DE102022205381A1 - Driver assistance system, method for determining an optimal driving trajectory, and motor vehicle - Google Patents

Abstract

The invention relates to a driver assistance system for a motor vehicle, with a travel trajectory planning device which is designed to calculate an optimal travel trajectory for the motor vehicle using a road model, object information regarding objects in the surroundings of the motor vehicle and a driving dynamics model of the motor vehicle. The travel trajectory planning device is further designed to take into account secondary conditions specified by actuator limitation information in order to calculate the optimal travel trajectory, the actuator limitation information comprising a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle.

Description

The invention relates to a driver assistance system and a method for determining an optimal driving trajectory. The invention further relates to a motor vehicle.

Driver assistance systems are used to autonomously or semi-autonomously control vehicles and can calculate the driving trajectories to be traveled.

With a model-predictive approach, an optimal trajectory can be calculated both for comfortable use cases (e.g. steady driving in a lane, system-initiated lane change) and for emergencies. For this purpose, a vehicle model, information about the vehicle's actuators and road friction can be taken into account. From this it can be calculated in advance whether or how well the trajectory can probably be traveled. In addition, the trajectory can be optimized according to several criteria, e.g. B. according to the set speed deviation, the lateral acceleration and the lateral jerk, the longitudinal acceleration and the longitudinal jerk. Different trajectories can be calculated for different driving maneuvers. Possible driving maneuvers include changing lanes, staying in lane or staying in lane while simultaneously braking to a certain speed.

The trajectories can be assigned a cost value so that the trajectories can be compared based on this cost value to determine the best maneuver.

The actuators of the motor vehicle may be subject to certain limitations, which may have physical origins, i.e. H. are determined by what is technically possible, or can also be specified for safety reasons. For example, the steering angle, steering angular speed or acceleration or deceleration, which are controlled during autonomous or semi-autonomous driving, can be limited in order to continue to give the driver the opportunity to intervene additionally.

If such information is not taken into account when calculating the trajectory, it may happen that the calculated trajectory is actually not implementable at all.

It is therefore an object of the invention to find an optimal driving trajectory that can actually be driven.

This task is solved by a driver assistance system for a motor vehicle, a motor vehicle and a method for determining an optimal driving trajectory for a motor vehicle with the features of the independent patent claims.

Further preferred embodiments are the subject of the subclaims.

According to a first aspect, the invention relates to a driver assistance system for a motor vehicle, with a travel trajectory planning device which is designed to calculate an optimal travel trajectory for the motor vehicle using a road model, object information regarding objects in the surroundings of the motor vehicle and a driving dynamics model of the motor vehicle. The travel trajectory planning device is further designed to take into account secondary conditions specified by actuator limitation information in order to calculate the optimal travel trajectory, the actuator limitation information comprising a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle.

According to a second aspect, the invention relates to a motor vehicle with a driver assistance system according to the invention.

According to a third aspect, the invention relates to a method for determining an optimal travel trajectory for a motor vehicle. The method includes receiving actuator limitation information, wherein the actuator limitation information includes a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle. The method further includes calculating an optimal travel trajectory for the motor vehicle using a road model, object information relating to objects in the surroundings of the motor vehicle and a driving dynamics model of the motor vehicle, with additional conditions specified by actuator limitation information being taken into account to calculate the optimal travel trajectory.

When calculating the optimal trajectory, the travel trajectory planning device takes into account the future time course of the limitation of at least one actuator parameter of at least one actuator of the motor vehicle. The future time course can be specified as a continuous or discrete-time function and specifies limitations to the actuator parameters. The at least one actuator can therefore only be controlled based on actuator parameters that comply with the specified limitation. For example, a time course of a maximum permissible actuator parameter can be specified. Provision can be made to determine a time course of a maximum permissible range of the actuator parameter. The time course can cover a predetermined period of time, for example at least 5 seconds, preferably at least 8 seconds. By taking the time course into account, it can be guaranteed that the calculated optimal trajectory can actually be driven within this period. Drivability will therefore not only be guaranteed at this point in time, but for an entire maneuver, even if an actuator reaches its limits. The limitations can be safety limits or physical limits.

