Road branch detection and path selection for lane centering

Patent metadata

Field	Value
Publication number	US-9830517-B2
Application number	US-201414308818-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Jun 19, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

Lane feature data is processed to compute a feed-forward lane curvature of a left lane boundary and a right lane boundary. A look-ahead lane width and a near lane width are computed based on left and right lane boundaries. A lane width increase is computed to detect a lane split or lane merge based on differences between increasing lane widths. A side of the vehicle on which the lane split or merge occurred is identified or determined. The lane boundary on the side on which the lane split or merged occurred is ignored, and a single-sided lane centering calculation is performed based on the non-ignored lane boundary.

First claim

The invention claimed is:

1. An apparatus, comprising:
circuitry configured to:
process lane feature data to compute left and right lane clothoids;
compute a look-ahead lane width and a near lane width based on the left and right lane clothoids;
compute a lane width increase to detect a lane split or lane merge based on differences between the look-ahead and near lane widths;
determine on which side of a vehicle the lane split or the lane merge occurred;
perform a single-sided lane centering calculation based on the left clothoid or the right clothoid corresponding to the side of the vehicle on which the lane split or the lane merge did not occur; and
center the vehicle in a lane by transmitting control signals to one or more actuators of the vehicle.

2. The apparatus of claim 1 , wherein the circuitry is further configured to obtain the lane feature data from at least one image taken from one or more vehicle-mounted cameras.

3. The apparatus of claim 1 , wherein the circuitry is further configured to determine the lane split is detected when the lane width increase is greater than a first threshold.

4. The apparatus of claim 3 , wherein the circuitry is further configured to determine that the near lane width is the lane width at the vehicle's proximate location.

5. The apparatus of claim 4 , wherein the circuitry is further configured to determine that the look-ahead lane width is the lane width further ahead of the vehicle than the near lane width.

6. The apparatus of claim 5 , wherein the circuitry is further configured to compute an instantaneous offset jump to detect the lane merge based on differences between the left or right clothoid stored in memory and the current left or right clothoid.

7. The apparatus of claim 6 , wherein the circuitry is further configured to determine that the lane merge is detected if the instantaneous offset jump is greater than a second threshold and no lane split is detected.

8. The apparatus of claim 7 , wherein the circuitry is further configured to perform a verification of the lane split or the lane merge with stored map data.

9. The apparatus of claim 8 , wherein the circuitry is further configured to ignore the left or right clothoid on the side of the vehicle where the lane split or merge occurred.

10. The apparatus of claim 9 , wherein the circuitry is further configured to calculate a vehicle offset from the side of the vehicle opposite the side where the lane split or lane merge occurred.

11. The apparatus of claim 10 , wherein the circuitry is further configured to begin performing the single-sided lane centering calculation a predetermined number of consecutive samples after the lane split or the lane merge is detected.

12. The apparatus of claim 11 , wherein the circuitry is further configured to perform the single-sided lane centering calculation until the vehicle has traveled a predetermined distance.

13. The apparatus of claim 1 , wherein the circuitry is further configured to determine the side on which the lane split or the lane merge occurred based on whether the vehicle is traveling in a “leftmost” lane, a “rightmost” lane, or an “other” lane.

14. The apparatus of claim 2 , wherein the lane feature data includes lane marker information from the left and right sides of the vehicle.

15. The apparatus of claim 14 , wherein the lane marker information includes one or more of position, curvature, curvature derivative, shape, color, and type of lane markers, and the circuitry is configured to compute the left and right clothoids based on the lane marker information.

16. The apparatus of claim 15 , wherein the circuitry is further configured to compute the left and right clothoids that delineate one or more of the position, curvature, curvature derivative, and direction of left and right boundaries of the lane in which the vehicle is traveling.

17. The apparatus of claim 1 , wherein the circuitry is further configured to:
obtain a current position of the vehicle;
correlate the current position of the vehicle in stored map data; and
detect the lane splits and the lane merges based on the stored map data when the current position of the vehicle is determined to be accurate within a predetermined tolerance.

18. A method, comprising:
processing lane feature data to compute left and right lane clothoids;
computing a look-ahead lane width and a near lane width based on the left and right lane clothoids;
computing a lane width increase to detect a lane split or lane merge based on differences between the look-ahead and near lane widths;
determining on which side of a vehicle the lane split or the lane merge occurred;
performing a single-sided lane centering calculation based on the left clothoid or the right clothoid corresponding to the side of the vehicle on which the lane split or lane merge did not occur; and
centering the vehicle in a lane by transmitting control signals to one or more actuators of the vehicle.

19. A non-transitory computer-readable storage medium including executable instructions, which when executed by circuitry, causes the circuitry to perform the method according to claim 18 .

20. A system, comprising:
one or more sensors to obtain lane feature data; and
a controller including a processor configured to:
process the lane feature data to compute left and right lane clothoids;
compute a look-ahead lane width and a near lane width based on the left and right lane clothoids;
compute a lane width increase to detect a lane split or lane merge based on differences between the look-ahead and near lane widths;
determine on which side of a vehicle the lane split or the lane merge occurred;
perform a single-sided lane centering calculation based on the left clothoid or the right clothoid corresponding to the side of the vehicle on which the lane split or the lane merge did not occur; and
center the vehicle in a lane by transmitting control signals to one or more actuators of the vehicle.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Vladimerou Vladimeros
• Pandita Rohit

Classifications

• G06K9/00798 Primary

  Physics · mapped topic

• G06V20/588 Primary

  Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road · CPC title