Method and driver assistance system for assisting in reversing, and motor vehicle

Abstract

The invention relates to a method and a driver assistance system for assisting in reversing in the case of a vehicle trailer combination, first of all, a forward trajectory of the vehicle is stored during forward travel, and an object is detected by means of a sensor device of the traction vehicle, said object being arranged laterally next to the forward trajectory. A reverse trajectory is planned, which deviates as little as possible from the traveled forward trajectory. If the object is located in the planned backing trajectory, the corresponding detected object is classified as a collision object. In this case, a new reverse trajectory is generated, which does not collide with an object. And reversing the trailer combination along the new reversing trajectory by means of the driver assistance system. According to the invention, a current deviation of an actual backing trajectory of the trailer vehicle from a new backing trajectory is determined, and if the current deviation is greater than a permissible limit deviation, the trailer combination is completely stopped by means of a driver assistance system for carrying out a correction action. After the correction action is performed, the auxiliary backing-up is resumed.

Description

Technical Field

[0001] The invention relates to a method for assisted reversing in a tow-and-trailer combination having a towing vehicle and a towed vehicle coupled to the towing vehicle and a driver assistance system. Background Art

[0002] For inexperienced drivers, reversing in a vehicle-trailer combination, to which a trailer is coupled, is often difficult. Therefore, in modern motor vehicles, assistance systems are now increasingly frequently provided, which assist the driver when reversing with a trailer. When moving forward, the steering axle is the frontmost axle of the axles of the trailer combination, as seen in the direction of travel, and the trailer vehicle is towed. In contrast, when reversing, the steering axle of the trailer combination is the last axle of the trailer combination, as seen in the direction of travel, and the trailer vehicle is pushed. The trailer vehicle usually has a rigid axle, which forms the first axle of the trailer combination when reversing with the trailer combination. Therefore, when reversing with the trailer combination, the pushing tractor vehicle must drive through a relatively wide swinging road in order to steer the coupled trailer vehicle appropriately, since the trailer vehicle is not very steerable due to its rigid axle. Therefore, a driving trajectory for the forward movement is obtained for the towing vehicle and for the trailer vehicle respectively, which is different from the driving trajectory for the reverse movement. It is usually necessary to drive backward as accurately as possible along the route just driven forward in the case of a trailer combination, for example, in order to be able to pass oncoming traffic in a narrow area or to push back from a narrow blind alley entrance. However, due to the different driving trajectories, it can happen that when driving forward along the forward trajectory, objects are passed by, which are located in the reverse movement trajectory as obstacles when reversing.

[0003] US2022 / 0230544A1 proposes a system by which a trailer towed by a vehicle is prevented from colliding with a collision object arranged laterally beside the trailer while continuing to move forward without change. A sensor device detects the object, and a control device provides a warning notification to the driver, which instructs the driver how to steer or control the vehicle in order to avoid the impending collision. If the collision object cannot be circumvented while continuing to move forward, the control device instructs the driver to reverse.

[0004] US2014 / 0222228A1 discloses a trailer-backup assist system, wherein the path of the vehicle-trailer-trailer combination is changed if the vehicle-trailer-trailer combination is about to collide with a collision object. In order to detect the collision object, a detection unit is used, which requires a sensor at the trailer.

[0005] In addition, US2019 / 0086204A1 discloses a method for determining the length of a trailer attached to a towing vehicle. To this end, it is necessary to drive the towing combination with the trailer backward at least once. If the object recognition system recognizes an object along the planned path, the path planning system recalculates the planned path in order to avoid the object. In addition, the collision probability can be determined, and if the collision probability exceeds a preset threshold, the path planning system adapts the path and sends it to the driver assistance system.

[0006] However, conventional driver assistance systems, which are designed to control the steering of a motor vehicle, do not allow the maximum possible steering angle to be implemented with the steering of the motor vehicle due to control technology specifications, at least when the motor vehicle is to be moved backwards with the aid of the driver assistance system. Therefore, if the driver has fully utilized the maximum possible steering angle when driving forward over a route that is to be driven backwards again as accurately as possible with the towed vehicle, conventional driver assistance systems cannot independently drive back over this route once. If possible, reversing with the assistance of conventional driver assistance systems is then terminated and the driver is again on his own. Therefore, there is a need for a system that eliminates this problem. Summary of the invention

[0007] The object of the present invention is to provide a solution in order to make assisted reversing in the case of a vehicle-trailer combination particularly reliable, safe and designed as simply and inexpensively as possible for the human driver of the tow-trailer combination.

[0008] The object is achieved by the subject matter of the technical solution of the present invention. Other possible embodiments of the present invention are disclosed in the description and the drawings. The features, advantages and possible embodiments described within the scope of the description for the method and driver assistance system for assisted reversing in a towing combination and one of the motor vehicles can be regarded as features, advantages and possible embodiments of other subjects and any possible combination of subjects at least by analogy across categories and across embodiments.

[0009] According to the present invention, a method for assisting reversing in the case of a vehicle-trailer combination is proposed. The vehicle-trailer combination is referred to herein as a trailer combination and comprises a towing vehicle and a towing vehicle coupled to the towing vehicle by means of a trailer coupling. One of the vehicles is equipped with a driver assistance system, which is configured to implement the method and also belongs to the present invention. Therefore, the towing vehicle has a driver assistance system in particular. It is conceivable that the towing combination has a driver assistance system in such a way that one or some of the driver assistance system modules of the driver assistance system are arranged on the towing vehicle, while one or some of the driver assistance system modules of the same driver assistance system are arranged on the towing vehicle. Alternatively or additionally, it is conceivable that one or some of the driver assistance system modules of the same driver assistance system are constructed outside the towing combination, for example in the form of a driver assistance system module coupled to other driver assistance system modules for data transmission or as part thereof. In addition, according to the present invention, a motor vehicle, in particular a passenger car, is proposed, which has a driver assistance system and is set up to act as a towing vehicle for the towing combination.

[0010] In particular, the method is a computer-implementable method, which means that at least some of the method steps explained in more detail below can be implemented with the aid of a computer set up for electronic data processing. In this case, the present invention also proposes not only a computer program but also a computer-readable storage medium on which the computer program is stored. When the program instructions of the computer program are implemented by the computer, the computer program causes the computer to implement a method for assisted reversing in the case of a vehicle-trailer combination. The computer is in particular a driver assistance system or one of the driver assistance system modules or a group of driver assistance system modules, optionally in combination with a computer device external to the trailer combination. In addition, the present invention then proposes a computer program, which, when its program instructions are implemented by the computer or the driver assistance system, causes the computer or the driver assistance system to implement a method for assisted reversing in the case of a vehicle-trailer combination. Therefore, the driver assistance system module explained below can be a software module or a program module of the computer program.

