Lane line estimating apparatus

• US 8,611,609 B2
• Filed: 09/08/2011
• Issued: 12/17/2013
• Est. Priority Date: 09/08/2010
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Oyama, Hajime
• Primary Examiner(s): SHAH, UTPAL D
• Application Number:
  US13/228,130
• Publication Number:
  US 20120057757A1
• Time in Patent Office: 831 Days
• Field of Search: 382/103, 382/104
• US Class Current: 382/104
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

A fixed data memory stores data of a normal lane width between lane lines and a narrow lane width between inner guide lines of double white lines. A lane-line candidate setting section detects lane-line detection points on both sides of a driving lane using a captured image, and sets lane-line candidate points on the opposite lane lines at spaces of the widths and therebetween, using the detection points as starting points. A curve approximation processing section sets virtual lines on both sides of the driving lane from a curve approximation equation obtained using the detection and candidate points. A lane-line position setting section obtains dispersions of the candidate points to the left and right virtual lines, and estimates the type of at least one of the left and right virtual lines.

Claims

1. A lane line estimating apparatus comprising:

an imaging unit mounted on a vehicle and configured to image an external environment of the vehicle;

a storage unit configured to store data of a lane-line width for each of plural predetermined lane-line types;

a lane-line candidate point setting unit configured to detect left-hand and right-hand lane-line detection points on a driving lane, on which the vehicle runs, based upon an image of the external environment imaged by the imaging unit, and to set lane-line candidate points on locations, at a space of the lane-line width for each of plural predetermined lane-line types on lane-lines opposite to the detected left-hand and right-hand lane-line detection points;

a curve approximation processing unit configured to obtain a curve approximation equation based upon the lane-line detection points and the lane-line candidate points set on a lane-line of the lane-line detection points, in order to set virtual lines on lane-lines on a left side and on a right side of the driving lane from the curve approximation equation; and

a lane-line type estimating unit configured to obtain a dispersion of the virtual lines set by the curve approximation processing unit so as to estimate the lane-line type of at least one of the left-hand and right-hand virtual lines from the pair of left-hand and right-hand virtual lines indicating a smallest dispersion.

2. The lane line estimating apparatus according to claim 1, wherein the data of the lane-line width stored in the storage unit includes data of a normal width indicating a width between inner edges of lane lines, defining the driving lane on the left side and on the right side thereof, and data of a narrow width indicating a width between inner edges of inner guide lines of double white lines;

and

wherein the lane-line types estimated by the lane-line type estimating unit include at least both-side true lane lines corresponding to the lane lines on the left side and on the right side of the driving lane, a one-side true lane line corresponding to the lane line on one side, and both-side guide lines corresponding to the inner guide lines on the left side and on the right side.

3. The lane line estimating apparatus according to claim 2, further comprising a lane-line position setting unit.

4. The lane line estimating apparatus according to claim 3, wherein if the lane-line type estimating unit estimates that the lane-line type includes the both-side true lane lines, then the lane-line position setting unit confirms the positions of the virtual lines as the positions of true lane lines.

5. The lane line estimating apparatus according to claim 3, wherein if the lane-line type estimating unit estimates that the lane line type comprises the one-side true lane line, then the lane-line position setting unit determines whether a virtual line of the virtual lines comprises the lane line or the guide line based upon a distance between an outer edge of the lane line and the virtual line;

wherein, if the lane-line position setting unit determines that the virtual line comprises the lane line, then the lane-line position setting unit confirms the position of the virtual line as the position of the true lane line, and confirms the position where the other of the virtual lines is shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual line comprises a guide line, then the lane-line position setting unit confirms the position of the other of the virtual lines as the position of the true lane line, and confirms the position where the virtual line is shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the position of the true lane line.

6. The lane line estimating apparatus according to claim 3, wherein if the lane-line type estimating unit determines that the lane-line type of the virtual lines comprises the both-side guide lines, then the lane-line position setting unit determines whether a virtual line of the virtual lines comprises the lane line or the guide line based upon the distance between an outer edge of the lane line and the virtual line;

wherein, if the lane-line position setting unit determines that the virtual line comprises the lane line, then the lane-line position setting unit confirms the position of the virtual line as the position of the true lane line, and determines the position where the other of the virtual lines is shifted to the outside of the driving lane by an amount corresponding to the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual line comprises the guide line, then the lane-line position setting unit determines whether the other of the virtual lines comprises the lane line or the guide line based upon the distance between the outer edge of the other lane line and the other of the virtual lines, and if the lane-line position setting unit determines that the other of the virtual lines comprises the lane line, then the lane-line position setting unit confirms the position of the other of the virtual lines as the position of the true lane line, and confirms the position where the virtual line is shifted to the outside of the driving lane by an amount corresponding to the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual lines on both sides are the guide lines, then the lane-line position setting unit confirms the positions where the virtual lines on the left side and on the right side are respectively shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the positions of the true lane lines.

