Vehicle behavior control device

• US 20050029754A1
• Filed: 07/02/2004
• Published: 02/10/2005
• Est. Priority Date: 07/08/2003
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ueno, Hiroshi, Yamada, Noritaka, Miwa, Yukihisa, Kobayashi, Yasushi
• Granted Patent: US 7,337,047 B2
• Time in Patent Office: Days
• US Class Current: 280/5.502
• CPC Class Codes: B60G 2800/0124 Roll-over conditions
• CPC Class Codes: B60G 2800/922 EBV - Electronic brake force distribution
• CPC Class Codes: B60T 2230/03 Overturn, rollover
• CPC Class Codes: B60T 8/17554 specially adapted for enhancing stability around the vehicles longitudinal axle, i.e. roll-over prevention road vehicle drive control systems for roll-over prevention otherwise than by controlling a particular sub-unit B60W30/04
• CPC Class Codes: B60T 8/17558 specially adapted for collision avoidance or collision mitigation road vehicle drive control systems for collision avoidance otherwise than by controlling a particular sub-unit B60W30/09
• CPC Class Codes: B60T 8/243 for roll-over protection

Abstract

The inventive vehicle behavior control device employs a novel control strategy, suppressing deterioration of a vehicle behavior which would be induced during control processes, and being useful especially for correcting or inhibiting excessive deterioration of a vehicle behavior such as when a risk of rolling-over is detected. The device firstly judges if a possibility of rolling-over of the vehicle is high and calculates a target braking control amount for reducing the possibility of rolling-over in accordance with the result of the judgment of a possibility of rolling-over of the vehicle, where the target control amount when the possibility of rolling-over is high is set higher than when the possibility is low. Then, under control of the inventive control device, wheel braking force is controlled based upon the target braking control amount. After the starting of control of the wheel braking force, however, increasing and decreasing gradients of wheel braking force is restricted when a high possibility of rolling-over is judged.

Claims

1. A device for controlling a behavior of a vehicle;

the device judging a possibility of rolling-over of the vehicle;

calculating a target braking control amount for reducing the possibility of rolling-over such that the target braking control amount when the possibility of rolling-over is high is higher than when the possibility is low;

controlling wheel braking force based upon the target braking control amount;

wherein increasing and decreasing gradients of the wheel braking force is restricted after the starting of control of the wheel braking force based upon the target braking control amount when the possibility is high.

2. A device according to claim 1, wherein a possibility of rolling-over of the vehicle based upon driving operation of a driver and a possibility of rolling-over of the vehicle based upon the behavior of the vehicle are judged;

and the target braking control amount when the possibility of rolling-over of the vehicle based upon the driving operation is high is rendered larger than that when the possibility of rolling-over of the vehicle based upon the driving operation is not high while the possibility of rolling-over of the vehicle based upon the vehicle behavior is high.

3. A device according to claim 1, wherein a possibility of rolling-over of the vehicle based upon a driving operation of a driver is judged based upon a steering angle and a steering speed;

and a possibility of rolling-over based upon the behavior of the vehicle is judged based upon condition of the vehicle.

4. A device according to claim 3, wherein the condition of the vehicle includes a yaw rate, a lateral deceleration and vehicle speed.

5. A device according to claim 2, the device detecting steering condition for emergency avoidance;

and wherein, when the steering condition for emergency avoidance is detected, it is judged that the possibility of rolling-over of the vehicle based upon the driving operation is high.

6. A device according to claim 1, wherein the target braking control amount is a target wheel slip ratio, and the wheel braking force is feedback-controlled based upon the target wheel slip ratio and an actual wheel slip ratio.

7. A device according to claim 1, wherein a weight of the vehicle is detected;

the target braking control amount is modified based upon the vehicle weight, the target control amount being set larger as the vehicle weight is heavier.

8. A device according to claims 1, wherein a liability to rolling of the vehicle is detected;

and the target braking control amount is modified based upon the liability to rolling, the target braking control amount being set larger as the liability to rolling is larger.

9. A device according to claim 2, wherein the increasing and decreasing gradients are restricted when the possibility of rolling-over of the vehicle based upon the driving operation is high and the increasing and decreasing gradients are not restricted when the possibility of rolling-over of the vehicle based upon the driving operation is not high while the possibility of rolling-over of the vehicle based upon the vehicle behavior is high.

10. A device for controlling a behavior of a vehicle;

the device judging a possibility of rolling-over of the vehicle;

calculating a target braking control amount for reducing the possibility of rolling-over such that the target braking control amount when the possibility of rolling-over is high is higher than when the possibility is low;

controlling wheel braking force based upon the target braking control amount;

wherein a degree of rolling oscillation or pitching oscillation of the vehicle is judged when the possibility is high; and

increasing and decreasing gradients of wheel braking force when the degree of rolling oscillation or pitching oscillation is higher is restricted to a larger degree than when the degree of rolling or pitching oscillation is lower.

11. A device according to claim 10, wherein a degree of the restriction of increasing and decreasing gradients of the wheel braking force under control of the device based upon the target braking control amount is varied depending upon a degree of the rolling and/or pitching oscillations.

12. A device according to claims 10, wherein a possibility of rolling-over of the vehicle based upon driving operation of a driver and a possibility of rolling-over of the vehicle based upon the behavior of the vehicle are judged;

and the target braking control amount when the possibility of rolling-over of the vehicle based upon the driving operation is high is rendered larger than that when the possibility of rolling-over of the vehicle based upon the driving operation is not high while the possibility of rolling-over of the vehicle based upon the vehicle behavior is high.

13. A device according to claim 10, wherein a possibility of rolling-over of the vehicle based upon a driving operation of a driver is judged based upon a steering angle and a steering speed;

and a possibility of rolling-over based upon the behavior of the vehicle is judged based upon condition of the vehicle.

14. A device according to claim 13, wherein the condition of the vehicle includes a yaw rate, a lateral deceleration and vehicle speed.

15. A device according to claim 12, the device detecting steering condition for emergency avoidance;

and wherein, when the steering condition for emergency avoidance is detected, it is judged that the possibility of rolling-over of the vehicle based upon the driving operation is high.

16. A device according to claim 10, wherein the target braking control amount is a target wheel slip ratio, and the wheel braking force is feedback-controlled based upon the target wheel slip ratio and an actual wheel slip ratio.

17. A device according to claim 10, wherein a weight of the vehicle is detected;

the target braking control amount is modified based upon the vehicle weight, the target control amount being set larger as the vehicle weight is heavier.

18. A device according to claim 10, wherein a liability to rolling of the vehicle is detected;

and the target braking control amount is modified based upon the liability to rolling, the target braking control amount being set larger as the liability to rolling is larger.

19. A device according to claim 12, wherein the increasing and decreasing gradients are restricted when the possibility of rolling-over of the vehicle based upon the driving operation is high and the increasing and decreasing gradients are not restricted when the possibility of rolling-over of the vehicle based upon the driving operation is not high while the possibility of rolling-over of the vehicle based upon the vehicle behavior is high.