[0011] In a method for assisted reversing with a trailer combination, first in step S1 of the method the trailer combination is advanced in an assisted or unassisted manner, i.e. manually, purely by a human driver, or fully or partially assisted by a driver assistance system. In this case, the corresponding forward trajectory of the trailer combination is stored in the driver assistance system, for example in a trajectory memory of the driver assistance system, which is implemented as a ring memory in a possible embodiment. The forward trajectory of the trailer combination has a forward trajectory of the towing vehicle and a forward trajectory of the towing vehicle; however, since these forward trajectories hardly deviate from each other when the trailer combination is advanced, unlike when the trailer combination is reversed, they are assumed to be superimposed in a very similar manner. Objects arranged laterally next to the forward trajectory are detected during the advancement by means of a sensor device of the towing vehicle. The sensor device has, for example, an ultrasonic sensor, a laser sensor, a radar sensor, a lidar sensor, an infrared sensor and / or a camera sensor. Sensor data acquired by means of the sensor device and characterizing objects next to the forward trajectory are provided to the driver assistance system, in particular as a point cloud. The position of the object is thereby stored, for example in an object memory of the driver assistance system.

[0012] During or after the forward movement, in step S2, a reversing trajectory for the towing combination and a corresponding individual reversing corridor for each vehicle are planned, for example, by means of a reversing trajectory generation module of a driver assistance system. Here, the reversing trajectory of the towing combination or for the towing combination is planned so that the reversing trajectory deviates as little as possible from the forward trajectory that has been driven over. Thus, the forward trajectory can serve as a reference trajectory for the upcoming reversing. The individual reversing corridor for each vehicle corresponding to the reversing trajectory of the towing combination is planned separately for each vehicle of the towing combination. Thus, a reversing corridor for the towing vehicle is planned, and a separate reversing corridor is planned for the towing vehicle.

[0013] In step S3 of the method, the detected objects are classified, for example, by means of an object classification module of the driver assistance system. In this case, the corresponding detected object is classified as a collision object if the corresponding object is located in one or both planned reversing paths. It is possible that the corresponding detected object is instead classified as a non-collision object if the detected object is not located in any reversing path when reversing with the towing combination.

[0014] Step S4 of the method provides that, if one or more of the detected objects are classified as collision objects, a new reversing trajectory is generated for the trailer combination by means of the reversing trajectory generation module and thus a corresponding new, vehicle-independent reversing corridor is generated for each vehicle. The corresponding new, vehicle-independent reversing corridor is generated in this case in such a way that it deviates as little as possible from the corresponding reversing corridor planned in step S2. However, both new reversing corridors are generated in any case in such a way that the objects of the detected objects that are classified as collision objects are now not located in any of the new, vehicle-independent reversing corridors.

[0015] In step S5 of the method, the towing combination is reversed in a reversing assistance operating mode, which is implemented, for example, by means of a vehicle control module of a driver assistance system, wherein the driver assistance system, in particular its vehicle control module, intervenes in the lateral guidance of the towing vehicle at least in such a way that the towing combination is driven along a new reversing trajectory and thus through a new reversing corridor that is separate for each vehicle. For example, the driver assistance system can be switched to the reversing assistance operating mode by the driver of the towing vehicle making a corresponding input to the driver assistance system, for example giving a voice command or operating a switch surface, etc. By activating the reversing assistance operating mode, in particular the vehicle control module of the driver assistance system is switched to active operation or assistance operation.

[0016] In step S6 of the method, the current deviation of the actual reversing trajectory of the towing vehicle and the new reversing trajectory is determined in the assisted reversing by means of a driver assistance system, for example by means of a deviation detection module of the driver assistance system. If the current deviation is greater than the permissible limit deviation, the towing combination is completely stopped by means of the driver assistance system in order to implement corrective action. In other words, the assisted reversing function is deactivated at least in order to be able to implement corrective action. The corrective action can be implemented completely or partially by the driver assistance system. However, it is also conceivable that the corrective action requires the intervention or participation of the driver of the towing combination. After the implementation of the corrective action, the assisted reversing is resumed or reactivated.

[0017] In the method or with the aid of a driver assistance system, the travelled forward trajectory of the towing combination is recorded as it moves forward. For example, the travelled trajectory can be recorded continuously in a ring memory of the driver assistance system. For example, the trajectory is always stored for a preset completed driving route length, for example for the last 100 meters or the like. The driver can drive practically as he pleases. In this regard, particular emphasis is placed on the fact that the driver can fully utilize the entire maximum possible steering angle of the towing vehicle. This is because corrective actions can compensate for the steering angle of the towing vehicle that is limited in terms of control technology. The method thus solves the problem of assisted reversing, namely that conventional driver assistance systems do not reproduce the maximum possible steering angle of the towing vehicle.

[0018] Thanks to the method, the problem of the prior art that objects that are driven past without collision during forward movement can lead to a collision with the towing combination during reverse movement along the forward trajectory is also eliminated. In addition, the method covers all possible towing vehicles, since these do not need to have special equipment / equipment. This is because during the assisted reversing, the driver assistance system does not rely (or no longer relies) on the sensors of the towing combination, since the sensor detection of the reversing trajectory to be traveled has already been carried out during the forward movement. The rear sensors of the towing vehicle are usually always deactivated when operating with the towing vehicle, so as not to provide any false information to the driver. If it should happen that reversing cannot be carried out at all or cannot be carried out further, in the method, it is particularly provided that the assistance is adjusted and the control of the towing combination is (again) completely handed over to the human driver, or the reversing assistance operating mode is not activated from the beginning - if possible with the output of a warning message to the driver. In particular, it is conceivable that the method uses a static map, with the help of which the driver assistance system intervenes in the lateral guidance of the towing vehicle. Furthermore, it is conceivable that if it is determined that the planned reversing cannot be carried out, a warning is issued to the driver by means of a driver assistance system. It goes without saying that in order to implement the method, the geometrical properties of the tractor vehicle and the trailer vehicle must be provided to the driver assistance system in advance. For example, the user can store the dimensions of the trailer vehicle in the driver assistance system via a human-machine interface. Furthermore, it can be provided that the user also enters the dimensions of the tractor vehicle into the driver assistance system, for example if the tractor vehicle deviates from its standard dimensions due to additional equipment or loading.

[0019] According to another possible embodiment, it is provided that the driver assistance system completely takes over the lateral guidance of the towing vehicle and / or the longitudinal guidance of the towing vehicle in step S5. As a result, the human driver is completely excluded from the control of the towing combination as a possible source of error when reversing with the towing combination. This ensures, for example, that the driver does not reverse too quickly, which could have a negative impact on driving stability. In this respect, this is done completely autonomously with the towing combination.

