Active rollover protection utilizing steering angle rate map

• US 20050222727A1
• Filed: 04/02/2004
• Published: 10/06/2005
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Continental Teves Incorporated (Continental AG)
• Inventors: Hille, Christian A., McClain, Jeremy J.
• Granted Patent: US 7,369,927 B2
• Time in Patent Office: Days
• US Class Current: 701/38
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2030/043 about the roll axis
• CPC Class Codes: B60W 2050/0026 Lookup tables or parameter maps
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2510/205 Steering speed
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 30/04 related to roll-over prevention

Abstract

An apparatus and method for protecting against rollover in a vehicle. The method and apparatus determine a rollover tendency of the vehicle based on the lateral acceleration, the vehicle speed and the change rate of the steering angle. A database of empiric data is preferably provided that includes values for a critical change rate of the steering angle corresponding to specific lateral accelerations in specific vehicle speeds. A critical change rate of the steering angle is determined based on the sensed lateral acceleration and vehicle speed.

Claims

1. A method for protecting against rollover in a vehicle comprising the steps of:

sensing a lateral acceleration;

sensing a vehicle speed;

sensing a change rate of the steering angle;

determining a rollover tendency of the vehicle based on the lateral acceleration, vehicle speed, and change rate of the steering angle; and

reducing the rollover tendency of the vehicle.

2. The method of claim 1, further comprising the step of providing a database of empiric data including values for a critical change rate of the steering angle corresponding to specific lateral accelerations and specific vehicle speeds.

3. The method of claim 2, further comprising the step of determining a critical change rate of the steering angle based on the lateral acceleration and vehicle speed.

4. The method of claim 3, wherein the step of determining a rollover tendency includes comparing the change rate of the steering angle to the critical change rate of the steering angle.

5. The method of claim 1, wherein the step of determining a rollover tendency includes determining a critical change rate of the steering angle from a database having critical change rate values corresponding to specific combinations of lateral acceleration and vehicle speed.

6. The method of claim 5, wherein the critical change rate values are empirically determined for the vehicle.

7. The method of claim 5, wherein the step of reducing the rollover tendency includes generating a correction signal based on the change rate of the steering angle and the critical change rate value.

8. The method of claim 1, wherein the step of reducing the rollover tendency includes the steps of generating a correction signal indicative of rollover tendency and sending the correction signal to an actuator for reducing the rollover moment of the vehicle.

9. The method of claim 8, wherein the actuator is a steer-by-wire system, and wherein the steer-by-wire system reduces driver input so the input never exceeds a critical change rate of the steering angle.

10. The method of claim 8, wherein the correction signal has a variable strength.

11. The method of claim 7, wherein the correction signal is generated when the change rate of the steering angle is greater than the critical change rate value.

12. A method of protecting against rollover in a vehicle comprising the steps of:

detecting a change rate of the steering angle;

determining a critical change rate corresponding to the vehicle'"'"'s current speed and the vehicle'"'"'s current lateral acceleration;

comparing the critical change rate to the detected change rate of the steering angle to determine a rollover tendency; and

reducing the rollover tendency of the vehicle.

15. An active rollover protection system for a motor vehicle comprising:

a lateral acceleration sensor providing a first signal indicative of a lateral acceleration of the vehicle;

a vehicle speed sensor providing a second signal indicative of a vehicle speed;

a steering angle sensor providing a third signal indicative of a change rate of the steering angle;

a database having critical change rates values corresponding to specific combinations of lateral acceleration and vehicle speed;

a controller receiving the first, second and third signals, the controller determining the critical change rate value corresponding to the first and second signals, the controller comparing the critical change rate value with the third signal to determine a rollover tendency, the controller sending a signal; and

an actuator capable of reducing the rollover tendency, the controller sending a correction signal to the actuator indicative of the rollover tendency.

13. The method of claim 18, wherein the step of determining a critical change rate of the steering angle includes reading from a database having critical change rate values corresponding to specific combinations of lateral acceleration and vehicle speed.

14. The method of claim 18, wherein the step of reducing the rollover tendency includes generating a correction signal indicative of the rollover tendency and sending the correction signal to an actuator for reducing the rollover moment of the vehicle.

16. The active rollover protection system of claim 15, wherein the actuator is a brake control system.

17. The active rollover protection system of claim 15, wherein the actuator is an engine control unit.

18. The active rollover protection system of claim 15, wherein the actuator is an active steering system.

19. The active rollover protection system of claim 15, wherein the actuator reduces the rollover moment of the vehicle.

20. The active rollover protection system of claim 15, the correction signal having a variable strength substantially proportional to a comparison between the critical change rate value and the change rate of the steering angle.