Unintentional lane departure can be prevented and the driver does not need to intervene. In particular, the vehicle can drive on the desired trajectory even with low friction, for example due to snow or ice.

Autonomous driving functions can be guaranteed even if the functionality of the actuator devices is limited. Even in the event of a failure, an autonomous vehicle must continue to function and drive safely until the driver takes over command. In the event of a disturbed steering torque, e.g. if the second coil of the steering motor fails, the travel trajectories can be planned so that they can also be driven with the disturbed steering torque.

According to a further embodiment, the driver assistance system comprises a maneuver planning device which is designed to generate a list of driving maneuvers. The travel trajectory planning device is designed to calculate an optimal travel trajectory for each driving maneuver in the list of driving maneuvers. The maneuver planning device is further designed to select a travel trajectory to be traveled from the travel trajectories calculated by the travel trajectory planning device. By separating the generation of maneuvers and the calculation of travel trajectories, the entire planning can be simplified.

According to a further embodiment of the driver assistance system, the maneuver planning device is further designed to select the travel trajectory to be traveled using a cost function which depends on safety criteria, comfort criteria and/or a driver request. For example, if the driver wants to change lanes, a lane change travel trajectory is preferably selected if it can be driven while complying with the additional conditions.

According to a further embodiment of the driver assistance system, the maneuver planning device is further designed to reject a maneuver from the list of driving maneuvers if the travel trajectory planning device cannot determine a trajectory for the maneuver. If a maneuver requested by a driver or global planner is not feasible, this can be reported back. Examples include changing lanes or exiting a driveway with a sharp curve at the current speed.

According to a further embodiment of the driver assistance system, the maneuver planning device is further designed to request an optimal travel trajectory for at least one emergency maneuver from the travel trajectory planning device. Optimal emergency responses can be determined because the possible future options including vehicle dynamics can be calculated and thus the optimal option can be chosen.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future time profile of a maximum possible steering angular speed.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future time course of a maximum possible steering angle.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future time course of a maximum possible delay.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future time course of a maximum possible acceleration.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future time profile of a maximum speed, wherein the optimal travel trajectory can be traveled at a speed smaller than the maximum speed.

According to a further embodiment of the driver assistance system, the travel trajectory planning device is designed to take a coefficient of friction into account to calculate the optimal travel trajectory.

According to a further embodiment of the driver assistance system, the actuator limitation information includes a future temporal Course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle, which is predetermined for safety reasons. The limits selected for safety reasons can be lower than the physically possible limits. This can ensure that the driver can continue to intervene.

According to a further embodiment, the driver assistance system comprises a motion control device which is designed to calculate the actuator limitation information using actuator models and/or interface signals from the actuators. For this purpose, the movement control device can, for example, detect the current and future acceleration potential of the drive train.

According to a further embodiment, the driver assistance system comprises a motion control device which is designed to calculate the actuator limitation information using the road model. For this purpose, the movement control device can, for example, take into account a road model and a current driving speed.

According to a further embodiment of the driver assistance system, the movement control device is further designed to calculate the actuator limitation information based on the optimal travel trajectory determined by the travel trajectory planning device. This creates feedback, which can improve the calculation of the optimal travel trajectory. For this purpose, an interface to the movement control device can be provided, via which, in addition to the travel trajectory to be carried out, travel trajectories can also be transmitted for testing. The movement control device continues to use the travel trajectory to be carried out to control the actuators, but in a further step checks all travel trajectories transmitted for testing. For each tested travel trajectory, the actuator limitations are now transmitted to the maneuver planning device as well as information as to whether the respective travel trajectory can be carried out. A speed profile is transmitted specifically for the correct processing of the steering limit, with which a requested trajectory would be feasible. For example, if it is not possible to change lanes at the planned speed, but this is possible with a lower speed, then the travel trajectory planner receives this future limit speed as a signal over time and can plan a drivable lane change trajectory in the next planning cycle.

Depending on the existence of favorable additional travel trajectories, the maneuver planning device can decide whether the travel trajectory for a specific maneuver that cannot be carried out is rejected and thus, for example, simply “keeping in lane” instead of “changing lane” is carried out.