[0020] According to another possible embodiment, the corrective action comprises the following steps: In step S6.1, a deviation point is determined with the aid of a driver assistance system, for example with the aid of a deviation detection module of the driver assistance system, which is located on the new reversing trajectory and at which the deviation of the actual towing vehicle-reversing trajectory exceeds a limit deviation. In step S6.2, it is then provided that—with the aid of the driver and / or with the aid of the driver assistance system—a forward correction towing is carried out, in which the towing combination moves forward. Therefore, in order to carry out the forward correction towing, the driving direction of the towing combination is switched. Then, in step S6.3, a corrected reversing trajectory is generated with the aid of the driver assistance system (for example, a reversing trajectory generation module). The corrected reversing trajectory has two trajectory sections, namely a first trajectory section and a second trajectory section connected to the first trajectory section. The first trajectory section connects the end position of the towing combination (the towing combination reaches the end position after the forward correction towing) and the deviation point. The second trajectory section connects the deviation point and the end of the new reversing trajectory. In particular, it is provided that the second trajectory section is planned in such a way that it deviates as little as possible from the new reversing trajectory between the deviation point and the end of the new reversing trajectory. It can also be provided that previously successfully completed sections of the new reversing trajectory are deleted in order to save storage capacity. In step S6.4, the towing and trailer combination is reversed with the aid of the driver assistance system, wherein the driver assistance system intervenes at least in the lateral guidance of the towing vehicle in such a way that the towing and trailer combination travels along the corrected reversing trajectory. As a result, reversing with the towing and trailer combination is designed to be particularly easy or inexpensive for a human driver.

[0021] In this context, another possible embodiment provides that the driver assistance system completely takes over the lateral guidance of the towing vehicle and / or the longitudinal guidance of the towing vehicle in step S6.4. In other words, the reversing of the towing combination along the corrected reversing trajectory takes place completely autonomously, which is even easier for the driver and thus excludes the driver as a source of error from the control of the towing combination.

[0022] According to another possible embodiment, an ideal end position for the forward corrective towing is planned with the aid of a driver assistance system. The ideal end position is characterized in particular in that it can be reached particularly easily or efficiently with the towing combination and in that it is just so far away from the new reversing trajectory that it is particularly easy to cut into the new reversing trajectory again after the forward corrective towing. A correction driving trajectory is then planned with the aid of the driver assistance system for the forward corrective towing towards the ideal end position, for example with the aid of a reversing trajectory generation module. The forward corrective towing is then carried out along the corrective driving trajectory—with the aid of the driver and / or with the aid of the driver assistance system. Prior to, simultaneously with or after this, a first trajectory section is planned between the ideal end position and the deviation point with the aid of the driver assistance system, which first trajectory section is part of the corrected reversing trajectory as described above.

[0023] According to another possible embodiment, in order to carry out the forward correction towing, full control of the longitudinal and transverse guidance of the towing vehicle is handed over to the human driver of the towing vehicle, who then carries out the forward correction towing with the towing combination. Nevertheless, the driver can still be supported by the driver assistance system - even if the driver assistance system does not actively intervene in the longitudinal and / or transverse guidance of the towing vehicle -, for example by displaying the forward correction towing to be carried out to the driver, for example on a display of the towing vehicle. In this case, the driver monitors the surroundings of the towing combination during the forward correction towing to ensure that the towing combination does not collide with objects during the forward correction towing.

[0024] In an alternative to this, it is provided that the driver assistance system completely takes over the lateral guidance of the tractor vehicle and / or the longitudinal guidance of the tractor vehicle in order to implement the forward corrective traction. This means that the implementation of the forward corrective traction is carried out partially or completely autonomously, thereby further relieving the driver.

[0025] In particular, it is provided that steps S1 to S5 are used analogously in order to carry out a forward correction traction and to drive onto a new reversing trajectory again via the deviation point.

[0026] In another possible embodiment, the current deviation of the actual towing vehicle reversing trajectory from the new reversing trajectory is determined by determining the Euclidean distance between the actual towing vehicle reversing trajectory and the current position point at the current position point of the towing combination located on the new reversing trajectory during assisted reversing with the aid of the driver assistance system. Alternatively or additionally, the current deviation is determined by determining the angle between a tangent branching off from the new reversing trajectory at the current position point and a tangent to the actual towing vehicle reversing trajectory at the current position point at the towing combination during reversing. This makes it possible to detect the deviation of the towing vehicle particularly easily and reliably.

[0027] According to another possible design, for each vehicle of the trailer combination, a hypothetical (first) collision rectangle is predefined for the driver assistance system, which collision rectangle completely surrounds the corresponding vehicle and is guided together with the vehicle. It is provided that the geometric center of gravity of the collision rectangle is located on the longitudinal center axis (X axis) of the vehicle. In addition, the transverse axis (Y axis) of the vehicle and the transverse axis of the collision rectangle are arranged at least parallel to each other. The collision rectangle is predefined for each vehicle in particular such that the outer contour of the relevant vehicle and the edges of the collision rectangle are spaced apart from each other at a first safety distance, which is less than 75 centimeters, in particular less than 50 centimeters, in particular 25 centimeters. In addition, for each vehicle of the trailer combination, a hypothetical surrounding circle is predefined for the driver assistance system, and the corner points of the relevant collision rectangle are always located on this surrounding circle. Therefore, the surrounding circle, like the collision rectangle, is guided together with the corresponding vehicle during vehicle movement. In this design, it is also provided that if the corresponding object intersects one or two of the surrounding circles when advancing, the detected object is respectively classified as a critical object, for example, by means of an object classification module of the driver assistance system. It is possible that the corresponding detected object is instead classified as a non-critical object if the corresponding object does not intersect any of the vehicle's surrounding circles when being driven past. Then, in step S3 of the method, only those detected objects that would intersect the collision rectangle during assisted reversing with the aid of the driver assistance system are classified as the corresponding collision object. In this way, computing power can be saved because the number of objects to be classified is smaller than if all objects detected with the aid of the sensor device were to be classified, wherein the objects would then include objects that are irrelevant for a planned collision-free reversing.

