Device and method for operating a motor vehicle

• US 20030122417A1
• Filed: 10/21/2002
• Published: 07/03/2003
• Est. Priority Date: 10/28/2000
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kraemer, Wolfgang, Muenz, Rainer, Hackl, Matthias
• Granted Patent: US 6,863,356 B2
• Time in Patent Office: Days
• 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 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 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 the at least one axle by intervening in a steering of the vehicle,

wherein the action of the yawing moment compensator on the steering is not performed or only to a lesser degree when the vehicle controller is adjusting braking forces.

2. The method as recited in claim 1,

wherein the axle is the front and/or the rear axle.

3. The method as recited in claim 1 or 2,

wherein the action on a steering of the vehicle is performed using a compensation steering angle determined as a function of the braking forces of individual wheels.

4. The method as recited in claim 1, 2, or 3,

wherein a compensation steering angle (δ

, δ

_ideal, δ

_GMK, δ

_A, δ

_H) dependent on a difference (Δ

P) of separately controlled braking pressures (P_vl, P_vr, P_hl, P_hr) of the front and/or rear wheels is adjusted at one rear-wheel steering system or is superimposed on a front-wheel or rear-wheel steering angle to at least partially compensate for the yawing moment of the vehicle.

5. The method as recited in claim 4,

wherein the value of the compensation steering angle (δ

, δ

_ideal, δ

_GMK, δ

_A, δ

_H) is set to zero in a predefined or variable range of small braking pressure differences (Δ

P), called the dead zone in the Specification, and is set to a value not equaling zero outside of the dead zone.

6. The method as recited in one of claims 3, 4, or 5,

wherein in each case separate partial compensation steering angles (δ

_GMKV and δ

_GMKh) are determined for the front wheels and the rear wheels, and the compensation steering angle (δ

, δ

_ideal, δ

_GMK, δ

_A, δ

_H) is determined as a function of the partial compensation steering angles (δ

_GMKV and δ

_GMKh).

7. The method as recited in claim 6,

wherein the compensation steering angle (δ

, δ

_ideal, δ

_GMK, δ

_A, δ

_H) is determined by adding the partial compensation steering angles (δ

_GMKV and δ

_GMKh).

8. The method as recited in one of the preceding claims,

wherein at least one partial compensation steering angle (δ

_GMKV or δ

_GMKh) is determined after the dead zone is exceeded by adding the product of a constant and the initial value of the dead zone and the product of a variable amplification and the initial value of the dead zone.

9. The method as recited in one of claims 3 through 8,

wherein the compensation steering angle (δ

_A) is stored while the vehicle controller is adjusting braking forces.

10. The method as recited in claim 9,

wherein the stored compensation steering angle (δ

_H) is essentially continuously transferred to an instantaneous compensation steering angle (δ

_A, δ

_A′

) after the vehicle controller finishes adjusting the braking forces.

11. A device for operating a vehicle having a vehicle controller for individually adjusting braking forces of the wheels of at least one axle of the vehicle and a yawing moment compensator for at least partially compensating 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, in particular for operating a vehicle in accordance with a method as recited in one of the preceding claims,

wherein the device for operating a vehicle has a selector (50) for preventing or reducing the action of the yawing moment compensator on the steering when the vehicle controller is adjusting braking forces.