Method and control unit for determining a cutting trajectory of a curve section of a roadway

• US 20130006473A1
• Filed: 11/30/2010
• Published: 01/03/2013
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Buerkle, Lutz, Fischer, Michael, Maurer, Thomas
• Granted Patent: US 9,278,712 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence

Abstract

A method for determining a cutting trajectory that enables a curve section of a lane to be cut by a vehicle. In the method, information about the curve section is received, and the curve section is divided into at least one curve segment having a segment length and a start curvature, the curve segment being a straight-line segment or a circular arc segment or a curve segment whose curvature is a function of an arc length of the curve segment. This is followed by determination of a cutting trajectory from the at least one curve segment, so that, at a specific point of the curve section, the cutting trajectory has a predetermined offset relative to a center of the lane.

Claims

1-15. -15. (canceled)

16. A method for determining a cutting trajectory that enables a curve section of a lane to be cut by a vehicle, the method comprising:

receiving information about the curve section via an interface;

dividing the curve section into at least one curve segment having a segment length and a start curvature, the curve segment being a straight-line segment or a circular arc segment or a curve segment whose curvature is a function of an arc length of the curve segment; and

determining a cutting trajectory from the at least one curve segment, so that, at a specific point of the curve section, the cutting trajectory has a predetermined offset relative to a center of the lane.

17. The method of claim 16, wherein the cutting trajectory includes at least one trajectory segment with the segment length and the start curvature, the trajectory segment being a straight-line segment or a circular arc segment or a curve segment whose curvature is a function of the arc length of the trajectory segment.

18. The method of claim 16, wherein the cutting trajectory is so determined that a maximum curvature of the cutting trajectory is less than a maximum curvature of the curve section.

19. The method of claim 16, wherein the curve section is divided into a plurality of curve segments having a segment length and a start curvature, the start curvature corresponding to an end curvature of a preceding curve segment, and the curvature thereof either being constant over the arc length of the curve segment in the form of a straight-line segment or circular arc segment or changing linearly with the arc length of the curve segment in the form of a clothoid segment.

20. The method of claim 16, wherein the cutting trajectory is divided into a plurality of trajectory segments having a segment length and a start curvature, the start curvature corresponding to the end curvature of a preceding trajectory segment, and the curvature thereof either being constant over the arc length of the trajectory segment in the form of a straight-line segment or circular arc segment or changing linearly with the arc length of the trajectory segment in the form of a clothoid segment.

21. The method of claim 16, wherein the straight-line length, the clothoid length, the start curvature of the clothoid, the clothoid parameter, the circular arc length and the circular arc curvature are so adjusted that a maximum curvature of the clothoid trajectory and a curvature of the circular arc trajectory is in each case less than a maximum curvature of the curve section, and in which a straight-line trajectory is determined which is associated with the straight-line segment, a clothoid trajectory is determined which is associated with the clothoid segment, and a circular arc trajectory is determined which is associated with the circular arc segment, and in which the cutting trajectory is determined from the straight-line trajectory, the clothoid trajectory and the circular arc trajectory.

22. The method of claim 16, wherein the straight-line trajectory, the clothoid trajectory and the circular arc trajectory are so determined that the cutting trajectory has, at an apex of the curve section, a predetermined offset toward the inside of the curve relative to the center of the lane.

23. The method of claim 16, wherein the straight-line trajectory, the clothoid trajectory and the circular arc trajectory are so determined that an angular direction of the cutting trajectory at a start point corresponds to an angular direction of the center of the lane at a start point and an angular direction of the cutting trajectory at an end point corresponds to an angular direction of the center of the lane at an end point.

24. The method of claim 16, wherein the straight-line trajectory, the clothoid trajectory and the circular arc trajectory are determined taking into consideration a vehicle speed and a curve section curvature.

25. The method of claim 16, wherein in a region directly adjoining the curve section, at least one further clothoid trajectory or at least one further circular arc trajectory are determined so that a further curve trajectory has, in the region, a further predetermined offset relative to the center of the lane.

26. The method of claim 16, further comprising:

ascertaining a lateral guidance of the vehicle based on the cutting trajectory, the lateral guidance being suitable for steering the vehicle through the curve section along the cutting trajectory.

27. The method of claim 16, further comprising:

dividing a route section of the roadway into a plurality of curve sections representing a curve entry, a curve that becomes tighter or that opens out, an S-bend and/or a curve exit, and for each of the plurality of curve sections a cutting trajectory is determined, and a trajectory for the route section is formed by stringing together the cutting trajectories of the plurality of curve sections.

28. A control unit for determining a cutting trajectory that enables a curve section of a lane to be cut by a vehicle, comprising:

a receiving arrangement to receive information about the curve section via an interface;

a dividing arrangement to divide the curve section into at least one curve segment having a segment length and a start curvature, the curve segment being a straight-line segment or a circular arc segment or a curve segment whose curvature is a function of an arc length of the curve segment; and

a determining arrangement to determine a cutting trajectory from the at least one curve segment, so that, at a specific point of the curve section, the cutting trajectory has a predetermined offset relative to a center of the lane.

29. A computer readable medium having a computer program, which is executable by a processor, comprising:

a program code arrangement having program code for determining a cutting trajectory that enables a curve section of a lane to be cut by a vehicle, by performing the following;

receiving information about the curve section via an interface;

dividing the curve section into at least one curve segment having a segment length and a start curvature, the curve segment being a straight-line segment or a circular arc segment or a curve segment whose curvature is a function of an arc length of the curve segment; and

determining a cutting trajectory from the at least one curve segment, so that, at a specific point of the curve section, the cutting trajectory has a predetermined offset relative to a center of the lane.

30. A method for determining a trajectory that enables a curve section of a lane to be cut by a vehicle, the method comprising:

receiving information about the curve section via an interface;

dividing the curve section into a straight-line segment having a straight-line length, into a clothoid segment having a clothoid length, a clothoid start curvature and a clothoid parameter, and into a circular arc segment having a circular arc length and a circular arc curvature;

determining a straight-line trajectory for the straight-line segment, a clothoid trajectory for the clothoid segment and a circular arc trajectory for the circular arc segment, based on an adjustment rule which is designed to adjust the straight-line length, the clothoid length, the clothoid start curvature, the clothoid parameter, the circular arc length and the circular arc curvature in such a manner that a curvature of the clothoid trajectory and a curvature of the circular arc trajectory is in each case less than a maximum curvature of the curve section; and

determining a cutting trajectory from the straight-line trajectory, the clothoid trajectory and the circular arc trajectory.