Method for Increasing the Driving Stability of a Motor Vehicle

• US 20080147273A1
• Filed: 03/15/2005
• Published: 06/19/2008
• Est. Priority Date: 03/16/2004
• Status: Active Grant

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG)
• Inventors: Bauer, Urs, Schafiyha, Schahrad, Capellaro, Stephan, Gille, Michael, Muntu, Matthias, Roll, Georg
• Granted Patent: US 7,860,623 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B60T 2230/02 Side slip angle, attitude angle, floating angle, drift angle
• CPC Class Codes: B60T 2260/024 Yawing moment compensation during mu-split braking
• CPC Class Codes: B60T 2270/213 Driving off under Mu-split conditions
• CPC Class Codes: B60T 8/175 Brake regulation specially adapted to prevent excessive wheel spin during vehicle acceleration, e.g. for traction control safety devices for propulsion unit control responsive to, or preventing, skidding of wheels B60K28/16
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence

Abstract

A process for increasing the stability of a vehicle upon acceleration on a roadway with a non-homogenous coefficient of friction, whereby a drive wheel is acted on by a braking force on a side with a low coefficient of friction by means of a drive slip regulation. A value (p_ASR) is determined which corresponds to the braking force (F_B,ASR) set by the drive slip regulation (ASR). The value determined (p_ASR) is used for the determination of a disrupting yaw momentum (M_Z), and a control portion (Δδ_Z) of a supplemental steering angle (Δδ) is determined in dependence on the disrupting yaw momentum (M_Z). An apparatus for the implementation of the process is also provided.

Claims

1-16. -16. (canceled)

17. Method for increasing the stability of a vehicle upon acceleration on a roadway with a non-homogenous coefficient of friction, whereby a drive wheel is acted on with a braking force on a side with a low coefficient of friction by means of acceleration slip regulation, comprising:

determining a value which corresponds to the braking force set by the means of acceleration slip regulation;

determining a disrupting yaw momentum from the determined value; and

determining a control portion of a supplemental steering angle based on the disrupting yaw momentum.

18. Method in accordance with claim 17, wherein the determined value is a braking pressure which is set by acceleration slip regulation in a wheel brake of the drive wheel on the side with a low coefficient of friction.

19. Method in accordance with claim 17, wherein the supplemental steering angle is set on at least one steerable wheel of the vehicle.

20. Method in accordance with claim 17, wherein a supplemental steering momentum is determined in dependence on the supplemental steering angle, and a steering line of the vehicle is acted on by the supplemental steering momentum.

21. Method in accordance with claim 17, wherein the control portion of the supplemental steering angle is computed by means of a control law with the form:

Δ

δ

_Z=K_M(v)·

{circumflex over (M)}_Z,

whereby Δ

δ

_Z signifies the control portion of the supplemental steering angle, K_M signifies an amplification factor, v signifies a reference speed of the vehicle, and {circumflex over (M)}_Z signifies an estimated value for the disrupting yaw momentum.

22. Method in accordance with claim 17, wherein a regulation portion of the supplemental steering angle is determined in dependence on a standard deviation between a control value and a reference value measured by means of vehicle sensors or computed from measuring signals of vehicle sensors, and the supplemental steering angle corresponds to a sum of the regulation portion and the control portion.

23. Method in accordance with claim 22, wherein the regulation portion of the supplemental steering angle is determined in dependence on a deviation of the yaw rates between the yaw rate of the vehicle and a reference yaw rate of the vehicle, whereby the reference yaw rate is determined by means of at least one preset value preset by a vehicle driver in a vehicle model.

24. Method in accordance with claim 22, wherein the regulation portion of the supplemental steering angle is determined by means of a control law with the form:

Δ

δ

_R=K_FB,P(v)·

Δ

{dot over (ψ

)}+K_FB,I(v)·

Δ

ψ

+K_FB,D(v)·

Δ

{umlaut over (ψ

)}

whereby, Δ

δ

_R signifies the regulation portion of the supplemental steering angle K_FB,P, K_FB,I and K_FB,D each signify an amplification factor, v signifies the reference speed of the vehicle, Δ

{dot over (ψ

)} signifies the deviation of the yaw rates, Δ

ψ

signifies a yaw angle deviation, and Δ

{umlaut over (ψ

)} signifies a yaw acceleration deviation.

25. Method in accordance with claim 22, wherein the regulation portion of the supplemental steering angle is determined in dependence on a side-slip angle deviation between an estimated side-slip angle of the vehicle and a reference side-slip angle, whereby the reference side-slip angle is preset by a threshold value.

26. Method in accordance with claim 22, wherein the regulation portion of the supplemental steering angle is determined in dependence on a lateral acceleration deviation between a measured lateral acceleration of the vehicle and a reference lateral acceleration, whereby the reference lateral acceleration is preset by a threshold value.

27. Method in accordance with claim 17, wherein the supplemental steering angle is set on a steerable wheel by means of a steer-by-wire steering unit.

28. Method in accordance with claim 17, wherein the supplemental steering angle is set on a steerable wheel set by means of a superimposition steering.

29. Method in accordance with claim 17, wherein in addition to a steering movement commanded by a vehicle driver, an additional steering movement is carried out in accordance with the supplemental steering angle.

30. Method in accordance with claim 17, wherein a supplemental steering momentum is set by means of an electrical or hydraulic servo-steering unit.

31. Method in accordance with claim 17, wherein a supplemental steering momentum is set by means of a steer-by-wire steering unit.

32. An apparatus for increasing the stability of a vehicle in an acceleration on a roadway with a non-homogenous coefficient of friction, comprising:

a control means for the implementation of a drive slip regulation, which controls the influencing of a drive wheel on a side with a low coefficient of friction by a braking force;

a determination unit for determining a value which corresponds to the braking force set by the control means; and

an estimation unit for estimating a disrupting yaw momentum with consultation of the determined value;

whereby the control unit determines a control portion of a supplemental steering angle in dependence on the estimated disrupting yaw momentum.