Traction control system including setpoint slip adjustment

• US 6,829,529 B2
• Filed: 03/25/2003
• Issued: 12/07/2004
• Est. Priority Date: 03/26/2002
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Sauter, Thomas, Trefzer, Mirko
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US10/400,099
• Publication Number:
  US 20030216850A1
• Time in Patent Office: 623 Days
• Field of Search: 701/70, 701/78, 701/82, 701/83, 701/84, 701/87, 701/90, 303/122.01, 303/122.03, 303/133, 303/139, 303/151, 303/167, 180/244, 180/275
• 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 2270/211 Setting or adjusting start-control threshold
• CPC Class Codes: B60T 2270/213 Driving off under Mu-split conditions
• 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 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill

Abstract

A method for providing traction control when starting off a vehicle on a road surface having different adhesive friction values between the right and left sides of the vehicle, the driven low-μ wheel being regulated to a specified setpoint slip pre-control value by a braking intervention if spinning occurs. In order to improve driving comfort, the engine speed is adjusted to the particular standing start conditions. To this end, the engine torque actually required for starting off is determined as soon as the vehicle is set in motion and has exceeded a specified speed threshold, and the engine speed actually required for starting off under the given conditions is determined from this. From this in turn, a new, corrected setpoint slip value is calculated and the setpoint slip is abruptly reduced or increased from the setpoint slip pre-control value to the newly calculated, corrected setpoint slip value.

Claims

1. A method for providing traction control when starting off a motor vehicle on a road surface having different adhesive friction values between a right side and a left side of the motor vehicle, the method comprising:

regulating a driven low-μ

wheel to a predefined setpoint slip pre-control value by a braking intervention when spinning occurs;

determining an instantaneous engine speed which is present when one of the motor vehicle is driven off and a low speed threshold is exceeded;

calculating a corrected setpoint slip value based on the instantaneous engine speed; and

one of abruptly reducing and increasing a setpoint slip from the predefined setpoint slip pre-control value to the corrected setpoint slip value.

2. The method of claim 1, further comprising:

determining an engine torque actually required;

wherein the instantaneous engine speed is determined using the engine torque actually required and at least one rotational speed-torque characteristic curve.

3. The method of claim 1, further comprising:

linearly reducing the setpoint slip for the driven low-μ

wheel, after one of abruptly reducing and increasing the setpoint slip.

4. The method of claim 1, wherein an engine torque is increased as a vehicle speed increases.

5. A traction control system for starting off a motor vehicle on a road surface having different adhesive friction values between a right side and a left side of the motor vehicle, the traction control system comprising:

a first arrangement to regulate a driven low-μ

wheel to a predefined setpoint slip pre-control value by a braking intervention when spinning occurs;

a second arrangement to determine an instantaneous engine speed which is present when one of the motor vehicle is driven off and a low speed threshold is exceeded;

a third arrangement to calculate a corrected setpoint slip value based on the instantaneous engine speed; and

a fourth arrangement to one of abruptly reduce and increase a setpoint slip from the predefined setpoint slip pre-control value to the corrected setpoint slip value.