Detection and Control of Power Induced Hop During Traction Control in a Vehicle

• US 20090107747A1
• Filed: 10/26/2007
• Published: 04/30/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Dunn, Daniel, Perlick, Don, Fodor, Michael Glenn, Luehrsen, Eric
• Granted Patent: US 8,140,238 B2
• Time in Patent Office: Days
• US Class Current: 180/197
• 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 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/18 Roll
• CPC Class Codes: B60W 2520/26 Wheel slip
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels

Abstract

A method for controlling a powertrain of a vehicle with wheels during a traction control event is provided. The method comprises adjusting wheel torque in response to an amplitude of a band-pass filtered driven wheel speed and a direction of acceleration of driven wheels.

Claims

1. A method for controlling a powertrain of a vehicle with wheels during a traction control event, the method comprising:

adjusting wheel torque in response to an amplitude of a band-pass filtered driven wheel speed and a direction of acceleration of driven wheels.

2. The method of claim 1, wherein adjusting wheel torque includes adding a negative torque to the wheels if the wheel acceleration is greater than zero.

3. The method of claim 2, wherein adjusting wheel torque includes adding a torque to the wheels if the vehicle acceleration is less than zero where the added torque decreases as the amplitude increases.

4. The method of claim 3, wherein a negative torque is added to the wheel if the amplitude is greater than a threshold.

5. The method of claim 4, further comprising modifying a slip target based on the amplitude and a road condition, where the slip target is increased with increasing hop for a first road condition, and the slip target is decreased with increasing hop for a second road condition.

6. The method of claim 5, further comprising adjusting the wheel torque based on a wheel speed change wherein the wheel speed change is a difference between a modified slip target and a wheel speed.

7. The method of claim 1, wherein adjusting the wheel torque further includes adding a touchdown torque to the wheel if a wheel slip is less than a threshold.

8. The method of claim 1, wherein driven wheel speeds are sampled by a band-pass filter at a sample spacing greater than 1.5 radians.

9. The method of claim 1, wherein a center frequency of a band-pass filter is adjusted based on one of road surface condition, vehicle operation condition, and the vehicle configuration.

10. The method of claim 9, wherein the road surface condition includes friction coefficient of surface-tire interaction.

11. The method of claim 9, wherein the vehicle operating condition includes a vehicle speed.

12. The method of claim 9, wherein the vehicle configuration includes one of a transmission gear ratio and an estimated vehicle weight.

13. A method for controlling a powertrain of a vehicle with wheels during a traction control event, the method comprising:

detecting a hop level by processing signals of driven wheel speed;

adjusting wheel torque in a first direction and in a first proportion to a wheel slip change when an acceleration of driven wheels is greater than zero; and

adjusting the wheel torque in a second direction and in a second proportion to the wheel slip change when the acceleration is less than zero, wherein the second proportion is adjusted responsive to the hop level.

14. The method of claim 13, wherein adjusting the wheel torque in the first direction includes adding a negative torque to the wheel torque and the first proportion is independent of the hop level.

15. The method of claim 13, wherein adjusting the wheel torque in the second direction includes adding a torque to the wheel torque and the second proportion is adjusted to decrease as the hop level increases.

16. The method of claim 13, wherein adjusting the wheel torque includes adding a touchdown torque to the wheel if a wheel slip is less than a threshold.

17. The method of claim 13, wherein the signals of driven wheel speed are processed by a band-pass filter and a low pass filter to produce signals indicative of the hop level wherein a sampling spacing of the band-pass filter is greater than 1.5 radians and the low pass filter includes two time constants.

18. A method for controlling a powertrain of a vehicle with wheels during a traction control event, the method comprising:

adjusting wheel torque responsive to a gain, a wheel speed error, and an acceleration of driven wheels, where the gain is adjusted based on a hop level, a direction of the wheel speed error, and a direction of the acceleration.

19. The method of claim 18, wherein the wheel speed error is a difference between a slip target and a driven wheel speed.

20. The method of claim 18, wherein a touchdown torque is added to the wheel torque when a wheel slip is less than a slip threshold and a duration for the hop is less than a time threshold.