Driving dynamic control or regulating system and method for a two-track, two-axle motor vehicle

• US 7,480,553 B2
• Filed: 07/31/2007
• Issued: 01/20/2009
• Est. Priority Date: 02/01/2005
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Hofmann, Martin, Webers, Klaus
• Primary Examiner(s): To; Tuan C
• Application Number:
  US11/882,271
• Publication Number:
  US 20070271018A1
• Time in Patent Office: 539 Days
• Field of Search: 701/69, 180/245, 180/246, 180/247, 180/248
• US Class Current: 701/69
• CPC Class Codes: B60G 17/0152 characterised by the action on a particular type of suspension unit B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0162 mainly during a motion involving steering operation, e.g. cornering, overtaking B60G17/0164 takes precedence
• CPC Class Codes: B60G 21/0555 including an actuator inducing vehicle roll
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/32 Torque on propulsion shaft
• CPC Class Codes: B60G 2400/822 Road friction coefficient determination affecting wheel traction
• CPC Class Codes: B60G 2800/012 Rolling condition

Abstract

A system and method are provided for controlling or automatically controlling the driving dynamics of a two-track, two-axle motor vehicle having only one driven axle, which, for the rolling moment support, has a system for changing the distribution of the wheel contact forces to the left and right wheel respectively of each axle. The fractions of the rolling moment support taken over by the front axle and by the rear axle are changeable as a function of the drive torque provided by the drive assembly of the motor vehicle. For this purpose, a desired wheel contact force for the driven wheels can be determined from the drive torque, and by way of this desired wheel contact force, the distribution of the rolling torque support can be determined. A change of the distribution of the rolling moment support as a function of the drive torque of the drive assembly is preferably carried out only if the otherwise available contact force would otherwise not be sufficient for the transmission of the drive torque to the road. A slip control may be superimposed on this pilot control, which slip control seeks to minimize the deviation between the determined rotational speed difference of the driven wheels and the rotational speed difference corresponding to the respective driving condition.

Claims

1. A system for controlling or regulating driving dynamics of a two-track, two-axle motor vehicle having only one driven axle, the system comprising:

a wheel contact force distribution system providing a rolling moment support, the system being operatively configured to change a distribution of wheel contact force to a left and a right wheel, respectively, of each axle;

wherein fractions of the rolling moment support taken over by the front axle and by the rear axle are changeable as a function of a marginal condition;

wherein a drive torque indicator quantity represents the marginal condition; and

wherein a desired wheel contact force for the driven wheels is determined from the drive torque, by which the distribution of the rolling moment support is determined.

2. The system according to claim 1, wherein the drive torque indicator quantity is the drive torque value itself or a quantity directly related thereto.

3. The system according to claim 1, wherein, for determining the desired wheel contact force, an estimated or measured value for a coefficient of friction between the driven wheels and the road is used.

4. The system according to claim 1, wherein a change of the distribution of the rolling moment support as a function of the drive torque indicator quantity is carried out only when an available contact force at one of the left and right wheels otherwise would not be sufficient for transmitting drive torque to the road.

5. The system having a pilot control according to claim 1, further comprising a slip control superimposed on the pilot control, which slip control seeks to minimize the deviation between a determined rotational speed difference of the driven wheels and a rotational speed difference corresponding to the respective driving condition.

6. The system according to claim 5, further comprising a yaw rate controller, which also carries out a distribution of the rolling moment support, wherein, in the case of a change of the distribution of the rolling moment support in opposite directions by the yaw rate controller, on the one hand, and by a slip regulator, on the other hand, the yaw rate controller has priority.

7. The system according to claim 1, wherein in addition to active divided stabilizers, whose stabilizer halves are rotatable against one another, the system for changing the distribution of the wheel contact forces appropriately triggers dampers, which are assigned to the individual vehicle wheels and are adjustable with respect to their characteristics.

8. The system according to claim 1, which the system for changing the distribution of the wheel contact forces appropriately triggers active suspension systems assigned to the individual wheels.

9. A method for controlling driving dynamics of a two-track, two-axle motor vehicle having only a single driven axle, the method comprising the acts of:

determining a drive torque indicative value based on a drive assembly of the motor vehicle;

distributing a rolling moment support between a front axle and a rear axle of the two-axle motor vehicle as a function of the drive torque indicative value, which rolling limit support operates by changing a distribution of wheel contact forces to a left and right wheel, respectively, of each of the front and rear axle; and

determining a desired wheel contact force for driven wheels of the motor vehicle from the drive torque indicative value, and utilizing the desired wheel contact force to distribute the rolling moment support.

10. The method according to claim 9, wherein for determining the desired wheel contact force, an estimated or measured value for a coefficient of friction between the driven wheels in a road is utilized.

11. The method according to claim 9, wherein the drive torque indicative value is the drive torque value provided by the drive assembly of the motor vehicle.