Selectable lane-departure warning system and method

• US 20070069874A1
• Filed: 09/22/2006
• Published: 03/29/2007
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Huang, Jihua, Chin, Yuen-Kwok, Lin, William
• Granted Patent: US 7,561,032 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B62D 15/029 Steering assistants using warnings or proposing actions to the driver without influencing the steering system

Abstract

A selectable lane departure detection system (10) adapted for use by an operator, and with a vehicle (12) traveling upon a thoroughfare having lane-markings (16), and including at least one vehicle condition sensor (22 through 28), a tracking sensor (20) or differential global positioning system (38) configured to determine the location and configuration of the lane-markings (16), and a controller (32) communicatively coupled to the sensors (20 through 28), and configured to determine a spatial relationship between the vehicle (12) and lane-markings (16), determine a sporty driving maneuver by or preference of the operator, modify a predefined warning threshold when so determined, compare the relationship to the adjusted threshold, and issue a warning when the relationship does not exceed the threshold.

Claims

1. A selectable lane-departure warning system adapted for use with a vehicle traveling upon a thoroughfare having at least one lane-marking, and by an operator, said system comprising:

a driving-mode selection device selectable between a plurality of driving modes by the operator, and presenting a current selected driving mode;

at least one sensor operable to detect the relative location and configuration of the lane-marking; and

a controller communicatively coupled to the device and sensor, and configured to modify a predetermined warning threshold to one of a plurality of adjusted thresholds, wherein each adjusted threshold is correlated to a separate one of the plurality of driving modes,

said sensor and controller being cooperatively configured to determine a spatial relationship between the vehicle and lane-marking, and produce a lane departure warning, when the spatial relationship exceeds the adjusted threshold correlative to the current selected driving mode.

2. The system as claimed in claim 1,

said driving modes including a sporty driving mode,

said controller being configured to modify the pre-determined threshold, when the sporty driving mode is selected.

3. The system as claimed in claim 1,

said at least one sensor being a vision sensor including a camera, and image processing unit.

4. The system as claimed in claim 1,

said spatial relationship being the time-to-lane-crossing (TTLC), as measured between the vehicle and lane-marking.

5. The system as claimed in claim 1,

said controller being configured to produce the warning, when the absolute relative distance between the vehicle and lane-marking is less than a predetermined threshold, and then deactivate the warning, when the relative distance returns to a value greater than the threshold, so as to present a warning zone.

6. The system as claimed in claim 1,

said sensor being further configured to determine the curvature of said lane-marking,

said controller being further configured to compare the curvature to a curvature threshold, so as to determine a curved lane, and reduce the warning threshold, when a curved lane is determined.

7. The system as claimed in claim 6,

said controller being further configured to modify the predetermined threshold by multiplying it by a reduction factor, k.

8. The system as claimed in claim 7,

said factor being a function of the vehicle speed, and yaw rate, k(ν

_x,r).

9. The system as claimed in claim 1;

and

at least one vehicle condition sensor configured to determine a current vehicle condition,

said controller being communicatively coupled to said at least one vehicle condition sensor, and further configured to modify the predetermined threshold based on the condition, so as to correlate each of said adjusted thresholds with a driving mode and the condition.

10. The system as claimed in claim 9,

said at least one vehicle condition sensor including a steering angle sensor, an accelerometer, a yaw gyro, or a wheel speed sensor.

11. The system as claimed in claim 10;

and

a plurality of vehicle condition sensors including a steering angle sensor, an accelerometer, a yaw gyro, and a wheel speed sensor.

12. The system as claimed in claim 9,

said tracking sensor and controller being cooperatively configured to detect left and right lane-markings, determine a roadway centerline, and the roadway heading,

said at least one condition sensor including a vehicle speed sensor and a heading sensor, and configured to provide a current vehicle speed, ν

_x, and heading, said controller being configured to predict a lateral displacement, from the center line at a future time, Δ

y(t_ahead), and modify the predetermined threshold based on the predicted lateral displacement.

