Lane departure prevention system

• US 20060149448A1
• Filed: 12/20/2005
• Published: 07/06/2006
• Est. Priority Date: 12/21/2004
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Matsumoto, Shinji, Tange, Satoshi
• Granted Patent: US 7,539,566 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/083 using active brake actuation
• CPC Class Codes: B60T 2201/086 using driver related features
• CPC Class Codes: B60T 2201/089 using optical detection
• CPC Class Codes: B60T 8/17557 specially adapted for lane departure prevention road vehicle drive control systems for lane keeping otherwise than by controlling a particular sub-unit B60W30/12

Abstract

A lane departure prevention system comprises a traveling status detecting unit for detecting current lateral displacement and current yaw angle of a vehicle relative to a lane of travel, a departure detecting unit for detecting whether the vehicle is tending to depart from the lane of travel on the basis of current lateral displacement of the vehicle relative to the lane of travel as detected by the traveling status detecting unit; and a departure avoidance control unit for controlling the vehicle to avoid lane departure when the departure detecting unit detects that the vehicle is tending to depart from the lane of travel. The departure avoidance control unit calculating the extent of control necessary to avoid lane departure on the basis of current yaw angle of the vehicle detected by the traveling status detecting unit. Provision is made for preventing lane departure on a curving as well as a straight road.

Claims

1. A lane departure prevention system comprising:

a traveling status detecting unit for detecting current lateral displacement and current yaw angle of a vehicle relative to a lane of travel;

a departure detecting unit for detecting whether the vehicle is tending to depart from the lane of travel on the basis of current lateral displacement of the vehicle relative to the lane of travel as detected by said traveling status detecting unit; and

a departure avoidance control unit for controlling the vehicle to avoid lane departure when said departure detecting unit detects that the vehicle is tending to depart from the lane of travel,

said departure avoidance control unit calculating the extent of control necessary to avoid lane departure on the basis of current yaw angle of the vehicle detected by said traveling status detecting unit.

2. The lane departure prevention system according to claim 1, wherein said departure avoidance control unit calculates the extent of control to increase as the yaw angle increases in a lane departing direction.

3. The lane departure prevention system according to claim 1, wherein when the yaw angle is in a departure-avoiding direction, the departure-avoiding control unit calculates the extent of control to be smaller than that when the yaw angle is in the lane departing direction.

4. The lane departure prevention system according to claim 1, further including a road curvature detecting unit for detecting road curvature and the curve direction of the lane of travel,

wherein said departure avoidance control unit calculates the extent of control on the basis of current yaw angle, and on the basis of the road curvature and the lane curve direction detected by the road curvature detecting unit.

5. The lane departure prevention system according to claim 4, wherein said departure avoidance control unit calculates the extent of control to increase as the road curvature increases, when the vehicle is tending to depart outwardly from the curve direction.

6. The lane departure prevention system according to claim 1, wherein said departure avoidance control unit calculates a reference control extent on the basis of current lateral displacement of the vehicle detected by said traveling status detecting unit, and

wherein said departure avoidance control unit corrects the reference control extent on the basis of current yaw angle and then calculates the extent of control necessary to avoid lane departure.

7. The lane departure prevention system according to claim 4, wherein said departure avoidance control unit calculates a reference control extent on the basis of current lateral displacement of the vehicle detected by the traveling status detecting unit, and

wherein said departure avoidance control unit corrects the reference control extent on the basis of current yaw angle, the road curvature, and the curve direction and then calculates the control extent necessary to avoid lane departure.

12. The lane departure prevention system according to claim 1, wherein said departure avoidance control unit exercises said control by generating a yaw moment in a direction in which the vehicle avoids lane departure.

8. A lane departure prevention system comprising:

a traveling status detecting unit for detecting current lateral displacement and current yaw angle of a vehicle relative to a lane of travel;

a departure detecting unit for detecting whether the vehicle is tending to depart from the lane of travel on the basis of current lateral displacement of the vehicle relative to the lane of travel as detected by said traveling status detecting unit; and

a departure avoidance control unit for controlling the vehicle to avoid lane departure when said departure detecting unit detects that the vehicle is tending to depart from the lane of travel,

a road curvature detecting unit for detecting curvature of the lane of travel; and

a departure angle estimating unit for estimating the yaw angle of the vehicle with respect to the lane of travel as a departure angle after a predetermined period of time has passed, on the basis of the current yaw angle of the vehicle detected by the traveling status detecting unit and the road curvature detected by the road curvature detecting unit,

said departure avoidance control unit calculating the extent of control necessary to avoid lane departure on the basis of the departure angle of the vehicle estimated by said departure angle estimating unit.

9. The lane departure prevention system according to claim 8, wherein said departure avoidance control unit calculates the extent of control to increase as the estimated departure angle increases in a lane departing direction.

10. The lane departure prevention system according to claim 8, wherein when the estimated departure angle is in a departure-avoiding direction, said departure avoidance control unit calculates the extent of control to be smaller than that when the estimated departure angle is in the lane departing direction.

11. The lane departure prevention system according to claim 8, wherein said departure avoidance control unit calculates a reference control extent on the basis of current lateral displacement of the vehicle detected by said traveling status detecting unit, and

wherein said departure avoidance control unit corrects the reference control extent on the basis of the estimated departure angle and then calculates the control extent necessary to avoid lane departure.