METHOD FOR OPERATING A DRIVING ASSISTANT FOR AUTOMATED LATERAL GUIDANCE

Abstract

A method for operating a driving assistant for the automated lateral guidance of a motor vehicle. The method includes: carrying out an automated lane guidance of the motor vehicle in a first lane; ascertaining, by the motor vehicle, an obstacle situation of a further motor vehicle in the first lane; carrying out a lane release with the aid of an automated lane change of the motor vehicle into a second lane; ascertaining a lane return situation with regard to the motor vehicle; deciding on the lane return into the first lane, taking the lane return situation into account; carrying out a decided lane return into the first lane with the aid of an automated lane change; continuing the automated lane guidance of the motor vehicle in the first lane. A device for carrying out the method is also described.

Claims

1. A method for operating a driving assistant for lateral guidance of a motor vehicle, the method comprising the following steps: carrying out an automated lane guidance of the motor vehicle in a first lane; ascertaining, by the motor vehicle, an obstacle situation of a further motor vehicle in the first lane; carrying out a lane release using an automated lane change of the motor vehicle into a second lane; ascertaining a lane return situation with regard to the motor vehicle; deciding on the lane return into the first lane, taking the lane return situation into account; carrying out a decided lane return into the first lane using an automated lane change; and continuing the automated lane guidance of the motor vehicle in the first lane.

2. The method as recited in claim 1, wherein the lane return situation is ascertained when at least one of the following conditions is met: a non-obstacle situation of a further motor vehicle in the first lane is ascertained by the motor vehicle for a potential lane return of the motor vehicle into the first lane; a traffic gap in the first lane that is sufficient for a potential lane return of the motor vehicle is ascertained; a restriction of a movement option of the motor vehicle in the second lane is ascertained.

3. The method as recited in claim 2, wherein the non-obstacle situation of a further motor vehicle in the first lane is ascertained by the motor vehicle for a potential lane return of the motor vehicle into the first lane when at least one of the following conditions is met: in a rear field of the motor vehicle in the second lane, no further motor vehicle is ascertained in the first lane; a distance between the motor vehicle in the second lane and a following motor vehicle in the first lane is greater than a defined threshold value; a speed difference between the motor vehicle in the second lane and a following motor vehicle in the first lane is less than a defined threshold value; an acceleration difference between the motor vehicle in the second lane and a following motor vehicle in the first lane is less than a defined threshold value.

4. The method as recited in claim 1, further comprising: ascertaining a lane return option situation with regard to the motor vehicle in the first lane; and deciding to release the first lane by the motor vehicle, taking the lane return option situation into account.

5. The method as recited in claim 4, wherein the lane return option situation with regard to the motor vehicle in the first lane is ascertained when at least one of the following conditions is met: a lane return of the motor vehicle from the second lane back into the first lane is possible within a defined distance; a change of the motor vehicle into the second lane does not result in a restriction of a movement option of the motor vehicle within a defined distance.

6. The method as recited in claim 4, wherein the lane return option situation is taken into account as a prerequisite for the decision for the lane release, a negative decision for the lane release being made when a lane return option situation is not ascertained.

7. The method as recited in claim 1, wherein a data signal is generated using which an operator of the motor vehicle may be informed of the decided lane return into the first lane.

8. The method as recited in claim 1, wherein a data signal is generated using which surroundings of the motor vehicle may be informed of the decided lane return into the first lane.

9. The method as recited in claim 1, wherein an execution of the decided lane return into the first lane using an automated lane change takes place when no rejection of the decided lane return by an operator of the motor vehicle is ascertained.

10. The method as recite in claim 9, wherein the execution of the decided lane return into the first lane using the automated lane change when, within a defined time period after a driver is informed of the decided lane return into the first lane, no rejection of the decided lane return by the operator of the motor vehicle is ascertained.

11. A device configured to operate a driving assistant for lateral guidance of a motor vehicle, the device configured to: carry out an automated lane guidance of the motor vehicle in a first lane; ascertain, by the motor vehicle, an obstacle situation of a further motor vehicle in the first lane; carry out a lane release using an automated lane change of the motor vehicle into a second lane; ascertain a lane return situation with regard to the motor vehicle; decide on the lane return into the first lane, taking the lane return situation into account; carry out a decided lane return into the first lane using an automated lane change; and continue the automated lane guidance of the motor vehicle in the first lane.