Alternatively, the maneuver planning device can decide that the travel trajectory for a specific maneuver that cannot be carried out is recalculated based on the maximum feasible speed profile and / or further restrictions and transmitted again to the movement control device. If the newly calculated and checked travel trajectory can now be traveled, this travel trajectory is included in the maneuver planning device in the decision about the next travel trajectory to be carried out.

According to a further embodiment of the driver assistance system, drivability over a target navigation route can be evaluated based on a map. The travel trajectory planning device calculates a maximum speed along the route for a given steering limit (e.g. maximum steering angular speed as a function of time, maximum steering angle as a function of time). The replanning does not have to take place in a time frame of hundreds of milliseconds, but a time frame of around 8 seconds is sufficient. The maximum possible speed per travel trajectory is sent back to the maneuver planning device. If the possible speed deviates significantly from the speed intended by a global planner, which is calculated based on traffic rules, vehicle dynamics and back-end data about traffic flow, early driver takeover information is triggered. This process can also occur on a backend server.

According to a further embodiment of the driver assistance system, the travel trajectory planning device can calculate several travel trajectories if, for example, the parameters for the trajectory planning are not precisely known. The travel trajectory planning device can thus calculate travel trajectories for different friction values and, for example, the most likely or most conservative travel trajectory can be selected.

According to a further embodiment of the driver assistance system, the travel trajectory planning device calculates the future travel trajectories for the current setting speed based on the road model for, for example, the next two kilometers and displays the maximum drivable speeds to the higher-level maneuver planning device. The maneuver planning The device will request driver takeover via the human-machine interface if the calculated speed of the mobile trajectories deviates too far from the set speed or the speed that can be driven according to the speed limit.

The present invention is explained in more detail below using the exemplary embodiments shown in the schematic figures of the drawings.

• 1 ein Blockdiagramm eines Fahrerassistenzsystems für ein Kraftfahrzeug gemäß einer Ausführungsform der Erfindung;
• 2 ein Blockdiagramm eines Kraftfahrzeugs gemäß einer Ausführungsform der Erfindung;
• 3 einen beispielhaften zukünftigen zeitlichen Verlauf einer maximal möglichen Verzögerung;
• 4 einen beispielhaften zukünftigen zeitlichen Verlauf einer maximal möglichen Beschleunigung;
• 5 ein erstes beispielhaftes Szenario zur Erläuterung der Erfindung;
• 6 ein zweites beispielhaftes Szenario zu einem ersten Zeitpunkt zur Erläuterung der Erfindung;
• 7 das zweite beispielhafte Szenario zu einem zweiten Zeitpunkt;
• 8 eine Schnittstelle zwischen einer Manöverplanungseinrichtung und einer Fahrtrajektorienplanungseinrichtung gemäß einer Ausführungsform der Erfindung;
• 9 ein drittes beispielhaftes Szenario;
• 10 zeitliche Verläufe maximal möglicher Lenkwinkel;
• 11 zeitliche Verläufe maximal möglicher Lenkwinkel für verschiedene Geschwindigkeiten; und
• 12 ein Flussdiagramm eines Verfahrens zum Ermitteln einer optimalen Fahrtrajektorie für ein Kraftfahrzeug gemäß einer Ausführungsform der Erfindung.

Show it:

• 1 a block diagram of a driver assistance system for a motor vehicle according to an embodiment of the invention;
• 2 a block diagram of a motor vehicle according to an embodiment of the invention;
• 3 an exemplary future time course of a maximum possible delay;
• 4 an exemplary future time course of a maximum possible acceleration;
• 5 a first exemplary scenario to explain the invention;
• 6 a second exemplary scenario at a first point in time to explain the invention;
• 7 the second exemplary scenario at a second point in time;
• 8th an interface between a maneuver planning device and a travel trajectory planning device according to an embodiment of the invention;
• 9 a third exemplary scenario;
• 10 temporal progressions of maximum possible steering angles;
• 11 temporal progressions of maximum possible steering angles for different speeds; and
• 12 a flowchart of a method for determining an optimal travel trajectory for a motor vehicle according to an embodiment of the invention.