[0028] In relation to the collision rectangle, in an improved solution, it is provided that for each vehicle, an imaginary second collision rectangle completely located within the first collision rectangle and an imaginary third collision rectangle completely located within the second collision rectangle are preset. In particular, the collision rectangles are concentric with each other, that is, they share a common center of gravity, which is located on the longitudinal center axis of the vehicle. In a possible improved solution, the edges of the first collision rectangle and the outer contour of the relevant vehicle are spaced apart from each other at a first safety distance, which is, for example, 75 centimeters. For example, the edges of the second collision rectangle and the edges of the first collision rectangle are spaced apart from each other by 25 centimeters, whereby the edges of the second collision rectangle and the outer contour of the relevant vehicle are spaced apart from each other at a second safety distance of 50 centimeters. In addition, the edges of the third collision rectangle and the edges of the second collision rectangle are spaced apart from each other by 25 centimeters, whereby the edges of the third collision rectangle and the outer contour of the relevant vehicle are spaced apart from each other at a third safety distance of 25 centimeters. This should only be understood as a possible example: other distances between the edges of the collision rectangle or between the collision rectangle and the outer contour of the relevant vehicle are of course also possible. In this case, during assisted reversing with the aid of the driver assistance system, as long as the corresponding collision object intersects the first collision rectangle, but neither the second collision rectangle nor the third collision rectangle, the corresponding collision object is classified as a warning object, for example, by means of an object classification module. In response to the warning object, a warning action is performed with the aid of the driver assistance system. For example, the driver is informed that the trailer combination is approaching the collision object and / or the driving speed of the trailer combination is reduced and / or the driver is provided with a complete or partial re-takeover of the control of the trailer combination. In addition, during assisted reversing, as long as the corresponding collision object intersects the first collision rectangle and the second collision rectangle, but not the third collision rectangle, the corresponding collision object is classified as a warning object, wherein a warning action is performed in response to the warning object with the aid of the driver assistance system. For example, the driver is informed that the trailer combination is facing a collision threat, and / or the driving speed of the trailer combination is further reduced / reduced more strongly, and / or the driver is advised to completely re-take over the control of the trailer combination with greater urgency. If the collision object enters the innermost part of the collision rectangle, that is, enters the third collision rectangle, a collision emergency action can be performed. For example, the driver is informed of an imminent collision and / or the towing combination is completely stopped and / or the driver is allowed to fully take over control of the towing combination again. A three-stage warning system can thus be easily implemented, by means of which the driver of the towing combination is provided with information about the potential risk more clearly and / or, in the case of automatic braking, the braking is gradually applied before the driver is startled by full braking.

[0029] In order to plan or generate a new reversing trajectory or a new reversing channel that is separate for each vehicle, another possible embodiment is to plan a cut-out from the initially planned reversing trajectory. For this purpose, at the problem point of the initially planned reversing trajectory in step S2 (at which the reversing trajectory and the outer contour point of the collision object are spaced apart from each other at a minimum distance), a vertical line relative to the tangent of the reversing trajectory that intersects the outer contour point is created. Here, such a tangent among the tangents of the reversing trajectory is used, which branches off from the reversing trajectory at the problem point. Then, on the side of the reversing trajectory opposite to the outer contour point, a new planning point is placed on the straight extension of the vertical line, wherein a trajectory offset distance is constructed between the initially planned reversing trajectory and the new planning point. This trajectory offset distance is greater than zero in any case, but is nevertheless selected so that the trajectory offset distance is as close as possible to the initially planned reversing trajectory. At least when planning the cut-out for the first time, the trajectory offset distance is at most selected to be so long that it is possible to pass the problem point without collision with the trailer combination at the first approach by the driver assistance system. In particular, the track offset distance is limited, more precisely, by the sensor effective range of the sensor device of the towing vehicle, which is approximately four meters in each case in the lateral and perpendicular direction to the corresponding track traveled by the towing vehicle. In other words, the new planning point is arranged at most at the lateral outer boundary of the sensor effective range of the sensor device of the towing vehicle. For example, if the vertical lateral sensor effective range of the sensor device is four meters, the track offset distance is at most four meters. Then, a cut-out point is determined on the initially planned reversing trajectory, which is located before the problem point on the initially planned reversing trajectory relative to the reversing direction. This means that, in the case of further driving over the reversing trajectory, the towing combination will first reach the cut-out point and then the problem point. In step S4, for example, a new reversing trajectory section is planned between the cut-out point and the new planning point by means of a reversing trajectory generation module, and thus a new reversing channel section that is separate for each vehicle is planned for each vehicle, for cutting out from the initially planned reversing trajectory.

[0030] If it is determined during the planning of a new reversing passage section or a new reversing trajectory section that is separate for each vehicle and is cut out from the reversing trajectory of the initial planning that driving through these new reversing passage sections will lead to a secondary collision, then in a possible improvement, it is arranged to restart or repeat the planning of a new reversing passage section that is separate for each vehicle and is cut out from the reversing trajectory of the initial planning. For example, a secondary collision is a collision with another object among the detected objects, or a collision with another vehicle of the same object but in combination with a trailer, or a collision with another corresponding vehicle among the vehicles of the trailer combination. This secondary collision only becomes important when the planning of the reversing trajectory cut out from the initial planning has been implemented at least once. The replanning is then carried out under the following assumption that the new planning point is spaced apart from the reversing trajectory of the initial planning at a larger trajectory offset distance than during the first operation, so as to also avoid secondary collisions. Therefore, the new planning point moves further toward the sensor effective range boundary of the sensor device, but does not exceed the sensor effective range boundary here. Such a replanning may be necessary, for example, if, according to the first planning, the towing vehicle can be turned along the relevant new reversing path section without collision, but for this purpose the tractor vehicle must deviate further from the initially planned reversing trajectory and thus would collide with one of the detected objects. Alternatively or additionally, it can be provided that the replanning is carried out under the assumption that the cut-out point is closer to the towing combination, so that a less drastic turn with the towing vehicle is sufficient to bypass the relevant collision point with the towing combination.

[0031] In a possible improvement, the cut-in into the initially planned reversing trajectory is also planned. For this purpose, a cut-in point is determined on the initially planned reversing trajectory, which is located after the problem point on the initially planned reversing trajectory relative to the reversing direction. This means that when the reversing trajectory is further driven, the trailer combination will first reach the problem point and then the cut-in point. In step S4, for example, a new additional reversing trajectory section is planned between the new planned point and the cut-in point by means of a reversing trajectory generation module, and thus a new additional reversing channel section, which is separate for each vehicle, is planned for each vehicle for cutting into the initially planned reversing trajectory.

[0032] If it is determined during the planning of a new reversing channel section or a new reversing trajectory section for each vehicle that is separate for each vehicle in the reversing trajectory of the initial planning that driving through these new reversing channel sections will lead to additional / other secondary collisions, then in a possible improvement, it is provided that the planning of a new reversing channel section that is separate for each vehicle in the reversing trajectory of the initial planning is restarted or repeated. The additional / other secondary collisions will only become important if the planning of the cut-in into the reversing trajectory of the initial planning has been implemented at least once. The replanning is then carried out under the following assumption, that is, a cut-in point that is farther away from the trailer combination is determined, so that it is sufficient to use the towing vehicle to perform a less strong steering to bypass the relevant collision point by the trailer combination. Alternatively or additionally, it can be provided that the cut-out from the reversing trajectory of the initial planning is repeatedly planned as described above, and the new planning point is further moved to the sensor effective range boundary of the sensor device. By planning the cut-out or cut-in, in this method, the reversing trajectory of the initial planning is deviated from in an advantageous manner only to a particularly small extent.