13. The system as claimed in claim 12,

said condition and tracking sensors, and controller being cooperatively configured to determine an instantaneous lateral displacement between the vehicle and centerline, Δ

y,

said controller being further configured to predict the lateral displacement at t_ahead in accordance with the following formula;

Δ

Y(t_ahead)=Δ

y+(ν

_xt_ahead)sin(road_heading—

vehicle—

heading).

14. The system as claimed in claim 13,

said tracking sensor and controller being cooperatively configured to further determine the average lane width, lane width,

said spatial relationship being the time-to-lane-crossing (TTLC) between the vehicle and lane-marking, and determined according to the following formula:

$\mathrm{TTLC}=\frac{\left(\mathrm{lane\_width}/2\right)-\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>y}{v_x\times <br><br>\sin <br><br>\left(\mathrm{road\_heading}-\mathrm{vehicle\_heading}\right)}.$

15. A self-adjusting lane-departure warning system adapted for use with a vehicle traveling upon a thoroughfare having at least one lane-marking, said system comprising:

at least one vehicle condition sensor configured to determine a current vehicle condition,

at least one tracking sensor operable to detect the relative location and configuration of the lane-marking; and

a controller communicatively coupled to the vehicle condition and tracking sensors, and configured to compare the condition to a condition threshold, and autonomously modify a predetermined warning threshold to an adjusted threshold, wherein the adjusted threshold is correlated to the condition, when the condition exceeds the condition threshold,

said tracking sensor and controller being cooperatively configured to determine a spatial relationship between the vehicle and lane-marking, and produce a lane departure warning, when the spatial relationship exceeds the adjusted threshold.

16. The system as claimed in claim 15,

said at least one vehicle condition sensor including a steering angle sensor, an accelerometer, a yaw gyro, or a wheel speed sensor, so that said condition includes a steering wheel angle, a lateral acceleration value, a yaw rate, or a vehicle speed.

17. The system as claimed in claim 15,

said tracking sensor and controller being further configured to cooperatively determine a lane curvature, and compare the lane curvature to a curvature threshold, so as to determine a curved lane,

said controller being further configured to autonomously modify the predetermined warning threshold to the adjusted threshold, when the condition exceeds the condition threshold, and a curved lane is determined.

18. A selectable lane departure detection system adapted for use by an operator, and with a vehicle traveling upon a thoroughfare, said system comprising:

at least one vehicle condition sensor configured to determine a current vehicle condition;

a differential global positioning system (DGPS) configured to determine the current position coordinates of the vehicle;

a map database including a plurality of maps, wherein each map includes a plurality of thoroughfare position points, and indicia correlated with each of the points, and the indicia includes indication of a lane-marking location; and

a controller communicatively coupled to the vehicle condition sensor, DGPS, and database, and configured to match the current position coordinates with a thoroughfare position point, compare the condition to a condition threshold, and autonomously modify a predetermined warning threshold to an adjusted threshold, when the condition exceeds the condition threshold,

said controller, DGPS, and database being cooperatively configured to determine a spatial relationship between the vehicle position point and the nearest lane-marking position point, and produce a lane departure warning, when the spatial relationship exceeds the adjusted threshold.

19. The system as claimed in claim 18,

said indicia further including a thoroughfare curvature at the vehicle position point,

said controller being further configured to compare the curvature to a curvature threshold, so as to determine a curved lane, modify the predetermined threshold when the condition exceeds the condition threshold, and the curvature exceeds the curvature threshold.

20. The system as claimed in claim 18,

said DGPS, and controller being cooperatively configured to further determine a current vehicle heading,

said indicia further including a thoroughfare heading at the vehicle point,

said spatial relationship being the time-to-lane-crossing (TTLC) between the vehicle and nearest lane-marking, wherein the TTLC is a function of the difference between the vehicle and thoroughfare headings.