If it makes sense, the described configurations and further developments can be combined with one another as desired. Further possible refinements, further developments and implementations of the invention also include combinations of features of the invention described previously or below with regard to the exemplary embodiments that are not explicitly mentioned.

The accompanying drawings are intended to provide further understanding of embodiments of the invention. They illustrate embodiments and, in connection with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the advantages mentioned arise with regard to the drawings. The elements of the drawings are not necessarily shown to scale to one another. The same reference numbers designate the same or similar components.

1 shows a block diagram of a driver assistance system 10 for a motor vehicle. The driver assistance system 10 includes a travel trajectory planning device 1 and a maneuver planning device 2.

The maneuver planning device 2 receives information 4, which includes a road model, object information and driving information. The road model includes dimensions and spatial arrangements of roads, lanes and the like. The object information includes other road users and obstacles in the vicinity of the motor vehicle. The driving information includes, for example, the location, a current speed and a current acceleration of the motor vehicle. The information 4 may have been generated using sensors in the motor vehicle, such as radar sensors, cameras, laser sensors or ultrasonic sensors.

The maneuver planning device 2 generates a list with a large number of driving maneuvers based on the information 4 and the information of other devices, such as a maneuver test device 5, a mode and state manager 6, a global planning device 7 and a collision prevention device 8, which be described further below. Depending on existing lanes and the course of the road as well as other road users, the maneuver planning device 2 generates all possible driving maneuvers, such as lane changing, lane keeping, emergency braking in a current lane of the motor vehicle, emergency evasion in the current lane of the motor vehicle and emergency evasion into a lane adjacent to the current lane of the motor vehicle .

The maneuver planning device 2 includes a maneuver state device 21, which generates all the necessary travel trajectory requirements for the travel trajectory planning device 1. For example, a setting speed is specified.

The list of driving maneuvers is transmitted to the driving trajectory planning device 1. The travel trajectory planning device 1 calculates at most one travel trajectory for each driving maneuver in the list of driving maneuvers by optimizing a first cost function (numerical optimization). The optimization is carried out using the road model, the object information and a driving dynamics model of the motor vehicle.

The first cost function may depend on comfort parameters and security parameters. The comfort parameters serve to prevent excessive acceleration or excessive jerking, which the driver could find uncomfortable. For this purpose, the comfort parameters can include a lateral acceleration, a lateral jerk, a longitudinal acceleration and a longitudinal jerk. Higher values of these comfort parameters correspond to higher costs in the first cost function, so that values that are too large are prevented.

To calculate the optimal travel trajectory, the travel trajectory planning device 1 takes into account additional conditions, which the travel trajectory planning device 1 determines based on actuator limitation information. The additional conditions must be adhered to when optimizing the travel trajectory using the first cost function. The actuator limitation information includes a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle.

The travel trajectory planning device 1 can continue to optimize the travel trajectory using the first cost function, taking at least one further secondary condition into account. The at least one further secondary condition can be generated depending on the road model. For example, it can be required that a respective travel trajectory lies completely within a predetermined lane or within predetermined lanes. A maximum speed can also be transmitted, which must be maintained along the travel trajectory. Furthermore, a minimum distance to objects can be formulated as a secondary condition.

Furthermore, the travel trajectory planning device 1 can be designed to take into account a coefficient of friction of the road in order to calculate the optimal travel trajectory. The coefficient of friction can be determined using sensor data and/or weather data.

The travel trajectory planning device 1 receives the actuator limitation information from a motion control device 3 of the motor vehicle. It can be provided that the occupancy control device 3 calculates the actuator limitation information based on the optimal travel trajectory determined by the travel trajectory planning device 1. This can provide an opportunity for feedback, i.e. H. the travel trajectory planning device 1 determines the optimal travel trajectory taking into account the actuator limitation information and the occupancy control device 3 determines the actuator limitation information based on the optimal travel trajectory.

The maneuver planning device 2 selects exactly one travel trajectory to be traveled from the travel trajectories calculated by the travel trajectory planning device 1 by evaluating a second cost function. The maneuver planning device 2 ultimately selects a maneuver that has the lowest costs according to the second cost function. The second cost function can depend on safety criteria, comfort criteria and/or a driver's request. In addition to the costs of the travel trajectory, binary information that is not formulated within the cost function (e.g. collision, leaving the lane) can also be included in the evaluation.