[0033] Another possible design provides that before the driver assistance system or its vehicle control module intervenes for the first time in the lateral guidance of the towing vehicle, the switch-out from the initially planned reversing trajectory and the switch-in to the initially planned reversing trajectory are planned for the entire planned reversing trajectory. In other words, the planning period extends to the end of the planned reversing trajectory. This allows particularly safe and smooth assistance in reversing.

[0034] According to an alternative to this, a cut-out from the initially planned reversing trajectory is planned as soon as it is determined by means of the driver assistance system that a predefined planned minimum distance has been reached between the current position of the towing and trailer combination and the problem point. In this case, a cut-in into the initially planned reversing trajectory is planned when the towing and trailer combination is in a new reversing trajectory section. In this case, the planning period only covers a partial route of the planned reversing trajectory, whereby the computing power required in the method can be saved. As a result, the method can be implemented particularly efficiently.

[0035] Further features of the invention can be derived from the following description of the drawings and with the aid of the drawings. The features and feature combinations mentioned above in the description of the drawings and the features and feature combinations shown individually in the following description of the drawings and / or in the drawings can be used not only in the respectively indicated combination but also in other combinations or alone without departing from the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings illustrate a method for assisting reverse parking in a vehicle-trailer combination:

[0037] Figure 1A schematic top view of a vehicle-trailer combination in motion is shown,

[0038] Figure 2 shows a schematic top view of a vehicle-trailer combination in simulated reversing, wherein objects detected during forward movement are classified as corresponding collision objects,

[0039] Figure 3 A schematic top view of a vehicle-trailer combination is shown at the start of a reverse maneuver assisted by a driver assistance system, wherein an object prevents a collision-free reverse maneuver.

[0040] Figure 4 A schematic top view of a vehicle-trailer combination is shown, wherein a cut-out from an initially planned reversing trajectory is planned.

[0041] Figure 5 A schematic top view of a vehicle-trailer combination is shown, wherein a planned cut-in into an initially planned reversing trajectory is shown.

[0042] Figure 6 A schematic top view of a vehicle-trailer combination is shown, for which a collision-free reversing trajectory is planned.

[0043] Figure 7 A schematic top view of a vehicle-trailer combination is shown, wherein the actual reversing trajectory of the towed vehicle of the towed combination deviates from the newly planned collision-free reversing trajectory, and

[0044] Figure 8 A schematic top view of a vehicle-trailer combination is shown when performing a forward correction towing operation. DETAILED DESCRIPTION

[0045] In the following, a method for assisted reversing with a towing combination 1, a driver assistance system configured to implement the method, and a motor vehicle having the driver assistance system are explained in a common description. In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0046] A towing combination 1 is a vehicle towing combination comprising a towing vehicle 2 and a towing vehicle 3 coupled to the towing vehicle 2 by means of a trailer coupling. One of the vehicles 2, 3 (in this case the towing vehicle 2) is equipped with a driver assistance system which is configured to carry out the method. The towing vehicle 2 is designed as a passenger car in this case.

[0047] In the method for assisted reversing with a towing combination 1 , firstly in step S1 of the method the towing combination 1 is advanced. Figure 1, which shows a schematic top view of a towing combination 1 in forward motion. Here, a forward trajectory 4 of the towing combination 1, which represents the forward motion, is stored in a trajectory memory of the driver assistance system, which is implemented as a ring memory. The forward trajectory 4a of the tractor vehicle 2 and the forward trajectory 4b of the towing vehicle 3 hardly deviate from each other during the forward motion of the towing combination 1, so that they are assumed to be superimposed. During the forward motion, a point cloud is detected by means of a sensor device of the tractor vehicle 2, which detects an object 5 arranged laterally next to the forward trajectory 4. The point cloud detected by means of the sensor device is stored in an object memory of the driver assistance system.

[0048] Figure 2 A schematic top view of a towing combination 1 during simulated reversing is shown, wherein objects 5 detected during forward movement are classified as corresponding collision objects 6. During or after the forward movement, in step S2, a reversing trajectory 7 for the towing combination 1 and corresponding reversing paths 8, 9 for the vehicles 2, 3, which are separate for each vehicle, are planned with the aid of a reversing trajectory generation module of the driver assistance system in this example. Figure 3 ). The reversing trajectory 7 of the trailer combination 1 is planned in such a way that it deviates as little as possible from the traveled forward trajectory 4. The forward trajectory 4 therefore serves as a reference trajectory for the upcoming reversing. The reversing corridors 8, 9, which are separate for each vehicle and correspond to the reversing trajectory 7, are planned separately for each vehicle 2, 3. Therefore, a reversing corridor 8 for the tractor vehicle 2 and a reversing corridor 9 for the trailer vehicle 3 are planned. In step S3 of the method, the detected objects 5 are classified, currently with the aid of an object classification module of the driver assistance system. Here, the corresponding detected object 5 is classified as a collision object 6 when the corresponding object is located in one or both of the planned reversing corridors 8, 9. For this purpose, for example, reversing along the reversing trajectory 7 initially planned in step S2 is simulated, as shown in FIG. Figure 2 As shown in .

[0049] Figure 3 A schematic top view of a towing combination 1 at the start of reversing assisted by a driver assistance system is shown, wherein a collision object 6 initially prevents a collision-free reversing of the towing combination 1. This is because, as can be seen, the collision object 6 is located in the reversing path 9 of the towing vehicle 3. Step S4 of the method is provided in such a case to generate a new reversing trajectory 7a (see FIG. 1 ) by means of a reversing trajectory generation module. Figure 6 ), and thus for each vehicle 2, 3 a corresponding new, separate reversing lane 8a, 9a for each vehicle is generated (see Figure 6). The corresponding new reversing passage 8a, 9a, which is separate for each vehicle, is generated in such a way that the new reversing passage 8a, 9a, which is separate for each vehicle, deviates as little as possible from the corresponding reversing passage 8, 9 planned in step S2. However, the two new reversing passages 8a, 9a are generated in any case in such a way that the collision object 6 is not located in any of the new reversing passages 8a, 9a, which are separate for each vehicle.