12. A non-transitory machine-readable medium on which is stored a computer program for operating a driving assistant for lateral guidance of a motor vehicle, the computer program, when executed by a processor, causing the processor to perform the following steps: carrying out an automated lane guidance of the motor vehicle in a first lane; ascertaining, by the motor vehicle, an obstacle situation of a further motor vehicle in the first lane; carrying out a lane release using an automated lane change of the motor vehicle into a second lane; ascertaining a lane return situation with regard to the motor vehicle; deciding on the lane return into the first lane, taking the lane return situation into account; carrying out a decided lane return into the first lane using an automated lane change; and continuing the automated lane guidance of the motor vehicle in the first lane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] It is to be noted that the features stated individually in the description may be combined with one another in any technically meaningful manner, and represent further embodiments of the present invention. Further features and advantages of the present invention result from the description of exemplary embodiments with reference to the figures.

[0042] FIGS. 1A through 1D show a schematic illustration of a sequence of one embodiment of the method in a specific traffic situation.

[0043] FIG. 2 shows an illustration of the method steps of one specific embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0044] FIG. 1A-1D show a schematic illustration of a sequence of one example embodiment of the method of the present invention in a specific traffic situation, depicted in multiple sequences.

[0045] FIG. 1A shows the starting situation. A motor vehicle 1 (also referred to as ego-vehicle a) on a roadway 10 is illustrated. Roadway 10 includes three lanes: right lane 11a (also referred to as the second lane), middle lane 11b (also referred to as the first lane), and left lane 11c.

[0046] Motor vehicle 1 includes a driving assistance system 2, which is designed as a driving assistant for automated lane guidance. A sensor system 3 for surroundings detection is also illustrated. This sensor system includes a sensor 3a for front surroundings detection (a front camera, for example), a sensor 3b for rear surroundings detection (a rear camera, for example), and multiple sensors 3c for lateral surroundings detection (side cameras, for example). Of course, radar, LIDAR, or other suitable types of sensors may alternatively or additionally be used. Motor vehicle 1 also includes a processing unit 4 (also referred to as a control unit) for evaluating the sensor data and/or for carrying out the method and/or for activating the actuators. Motor vehicle 1 also includes an actuator system 5, which is made up, for example, of an actuator 5a for transverse control and an actuator 5b for longitudinal control. Furthermore, a device 6 for informing the driver is provided. This device may convey information to the driver, for example in a visual and/or acoustic and/or haptic manner.

[0047] In the illustration, motor vehicle 1 is moving on travel trajectory s.sub.a at speed V.sub.a. In the illustrated traffic situation, further road users are situated on roadway 10 in addition to motor vehicle 1: a vehicle b with a greater driving speed V.sub.b is situated behind ego-vehicle a in the same middle lane 11b. A vehicle c with a speed V.sub.c that is slightly less than speed V.sub.a of ego-vehicle a is situated ahead of ego-vehicle a, in right lane 11a in the travel direction. A further vehicle d is situated in left lane 11c, approximately at the level of vehicle b. Vehicle d is traveling at speed V.sub.d, which is similar to V.sub.b and greater than V.sub.a.

[0048] FIG. 1B shows an intermediate situation. Ego-vehicle a has ascertained the obstacle situation which it has created, and a decision for the automated lane release is made. The traffic situation behind ego-vehicle a (in particular, the distance and acceleration difference between ego-vehicle a and vehicle b) has been taken into account, and the traffic situation ahead of ego-vehicle a (in particular the distance and acceleration difference between ego-vehicle a and vehicle c) has been analyzed. It has been ascertained that a lane change is possible, and a lane release according to preset criteria appears to be appropriate. In addition, it has been ascertained that a subsequent lane return from the right to the middle lane appears to be possible without the movement option of ego-vehicle a being restricted by preceding vehicle b, for example having to carry out a brake application or reduce the present driving speed. An option for a lane return is thus also recognized. An automated lane change to the right lane is thus initiated. Travel trajectory s.sub.a already shows the planned lane change of ego-vehicle a from lane 11b to lane 11a.

[0049] FIG. 1C shows the next intermediate situation. Ego-vehicle a has carried out the automated lane change into second lane 11a, and now carries out an automatic lane guidance there in second lane 11a. At the same time, ego-vehicle a monitors the traffic situation in order to recognize a lane return situation. Since a further vehicle e is traveling directly behind vehicle b in the same lane, ego-vehicle a must allow both vehicles b and e to pass. Since no further vehicle is ascertained behind vehicle e in first lane 11b, a positive lane return situation is recognized as soon as vehicle e has reached the level of ego-vehicle a. Ascertained travel trajectory s.sub.a shows the subsequently planned lane return of ego-vehicle a from second lane 11a back to first lane 11b.

