METHOD FOR ASSISTING A VEHICLE USER DURING A LANE CHANGE MANEUVER, TAKING INTO ACCOUNT DIFFERENT AREAS IN THE VEHICLE'S ENVIRONMENT, AND A DRIVER ASSISTANCE SYSTEM FOR A VEHICLE

Description

[0001] The present invention relates to a method for assisting a vehicle user during a lane-changing maneuver. Furthermore, the present invention relates to a driver assistance system for a vehicle.

[0002] Driver assistance systems for performing at least partially automated lane-change maneuvers, or so-called lane-change assistance systems, are known from the prior art. With these driver assistance systems featuring automated or automatic lane-change functionality, the user or driver typically indicates a desired lane change through a specific control action. When such an action is detected, the driver assistance system maneuvers the vehicle along a planned trajectory into the adjacent lane or the target lane with automated lateral guidance and generally also with automated longitudinal guidance. In such driver assistance systems or lane-change assistance systems, the driver's lane-change request is usually signaled by activating a corresponding control element, such as a turn signal lever, to activate the turn signals visible outside the vehicle.

[0003] Common driver assistance systems, or lane change assist systems, generally monitor the vehicle's surroundings using appropriate sensors before initiating a lane change maneuver. Upon user input, the lane can then be changed if a free space is detected in the adjacent lane.

[0004] Furthermore, driver assistance systems are known from the prior art that support the vehicle user on a multi-lane road when approaching an exit. For example, following the input of a navigation destination, the driver assistance system can prepare all necessary lane changes until the exit is reached. To do this, the driver assistance system can first detect a free gap for the vehicle in the adjacent lane and then adjust the vehicle's speed for the subsequent lane change maneuver into the detected gap. The lane change maneuver itself can be carried out by a lane change assistance system, which is triggered automatically or after an input from the user.

[0005] In this context, DE 10 2020 117 161 A1 describes a vehicle system for operating a lane change assistance function of a motor vehicle. The vehicle system is configured to determine that the vehicle should perform a route-related lane change in order to travel along a planned route. Furthermore, the vehicle system is configured to select a gap for the route-related lane change from a set of gaps such that a gap in front of the vehicle has a higher priority in the selection process than a gap in rear of the vehicle.

[0006] Furthermore, DE 10 2020 117 160 B3 describes a vehicle system for operating a lane change assistance function of a motor vehicle. The vehicle system is configured to determine a value of an urgency measure for a route-related lane change, whereby the value of the urgency measure indicates the urgency for the vehicle to perform a lane change in order to travel along a planned route.

[0007] The object of the present invention is to provide a solution for how the operation of a driver assistance system of the type mentioned above can be carried out more efficiently with regard to the search and / or selection of gaps between road users.

[0008] This problem is solved according to the invention by a method and by a driver assistance system with the features according to the independent claims. Advantageous embodiments of the present invention are specified in the dependent claims.

[0009] A method according to the invention serves to assist a vehicle user during a lane-change maneuver. The method comprises receiving a navigation command to execute the lane-change maneuver from a second lane to a first lane of a road. Furthermore, the method comprises searching for gaps for the vehicle between other road users in the first lane and selecting one of the gaps for the lane-change maneuver. In addition, the method comprises defining a far field, a midfield, and a near field in the vehicle's environment, wherein the near field borders the vehicle, the midfield adjoins the near field, and the far field adjoins the midfield. Moreover, the far field lies outside the detection range of the vehicle's environmental sensors. The near field and the midfield lie within the detection range of the environmental sensors.Furthermore, the procedure includes performing the search and / or selection of the gap according to a predetermined sequence, in which first an area of ​​the far field, which lies in front of the vehicle in the direction of travel, is checked, then an area of ​​the middle field, which lies in front of the vehicle in the direction of travel, and subsequently the near field.