[0050] Figure 4 A schematic top view of a trailer combination 1 is shown, wherein a cut-out from the planned reversing trajectory 7 is planned, whereby a new first reversing trajectory section 10 for cutting out from the initially planned reversing trajectory 7 and thus a new first reversing channel section 11, 12, which is individual for each vehicle, is planned (see Figure 6 ). To this end, a problem point 13 is determined on the reversing trajectory 7 initially planned in step S2, at which the reversing trajectory 7 and the outer contour point 6a of the collision object 6 are spaced apart from each other at a minimum distance. A tangent 14 of the reversing trajectory 7 is then determined, which branches off at the problem point 13. A perpendicular line 15 relative to the tangent 14 is then created, which intersects the outer contour point 6a. A new planning point 16 is then arranged on the side of the reversing trajectory 7 opposite to the outer contour point 6a, on a straight extension of the perpendicular line 15, wherein a trajectory offset distance is constructed between the initially planned reversing trajectory 7 and the new planning point. The trajectory offset distance is greater than zero in any case, but is nevertheless selected so that the trajectory offset distance is as close as possible to the initially planned reversing trajectory 7. At least at the first planned cut-out, the trajectory offset distance is at most selected to be so long that it is possible for the driver assistance system to pass the problem point 13 without collision with the trailer combination 1 at the first approach. In particular, the trajectory deviation distance is limited, more precisely by the sensor range 17 of the sensor device of the towing vehicle 2, which is approximately four meters in each case laterally and perpendicularly to the respective trajectory 4, 7, 7a traveled by the towing vehicle 2. Then, a cut-out point 18 is determined on the initially planned reversing trajectory 7, which is located before the problem point 13 on the initially planned reversing trajectory 7 with respect to the reversing direction 19. In step S4, in this example, a new first reversing trajectory section 10 is planned between the cut-out point 18 and the new planned point 16 by means of a reversing trajectory generation module, and thus a new, vehicle-specific, reversing passage section 11, 12 is planned for each vehicle 2, 3 for cutting out from the initially planned reversing trajectory 7.

[0051] If it is determined during the planning of new reversing passage sections 11, 12 or new reversing trajectory sections 10 for cutting out from the initially planned reversing trajectory 7 that driving over these new reversing passage sections 10, 11 would lead to a secondary collision, it is provided that the planning of the new reversing passage sections 11, 12, which are individual for each vehicle, is restarted or repeated. The replanning is then performed under the assumption that the new planned point 16 is spaced apart from the initially planned reversing trajectory 7 at a greater trajectory offset than in the first run, in order to also avoid a secondary collision. Alternatively or additionally, the replanning is performed under the assumption that the cut-out point 18 is closer to the towing combination 1.

[0052] Currently, the cut-in into the initially planned reversing trajectory 7 is also planned. For this purpose, a cut-in point 20 is determined on the initially planned reversing trajectory 7, which is located behind the problem point 13 on the initially planned reversing trajectory 7 with respect to the reversing direction 19. In step S4, a new second reversing trajectory section 12 is planned between the new planning point 16 and the cut-in point 20 by means of the reversing trajectory generation module, and thus a new second reversing passage section 22, 23, which is separate for each vehicle, is planned for each vehicle for the cut-in into the initially planned reversing trajectory 7.

[0053] If, during the planning of a new second reversing passage section 22, 23 or a new reversing trajectory section 21, which is individual for each vehicle, for cutting into the initially planned reversing trajectory 7, it is determined that driving over these new reversing passage sections 22, 23 would lead to an additional / other secondary collision, it is provided that the planning of the new second reversing passage section 22, 23, which is individual for each vehicle, is restarted or repeated. The replanning then takes place under the assumption that a cutting-in point 20 is determined that is further away from the towing combination 1. Alternatively or additionally, the planning of the cut-out from the initially planned reversing trajectory 7 is repeated as described above, wherein the new planning point 16 is moved further toward the edge of the sensor range 17.

[0054] Figure 6A schematic top view of a tow combination 1 is shown for which a new collision-free reversing trajectory 7a is planned / has been planned. Based on the new reversing trajectory 7a, the tow combination 1 is reversed in a reversing assistance operating mode by means of a vehicle control module of a driver assistance system, wherein the vehicle control module of the driver assistance system intervenes at least in the transverse guidance of the towing vehicle 2 in such a way that the tow combination 1 travels along a new reversing trajectory 7a with new reversing trajectory sections 10, 21 and thus travels through a new reversing corridor 8a, 9a, which is individual for each vehicle, with new reversing corridor sections 11, 12, 22, 23. In step S5, the driver assistance system now completely takes over the transverse guidance of the towing vehicle 2 and / or the longitudinal guidance of the towing vehicle 2.

[0055] Before the driver assistance system or its vehicle control module intervenes for the first time in the lateral guidance of the towing vehicle 2, the exit from the initially planned reversing trajectory 7 and the entry into the initially planned reversing trajectory 7 can be pre-planned for the entire initially planned reversing trajectory 7. Alternatively, the exit from the initially planned reversing trajectory 7 is planned as soon as it is determined by means of the driver assistance system that a predefined planned minimum distance has been reached between the current position of the towing and coupling combination 1 and the problem point 13. In this case, the entry into the initially planned reversing trajectory 7 is planned when the towing and coupling combination 1 is located on the new first reversing trajectory section 10.

[0056] In re-referencing Figure 1 and Figure 2 In the case of , it is explained that according to the example described here, for each vehicle 2, 3, the driver assistance system is predefined with an imaginary first collision rectangle 24, which completely surrounds the corresponding vehicle 2, 3 and is guided together with the vehicle 2, 3. At present, the collision rectangle 24 is respectively predefined in such a way that the outer contour of the relevant vehicle 2, 3 and the edges of the collision rectangle 24 are spaced apart from each other at a first safety distance of 25 centimeters. In addition, for each vehicle 2, 3, the driver assistance system is predefined with an imaginary surrounding circle 25, on which the corner points of the relevant collision rectangle 24 are always located. In addition, in this example, it is provided that if the corresponding object 5 intersects one or two of the surrounding circles 25 when moving forward, the detected object 5 is respectively classified as a critical object. Then, in step S3 of the method, only those detected objects 5 that will intersect the collision rectangle 24 when assisting reversing with the help of the driver assistance system are classified as the corresponding collision object 6 if possible.

