Traction-slip control method with theoretical transversal acceleration and control circuit for carrying out such a traction-slip control method

• US 6,687,594 B1
• Filed: 03/28/2002
• Issued: 02/03/2004
• Est. Priority Date: 03/08/1999
• Status: Expired due to Term

• Current Assignee: Continental Teves AG & Co. OHG (Continental AG), Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Continental Teves AG & Co. OHG (Continental AG), Daimler AG (Mercedes-Benz Group AG)
• Inventors: Jung, Joachim, Fischle, Gerhard, Pfister, Carola, Steinbrück, Jörg, Schafiyha, Scharad, Schütz, Christof
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US09/914,809
• Time in Patent Office: 677 Days
• Field of Search: 701/82, 701/84, 701/87, 701/90, 701/71, 701/72, 701/74, 180/244
• US Class Current: 701/82
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60W 2050/0011 Proportional Integral Differential [PID] controller
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration

Abstract

The invention relates to a traction slip control method for an automotive vehicle wherein a traction slip control phase for a respective drive wheel is activated by way of a control strategy when the traction slip of said wheel exceeds a predeterminable slip threshold value This method includes a reference transverse acceleration that is recorded for a cornering maneuver to be expected, then an actual transverse acceleration is determined, a difference between the reference transverse acceleration (a_y-ref) and the actual transverse acceleration (a_y-ist) is calculated, and it is determined whether the amount of the difference exceeds a limit value, and wherein in the case when the amount of the difference exceeds the limit value, the control strategy is modified so that a higher torque can be achieved at least on two wheels than in the case that the amount of the difference does not exceed the limit value. Further, the invention provides a control circuit that implements the above method.

Claims

1. A traction slip control method for an automotive vehicle wherein a traction slip control phase for a respective drive wheel is activated by way of a control strategy when the traction slip of said wheel exceeds a predeterminable slip threshold value comprising the steps of:

determining a reference transverse acceleration for a cornering maneuver to be expected;

determining an actual transverse acceleration;

calculating a difference between the reference transverse acceleration (a_y-ref) and the actual transverse acceleration (a_y-ist); and

determining whether the amount of the difference exceeds a limit value, and wherein in the case that the amount of the difference exceeds the limit value, modifying the control strategy so that a higher torque can be achieved at least on two wheels than in the case that the amount of the difference does not exceed the limit value.

2. A traction slip control method as claimed in claim 1, wherein when the amount of the difference exceeds the limit value, a higher torque is achieved on all driven wheels.

3. A traction slip control method as claimed in claim 1 wherein the transverse acceleration is determined in dependence on the actual transverse acceleration.

4. A traction slip control method as claimed in claim 1 wherein the torque is only increased when the reference transverse acceleration (a_y-ref) is higher than a threshold value (K₂).

5. A traction slip control method as claimed in claim 1 wherein for at least one wheel of the vehicle, an engine torque is determined which can maximally be used on the said wheel.

6. A traction slip control method as claimed in claim 5 wherein for all driven wheels of the vehicle, each time that engine torque is determined that can maximally be used on them.

7. A traction slip control method as claimed in claim 5 wherein the maximally utilizable engine torque is determined by a slip requirement of at least one inward wheel.

8. A traction slip control method as claimed in claim 1 wherein an increase of the torque achieved on the wheels is carried out only when slip signals do not exceed a defined threshold value.

9. A control circuit for controlling the driving stability of a vehicle, wherein defining input quantities for fixing a course are sensed and processed so that traction slip control can be performed by influencing a transmission of engine torques to individual wheels, comprising:

a control circuit having a means for determining and/or storing a reference transverse acceleration for a cornering maneuver to be expected and a comparator;

wherein the comparator compares the reference transverse acceleration (a_y-ref) with a determined actual transverse acceleration, and it is determined whether the amount of the difference exceeds a limit value; and

wherein in the case that the amount of the difference exceeds the limit value, the slip control is modified so that a higher torque can be achieved at least on two wheels than in the case that the amount of the difference does not exceed the limit value.

10. A control circuit as claimed in claim 9, wherein the comparator determines a difference between the reference transverse acceleration (a_y-ref) and the actual transverse acceleration (a_y-ist).

11. A traction slip control method for an automotive vehicle wherein a traction slip control phase for a respective drive wheel is activated by way of a control strategy when the traction slip of said wheel exceeds a predeterminable slip threshold value comprising the steps of:

determining a reference transverse acceleration for a cornering maneuver to be expected;

determining an actual transverse acceleration;

calculating a difference between the reference transverse acceleration (a_y-ref) and the actual transverse acceleration (a_y-ist); and

determining whether the amount of the difference exceeds a limit value, and wherein in the case that the amount of the difference exceeds the limit value, modifying the control strategy so that a higher torque can be achieved on all driven wheels than in the case that the amount of the difference does not exceed the limit value.

12. A traction slip control method as claimed in claim 11 wherein the transverse acceleration is determined in dependence on the actual transverse acceleration.

13. A traction slip control method as claimed in claim 11 wherein the torque is only increased when the reference transverse acceleration (a_y-ref) is higher than a threshold value (K₂).

14. A traction slip control method as claimed in claim 11 wherein for at least one wheel of the vehicle, an engine torque is determined which can maximally be used on the said wheel.

15. A traction slip control method as claimed in claim 14 wherein for all driven wheels of the vehicle, each time that engine torque is determined that can maxim ally be used on them.

16. A traction slip control method as claimed in claim 14 wherein the maximally utilizable engine torque is determined by a slip requirement of at least one inward wheel.

17. A traction slip control method as claimed in claim 11 wherein an increase of the torque achieved on the wheels is carried out only when slip signals do not exceed a defined threshold value.