Vehicle stability control with lateral dynamics feedback

• US 20070112474A1
• Filed: 11/16/2005
• Published: 05/17/2007
• Est. Priority Date: 11/16/2005
• 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: Ryu, Jihan, Chen, Shih-Ken, Moshchuk, Nikolai
• Granted Patent: US 7,440,824 B2
• Time in Patent Office: Days
• US Class Current: 701/1
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/17551 determining control parameters related to vehicle stability used in the regulation, e.g. by calculations involving measured or detected parameters

Abstract

A system and method for estimating vehicle side-slip velocity that includes measuring the lateral acceleration of the vehicle, measuring the yaw rate of the vehicle, measuring the longitudinal speed of the vehicle and measuring the steering angle of the vehicle. The measured longitudinal speed is corrected to provide a true longitudinal speed using a filter factor based on the vehicle-dependent parameters and a steering angle. A constant is defined based on the measured longitudinal speed and a function is defined based on the combination of the vehicle-dependent parameters and the lateral acceleration. Side-slip acceleration is calculated using the measured lateral acceleration, the true longitudinal speed, the yaw rate, the constant and the function.

Claims

1. A method for estimating side-slip of a vehicle, said method comprising:

measuring the lateral acceleration of the vehicle and providing a measured lateral acceleration signal;

measuring the yaw rate of the vehicle and providing a measured yaw rate signal;

measuring the longitudinal speed of the vehicle and providing a measured longitudinal speed signal;

correcting the measured longitudinal speed signal to provide a true longitudinal speed signal;

defining a constant based on the measured longitudinal speed signal;

defining a function based on predetermined vehicle-dependent parameters and the measured lateral acceleration signal; and

estimating the side-slip by combining the measured lateral acceleration signal, the measured yaw rate signal, the true longitudinal speed signal, the constant and the function.

2. The method according to claim 1 wherein estimating the side-slip includes using the equation:

{dot over (V)}<sub>y—

estimated</sub>=A<sub>y—

measured</sub>−

r<sub>—

measured</sub>V<sub>x—

true</sub>−

kƒ

(A<sub>y—

measured</sub>)

where {dot over (V)}<sub>y—

estimated</sub> is estimated side-slip acceleration, A<sub>y—

measured</sub> is the measured lateral acceleration signal, r<sub>—

measured</sub> is the measured yaw rate signal, V<sub>x—

true</sub> is the true longitudinal speed signal, k is the constant and ƒ

is the function.

3. The method according to claim 1 wherein correcting the measured longitudinal speed signal includes filtering the measured longitudinal speed signal using vehicle-dependent parameters to provide a filtered longitudinal speed signal.

4. The method according to claim 3 wherein filtering the measured longitudinal speed signal includes using the equation:

5. The method according to claim 3 wherein correcting the measured longitudinal speed signal further includes providing a steering angle correction to the filtered longitudinal speed signal.

6. The method according to claim 5 wherein correcting the longitudinal speed signal includes providing a hand-wheel signal indicative of the position of a vehicle hand-wheel, ratioing the hand-wheel signal to provide a ratio signal and multiplying the ratio signal by the filtered longitudinal speed signal.

7. The method according to claim 1 wherein defining the function includes using a first set of vehicle-dependent parameters if the measured longitudinal speed signal is below a predetermined value and using a second set of vehicle-dependent parameters if the measured longitudinal speed signal is greater than or equal to the predetermined value.

8. The method according to claim 1 wherein defining the function include using the equation:

9. The method according to claim 1 wherein estimating the side-slip includes multiplying the constant and the function.

10. The method according to claim 1 wherein the method is used in a stability control system for the vehicle.

11. A system for estimating side-slip of a vehicle, said system comprising:

a lateral acceleration sensor for measuring the lateral acceleration of the vehicle and providing a measured lateral acceleration signal;

a yaw rate sensor for measuring the yaw rate of the vehicle and providing a measured yaw rate signal;

a longitudinal speed sensor for measuring the longitudinal speed of the vehicle and providing a measured longitudinal speed signal; and

a side-slip estimation processor for estimating the side-slip of the vehicle, said processor correcting the measured longitudinal speed signal to provide a true longitudinal speed signal, defining a constant based on the measured longitudinal speed signal, and defining a function based on predetermined vehicle-dependent parameters and the measured lateral acceleration signal, said processor estimating the side-slip by combining the measured lateral acceleration signal, the measured yaw rate signal, the true longitudinal speed signal, the constant and the function.