[0050] FIG. 1D shows the end situation. Ego-vehicle a has carried out the automated lane return into first lane 11b, and now continues to carry out the automated lane guidance in first lane 11b. Travel trajectory s.sub.a correspondingly points straight ahead.

[0051] FIG. 2 shows an illustration of the method steps of one specific embodiment of the present invention. The method starts in a first step S1. The automated lane guidance of ego-vehicle a in the first lane is carried out in a step S2. For example, the automated lane guidance is activated by the driver of the motor vehicle.

[0052] In a condition B1 it is then checked whether a lane release option situation (generally also referred as a driving option situation) is present, or whether a lane release option situation corresponds to a defined characteristic.

[0053] For example, for this purpose surroundings data are ascertained, and are analyzed for whether the present driving situation corresponds to a certain condition, so that an option for a lane release exists. In particular, it is checked whether in the present driving situation there is the possible option at all for carrying out a specific driving maneuver, in particular a lane change. For example, it is checked whether another lane to the right of the present lane is even present at all.

[0054] If the lane release option situation corresponds to a defined characteristic (Y branch), i.e., a lane release is possible in principle, in a further condition B2 it is checked whether an obstacle situation is present, or whether an obstacle situation corresponds to a defined characteristic.

[0055] For example, the traffic situation to the rear is monitored. In particular, the traffic situation directly behind the ego-vehicle is taken into account. It is checked, for example, whether a vehicle is traveling behind the ego-vehicle in the same lane. In a first embodiment, a lane release may take place as needed when a further vehicle is recognized within a defined distance behind the ego-vehicle. Alternatively or additionally, the speed or the speed difference between the two vehicles may be taken into account. In addition, the acceleration and/or acceleration differences between this vehicle and the ego-vehicle may be ascertained. It may thus be ascertained whether the ego-vehicle would represent an obstacle for an extrapolated continued travel of the vehicle that is closing in.

[0056] In addition, it is possible for the driver to have a setting option, for example to change the sensitivity of the lane release. It is thus possible for the driver, with the aid of the setting, to be able to influence the trigger thresholds, in particular the distance between the ego-vehicle and the following vehicle and/or their relative speeds in order to configure carrying out the function, in particular to configure a temporary release of the present lane with the aid of a lane change, for its requirements.

[0057] For the method, the surroundings of the vehicle are monitored with the aid of a sensor system. In particular a front camera and/or a rear sensor (for example, rear radar, rear camera, or rear LIDAR), and/or a surroundings sensor (for example, a 360° video system, corner radar) may be used. The ascertainment of the data with the aid of the sensor system may take place as a separate step within the scope of the method. It is subsequently evaluated, with the aid of a control unit, whether a lane release is necessary and possible. For example, the control unit may be a central computer control unit or a control unit of the sensor system or of an actuator, or the functionalities may be additionally implemented on such a control unit.

[0058] If the obstacle situation corresponds to a defined characteristic (Y branch), i.e., a defined obstacle is actually present, it is checked in a further condition B3 whether a lane release situation is present, or whether a lane release situation corresponds to a defined characteristic.

[0059] In one embodiment, the system may monitor the general traffic situation and carry out a situation-adaptive lane release. This means that only in defined traffic situations is a lane release decision ascertained and automatedly implemented if necessary. In particular, an ascertainment of a lane release decision takes place when another road user would be hindered by maintaining the present lane, and a lane release by the ego-vehicle may be carried out without significant losses in driving comfort and driving safety, and without a significant effect on the efficiency.

[0060] It is also possible that a driver setting with regard to the strictness of the determination criteria may be made. For a corresponding changed setting, release decisions would be output more frequently or less frequently.

[0061] If the lane release situation corresponds to a defined characteristic (Y branch), i.e., in the present situation a lane release should be carried out, taking the ascertained criteria into account, it is checked in a condition B4 whether a lane return option situation is present, or whether a lane return option situation corresponds to a defined characteristic.