[0010] This method is designed to assist the user or driver of the vehicle when maneuvering on a multi-lane road. A multi-lane road can be a highway, a federal road, an expressway, a motorway-like road, or the like. Preferably, the multi-lane road is a motorway. The road may, for example, have two carriageways, each with at least two lanes, referred to here as the first lane and the second lane. Both the vehicle itself and other road users can travel in a predetermined direction on these lanes. The road may also have additional lanes. In this case, the first lane may be adjacent to an exit or a deceleration lane leading to the exit. The first lane could, for example, be the right-hand lane of a motorway.

[0011] The vehicle's driver assistance system receives a navigation command instructing the vehicle to change lanes from the second lane to the first. Specifically, the command specifies that the vehicle should maneuver from the second lane, across the first lane, and onto the exit ramp. In other words, the vehicle should first change lanes from the second to the first and then exit the road. Furthermore, the vehicle may use the exit ramp to merge onto another road, such as at a highway interchange. This navigation command is generally provided by the vehicle's route guidance system.Alternatively or additionally, the navigation command can be justified by a corresponding user input.

[0012] Furthermore, the driver assistance system can be used to prepare for a lane change or lane change maneuver from the second lane to the first lane. To do this, the system's or the vehicle's environmental sensors can first search for available gaps in the first lane. This allows the system to identify gaps between other road users in the first lane that are suitable for the subsequent lane change maneuver.

[0013] Furthermore, the driver assistance system may be designed to adjust the vehicle's speed or longitudinal speed in preparation for a lane change maneuver. Specifically, the vehicle's speed can be reduced or adjusted to match the speed of other road users in the first lane. For example, the vehicle's speed can be adjusted to follow a gap in the target lane.

[0014] For example, if a free gap is found, a corresponding instruction can be given to the user to activate a control or the turn signal lever. Activating the control then triggers or initiates the lane change maneuver from the second lane to the first lane. The lane change maneuver can be carried out automatically by the driver assistance system or a lane change assist system.

[0015] According to the present invention, the far field, the midfield, and the near field are defined in the vehicle's environment. The near field borders the vehicle or its outer shell. The near field thus describes the immediate surroundings of the vehicle. The midfield surrounds or adjoins the near field. Both the near field and the midfield lie within the detection range of the vehicle's environmental sensors. The detection range describes the area that can be detected by the vehicle's environmental sensors, or the area in which objects can be detected by the environmental sensors. The vehicle's or the driver assistance system's environmental sensors can be configured as radar sensors, lidar sensors, cameras, ultrasonic sensors, or the like. The far field surrounds or adjoins the midfield.The far field, the midfield, and / or the near field can be defined relative to a reference point of the vehicle. The far field, the midfield, and / or the near field can therefore move with the vehicle. The far field, the midfield, and / or the near field can concentrically surround the vehicle or the vehicle's reference point. For example, a radius can be assigned to each of the far field, the midfield, and / or the near field.

[0016] The search for gaps between road users and / or the selection of a gap for a lane change maneuver in the first lane is carried out according to a predetermined sequence. This predetermined sequence stipulates that the far field, located in front of the vehicle in the direction of travel, is checked first. Following this, the midfield, also located in front of the vehicle in the direction of travel, is checked. Finally, the nearfield is checked for available gaps. In other words, according to the present invention, three horizons are used for gap searching and, preferably, also for selection and synchronization. These three horizons are formed by the far field, the midfield, and the nearfield. Furthermore, the strengths of the driver assistance system are utilized in each area or horizon.This allows optimization methods, empirical data, foresight, and heuristics to be combined into a cohesive whole. In this way, computing power and processing time can be saved. Overall, this makes the driver assistance system for supporting a user during a lane change more efficient in finding available gaps for a lane change maneuver.

[0017] When checking the far field, or the area of ​​the far field in the direction of travel ahead of the vehicle, it is preferable to predict traffic density and / or the average size of the gaps between road users in the first lane. In the far field, no other road users can be detected by the vehicle's or driver assistance system's environmental sensors. In this case, empirical data can be used, or the traffic density can be predicted. Traffic information, such as Real-Time Traffic Information (RTTI), can be used for this purpose. Furthermore, based on measurements from the environmental sensors in the mid- and near-field, traffic densities on the relevant lanes, or the first lane in the far field, can be determined. Extrapolations or estimates for the traffic density in the far field can then be made based on these measurements.In this case, relevant empirical data can also be taken into account.