[0057] Optionally, an imaginary second collision rectangle completely located within the first collision rectangle 24 and an imaginary third collision rectangle completely located within the second collision rectangle are predefined for each vehicle 2 and 3. In this case, the edges of the first collision rectangle 24 and the outer contour of the relevant vehicle are spaced apart from each other at a first safety distance, which is 75 centimeters. For example, the edges of the second collision rectangle and the edges of the first collision rectangle 24 are spaced apart from each other by 25 centimeters, whereby the edges of the second collision rectangle and the outer contour of the relevant vehicle 2, 3 are spaced apart from each other at a second safety distance of 50 centimeters. In addition, the edges of the third collision rectangle and the edges of the second collision rectangle are spaced apart from each other, for example, by 25 centimeters, whereby the edges of the third collision rectangle and the outer contour of the relevant vehicle 2, 3 are spaced apart from each other at a third safety distance of 25 centimeters. In this case, when assisting reversing with the aid of the driver assistance system, the corresponding collision object 6 is classified as a warning object as long as it intersects with the first collision rectangle 24, but does not intersect with the second collision rectangle or the third collision rectangle. In response to the warning object, a warning action is performed with the aid of the driver assistance system. For example, the driver is informed that the trailer combination 1 is approaching the collision object 6 and / or the driving speed of the trailer combination 1 is reduced and / or the driver is provided with a complete or partial re-takeover of the control of the trailer combination 1. In addition, in the assisted reversing, as long as the corresponding collision object 6 intersects with the first collision rectangle 24 and the second collision rectangle, but does not intersect with the third collision rectangle, the corresponding collision object 6 is classified as a warning object, wherein a warning action is implemented in response to the warning object with the help of the driver assistance system. For example, the driver is informed that the trailer combination 1 is facing a collision threat, and / or the driving speed of the trailer combination 1 is further reduced / reduced more strongly, and / or the driver is advised to fully re-take control of the trailer combination 1 with a higher urgency. If the collision object 6 enters the innermost part of the collision rectangle, that is, enters the third collision rectangle, a collision emergency action can be implemented. For example, the driver is informed that the collision is imminent, and / or the trailer combination 1 is completely stopped, and / or the driver is allowed to fully re-take control of the trailer combination 1.

[0058] Figure 7 A schematic top view of a towing combination 1 is shown, wherein the actual reversing trajectory of the towing vehicle of the towing combination 1 deviates from the newly planned collision-free reversing trajectory 7a. In step S6 of the method, the current deviation of the actual reversing trajectory 7b of the towing vehicle 3 from the new reversing trajectory 7a is determined in the assisted reversing process by means of a deviation detection unit of the driver assistance system. If the current deviation is greater than the permissible limit deviation, the towing combination 1 is completely stopped by means of the driver assistance system in order to implement corrective actions. The corrective actions can be implemented completely or partially by the driver assistance system. After the corrective actions have been implemented, the assisted reversing process is resumed or reactivated.

[0059] According to the example described here, in step S6.1, a deviation point 26 on the new reversing trajectory 7a is determined for corrective action, in the present case with the aid of a deviation detection module of the driver assistance system. At the deviation point 26, the deviation of the actual towing vehicle from the reversing trajectory 7b exceeds the limit deviation. In step S6.2, it is provided that a forward correction towing is carried out, in which the towing combination is driven forward. This is Figure 8 . Therefore, in order to implement the forward correction towing, the driving direction of the towing combination 1 or the towing vehicle 2 is switched. Then, in step S6.3, a corrected reversing trajectory 7c is generated with the aid of a reversing trajectory generation module. The corrected reversing trajectory has two trajectory segments 27 and 28, namely a first trajectory segment 27 and a second trajectory segment 28 connected to the first trajectory segment. The first trajectory segment 27 connects the end position 29 of the towing combination (the towing combination has reached this end position after the forward correction towing) and the deviation point 26. The second trajectory segment 28 connects the deviation point 26 and the end 30 of the new reversing trajectory 7a. For this purpose, the second trajectory segment 28 is planned so that the second trajectory segment deviates from the new reversing trajectory as little as possible between the deviation point 26 and the end 30 of the new reversing trajectory 7a. In addition, it is provided that the previously successfully completed segment 31 of the new reversing trajectory 7a is deleted from the ring memory of the driver assistance system in order to save storage capacity. In step S6 . 4 , the towing combination 1 is reversed with the aid of the driver assistance system, wherein the driver assistance system intervenes in the transverse guidance of the towing vehicle 2 at least in such a way that the towing combination 1 travels along the corrected reversing driving trajectory 7 c .

[0060] In the present case, it is provided that in step S6.4 the driver assistance system completely takes over the lateral and / or longitudinal guidance of the towing vehicle 2. In other words, the reversing of the towing combination 1 along the corrected reversing trajectory 7c is performed completely autonomously.

[0061] In a further development, an ideal end position for the forward correction towing is planned with the aid of the driver assistance system. The ideal end position is characterized in that it can be reached particularly easily or efficiently with the towing combination 1 and is just far enough from the new reversing trajectory 7a that it is particularly easy to cut into the new reversing trajectory 7a again after the forward correction towing. A correction driving trajectory 32 is then planned with the aid of the driver assistance system towards the ideal end position for the forward correction towing (see Figure 7), for example, with the aid of a reversing trajectory generation module. The correction driving trajectory 32 can be a straight line or a non-straight curve. In addition, the correction driving trajectory 32 can have both straight and non-straight parts. A forward correction traction is then performed along the correction driving trajectory 32. Before, at the same time or after this, a first trajectory section 27 is planned between the ideal end position and the deviation point 26 with the aid of a driver assistance system, which, as described above, is part of the corrected reversing trajectory 7c.

[0062] In order to implement a forward corrective traction, full control of the longitudinal and transverse guidance of the tractor vehicle 2 can be handed over to a human driver, who then implements a forward corrective traction with the trailer combination 1. The driver can be supported by a driver assistance system in this case—even if the driver assistance system does not actively intervene in the longitudinal and / or transverse guidance of the tractor vehicle 2 in such a case, for example by displaying the forward corrective traction to be carried out to the driver, for example in a display of the tractor vehicle 2. In the present case, it is provided that the driver assistance system completely takes over the transverse and / or longitudinal guidance of the tractor vehicle 2 in order to implement a forward corrective traction. This means that the implementation of the forward corrective traction is performed partially or completely autonomously.

[0063] In particular, it is provided that steps S1 to S5 are applied analogously in order to carry out a forward correction traction and to resume the new reversing trajectory 7 a via the deviation point 26 .

[0064] The current deviation of the actual towed vehicle reversing trajectory 7b from the new reversing trajectory 7a is determined, for example, by determining the Euclidean distance between the actual towed vehicle reversing trajectory 7b and the current position point at the current position point of the towed vehicle combination 1 on the new reversing trajectory 7a during assisted reversing with the aid of the driver assistance system. Alternatively or additionally, the current deviation is determined by determining the angle between the tangent branching off from the new reversing trajectory 7a at the current position point and the tangent of the actual towed vehicle reversing trajectory 7b at the current position point of the towed vehicle combination 1 during reversing.