Particularly due to the additional conditions, it may happen that the travel trajectory planning device 1 cannot determine a trajectory for a maneuver. In this case, the maneuver planning device 2 rejects the maneuver. The maneuver can, for example, be deleted from the maneuver list and the maneuver planning device 2 selects a maneuver from the remaining maneuvers and thus also the assigned optimal travel trajectory.

Furthermore, it can be provided that the maneuver planning device 2 requests an optimal travel trajectory for at least one emergency maneuver from the travel trajectory planning device 1.

The maneuver planning device 2 is coupled to the motion control device 3 via an interface 9, such as a CAN bus or the like, and outputs the selected travel trajectory to it. The movement control device 3 controls the actuator devices (such as an electronic braking system). The motion control device 3 may include a general software component for motion control and an actuator control device. The movement control device 3 can control the vehicle based on a control signal from the maneuver planning device 2, that is, for example, accelerate, brake or steer. The movement control device 3 controls the actuator devices in such a way that the motor vehicle is steered along the selected travel trajectory to be traveled, e.g. through steering torque request, braking torque request and/or axle torque request.

The system further comprises a mode and status manager 6, which is informed by the maneuver planning device 2 about the maneuver to be carried out and, conversely, transmits vehicle status information to the maneuver planning device 2, such as actions by the driver (e.g. setting a turn signal), which indicate a driver's request, which at the travel trajectories can be taken into account. Further information may include a state of degradation of the motor vehicle. For example, if the failure of the side sensors is reported, a lane change can no longer be requested.

The information from the mode and state manager 6 can be taken into account by the maneuver planning device 2 to generate the list of driving maneuvers. If the mode and state manager 6, for example, determines a driver's request to "change lanes", the maneuver planning device 2 adds the driving maneuver "lane change" to the list.

The driver assistance system 10 may include further optional components, which are shown in dashed lines and are described below. The driver assistance system 10 can include any combination of these components.

The maneuver planning device 2 may include a travel trajectory list evaluation device 24, which selects the travel trajectory. The list of travel trajectories available for selection consists of the travel trajectories optimized for a maneuver and, if necessary, a safety travel trajectory. The travel trajectory list evaluation device 24 transmits the selected travel trajectory to the movement control device 3 via the interface 9.

Furthermore, a collision prevention device 8 can be provided, which calculates whether a collision is imminent based on the road model, the object list and the driving information. Depending on this evaluation, the collision prevention device 8 recommends a maneuver to the maneuver planning device 2 (such as emergency braking or an evasive maneuver) and/or releases higher limits for the maneuver planning device 2, for example in longitudinal and lateral acceleration.

The information from the collision prevention device 8 can be taken into account by the maneuver planning device 2 to generate the list of driving maneuvers. For example, if the collision prevention device 8 determines that a collision is imminent, the maneuver planning device 2 adds the driving maneuvers “emergency avoidance” and “emergency braking” to the list.

Furthermore, the maneuver planning device 2 can include an aggregated cost device 23, which determines the aggregated costs of the travel trajectories using the second cost function, with information about possible collisions also being taken into account.

When selecting the maneuvers, the maneuver planning device 2 can also include information from a global planning device 7, for example the route of a navigation device of the motor vehicle can be included. For example, when selecting the maneuvers, distances to the next descent can be taken into account, so that only those maneuvers are suggested that make it possible to drive on the next descent.

Furthermore, a maneuver testing device 5 can be provided, which checks, for example, based on traffic rules, which maneuvers are permitted and transmits a list of the permitted maneuvers to the maneuver planning device 2.

Furthermore, the maneuver planning device 2 can include a collision reduction device 22, which evaluates the travel trajectories using a collision reduction method, so that the travel trajectory to be traveled is selected taking into account collision reduction in the event of an impending collision. For example, the travel trajectory with the lowest accident severity can be determined if only colliding travel trajectories remain in the list. Optionally, the driving trajectory with the minimum expected accident severity can also be selected (e.g. emergency braking in the lane, lateral shift to impact an object in front with 100% overlap of the front bumper and rear bumper). The time until impact can also be maximized for the actuators, for example for airbag conditioning or passenger positioning.