[0018] From the lane-specific traffic density or vehicle density, the average size of the gaps between road users in the far field can be derived. Furthermore, the average gap size in the far field at a specific location can be determined as a function of the vehicle's own speed, the average speed of all detected road users, current traffic information, and / or a location-specific experience coefficient. This experience coefficient can, for example, describe how the gaps in the lane tend to decrease as one approaches an exit. Thus, even from the point where the exit is located in the far field, an estimate of the traffic density or the availability of gaps for a lane-change maneuver can be made.

[0019] In another embodiment, when monitoring the midfield or the area of ​​the midfield in front of the vehicle, gaps between road users are detected using sensor data provided by the vehicle's environmental sensors. As previously explained, the vehicle's environmental sensors can detect other road users or vehicles in the near and midfield. In contrast to the far field, the midfield does not use average speeds and gap sizes, but rather considers actual measured values. This means, for example, that gaps actually existing between road users are detected based on the sensor data from the environmental sensors. Therefore, in the midfield, sensor technology and heuristics can be used for gap selection and synchronization.

[0020] In a further embodiment, a plurality of trajectories for possible lane-changing maneuvers into the gaps between road users in the first lane are determined for the near-field analysis. Thus, in the near-field, which is located in the immediate vicinity of the vehicle, a plurality of trajectories into the detected free gaps in the first lane can be calculated. In particular, the near-field can extend from the vehicle or the ego-vehicle to an optimization radius. This optimization radius can be determined based on the vehicle's own speed and an optimization time. This optimization time is, in particular, technically determined by the length of the trajectories to be compared. The optimization time, or...The length of the trajectories to be compared can depend on the computing capacity of the driver assistance system's processing unit, which calculates the trajectories. For example, the processing unit might be configured to calculate eight trajectories simultaneously, each with a duration of 10 seconds at the vehicle's current speed. In this case, the optimization time is 10 seconds, and eight driving maneuvers or trajectories can be compared in the near field. This allows for a precise analysis of the respective trajectories and the gaps for the lane-change maneuver.

[0021] In another embodiment, the plurality of trajectories for possible lane-change maneuvers, and one trajectory describing the vehicle continuing in the second lane, are evaluated based on a cost function. Thus, a plurality of driving maneuvers can be calculated in advance, and then one of the maneuvers can be selected. These driving maneuvers include, firstly, the possible lane-change maneuvers from the second lane to the first lane along the previously calculated trajectories. Another driving maneuver is the option of the vehicle remaining in the second lane, i.e., no lane change to the first lane is performed. According to a cost function, the respective trajectories or driving maneuvers can then be evaluated for selecting the gap.

[0022] When evaluating trajectories or calculating the cost function, corresponding priorities can also be considered. For example, gaps in front of the vehicle in the direction of travel can have a higher priority than gaps beside the vehicle. Similarly, gaps behind the vehicle in the direction of travel can have a lower priority than gaps beside the vehicle. Furthermore, the gaps between road users in the first lane can be prioritized according to their size or length relative to the direction of travel. Large gaps, for instance, can be given a higher priority than small ones. Additionally, the cost of the trajectory where the vehicle remains in the second lane can be adjusted depending on the distance to the exit. In particular, the cost can increase as the distance to the exit decreases.Furthermore, the trajectories in the cost function can be prioritized depending on their shape. For example, the trajectory with the minimum acceleration derivative can be prioritized. In other words, those trajectories that provide a comfortable driving experience during the lane-changing maneuver can be prioritized.