[0065] Reference numerals list

[0066] 1 trailer combination

[0067] 2Towing vehicle

[0068] 3Trailer

[0069] 4 The forward trajectory of the trailer combination

[0070] 4a The forward trajectory of the towing vehicle

[0071] 4b The forward trajectory of the towing vehicle

[0072] 5 Objects

[0073] 6 Collision Objects

[0074] 6a Outer contour point

[0075] 7 Reversing track of trailer combination

[0076] 7a New reverse track

[0077] 7b Actual trailer vehicle - reverse track

[0078] 7c Corrected reverse trajectory

[0079] 8 Reversing lane for towing vehicles

[0080] 8a New reversing lane for towing vehicles

[0081] 9Reversing lane for trailer vehicles

[0082] 9a New reversing lane for trailer vehicles

[0083] 10 New first reverse track section

[0084] 11 New first reverse lane section for towing vehicles

[0085] 12 New first reverse lane section for trailer vehicles

[0086] 13 Problem Points

[0087] 14 Tangent

[0088] 15 vertical lines

[0089] 16 new planning points

[0090] 17 Sensor effective range

[0091] 18 Cut-out point

[0092] 19 Reverse direction

[0093] 20 Entry Points

[0094] 21 New second reverse track section

[0095] 22 New second reverse lane section for towing vehicles

[0096] 23 New second reverse lane section for trailer vehicles

[0097] 24 First collision rectangle

[0098] 25 around the circle

[0099] 26 deviation points

[0100] 27 The first track section of the corrected reversing track

[0101] 28 The second track section of the revised reversing track

[0102] 29 terminal positions

[0103] 30 New reverse track terminal

[0104] 31 new reverse track successfully completed sections

[0105] 32 Correction of driving trajectory

[0106] S1-S6, S6.1-S6.4 Method steps

Claims

1. A method for assisted reversing in a towing combination (1), the towing combination having a tractor vehicle (2) and a coupled towed vehicle (3) and a driver assistance system, wherein: S1: First, the trailer combination (1) moves forward, wherein: - storing the corresponding forward trajectory (4) in the driver assistance system, - detecting an object (5) by means of a sensor device of the towing vehicle (2), the object being arranged laterally next to the forward trajectory (4), S2： - planning a reversing trajectory (7) which deviates as little as possible from the forward trajectory (4) being travelled, - for each vehicle (2, 3) of the trailer combination (1), planning a separate reversing channel (8, 9) for each vehicle corresponding to the planned reversing trajectory (7), S3: if the corresponding object (5) is located in one or both of the planned reversing lanes (8, 9), classifying the corresponding detected object (5) as a collision object (6), S4: If one or more of the detected objects (5) are classified as a corresponding collision object (6), a new reversing trajectory (7a) is generated and thus a corresponding new reversing passage (8a, 9a) is generated for each vehicle (2, 3), which is separate for each vehicle and deviates as little as possible from the corresponding planned reversing passage (8, 9), so that the collision object (6) is no longer located in any of the new reversing passages (8a, 9a) separate for each vehicle. S5: reversing the towing and trailer combination (1) with the aid of the driver assistance system, wherein the driver assistance system intervenes at least in the lateral guidance of the towing vehicle (2) in such a way that the towing and trailer combination (1) travels along the new reversing trajectory (7a) and thereby travels through the new reversing corridor (8a, 9a) which is separate for each vehicle, S6: With the aid of the driver assistance system, a current deviation between the actual reversing trajectory of the towed vehicle (3) and the new reversing trajectory (7a) is determined during assisted reversing, and if the current deviation is greater than an allowable limit deviation, the towed vehicle combination (1) is completely stopped with the aid of the driver assistance system to implement corrective action, and the assisted reversing is resumed after the corrective action has been implemented.

2. The method according to claim 1, characterized in that In step S5, the driver assistance system completely takes over the transverse guidance of the tractor vehicle (2) and / or the longitudinal guidance of the tractor vehicle (2).

3. The method according to claim 1 or 2, characterized in that: The corrective actions include the following steps: S6.1 With the aid of the driver assistance system: determining a deviation point on the new reversing trajectory (7a), at which the deviation of the actual towing vehicle from the reversing trajectory exceeds the limit deviation, S6.2 performs forward correction traction, during which the towing and trailer combination (1) moves forward, S6.3 Using the driver assistance system: generating a corrected reversing trajectory, wherein the corrected reversing trajectory has: - a first trajectory section between the end position of the towing combination (1) after forward correction towing and the deviation point, and - a second trajectory section between the deviation point and the end of the new reversing trajectory (7a), S6.4 With the aid of the driver assistance system: reversing the trailer combination (1), wherein the driver assistance system intervenes in the lateral guidance of the towing vehicle (2) at least in such a way that the trailer combination (1) travels along a corrected reversing trajectory.

4. The method according to claim 3, characterized in that In step S6.4, the driver assistance system completely takes over the transverse guidance of the tractor vehicle (2) and / or the longitudinal guidance of the tractor vehicle (2).

5. The method according to claim 3 or 4, characterized in that: - planning an ideal end position for the forward correction traction with the aid of the driver assistance system, - planning a corrected driving trajectory for the forward corrective traction in the direction of the desired end position by means of the driver assistance system, - carrying out said forward corrective traction along said corrective trajectory, - planning the first trajectory section between the ideal end position and the deviation point by means of the driver assistance system.

6. The method according to any one of claims 3 to 5, characterized in that In order to implement the forward corrective traction, full control of the longitudinal and transverse guidance of the tractor vehicle (2) is handed over to the human driver of the tractor vehicle, who then implements the forward corrective traction.

7. The method according to any one of claims 3 to 5, characterized in that In order to carry out the forward corrective traction, the driver assistance system completely takes over the transverse guidance of the tractor vehicle (2) and / or the longitudinal guidance of the tractor vehicle (2).

8. The method according to any one of the preceding claims, characterized in that The current deviation of the actual towed vehicle reversing trajectory from the new reversing trajectory (7a) is determined by determining, during assisted reversing with the aid of the driver assistance system, at a current position point of the towed vehicle combination (1) on the new reversing trajectory (7a) - determining the Euclidean distance between the actual towing vehicle-reversing trajectory and the current position point, and / or - determining the angle between the tangent line branching off from the new reversing trajectory (7a) at the current position point and the tangent line of the actual towed vehicle reversing trajectory. 9 . A driver assistance system configured to carry out a method according to claim 1 .

10. A motor vehicle having a driver assistance system according to claim 9, wherein: The motor vehicle is designed to serve as a towing vehicle (2) for the towing combination (1).

Images