Method of traction control for a motor vehicle

• US 9,707,967 B2
• Filed: 06/30/2015
• Issued: 07/18/2017
• Est. Priority Date: 06/30/2015
• Status: Active Grant

• Current Assignee: Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Kelsey-Hayes Co. (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Hartman, Patrick A., Timm, Greg, Breitner, Jeff, Mitchell, Craig B.
• Primary Examiner(s): Troost, Aaron L
• Application Number:
  US14/755,326
• Publication Number:
  US 20170001644A1
• Time in Patent Office: 749 Days
• CPC Class Codes: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• 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: B60T 8/3205 acceleration B60T8/34, B60T8/52, B60T8/54, B60T8/56, B60T8/58, B60T8/72, B60T8/86, B60T8/88 take precedence
• CPC Class Codes: B60T 8/4872 pump-back systems
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/18145 Cornering

Abstract

A method of traction control for a vehicle. Lateral and longitudinal accelerations are measured for a vehicle. A maximum supportable drive torque for a first wheel of the vehicle is calculated as a function of the lateral and longitudinal accelerations. A commanded vectoring brake torque is applied to the first wheel using a brake device. The commanded vectoring brake torque is an amount by which a driveline torque delivered to the first wheel exceeds the maximum supportable drive torque.

Claims

1. A vehicle traction control system comprising:

first and second wheels on an axle;

a plurality of acceleration sensors measuring a lateral acceleration and a longitudinal acceleration;

a controller in communication with the plurality of acceleration sensors and determining a maximum supportable drive torque for the first wheel as a function of the lateral acceleration and the longitudinal acceleration; and

a brake device for applying a commanded vectoring brake torque to the first wheel, wherein the commanded vectoring brake torque is an amount by which a driveline torque delivered to the first wheel exceeds the maximum supportable drive torque, wherein the maximum supportable drive torque is a function of a radius of a tire on the first wheel and a first wheel maximum longitudinal force; and

wherein the first wheel maximum longitudinal force is a function of a first wheel maximum force and a first wheel lateral force.

2. The vehicle traction control system of claim 1 wherein the brake device is a hydraulic brake system of the vehicle.

3. The vehicle traction control system of claim 1 wherein the brake device is an electric machine of the vehicle.

4. The vehicle traction control system of claim 1 wherein the vehicle is turning and the first wheel has a lesser turning radius than the second wheel.

5. The vehicle traction control system of claim 1 wherein the controller calculates a normal force acting on at least one of the first and second wheels against a roadway surface supporting the first and second wheels and wherein the normal force is used to calculate the maximum supportable drive torque.

6. The vehicle traction control system of claim 1 wherein the first wheel maximum force is a function of a normal force acting on the first wheel and a coefficient of friction for a roadway surface.

7. The vehicle traction control system of claim 1 wherein the first wheel lateral force is a function of normal forces acting on the first and second wheels.

8. A method of traction control for a vehicle comprising the steps of:

measuring a lateral acceleration and a longitudinal acceleration for a vehicle;

determining a maximum supportable drive torque for a first wheel of the vehicle as a function of the lateral acceleration and the longitudinal acceleration;

applying a commanded vectoring brake torque to the first wheel using a brake device, wherein the commanded vectoring brake torque is an amount by which a driveline torque delivered to the first wheel exceeds the maximum supportable drive torque;

calculating the maximum supportable drive torque as a function of a radius of a tire on the first wheel and a first wheel maximum longitudinal force; and

calculating the first wheel maximum longitudinal force acting on the first wheel as a function of a first wheel maximum force and a first wheel lateral force.

9. The method of traction control of claim 8 wherein the commanded vectoring brake torque is applied by a hydraulic brake system of the vehicle.

10. The method of traction control of claim 8 wherein the commanded vectoring brake torque is applied by an electric machine of the vehicle.

11. The method of traction control of claim 8 wherein the first wheel has a lesser turning radius than a second wheel on an axle with the first wheel.

12. The method of traction control of claim 8 comprising the further step of:

determining a normal force acting between one of the first wheel and a second wheel and a roadway surface, wherein the second wheel is on an axle with the first wheel and the normal force is used to calculate the maximum supportable drive torque.

13. The method of traction control of claim 8 comprising the further step of:

calculating the first wheel maximum force as a function of a normal force acting on the first wheel and a coefficient of friction for a roadway surface.

14. The method of traction control of claim 8 comprising the further step of:

calculating the first wheel lateral force as a function of the normal force acting on the first wheel and a normal force acting on a second wheel on an axle with the first wheel.

15. The method of traction control of claim 8 comprising the further step of:

designating the first wheel as an inner wheel and the second wheel as an outer wheel, wherein the inner wheel has a lesser turning radius than the outer wheel.

16. A method of traction control for an automotive vehicle comprising the steps of:

measuring a lateral acceleration and a longitudinal acceleration for a turning vehicle;

determining a first normal force acting on an inner wheel of the vehicle by a roadway surface, wherein the first normal force is a function of the lateral acceleration and the longitudinal acceleration;

determining a second normal force acting on an outer wheel of the vehicle by the roadway surface, wherein the second normal force is a function of the lateral acceleration and the longitudinal acceleration, and wherein the inner wheel has a lesser turn radius than the outer wheel;

determining a maximum supportable drive torque for the first wheel as a function of the first and second normal forces; and

applying a commanded vectoring brake torque to the inner wheel using a brake device, wherein the commanded vectoring brake torque is an amount by which a driveline torque delivered to the first wheel exceeds the maximum supportable drive torque.