[0023] In another embodiment, following a predetermined sequence for searching and / or selecting gaps after checking the near field, an area of ​​the midfield located behind the vehicle in the direction of travel, and / or an area of ​​the far field located behind the vehicle in the direction of travel, is examined. Thus, after checking the near field, those areas located behind the vehicle in the direction of travel can also be examined. Following the predetermined sequence, the midfield can be examined first, followed by the far field. This allows a lane-change maneuver into a gap located behind the vehicle in the direction of travel to be planned. This may mean that the vehicle's speed needs to be reduced. The vehicle can then essentially drop back to perform the lane-change maneuver.However, it is generally preferred that gaps be selected for the lane-changing maneuver which are located in front of the vehicle in the direction of travel.

[0024] In a further refinement, when searching for and / or selecting gaps in the regions, probabilities for a successful lane change maneuver are determined for each one. If the respective probability exceeds a threshold, the process moves to the next region according to a predetermined sequence. For example, the process can begin with the region of the far field located in front of the vehicle in the direction of travel. In this case, the probability can be determined that the predicted mean gap size is larger than a minimum gap size required for the vehicle to change lanes. This probability can then be scaled using appropriate experience coefficients that, for example, model uncertainties for events far in the future. The integral of these probabilities in the far field can then be determined up to a termination distance for a successful lane change.If the probability of a successful lane change in the far field exceeds the threshold, the search and / or selection of gaps can continue to be performed in the far field. However, if the probability falls below the threshold, the midfield can also be considered for the search and / or selection of gaps. In the midfield, a probability of a successful lane change can be determined analogously to the far field. If this probability falls below a threshold, the near field can be taken into account.

[0025] In another embodiment, the lane-change maneuver is planned such that the vehicle is maneuvered from the first lane onto an exit ramp. As explained at the outset, it is specifically intended that, based on the navigation command, the user receives support during the respective lane-change maneuvers between lanes until the exit ramp is reached. In principle, the method can also be used for roads with three or more lanes.

[0026] Furthermore, it is specifically intended that, until the exit is reached, a speed profile that can be exceeded and / or a non-exceedable speed limit can be specified for the vehicle. To prepare for the respective lane-changing maneuvers between lanes, the vehicle's speed or longitudinal speed can be adjusted and, in particular, reduced. For the vehicle's speed, a speed profile that can be exceeded can be specified as a soft boundary. This speed profile can define a target speed for the vehicle, starting from its current speed and extending to a target speed upon reaching the exit. Based on this speed profile, or...The costs for the trajectories, particularly the trajectory where the vehicle does not change lanes, can be determined based on the target speed. However, the speed profile or the specified target speed can be exceeded if necessary. Alternatively or additionally, non-exceedable speed limits can be specified for the vehicle's speed. Such speed limits could be, for example, the currently permitted maximum speed and / or a set speed specified by the driver.

[0027] A driver assistance system according to the invention for a vehicle is configured to carry out a method according to the invention and its advantageous embodiments. The driver assistance system can, in particular, include a computing unit, which can be formed by at least one electronic control unit. In principle, the computing unit can include at least one processor and / or a memory.

[0028] The driver assistance system, or rather the computing unit, is configured to receive the navigation command to perform the lane change maneuver from the second lane to the first lane of a road. Furthermore, the driver assistance system is configured to search for gaps between other road users in the first lane and select one of these gaps for the lane change maneuver. Additionally, the driver assistance system is configured to define a far field, a midfield, and a near field in the vehicle's environment, with the near field adjacent to the vehicle, the midfield adjacent to the near field, and the far field adjacent to the midfield. The far field lies outside the detection range of the vehicle's environmental sensors, while the near field and the midfield lie within the detection range of the environmental sensors.Furthermore, the driver assistance system is configured to perform the search and / or selection of gaps according to a predetermined sequence. This sequence involves first checking an area of ​​the far field located in front of the vehicle in the direction of travel, then an area of ​​the midfield located in front of the vehicle in the direction of travel, and finally the near field.

[0029] A vehicle according to the invention comprises a driver assistance system according to the invention. The vehicle is designed in particular as a passenger car.

[0030] The preferred embodiments and their advantages presented with reference to the method according to the invention apply accordingly to the driver assistance system according to the invention and to the vehicle according to the invention.

