Traffic lane deviation preventing system for a vehicle

• US 8,311,729 B2
• Filed: 03/28/2007
• Issued: 11/13/2012
• Est. Priority Date: 03/29/2006
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Saito, Toru, Kudo, Shinya, Oyama, Hajime
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): PECHE, JORGE O
• Application Number:
  US11/727,752
• Publication Number:
  US 20070233386A1
• Time in Patent Office: 2,057 Days
• Field of Search: 701/42, 701/117, 701/300, 701/122, 701/301, 701/466
• US Class Current: 701/300
• CPC Class Codes: B60W 2540/22 Psychological state; Stress level or workload
• CPC Class Codes: B60W 2540/221 Physiology, e.g. weight, heartbeat, health or special needs
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• 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
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

A traffic lane deviation preventing system includes a traffic line detecting unit for detecting traffic line positions on a road, a control unit for determining a possibility of a vehicle'"'"'s deviation from a traffic line based on the traffic line positions detected by the traffic line detecting unit and setting a travel target point to which the vehicle is to travel if it is determined that there is a possibility of a traffic line deviation. The control unit moves the travel target point toward the center of a traffic lane according to the passage of a control operation time.

Claims

1. A traffic lane deviation preventing system for a vehicle, comprising:

a traffic line detector for detecting the position of a traffic line on a road;

a controller for determining a possibility of vehicle deviation from the traffic line, based on the position of the traffic line detected by said traffic line detector,

said controller is configured to carry out deviation preventing control by setting a travel target point and transmitting a signal to a responsive unit so that the vehicle travels toward the travel target point when it is determined that vehicle deviation from the traffic line is possible; and

a counter for counting the passage of a control operation time of said deviation preventing control, wherein

said controller is further configured to set a current travel target point at a point moved from a previous travel target point set in a previous sampling cycle by a prescribed distance toward the center of a traffic lane in which the vehicle travels, with each sampling cycle, until said control operation time counted by said counter becomes a prescribed time.

2. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured such that, if the traffic line position is no longer detected by said traffic line detector after the start of control operation by said deviation preventing control, said controller continues to move said travel target point based on the previously detected position of the traffic line and continues the control operation by said deviation preventing control.

3. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to set said travel target point for the first time, to a point a prescribed distance ahead of the vehicle and a distance equal to a half of the vehicle width apart from the traffic line from which the vehicle is likely to deviate.

4. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to set said travel target point for the first time to a point a prescribed distance ahead of the vehicle and apart from the traffic line by the present distance between the vehicle and the traffic line from which the vehicle is likely to deviate.

5. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to set said travel target point for the first time to a point a prescribed distance ahead of the vehicle where a change at most equal to a prescribed threshold is generated in at least one of the yaw rate, the steering wheel torque, and the steering wheel angle of the steering wheel of the vehicle.

6. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to set said travel target point for the first time, to a point a prescribed distance ahead of the vehicle where a change larger than a prescribed threshold is generated in at least one of the yaw rate, the steering wheel torque, and the steering wheel angle of the steering wheel of the vehicle.

7. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to move said travel target point in said direction toward the center of said traffic lane by a prescribed distance per unit time.

8. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to move said travel target point so that the position of said travel target point at the end of the control operation by said deviation preventing control is in the center of a traffic lane calculated from the positions of traffic lines on the right and left of the vehicle detected by said traffic line detector.

9. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to move said travel target point so that said travel target point at the end of the control operation by said deviation preventing control is apart by a distance equal to a half of the vehicle width from a traffic line from which the vehicle is likely to deviate.

10. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured such that, if said travel target point reaches a prescribed position before said control operation time counted by said count means reaches the prescribed time, said controller ends the control operation by said deviation preventing control.

11. The traffic lane deviation preventing system for a vehicle according to claim 10, wherein said prescribed position is in the center of a traffic lane calculated from the positions of traffic lines on the right and left of the vehicle detected by said traffic line detector.

12. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to end the control operation by said deviation preventing control when an end of the vehicle deviating from a traffic line protrudes from the traffic line at least by a prescribed distance on the outer side of the traffic line.

13. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein, said controller is further configured such that after said controller ends the deviation preventing control, said controller does not start deviation preventing control when the vehicle moves away from the traffic line or continues to move across the traffic line.

14. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to end the control operation by said deviation preventing control when the steering of the steering wheel by the driver of the vehicle is detected.

15. The traffic lane deviation preventing system for a vehicle according to claim 14, wherein the system is further configured to detect the steering of the steering wheel by said driver by any of:

a steering wheel torque sensor which is configured to detect when a steering wheel torque exceeding a prescribed threshold is input, a steering wheel torque sensor which is configured to detect when a steering wheel torque continues to be input for a period exceeding prescribed duration, and a steering wheel angle sensor which is configured to detect when a differential value of the steering wheel angle of the steering wheel exceeds a prescribed threshold.

16. The traffic lane deviation preventing system for a vehicle according to claim 1, further comprising a solid object detector for detecting a solid object in an image produced by image-sensing a path ahead of the running vehicle including a road, wherein,

said controller is further configured such that, when a solid object is detected by said solid object detector on the side of a traffic line from which the vehicle is likely to deviate, said controller shortens the control operation time set at said counter and increases the moving distance of said travel target point per unit time.

17. The traffic lane deviation preventing system for a vehicle according to claim 1, further comprising a solid object detector for detecting a solid object in an image produced by image-sensing a path ahead of the running vehicle including a road, wherein,

said controller is further configured such that, when a solid object is detected by said solid object detector on a traffic line on the opposite side to the traffic line from which the vehicle is likely to deviate, said controller stops the movement of said travel target point in a location a prescribed distance apart from said solid object or ends the control operation by said deviation preventing control.

18. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured to indicate at a display connected thereto, or to output an audio sound, for notifying that the deviation preventing control is active.

19. The traffic lane deviation preventing system for a vehicle according to claim 1, wherein said controller is further configured such that, if the traffic line from which the vehicle is likely to deviate is indicated as a continuous line, said controller sets a control operation time that is shorter than a control operation time that would be set for a traffic line indicated as a broken line.

20. The traffic lane deviation preventing system for a vehicle according to claim 1, further comprising a wakefulness estimator for estimating the wakefulness of the driver, wherein

said controller is further configured to shorten the control operation time set at said counter and increase the moving distance of said travel target point per unit time if it is determined that the wakefulness of the driver is low based on an estimation result by said wakefulness estimator.

21. A traffic lane deviation preventing system for a vehicle, comprising:

a traffic line detector for detecting the position of a traffic line on a road;

a controller for determining a possibility of vehicle deviation from the traffic line based on the position of the traffic line detected by said traffic line detector,

said controller configured to carry out deviation preventing control by setting a travel target point and transmitting a signal to a responsive unit so that the vehicle travels toward the travel target point when it is determined that vehicle deviation from the traffic line is possible; and

a counter for counting sampling cycles based on a control operation time of said deviation preventing control, during which control operation time the vehicle travels toward the travel target point, wherein

said controller is further configured to control said travel target point to move from a previous travel target point in a direction toward the center of a traffic lane in which the vehicle travels, with each sampling cycle, until said control operation time becomes a prescribed time.

22. The traffic lane deviation preventing system for a vehicle according to claim 21, wherein said controller is further configured to control said travel target point to move a calculated moving distance for each sampling cycle based on a predetermined control operation time.

23. The traffic lane deviation preventing system for a vehicle according to claim 22, wherein said controller is further is configured to selectively correct the calculated moving distance of said travel target point for one or more sampling cycles after the start of the control operation time, and during the passing of the control operation time.