The components described above can be designed as separate hardware elements, such as microcontrollers, microcomputers, application-specific circuits or the like. Some or all of the components may also be implemented by a single hardware component.

2 shows a block diagram of a motor vehicle 100, which has a driver assistance system 10 described above.

3 shows an exemplary future course of a maximum possible deceleration, ie negative acceleration a as a function of time t. It is taken into account that the actuator device can only build up brake pressure after a first period of time and the maximum brake pressure has only built up after a second period of time.

4 shows an exemplary future time course of a maximum possible acceleration a. It is taken into account here that the actuator device only increases the acceleration a after a first period of time and the maximum acceleration a can only be provided after a second period of time.

Further actuator limitation information may include a future time course of a maximum possible steering angular speed or a maximum possible steering angle.

5 shows a first exemplary scenario to explain the invention. The motor vehicle 100 makes a left turn. The driver indicates that he wants to change lanes. If the actuator limitation information is not taken into account for calculating a first travel trajectory 502, the motor vehicle 100 leaves the road on the first travel trajectory 502. If the actuator limitation information is correctly taken into account as secondary conditions, an optimal travel trajectory 501 is calculated, which does not leave the road.

6 shows a second exemplary scenario to explain the invention. The motor vehicle 100 tries to avoid a collision with a vehicle in front through an evasive maneuver. In order to correctly calculate a safe travel trajectory or whether such a trajectory is even possible, it is necessary to take into account the actuator limitation information, which also includes the time course of the limitations of the actuators.

7 shows the second exemplary scenario at a later point in time. What is shown is a rear-end collision between the motor vehicle 100 and the vehicle in front. Such a non-frontal impact should be avoided as it can result in greater damage than a central impact. By taking the actuator limitation information into account, it can be recognized at an early stage whether an evasive maneuver is still possible or whether a central collision is preferable during an emergency braking maneuver, since the expected damage is lower.

8th shows an interface between the motion control device 3 and the travel trajectory planning device 1. An optimal travel trajectory 81 to be controlled and further travel trajectories for checking are transmitted from the travel trajectory planning device 1 to the motion control device 3 via the interface. The motion control device 3 uses the optimal travel trajectory 81 to be executed to control the actuators. The motion control device 3 further checks the travel trajectories 82 transmitted for testing. For each tested travel trajectory 82, the motion control device 3 transmits the actuator limitation information 83 to the travel trajectory planning device 1, as well as information as to whether the travel trajectory is passable.

9 shows a third exemplary scenario. A motor vehicle 100 is traveling on a road and wants to change lanes. A first trajectory 901 with determined location points 903 to 907 and a second trajectory 902 are shown.

10 shows the curves 1001 to 1005 of the maximum possible steering angle α as a function of time t for the location points 903 to 907. It is determined that the last two points 906, 907 are outside the curves 1003 to 1005 of the maximum possible steering angle a for the last three points 905 up to 907.

In this case, the maneuver planning device 2 can reject the maneuver and, for example, carry out a lane keeping maneuver instead of changing lanes. The maneuver planning device 2 can also have the travel trajectory for the lane change recalculated with a different speed profile and/or further restrictions and, if drivable, have this travel trajectory controlled.

11 shows temporal progressions of the maximum possible steering angle α for different speeds. For a first location point 903, a curve 1101 is illustrated for the maximum possible steering angle α as a function of time t for the current vehicle speed V_ist. The maneuver planning device 3 further transmits a scaling factor scaler for a changed vehicle speed, so that the travel trajectory planning device 1 can calculate travel trajectories with a changed vehicle speed.

12 shows a flowchart of a method for determining an optimal travel trajectory for a motor vehicle 100. The method can preferably be carried out by a driver assistance system 10 described above.

In a method step S1, a maneuver planning device 2 calculates a maneuver list with a large number of maneuvers.

In a method step S2, a motion control device 3 calculates actuator limitation information, which includes a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle 100.

In a method step S3, the travel trajectory planning device 1 receives the actuator limitation information and the maneuver list and calculates an optimal travel trajectory in a method step S4. Optionally, the optimal travel trajectory can be output to the movement control device 3. The motion control device 3 can determine the actuator limitation information taking the optimal trajectory into account.

