not by the second collision rectangle or by the third collision rectangle wherein a notice action is performed by means of the driver assistance system in response to the notice object;
• is classified as a warning object as long as the corresponding collision object is intersected by the first collision rectangle and by the second collision rectangle but not by the third collision rectangle, wherein a warning action is performed by the driver assistance system in response to the warning object.