Traction control system with active suspension

• US 5,517,414 A
• Filed: 10/03/1994
• Issued: 05/14/1996
• Est. Priority Date: 10/03/1994
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Motor Company
• Inventors: Hrovat, Davorin D.
• Primary Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US08/316,951
• Time in Patent Office: 589 Days
• Field of Search: 364/426.02, 364/426.03, 364/424.05, 303/95, 303/100, 303/139, 303/163, 303/150, 303/187, 180/197, 280/707
• US Class Current: 701/91
• CPC Class Codes: B60G 17/019 characterised by the type of sensor or the arrangement thereof B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2202/154 with an accumulator
• CPC Class Codes: B60G 2202/413 Hydraulic actuator
• CPC Class Codes: B60G 2204/80 Interactive suspensions; arrangement affecting more than one suspension unit
• CPC Class Codes: B60G 2400/208 of wheel rotation
• CPC Class Codes: B60G 2400/32 Torque on propulsion shaft
• CPC Class Codes: B60G 2400/51 in suspension unit
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2401/15 Doppler effect
• CPC Class Codes: B60G 2600/02 Retarders, delaying means, dead zones, threshold values, cut-off frequency, timer interruption
• CPC Class Codes: B60G 2800/21 Traction, slip, skid or slide control
• 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 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

Abstract

An active suspension system (12, 82a-d), coupled to each wheel of a motor vehicle is controlled to minimize or reduce wheel slippage. In response to detection of wheel slippage, the normal force applied to the slipping wheel is increased and the normal force applied to the wheel laterally opposite the slipping wheel is concurrently decreased (steps 240-384). The changes in normal force are limited to prevent inducing a wheel slip in the laterally opposite wheel (step 278-284). An engine controller (70) concurrently reduces engine torque to further reduce wheel slip.

Claims

1. A method for controlling wheel slip of a motor vehicle having an active suspension system applying a normal force to each wheel of the motor vehicle, comprising the steps of:

detecting wheel slip of one of the wheels;

increasing the normal force applied from the suspension system to said slipping wheel and concurrently decreasing the normal force to the wheel laterally opposite said slipping wheel in response to said wheel slip detection; and

increasing the normal force applied from the suspension system to the wheel diagonally opposite said slipping wheel in response to said wheel slip detection.

2. The method recited in claim 1 further comprising a step of decreasing the normal force applied from the suspension system to the wheel longitudinally opposite said slipping wheel in response to said wheel slip detection.

3. The method recited in claim 2 wherein said increases in normal forces are substantially equal.

4. The method recited in claim 3 wherein said increase in normal forces is substantially equal to said decrease in normal force.

5. A method for controlling wheel slip of a motor vehicle having at least one driven wheel coupled to an internal combustion engine and an active suspension system for applying a normal force to each wheel, comprising the steps of:

detecting wheel slip of one of the wheels;

increasing the normal force applied to said slipping wheel and concurrently decreasing the normal force applied to the wheel laterally opposite said slipping wheel in response to said detected wheel slip;

limiting said decrease in normal force to prevent slipping of said laterally opposite wheel; and

estimating a minimum normal force applied to said laterally opposite wheel based upon a ratio of road coefficient of friction encountered by said slipping wheel and said laterally opposite wheel.