Device and method for operating a motor vehicle

• US 6,863,356 B2
• Filed: 10/20/2001
• Issued: 03/08/2005
• Est. Priority Date: 10/28/2000
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kraemer, Wolfgang, Muenz, Rainer, Hackl, Matthias
• Primary Examiner(s): Graham, Matthew C.
• Application Number:
  US10/169,292
• Publication Number:
  US 20030122417A1
• Time in Patent Office: 1,235 Days
• Field of Search: 303/146, 303/147, 303/148, 303/149
• US Class Current: 303/146
• CPC Class Codes: B60T 2260/02 Active Steering, Steer-by-Wire
• CPC Class Codes: B60T 2260/022 Rear-wheel steering; Four-wheel steering
• CPC Class Codes: B60T 2260/024 Yawing moment compensation during mu-split braking
• 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: B60T 8/1764 Regulation during travel on surface with different coefficients of friction, e.g. between left and right sides, mu-split or between front and rear
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

Device and method are described for operating a vehicle using a vehicle controller to individually adjust braking forces of the wheels of at least one axle of the vehicle and using a yawing moment compensator to at least partially compensate for a yawing moment of the vehicle resulting from different braking forces of individual wheels of at least one axle by intervening in a steering of the vehicle, the action of the yawing moment compensator on the steering not being performed or only to a lesser degree while the vehicle controller is adjusting braking forces.

Claims

1. A method for operating a vehicle, comprising:

individually adjusting braking forces of wheels of at least one axle of the vehicle using a vehicle controller; and

using a yawing moment compensator to at least partially compensate for a yawing moment of the vehicle resulting from different braking forces of individual wheels of the at least one axle by determining a steering angle to be applied at a steered axle based on an instantaneous compensation steering angle, a compensation steering angle maintained during an intervention by the vehicle controller, and based on the vehicle controller intervening;

wherein the intervening action is one of not performed and performed to a lesser degree when the vehicle controller is adjusting braking forces.

2. The method according to claim 1, wherein the axle includes at least one of a front axle and a rear axle.

3. The method according to claim 1, wherein the intervening action is performed in the performing step in accordance with a compensation steering angle determined as a function of the braking forces of individual wheels.

4. The method according to claim 3, further comprising the step of storing the compensation steering angle while the vehicle controller is adjusting the braking forces.

5. The method according claim 4, further comprising the step of continuously transferring a stored compensation steering angle to an instantaneous compensation steering angle after the vehicle controller finishes adjusting the braking forces.

6. The method according to claim 1, further comprising the step of one of adjusting at one rear-wheel steering system and superimposing on one of a front-wheel and a rear-wheel steering angle a compensation steering angle to at least partially compensate for the yawing moment of the vehicle, the compensation steering angle dependent on a difference of separately controlled braking pressures.

7. The method according to claim 6, further comprising the step of setting a value of the compensation steering angle to zero within the dead zone and to a non-zero value outside of the dead zone, the dead zone being one of a predefined and variable range of small braking pressure differences.

8. The method of claim 1, wherein the vehicle intervention by the vehicle controller is represented by a factor having a value that depends on whether the vehicle controller is intervening.

9. The method of claim 8, wherein the factor is formed from a signal from the vehicle controller, wherein the signal represent whether the vehicle controller is intervening.

10. The method of claim 8, wherein the factor essentially corresponds to a first value when the vehicle controller is not intervening, and the factor essentially corresponds to another value when the vehicle controller is intervening.

11. The method of claim 10, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein each of the summands is weighted based on the factor.

12. The method of claim 8, wherein the factor essentially corresponds to zero when the vehicle controller is not intervening, and the factor essentially corresponds to one when the vehicle controller is intervening.

13. The method of claim 12, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein the first summand is weighted based on a number that is 1 minus the factor, and the second summand is weighted by the factor.

14. A method for operating a vehicle, comprising:

individually adjusting braking forces of wheels of at least one axle of the vehicle using a vehicle controller;

intervening in a steering operation of the vehicle using a yawing moment compensator to at least partially compensate for a yawing moment of the vehicle resulting from different braking forces of individual wheels of the at least one axle by determining a steering angle to be applied at a steered axle based on an instantaneous compensation steering angle, a compensation steering angle maintained during an intervention by the vehicle controller, and based on the vehicle controller intervening;

determining separate partial compensation steering angles for front wheels and rear wheels; and

determining the compensation steering angle as a function of the partial compensation steering angles;

wherein the intervening is one of not performed and performed to a lesser degree when the vehicle controller is adjusting braking forces, and

wherein the intervening is performed in the performing step in accordance with a compensation steering angle determined as a function of the braking forces of individual wheels.