In a further method step S5, the maneuver planning device 2 selects a travel trajectory from the determined optimal travel trajectories. The maneuver planning device 2 thus selects one of the maneuvers.

In a further method step S6, the selected travel trajectory is transmitted to the movement control device 3, which controls the actuators in order to move the motor vehicle along the selected travel trajectory.

Reference symbol list

1

Travel trajectory planning device

2

Maneuver planning facility

3

Motion control device

4

information

5

Maneuver testing facility

6

Mode and state manager

7

global planning facility

8th

Collision avoidance facility

10

Driver assistance system

21

Maneuver condition facility

22

Collision mitigation facility

23

Aggregate Cost Setup

24

Travel trajectory list evaluation facility

81

optimal travel trajectory

82

Travel trajectory for review

83

Actuator limitation information

100

motor vehicle

501, 502

Trajectories

901, 902

Trajectories

903-907

Location points

1001-1005

Time courses of maximum possible steering angles

1101, 1102

Time courses of maximum possible steering angles

S1-S6

Procedural steps

Claims (15)

Driver assistance system (10) for a motor vehicle (100), with: a travel trajectory planning device (1), which is designed to calculate an optimal travel trajectory for the motor vehicle (100) using a road model, object information regarding objects in the surroundings of the motor vehicle (100) and a driving dynamics model of the motor vehicle (100); wherein the travel trajectory planning device (1) is further designed to take into account secondary conditions specified by actuator limitation information in order to calculate the optimal travel trajectory, the actuator limitation information comprising a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle (100). Driver assistance system (10). Claim 1 , with: a maneuver planning device (2), which is designed to generate a list of driving maneuvers; wherein the travel trajectory planning device (1) is designed to calculate an optimal travel trajectory for each driving maneuver in the list of driving maneuvers; and wherein the maneuver planning device (2) is further designed to select a travel trajectory to be traveled from the travel trajectories calculated by the travel trajectory planning device (1). Driver assistance system (10). Claim 2 , wherein the maneuver planning device (2) is further designed to calculate the travel trajectory to be traveled using a cost function choose which depends on safety criteria, comfort criteria and/or a driver's wishes. Driver assistance system (10). Claim 2 or 3 , wherein the maneuver planning device (2) is further designed to reject a maneuver from the list of driving maneuvers if the travel trajectory planning device (1) cannot determine a trajectory for the maneuver. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time course of a maximum possible steering angular velocity. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time profile of a maximum possible steering angle. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time course of a maximum possible delay. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time course of a maximum possible acceleration. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time course of a maximum speed, the optimal travel trajectory being able to be traveled at a speed smaller than the maximum speed. Driver assistance system (10) according to one of the preceding claims, wherein the travel trajectory planning device (1) is designed to take a coefficient of friction into account to calculate the optimal travel trajectory. Driver assistance system (10) according to one of the preceding claims, wherein the actuator limitation information includes a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle (100), which is predetermined for safety reasons. Driver assistance system (10) according to one of the preceding claims, with a movement control device (3) which is designed to calculate the actuator limitation information based on the optimal travel trajectory determined by the travel trajectory planning device (1). Driver assistance system (10). Claim 12 , wherein the movement control device (3) is further designed to check the actuator limitation information based on a set of optimal travel trajectories generated by the travel trajectory planning device (1) with regard to drivability and to send a result of the test regarding drivability and the respective actuator limitation information to the maneuver planning device (2 ) transferred to. Motor vehicle (100) with a driver assistance system (10) according to one of the preceding claims. Method for determining an optimal travel trajectory for a motor vehicle (100), with the steps: Receiving (S2) actuator limitation information, the actuator limitation information comprising a future time course of a limitation of at least one actuator parameter of at least one actuator of the motor vehicle (100); and Calculating (S3) an optimal travel trajectory for the motor vehicle (100) using a road model, object information regarding objects in the surroundings of the motor vehicle (100) and a driving dynamics model of the motor vehicle (100), wherein to calculate the optimal travel trajectory, additional conditions specified by actuator limitation information are taken into account .

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