[0062] For example, for this purpose surroundings data are ascertained, and are analyzed for whether the present driving situation corresponds to a certain condition, so that there is an option for a lane return. In particular, it is checked whether there is a certain likelihood in the present driving situation for the option to carry out a real-time lane return.

[0063] In particular, an ascertainment of a positive lane change decision to travel from the present lane into a target lane of the lane change takes place when a lane return of the ego-vehicle from the target lane of the lane change (for example, the right lane of a three-lane roadway) back into the present lane (for example, the middle lane of a three-lane roadway) appears to be possible, in particular appears to be possible within a defined distance.

[0064] In this context, it is not an actual lane return that is to be immediately carried out that is analyzed, but, rather, the option for or the likelihood of a later lane return, in particular a lane return after resolving the obstacle situation in the first lane.

[0065] If the lane return option situation corresponds to a defined characteristic (Y branch), i.e., in the present situation a lane return appears to be possible, taking the ascertained criteria into account, a decision for the automated lane release is made and carried out in a next step S3.

[0066] This is followed by carrying out the automated lane guidance of the ego-vehicle in the second lane in a step S4.

[0067] While the automated lane guidance is being carried out in step S4, in a further condition B5 it is checked whether a lane return situation is present, or whether a lane return situation corresponds to a defined characteristic.

[0068] In one embodiment, the system may monitor the general traffic situation and carry out a situation-adaptive lane return. This means that only in defined traffic situations is a lane return recommendation ascertained and automatedly carried out.

[0069] In particular, an ascertainment of a lane return decision takes place when it is ascertained that, if a lane return from the present lane (for example, the right lane of a three-lane roadway) back into the target lane of the lane return (for example, the middle lane of a three-lane roadway) would be made, the ego-vehicle would not hinder any motor vehicles in this target lane of the lane return.

[0070] In this context, an actual lane return to be carried out at that time is analyzed.

[0071] In a first embodiment, a lane return may take place when no further motor vehicle is recognized behind the ego-vehicle in the target lane of the lane return. Similarly, a lane return may take place when, although a further motor vehicle is recognized in the target lane of the lane return, the distance between the two vehicles is greater than a defined threshold value.

[0072] As an alternative or in addition to the distance, the speed or the speed difference between the two vehicles may be taken into account. In addition, the acceleration and/or acceleration differences between this vehicle and the ego-vehicle may be ascertained. It may thus be ascertained, for a potential lane return, whether the ego-vehicle would represent an obstacle during extrapolated further travel of the vehicle that is closing in.

[0073] In addition, it is possible for the driver to have a setting option, for example to change the sensitivity of the lane return. It is thus possible for the driver, with the aid of the setting, to be able to influence the trigger thresholds, in particular the distance between the ego-vehicle and the following vehicle and/or their relative speeds in order to configure the execution of the driving function for its requirements.

[0074] If the lane return situation corresponds to a defined characteristic (Y branch), i.e., in the present situation a lane return appears to be possible, taking the ascertained criteria into account, the information concerning the decided, i.e., imminent, automated lane return is communicated to the driver in a next step S5.

[0075] This means that with the aid of a communication device, the imminent interruption of the lane guidance function in the present lane and/or the planned driving maneuver are/is communicated to the driver. For example, an acoustic and/or haptic and/or visual output or physical contact (such as vibration) to the driver may take place. In addition, an automated setting of the blinker in the planned lane change direction may be used.

[0076] The driver may also be provided with the option of preventing the planned driving maneuver, and instead, continuing to carry out the present automated lane guidance function. According to the information to the driver, it is checked in a condition B6 whether a rejection of the planned automated lane change by the driver is recognized. For example, an acoustic objection by the driver may be ascertained. A deactivation of the set blinker may also be regarded as a rejection. Condition B6 may be associated, for example, with a temporal threshold, so that, for example, it is awaited for a defined time whether a negative response of the driver is ascertained. For example, 2 to 5 seconds may be defined as a defined time. If no response, or at least no negative response, of the driver is ascertained, it may be assumed that no rejection of the driver concerning the planned automated lane change is present.

[0077] If no rejection of the planned automated lane return is ascertained, in a step S6 the planned lane return is automatedly carried out and the motor vehicle changes from the second lane into the first lane. If no termination of the method is recognized, it is then checked in a subsequent condition B7 whether a termination of the method is present. If this is the case (Y branch), the method is thus ended with step S7. If this is not the case (N branch), a further execution of the automated lane guidance of the ego-vehicle in the first lane takes place with step S2.