Lane keeping for autonomous vehicles

1. A system for controlling a lane keeping feature of a vehicle, the lane keeping feature having a predefined safety requirement criterion for keeping the vehicle within bounds while the lane keeping feature is active, the system comprising:

a road estimation module configured to:

receive sensor data comprising information about a sur-rounding environment of the vehicle;

determine a drivable area based on the sensor data, the drivable area comprising a left boundary and a right boundary extending along a direction of travel of the vehicle, wherein each boundary comprises a plurality of points distributed along each boundary, each point being associated with a confidence level; and

a trajectory planning module configured to:

receive the determined drivable area;

determine a nominal trajectory based on the received drivable area, wherein the nominal trajectory is further determined based on the predefined safety requirement criterion and a predefined availability criterion; and

determine a back-up stop trajectory for the vehicle based on the received drivable area, the back-up stop trajectory being further determined based on a predefined confidence criterion,

wherein the predefined confidence criterion is dependent on a predefined value of frequency of back-up stops that is based on the predefined availability criterion for the nominal trajectory.

2. The system according to claim 1 , further comprising:

a vehicle control module configured to:

obtain the determined nominal trajectory and the determined back-up stop trajectory; and

send a control signal to at least one actuator in order to manoeuvre the vehicle based on the determined nominal trajectory or the back-up stop trajectory.

3. The system according to claim 1 , wherein the predefined availability criterion defines a probability of an updated nominal trajectory not being available in a subsequent time step.

4. The system according to claim 1 , wherein the nominal trajectory is based on a first subset of points of the plurality of points, the first subset of points being associated with a confidence level above a first predefined threshold.

5. The system according to claim 4 , wherein a back-up stop trajectory is based on a second subset of points of the plurality of points, the second subset of points being associated with a confidence level above a second predefined threshold, wherein the second predefined threshold is lower than the first predefined threshold.

6. The system according to claim 5 , wherein the back-up stop trajectory has a first time horizon and the nominal trajectory has a second time horizon, the first time horizon being longer than the second time horizon.

7. The system according to claim 1 , wherein the predefined value of frequency of stops in lane is in the range from one stop per 10 3 h to one stop per 10 5 h.

8. The system according to claim 1 , wherein the predefined availability criterion is in the range from not available once per 10 3 h to not available once per 10 5 h.

9. A vehicle comprising:

a perception system comprising at least one sensor for monitoring a surrounding environment of the vehicle;

a system for controlling a lane keeping feature of a vehicle, the lane keeping feature having a predefined safety requirement criterion for keeping the vehicle within bounds while the lane keeping feature is active, the system comprising:

a road estimation module configured to:

receive sensor data comprising information about a surrounding environment of the vehicle;

determine a drivable area based on the sensor data, the drivable area comprising a left boundary and a right boundary extending along a direction of travel of the vehicle, wherein each boundary comprises a plurality of points distributed along each boundary, each point being associated with a confidence level; and

a trajectory planning module configured to:

receive the determined drivable area;

determine a nominal trajectory based on the received drivable area, wherein the nominal trajectory is further determined based on the predefined safety requirement criterion and a predefined availability criterion; and

determine a back-up stop trajectory for the vehicle based on the received drivable area, the back-up stop trajectory being further determined based on a predefined confidence criterion,

wherein the predefined confidence criterion is dependent on a predefined value of frequency of back-up stops that is based on the predefined availability criterion for the nominal trajectory.

10. A method for controlling a lane keeping feature of a vehicle, the lane keeping feature having a predefined safety requirement criterion for keeping the vehicle within bounds while the lane keeping feature is active, the method comprising:

receiving sensor data comprising information about a surrounding environment of the vehicle;

determining a drivable area based on the sensor data, the drivable area comprising a left boundary and a right boundary extending along a direction of travel of the vehicle, wherein each boundary comprises a plurality of points distributed along each boundary, each point being associated with a confidence level;

determining a nominal trajectory based on the drivable area, wherein the nominal trajectory is further determined based on the predefined safety requirement criterion and a predefined availability criterion; and

determining a back-up stop trajectory for the vehicle based on the drivable area, the back-up stop trajectory being further determined based on a predefined confidence criterion,

wherein the predefined confidence criterion is dependent on a predefined value of frequency of back-up stops that is based on the predefined availability criterion for the nominal trajectory.

11. The method according to claim 10 , further comprising:

sending a control signal to at least one actuator in order to manoeuvre the vehicle based on the determined nominal trajectory or the back-up stop trajectory.

12. The method according to claim 10 , wherein the predefined value of frequency of stops in lane is in the range from one stop per 10 3 h to one stop per 10 5 h.

13. The method according to claim 10 , wherein the predefined availability criterion is in the range from not available once per 10 3 h to not available once per 10 5 h.

14. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a vehicle control system, the one or more programs comprising instructions for performing the method for controlling a lane keeping feature of a vehicle, the lane keeping feature having a predefined safety requirement criterion for keeping the vehicle within bounds while the lane keeping feature is active, the method comprising:

receiving sensor data comprising information about a surrounding environment of the vehicle;

determining a drivable area based on the sensor data, the drivable area comprising a left boundary and a right boundary extending along a direction of travel of the vehicle, wherein each boundary comprises a plurality of points distributed along each boundary, each point being associated with a confidence level;

determining a nominal trajectory based on the drivable area, wherein the nominal trajectory is further determined based on the predefined safety requirement criterion and a predefined availability criterion; and

determining a back-up stop trajectory for the vehicle based on the drivable area, the back-up stop trajectory being further determined based on a predefined confidence criterion,

wherein the predefined confidence criterion is dependent on a predefined value of frequency of back-up stops that is based on the predefined availability criterion for the nominal trajectory.