7. A lane line estimating apparatus according to claim 3, wherein, if the lane-line type estimating unit estimates that lane type of the virtual lines on the left side and on the right side comprises the one-side true lane line, then the lane-line position setting unit determines whether the one-side true lane line comprises the lane line, the guide line, or a line located between the lane line and the guide line, based upon the distance between the virtual line and the outer edge of the lane line of the virtual line side, and if the lane-line position setting unit determines that the virtual lines on both sides are the lines between the corresponding lane line and the corresponding guide line, then the lane-line position setting unit confirms the positions where the virtual lines on the left side and the right side are respectively shifted to the left and to the right of the driving lane by an amount corresponding to a fourth of the difference between the normal width and the narrow width as the positions of the true lane lines.

8. The lane line estimating apparatus according to claim 3, wherein if the lane-line type estimating unit estimates that the lane-line type comprises the one-side true lane line, then the lane-line position setting unit determines whether a virtual line of the virtual lines comprises the lane line or the guide line based upon a distance between an outer edge of the lane line and the virtual line;

wherein, if the lane-line position setting unit determines that the virtual line comprises the lane line, then the lane-line position setting unit confirms the position of the virtual line as the position of the true lane line, and confirms the position where the other of the virtual lines is shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual line comprises a guide line, then the lane-line position setting unit confirms the position of the other of the virtual lines as the position of the true lane line, and confirms the position where the virtual line is shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the position of the true lane line.

9. The lane line estimating apparatus according to claim 3, wherein if the lane-line type estimating unit determines that the lane-line type of the virtual lines comprises the both-side guide lines, then the lane-line position setting unit determines whether a virtual line of the virtual lines comprises the lane line or the guide line based upon the distance between an outer edge of the lane line and the virtual line;

wherein, if the lane-line position setting unit determines that the virtual line comprises the lane line, then the lane-line position setting unit confirms the position of the virtual line as the position of the true lane line, and determines the position where the other of the virtual lines is shifted to the outside of the driving lane by an amount corresponding to the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual line comprises the guide line, then the lane-line position setting unit determines whether the other of the virtual lines comprises the lane line or the guide line based upon the distance between the outer edge of the other lane line and the other of the virtual lines,

if the lane-line position setting unit determines that the other of the virtual lines comprises the lane line, then the lane-line position setting unit confirms the position of the other of the virtual lines as the position of the true lane line, and confirms the position where the virtual line is shifted to the outside of the driving lane by an amount corresponding to the difference between the normal width and the narrow width as the position of the true lane line; and

wherein, if the lane-line position setting unit determines that the virtual lines on both sides comprise the guide lines, then the lane-line position setting unit confirms the positions where the virtual lines on the left side and on the right side are respectively shifted to the outside of the driving lane by an amount corresponding to a half of the difference between the normal width and the narrow width as the positions of the true lane lines.

10. The lane line estimating apparatus according to claim 3, wherein the curve approximation processing unit is configured to obtain a center curve approximation equation based upon the virtual lines on the left side and on the right side of the driving lane.

11. The lane line estimating apparatus according to claim 1, wherein the detection points correspond to at least one of inner edges of lane lines, inner edges of inner guide lines of double white lines, and an edge portion between an inside of a track and a road surface.

12. The lane line estimating apparatus according to claim 2, wherein the lane-line candidate point setting unit is configured to set normal lane-line candidate points on the opposite lane line at a space of the normal width, using the left-hand and right-hand lane-line detection points as starting points.

13. The lane line estimating apparatus according to claim 12, wherein the lane-line candidate point setting unit is configured to set narrow lane-line candidate points on the opposite lane line at a space of the narrow width, using the left-hand and right-hand lane-line detection points as the starting points.

14. The lane line estimating apparatus according to claim 13, wherein the lane-line candidate point setting unit is configured to set narrow normal lane-line candidate points on the opposite lane line at a predetermined position between the normal lane-line candidate points and narrow lane-line candidate points.

15. The lane line estimating apparatus according to claim 14, wherein the curve approximation processing unit is configured to obtain candidate point curve approximation equations based upon each of the normal lane-line candidate points, the narrow lane-line candidate points, and the normal narrow lane-line candidate points set by the lane-line candidate point setting unit, in order to set virtual lines on the left side and on the right side of the driving lane from each of the candidate point curve approximation equations, respectively.