12. The system according to claim 11 wherein the side-slip estimation processor estimates the side-slip using the equation:

{dot over (V)}<sub>y—

estimated</sub>=A<sub>y—

measured</sub>−

r<sub>—

measured</sub>V<sub>x—

true</sub>−

kƒ

(A<sub>y—

measured</sub>)

where {dot over (V)}<sub>y—

estimated</sub> is estimated side-slip acceleration, A<sub>y—

measured</sub> is the measured lateral acceleration signal, r<sub>—

measured</sub> is the measured yaw rate signal, V<sub>x—

true</sub> is the true longitudinal speed signal, k is the constant and ƒ

is the function.

13. The system according to claim 11 wherein the side-slip estimation processor corrects the measured longitudinal speed signal by filtering the measured longitudinal speed signal using vehicle-dependent parameters to provide a filtered longitudinal speed signal.

14. The system according to claim 13 wherein the side-slip estimation processor filters the measured longitudinal speed signal using the equation:

15. The system according to claim 13 wherein the side-slip estimation processor corrects the measured longitudinal speed signal by providing a steering angle correction to the filtered longitudinal speed signal.

16. The system according to claim 15 wherein the side-slip estimation processor corrects the longitudinal speed signal by providing a hand-wheel signal indicative of the position of a vehicle hand-wheel, ratioing the hand-wheel signal to provide a ratio signal and multiplying the ratio signal by the filtered longitudinal speed signal.

17. The system according to claim 11 wherein the side-slip estimation processor defines the function by using a first set of vehicle-dependent parameters if the measured longitudinal speed signal is below a predetermined value and using a second set of vehicle-dependent parameters if the measured longitudinal speed signal is greater than or equal to the predetermined value.

18. The system according to claim 11 wherein the side-slip estimation processor defines the function by using the equation:

19. The system according to claim 11 wherein the side-slip estimation processor estimates the side-slip by multiplying the constant and the function.

21. The system according to claim 11 wherein the side-slip estimation processor estimates the side-slip using the equation:

{dot over (V)}<sub>y—

estimated</sub>=A<sub>y—

measured</sub>−

r<sub>—

measured</sub>V<sub>x—

true</sub>−

kƒ

(A<sub>y—

measured</sub>)

where {dot over (V)}<sub>y—

estimated</sub> is estimated side-slip acceleration, A<sub>y—

measured</sub> is the measured lateral acceleration signal, r<sub>—

measured</sub> is the measured yaw rate signal, V<sub>x—

true</sub> is the true longitudinal speed signal, k is the constant and ƒ

is the function.

22. The system according to claim 13 wherein the side-slip estimation processor filters the measured longitudinal speed signal using the equation:

23. The system according to claim 11 wherein the side-slip estimation processor defines the function by using the equation:

24. The system according to claim 11 wherein the side-slip estimation processor defines the function by using a first set of vehicle-dependent parameters if the measured longitudinal speed signal is below a predetermined value and using a second set of vehicle-dependent parameters if the measured longitudinal speed signal is greater than or equal to the predetermined value.

20. A system for estimating side-slip of a vehicle, said system comprising:

a lateral acceleration sensor for measuring the lateral acceleration of the vehicle and providing a measured lateral acceleration signal;

a yaw rate sensor for measuring the yaw rate of the vehicle and providing a measured yaw rate signal;

a longitudinal speed sensor for measuring the longitudinal speed of the vehicle and providing a measured longitudinal speed signal;

a hand-wheel angle sensor for measuring the position of a vehicle hand-wheel and providing a hand-wheel signal; and

a side-slip estimation processor for estimating the side-slip of the vehicle, said side-slip estimation processor correcting the measured longitudinal speed signal to provide a true longitudinal speed signal by filtering the measured longitudinal speed signal using vehicle-dependent parameters to provide a filtered longitudinal speed signal and correcting the filtered longitudinal speed signal to provide a steering angle correction using the hand-wheel signal, said side-slip estimation processor defining a constant based on the measured longitudinal speed signal and defining a function based on the predetermined vehicle-dependent parameters and the measured lateral acceleration signal, said side-slip estimation processor estimating side-slip acceleration of the vehicle using an equation that combines the measured lateral acceleration signal, the measured yaw rate signal, the true longitudinal speed signal, the constant and the function, wherein the equation multiplies the constant and the function.