15. The method according to claim 14, wherein the compensation steering angle determining step includes the substep of adding the partial compensation steering angles to determine the compensation steering angle.

16. The method according to claim 14, further comprising the step of adding a product of a constant and an initial value of a dead zone and a product of a variable amplification and the initial value of the dead zone to determine at least one partial compensation steering angle, the determination occurring after the dead zone is exceeded.

17. The method of claim 14, wherein the vehicle intervention by the vehicle controller is represented by a factor having a value that depends on whether the vehicle controller is intervening.

18. The method of claim 17, wherein the factor is formed from a signal from the vehicle controller, wherein the signal represent whether the vehicle controller is intervening.

19. The method of claim 18, wherein the factor essentially corresponds to a first value when the vehicle controller is not intervening, and the factor essentially corresponds to another value when the vehicle controller is intervening.

20. The method of claim 19, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein each of the summands is weighted based on the factor.

21. The method of claim 17, wherein the factor essentially corresponds to zero when the vehicle controller is not intervening, and the factor essentially corresponds to one when the vehicle controller is intervening.

22. The method of claim 21, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein the first summand is weighted based on a number that is 1 minus the factor, and the second summand is weighted by the factor.

23. An apparatus for operating a vehicle, comprising:

an adjusting arrangement to adjust braking forces of wheels of at least one axle of the vehicle using a vehicle controller;

an intervening arrangement to intervene in a steering operation of the vehicle using a yawing moment compensator to at least partially compensate for a yawing moment of the vehicle resulting from different braking forces of individual wheels of the at least one axle; and

a determining arrangement to determine separate partial compensation steering angles for front wheels and rear wheels, and to determine the compensation steering angle as a function of the partial compensation steering angles, and determining a steering angle to be applied at a steered axle based on an instantaneous compensation steering angle, a compensation steering angle maintained during an intervention by the vehicle controller, and based on the vehicle controller intervening;

wherein the intervening is one of not performed and performed to a lesser degree when the vehicle controller is adjusting braking forces, and the intervening is performed in accordance with a compensation steering angle determined as a function of the braking forces of individual wheels.

24. The apparatus of claim 23, wherein the vehicle intervention by the vehicle controller is represented by a factor having a value that depends on whether the vehicle controller is intervening.

25. The apparatus of claim 24, wherein the factor is formed from a signal from the vehicle controller, wherein the signal represent whether the vehicle controller is intervening.

26. The apparatus of claim 25, wherein the factor essentially corresponds to a first value when the vehicle controller is not intervening, and the factor essentially corresponds to another value when the vehicle controller is intervening.

27. The apparatus of claim 26, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein each of the summands is weighted based on the factor.

28. The apparatus of claim 24, wherein the factor essentially corresponds to zero when the vehicle controller is not intervening, and the factor essentially corresponds to one when the vehicle controller is intervening.

29. The apparatus of claim 28, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein the first summand is weighted based on a number that is 1 minus the factor, and the second summand is weighted by the factor.

30. A device for operating a vehicle, comprising:

a vehicle controller configured to individually adjust braking forces of wheels of at least one axle of the vehicle;

a yawing moment compensator configured to at least partially compensate for a yawing moment of the vehicle resulting from different braking forces of individual wheels of the at least one axle by intervening in a steering of the vehicle by determining a steering angle to be applied at a steered axle based on an instantaneous compensation steering angle, a compensation steering angle maintained during an intervention by the vehicle controller, and based on the vehicle controller intervening; and

a selector configured to one of prevent and reduce an action of the yawing moment compensator on the steering when the vehicle controller is adjusting braking forces.

31. The device of claim 30, wherein the vehicle intervention by the vehicle controller is represented by a factor having a value that depends on whether the vehicle controller is intervening.

32. The device of claim 31, wherein the factor is formed from a signal from the vehicle controller, wherein the signal represent whether the vehicle controller is intervening.

33. The device of claim 32, wherein the factor essentially corresponds to a first value when the vehicle controller is not intervening, and the factor essentially corresponds to another value when the vehicle controller is intervening.

34. The device of claim 33, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein each of the summands is weighted based on the factor.

35. The device of claim 31, wherein the factor essentially corresponds to zero when the vehicle controller is not intervening, and the factor essentially corresponds to one when the vehicle controller is intervening.

36. The device of claim 35, wherein the steering angle to be applied corresponds to a sum of the instantaneous compensation steering angle and the compensation steering angle maintained while the vehicle controller is intervening, wherein the first summand is weighted based on a number that is 1 minus the factor, and the second summand is weighted by the factor.