[0031] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawings. These show: Fig. 1 a schematic representation of a vehicle which has a driver assistance system to support a user during a lane change maneuver; Fig. 2 a schematic flowchart which illustrates a search for and synchronization of gaps between road users for the lane change maneuver; Fig. 3 the vehicle according to Fig. 1 , which is located on a multi-lane road, where a driving maneuver is planned starting from a second lane via a first lane to an exit of the road; Fig. 4 schematic representations of a target speed profile and speed limits; and Fig. 5 a schematic flowchart which describes a search and / or elimination of gaps in a far field, a mid-field and a near-field in a vicinity of the vehicle.

[0032] In the figures, identical or functionally equivalent elements are given the same reference symbols.

[0033] Fig. 1 Figure 1 shows a vehicle 1, which in this case is a passenger car, in a top view. The vehicle 1 includes a driver assistance system 2, which can assist a user when performing lane-changing maneuvers. The driver assistance system 2 includes a computing unit 3, which can, for example, be formed by at least one electronic control unit.

[0034] Furthermore, the driver assistance system 2 comprises two environmental sensors 4. In the present embodiment, the driver assistance system 2 comprises four environmental sensors 4, two of which are arranged in a front area 6 and two of which are arranged in a rear area 7 of the vehicle 1. The environmental sensors 4 are arranged in the respective corners of the vehicle 1. The environmental sensors 4 can preferably be configured as radar sensors. The environmental sensors 4 can be used to perform measurements in order to detect objects and, in particular, other road users 13 in the vicinity 5 of the vehicle 1.

[0035] The computing unit 3 is further configured to receive a navigation command from a navigation system 8. In addition, the computing unit 3 is configured to record an operation performed by the user on a control element 9. The control element 9 can be, in particular, a turn signal lever. As soon as the turn signal lever or the control element 9 is operated by the user, the corresponding turn signals 11 of the vehicle 1 can be activated. Furthermore, the driver assistance system 2 includes an output device 10 by means of which a message can be issued to the user. This message can be issued visually, audibly, and / or haptically.

[0036] The computing unit 3 or the driver assistance system 2 is further configured to control a drive motor and / or a braking system of the vehicle 1. Thus, the speed or longitudinal speed of the vehicle 1 can be influenced. It may also be provided that the driver assistance system 2 or the computing unit 3 can output control signals to intervene in a steering system of the vehicle 1.

[0037] In the vicinity 5 of vehicle 1, gaps 12 between road users 13 are to be searched for. This gap search is part of a gap synchronization, which is related to Fig. 2 will be explained. Fig. 2 Figure 1 shows a schematic flowchart describing gap detection and / or gap synchronization. In step S1, the process is started and the conditions for the carrier of a function master 14 are checked. This is the case, for example, when the navigation command is received, which describes that vehicle 1 should be maneuvered via lanes 17, 18, and 19 of road 22 to an exit 21 of road 22. In step S2, a trigger for adjacent lane synchronization is then sent. In block 15, which is assigned to gap detection, the best gap 12 is selected from a multitude of detected gaps 12 between road users 13 and sent out in step S3 as the best target for the lane change maneuver of vehicle 1. In block 16, which is assigned to longitudinal synchronization, the cost function for the lane change maneuver is then evaluated.If, during the gap search, a better gap 12 is detected, it is sent as the target in step S4. Once synchronization is complete, a corresponding signal is sent in step S5.

[0038] Fig. 3 Figure 1 shows vehicle 1 in a traffic situation. Vehicle 1 is located on road 22, which has several lanes 17, 18, and 19. In this example, road 22 comprises a first lane 17, a second lane 18, and a third lane 19. In the example shown, vehicle 1 is in the second lane 18, or the middle lane. Based on the navigation command, vehicle 1 is to be maneuvered from the second lane 18 to the first lane 17 and then onto a deceleration lane 20 to reach an exit 21 of road 22. Vehicle 1 is thus to perform a lane change maneuver from the second lane 18 to the first lane 17 and another lane change maneuver from the first lane 17 to the deceleration lane 20. For each lane change maneuver, corresponding gaps 12 are searched for and selected.

