METHOD AND SYSTEM FOR LANE-KEEPING CONTROL

• US 20110231062A1
• Filed: 03/16/2011
• Published: 09/22/2011
• Est. Priority Date: 03/17/2010
• Status: Active Grant

• Current Assignee: HL Klemove Corporation
• Original Assignee: Mando Corporation
• Inventors: KIM, Soon Tae
• Granted Patent: US 8,626,391 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• 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

The present invention relates to a lane-keeping control, and more particularly to a lane-keeping control method and system which can estimate in advance a vehicle condition at a predetermined distance ahead of the vehicle, and which allow lane-keeping control to be conducted stably and efficiently in accordance with the estimated result.

Claims

1. A lane-keeping control system calculating a look-ahead distance on the basis of a vehicle condition, and conducting lane-keeping control on the basis of the calculated look-ahead distance.

2. The lane-lane keeping control system as claimed in claim 1, wherein the inventive lane-keeping control system comprises:

an estimated control entry boundary arrival time setting unit for setting an estimated control entry boundary arrival time to be taken by a vehicle to arrive at a control entry boundary, wherein the control entry boundary is set for entering lane-keeping control for the vehicle;

a look-ahead distance calculating unit for calculating a look-ahead distance on the basis of the estimated control entry boundary arrival time and the vehicle'"'"'s velocity;

a crosswise error calculating unit for calculating a crosswise error of the vehicle estimated ahead of the look-ahead distance;

a lane-keeping control entry determining unit for determining whether to enter the lane-keeping control on the basis of the crosswise error and the control entry boundary;

a lane-keeping control torque producing unit for producing lane-keeping control torque in a direction opposite to the lane-departure direction when it is determined that it is necessary to enter lane-keeping control as the result of the determination by the lane-keeping control entry determining unit, wherein the lane-keeping control torque urges the vehicle to return to the inside of the control entry boundary; and

a torque release unit for releasing the lane-keeping control torque when it is determined that the vehicle has returned to the inside of a control release boundary, after the lane-keeping control torque was produced, wherein the control release boundary is set for releasing the lane-keeping control for the vehicle.

3. The lane-keeping control system as claimed in claim 2, wherein the estimated control entry boundary arrival time setting unit sets the estimated control entry boundary arrival time in such a manner that a system transfer characteristic condition can be met, in which the estimated control entry boundary arrival time is determined by a camera data operation period, a vehicle network transmission period, and a torque increasing time.

4. The lane-keeping control system as claimed in claim 3, wherein the torque increasing time is determined by the maximum allowed torque and the maximum torque change rate.

5. The lane-keeping control system as claimed in claim 2, wherein the look-ahead distance calculating unit calculates the look-ahead distance by multiplying the estimated control entry boundary time and the vehicle'"'"'s velocity.

6. The lane-keeping control system as claimed in claim 2, wherein the crosswise error calculating unit calculates the vehicle'"'"'s crosswise error estimated ahead of the look-ahead distance on the basis of the lane information acquired from the camera and the vehicle'"'"'s yaw rate.

7. The lane-keeping control system as claimed in claim 2, further comprising a boundary setting unit, wherein the boundary setting unit determines a virtual line by connecting first points positioned at a first distance from a lane indication line to the inside of the road, and sets the virtual line as the control entry boundary, and the boundary setting unit determines a virtual line by connecting second points positioned at a second distance from the control entry boundary to the inside of the road, and sets the virtual line as the control release boundary.

8. The lane-keeping control system as claimed in claim 7, wherein the boundary setting unit sets the control entry boundary on the basis of the road'"'"'s width.

9. The lane-keeping control system as claimed in claim 8, wherein if the road'"'"'s width is within a predetermined road'"'"'s width range, the boundary setting unit sets the control entry boundary in such a manner that the first distance to the inside of the road from the lane indication line is proportional to the road'"'"'s width.

10. The lane-keeping control system as claimed in claim 7, wherein the boundary setting unit adjusts the distance between the control entry boundary and the control release boundary in accordance with the road'"'"'s curvature.

11. The lane-keeping control system as claimed in claim 10, wherein if the road'"'"'s curvature is within a predetermined road'"'"'s curvature range, the boundary setting unit sets the control entry boundary in such a manner that the first distance to the inside of the road from the lane indication line is proportional to the road'"'"'s curvature.

12. The lane-keeping control system as claimed in claim 10, wherein the boundary setting unit sets the control entry boundary and the control release boundary to coincide with each other on a straight road, but not to coincide with each other on a curved road.

13. The lane-keeping control system as claimed in claim 12, wherein the lane-keeping control torque producing unit produces torque which urges the vehicle to follow the curved road when the vehicle is positioned between the control entry boundary and the control release boundary in the curved road.

14. The lane-keeping control system as claimed in claim 1, wherein the lane-keeping control system comprises:

a look-ahead distance setting unit for setting a look-ahead distance on the basis of at least one information item of a vehicle condition and a road condition;

a lane information acquiring unit for acquiring lane information in accordance with the set look-ahead distance;

an auxiliary steering torque calculating unit for calculating auxiliary steering torque for lane-keeping control on the basis of the acquired lane information; and

a lane-keeping control unit for conducting lane-keeping control by producing the calculated auxiliary steering torque at a steering control apparatus.

15. The lane-keeping control system as claimed in claim 14, wherein the vehicle condition includes the vehicle'"'"'s velocity, and the road condition includes at least one of the road'"'"'s curvature and width.

16. The lane-keeping control system as claimed in claim 15, wherein the look-ahead distance setting unit sums a first look-ahead distance corresponding to the vehicle'"'"'s velocity, a second look-ahead distance corresponding to the road'"'"'s curvature, and a third look-ahead distance corresponding to the vehicle'"'"'s width, and sets the value obtained thereby as the look-ahead distance.

17. The lane-keeping control system as claimed in claim 16, wherein the first look-ahead distance proportionally corresponds to the vehicle'"'"'s velocity in a predetermined vehicle'"'"'s velocity range, the second look-ahead distance proportionally corresponds to the road'"'"'s curvature in a predetermined road'"'"'s curvature range, and the third look-ahead distance proportionally corresponds to the road'"'"'s width in a predetermined road'"'"'s width range.

18. A lane-lane keeping control method comprises the steps of:

calculating an estimated control entry boundary arrival time to be taken by a vehicle to arrive at a control entry boundary, wherein the control entry boundary is set for entering lane-keeping control for the vehicle;

calculating a look-ahead distance on the basis of the estimated control entry boundary arrival time and the vehicle'"'"'s velocity;

calculating a crosswise error of the vehicle estimated ahead of the look-ahead distance;

determining whether to enter the lane-keeping control on the basis of the crosswise error and the control entry boundary;

producing lane-keeping control torque in a direction opposite to the lane-departure direction when it is determined that it is necessary to enter lane-keeping control as the result of the determination by the lane-keeping control entry determining unit, wherein the lane-keeping control torque urges the vehicle to return to the inside of the control entry boundary; and

releasing the lane-keeping control torque when it is determined that the vehicle has returned to the inside of a control release boundary after the lane-keeping control torque was produced, wherein the control release boundary is set for releasing the lane-keeping control for the vehicle.