Method and device for traction control (TCS) of a motor vehicle as a function of radius of curve and transverse acceleration

• US 6,564,138 B1
• Filed: 01/14/2002
• Issued: 05/13/2003
• Est. Priority Date: 12/07/1999
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schmitt, Johannes, Sauter, Thomas, Zoebele, Andreas
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US09/890,834
• Time in Patent Office: 484 Days
• Field of Search: 701/82, 701/90, 701/72, 303/139, 303/140, 180/197
• 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: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 2210/24 Curve radius
• 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: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 30/18145 Cornering

Abstract

A method and a device, respectively, for providing traction control of a motor vehicle in which the slip of the driven wheel of the motor vehicle on the inside of the curve is only regulated when its slip exceeds a predefined slip threshold. The predefined slip threshold is weighted with a weighting factor as a function in dependence on the occurring transverse acceleration, and in this connection, the weighting factor is given by an equation as being inversely proportional to the radius of curve of the road.

Claims

1. A method for providing traction control for a motor vehicle operating on a curve of a road, the method comprising the steps of:

recording, using at least one sensor, an acceleration in a transverse axis, a driving speed of the motor vehicle, a speed of a wheel and a radius of a curve of a road;

determining a slip value of a wheel from recorded values;

comparing the slip value with a predefined slip threshold;

at least one of braking the wheel on an inside of the curve of the road upon exceeding the predefined slip threshold, and reducing a drive torque of an engine of the motor vehicle to limit a traction of the motor vehicle upon exceeding the predefined slip threshold; and

changing the predefined slip threshold for the wheel on the inside of the curve of the road upon exceeding the predefined slip threshold, wherein the predefined slip threshold is determined as a function of the acceleration in the traverse axis according to a straight line equation of LAMB AY=OFF AY+AY FAK*AY, where OFF AY is a constant offset value and AY FAK is a slope parameter for the straight line equation.

2. The method of claim 1, wherein the constant offset value is determined empirically for a vehicle type.

3. The method of claim 1, wherein the slope parameter is determined empirically for a vehicle type.

4. The method of claim 1, wherein the slip threshold is calculated as a function of the radius of the curve of the road according to the following equation:

LAMB AY RAD=LAMB AY*G, where LAMB AY RAD is the predefined slip threshold taking into consideration the radius, RAD being the radius, and G a weighting factor G.

5. The method of claim 4, wherein the weighting factor is calculated according to another straight line equation of G=OFF RAD−

STEI RAD*RAD, where OFF RAD is a fixed offset value for the radius RAD, STEI RAD is a slope measure for the another straight line equation giving consideration to the radius and the radius RAD is of the radius of the curve of the road.

6. The method of claim 1, wherein a direction of the curve of the road is determined.

7. The method of claim 1, wherein the predefined slip threshold is limited to a minimum value.

8. A device for providing traction control for a motor vehicle, the device comprising:

at least one sensor for recording a transverse acceleration of the motor vehicle, a driving speed and a slip of a wheel;

a control device for providing a slip threshold; and

a controlling device for controlling the slip of the wheel on an inside of a curve of a road;

wherein the control device includes an arrangement for determining the slip threshold by increasing the slip threshold as a function of the transverse acceleration of the motor vehicle and by decreasing the slip threshold as a function of a weighted radius of the curve.

9. The device of claim 8, wherein the arrangement for determining the slip threshold includes a software program.

10. The device of claim 8, wherein the device is at least one of a component part of at least one of a higher-level vehicle control unit, a control unit for controlling driving dynamics and an anti-lock braking system.