[0039] For the search for gaps 12 and the gap synchronization, a near field 23, a mid field 24, and a far field 25 are defined in the environment 5 of the vehicle 1. The far field 25 lies outside the detection range of the environmental sensors 4 of the driver assistance system 2. This means that the road users 13 located in the far field 25 cannot be detected by the environmental sensors 4. The road users 13 in the far field 25 are predicted road users 26. These predicted road users 26 can be estimated based on measurements taken by the environmental sensors 4 in the near field 23 and the mid field 24. Additionally, data from traffic services and / or empirical values ​​can be used.

[0040] The central field 24 and the near field 23 lie within the detection range of the environmental sensors 4. In this example, the central field 24 is defined by a radius rh. Within the central field, the gaps 12 between the road users 13 in the first lane 17 can be detected based on measurements from the environmental sensors 4. The near field 23 is directly adjacent to the vehicle 1 or its outer shell. In this example, the near field 23 is defined by a radius ro. Within the near field 23, different trajectories T1 and T2 can be calculated for possible lane-change maneuvers from the second lane 18 to the first lane 17. Furthermore, a trajectory T3 is determined, which describes the situation where the vehicle 1 remains in the second lane 18, i.e., no lane change is performed by the vehicle 1.Furthermore, a lane-specific abort distance 27 is defined for the respective lanes 17, 18, and 19. If vehicle 1 reaches this area, the maneuvering of vehicle 1 towards exit 21 can be aborted.

[0041] Fig. 4 shows a possible speed profile for vehicle 1 until reaching exit 21. The diagram is based on... Fig. 4 The abscissa represents the distance D to reach exit 21 (D = 0). The ordinate represents the velocity v. Here, vZ describes a target speed that vehicle 1 should reach upon reaching exit 21. The curve Vtarget describes a target speed that can be predefined. This can describe the speed profile of vehicle 1 from its current position until reaching exit 21. However, this speed profile can be exceeded by vehicle 1. This is illustrated by the actual speed vactual of vehicle 1. Furthermore, hard limits or non-exceedable speed limits are defined by a set speed vS, which is specified by the user for speed control, and a maximum permissible speed vL.

[0042] Fig. 5Figure 1 schematically illustrates a procedure for gap detection in the far field 25, the midfield 24, and the near field 23. The procedure is initiated in step S6. In area 29 of the far field 25, located ahead of vehicle 1 in the direction of travel, further road users 26 are predicted for the relevant lanes 17 and 18. For this purpose, the road users 13 detected in the midfield 24 based on sensor data from the environmental sensors 4 can be extrapolated. Traffic information and empirical data can also be used. The estimation in the far field 25, or in area 29 of the far field 25, can be continuously repeated in step S7. This might be necessary, for example, if vehicle 1 is still several kilometers from exit 21 and / or if no high traffic volume is expected in the vicinity of the exit.

[0043] Furthermore, a probability of a successful lane change is calculated. If this probability falls below a certain threshold, in step S8, an additional area 28 of the central field 24, located in front of vehicle 1 in the direction of travel, is used to search for and / or select the gaps 13. In step S9, the road users 13 and the gaps 12 between them are continuously determined based on the sensor data from the environmental sensors 5. Here, too, a probability of a successful lane change is calculated. If this probability falls below a certain threshold, the search is extended to the near field 23 in step S10.

[0044] During the near-field 23 check, the respective trajectories T1 and T2 for the possible lane-change maneuvers into the free gaps 13 are continuously determined in step S11. Additionally, the trajectory T3 is determined for the case where vehicle 1 remains in the second lane 18. For each trajectory T1 to T3, the costs of the trajectories are then evaluated against each other based on a cost function. If the respective costs of trajectories T1 and T2 for the possible lane-change maneuvers are below a threshold, synchronization to the optimal gap 13 in the near-field 23 can occur. In step S12, a signal can be sent indicating that the synchronization, or the selection of gap 13, is complete as soon as the cost of a trajectory T1 or T2 for a possible lane-change maneuver exceeds the cost of trajectory T3, in which vehicle 1 remains in the second lane 18.

[0045] If the respective costs of the trajectories T1 and T2 for the possible lane-change maneuvers exceed the threshold, in step S12, a region 30 of the midfield 24, located behind vehicle 1 in the direction of travel, is examined. For this purpose, the speed of vehicle 1 can also be reduced. In step S13, a probability for a successful lane change can then be continuously determined. If this probability exceeds a threshold, the system can, for example, wait until a suitable gap 12 for a lane-change maneuver is available in the nearfield 23. If, however, the probability falls below the threshold, the speed of vehicle 1 can be further reduced. Alternatively, a region 31 of the farfield 24, located behind vehicle 1 in the direction of travel, can be examined.

Claims

1. Method for assisting a user of a vehicle (1) during a lane change manoeuvre, comprising the steps of: - receiving a navigation command to carry out the lane change manoeuvre from a second lane (18) to a first lane (17) of a road (22), - searching for gaps (12) for the vehicle (1) between further road users (13) in the first lane (17), and - selecting one of the gaps (12) for the lane change manoeuvre, - defining a far field (25), a mid field (24) and a near field (23) in the surroundings (5) of the vehicle (1), wherein the near field (23) adjoins the vehicle (1), the mid field (24) adjoins the near field (23) and the far field (25) adjoins the mid field (24), - wherein the near field (23) and the mid field (24) are within a capture range of environmental sensors (4) of the vehicle (1), and - searching for and / or selecting the gap (12) according to a predetermined order, characterized in that the far field (25) is outside the capture range of the environmental sensors (4), and in that, in accordance with the predetermined order, first an area (29) of the far field (25) that is in front of the vehicle (1) in the direction of travel, then an area (28) of the mid field (24) that is in front of the vehicle (1) in the direction of travel and then the near field (23) are checked.

2. Method according to Claim 1, characterized in that a traffic density and / or an average size of the gaps (12) between the road users (13) is / are predicted when checking the area (29) of the far field (25) for the first lane (17).

3. Method according to Claim 1 or 2, characterized in that the gaps (12) between the road users (13) are detected on the basis of sensor data, which are provided by the environmental sensors (4), when checking the area (28) of the mid field (24).

4. Method according to one of the preceding claims, characterized in that a plurality of trajectories (T1, T2) for possible lane change manoeuvres into the gaps (12) between the road users (13) in the first lane (17) are determined for checking the near field (23).

5. Method according to Claim 4, characterized in that the plurality of trajectories (T1, T2) for the possible lane change manoeuvres and a trajectory (T3) that describes an onward journey of the vehicle (1) in the second lane (18) are assessed on the basis of a cost function.

6. Method according to one of the preceding claims, characterized in that in accordance with the predetermined order for searching for and / or selecting the gaps, after the near field (23) has been checked, an area (30) of the mid field (24) that is behind the vehicle (1) in the direction of travel and / or an area (31) of the far field (25) that is behind the vehicle (1) in the direction of travel is / are examined.

7. Method according to one of the preceding claims, characterized in that probabilities of a successful lane change manoeuvre are respectively determined when searching for and / or selecting the gaps in the areas (28, 29, 30, 31) and, if the respective probability falls below a limit value, there is a changeover to the next area (28, 29, 30, 31) in accordance with the predetermined order.

8. Method according to one of the preceding claims, characterized in that the lane change manoeuvre is planned such that the vehicle (1) is manoeuvred from the first lane (17) to an exit ramp (21) of the road (22).

9. Method according to Claim 8, characterized in that a speed profile that can be exceeded and / or a speed limit that cannot be exceeded is / are predefined for a speed (v) of the vehicle (1) until the exit ramp is reached.

10. Driver assistance system (2) for a vehicle (1), wherein the driver assistance system (2) is set up to carry out a method according to one of the preceding claims.