Vehicle traction control system

• US 4,721,176 A
• Filed: 11/28/1986
• Issued: 01/26/1988
• Est. Priority Date: 06/13/1986
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Kabasin, Daniel F., Stoltman, Donald D.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Watts, Charles R.
• Application Number:
  US06/935,971
• Time in Patent Office: 424 Days
• Field of Search: 180/197, 123/198 DB, 123/333, 123/344, 123/350, 123/361, 123/399, 123/478, 123/481, 123/334, 123/335, 303/96, 303/97
• US Class Current: 180/197
• 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

Abstract

This invention relates to a traction control system for a vehicle that combines the control of both air and fuel delivered to the vehicle engine for limiting the slip of the vehicle driven wheels.

Claims

1. A traction control system for a vehicle having an internal combustion engine with combustion chambers into which an air and fuel mixture is drawn and ignited to undergo combustion, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in the event excessive torque is applied thereto by the engine, the system comprising, in combination:

air flow control means including a throttle valve for regulating mass air flow into the engine in response to a vehicle operator air flow command;

means for determining driven wheel slip that is a function of the difference between the driven and undriven wheel speeds; and

means responsive to predetermined excessive values of the determined driven wheel slip for (A) adjusting the air flow control means to reduce, after an air flow control delay, the mass air flow into the engine to reduce the torque applied to the driven wheel after the air flow control delay and (B) adjusting a predetermined engine parameter to produce a substantially instantaneous reduction in the torque applied to the driven wheel for a predetermined time period substantially equal to the air flow control delay to provide a reduction in torque applied to the driven wheel by the engine during the air flow control delay.

2. The traction control system of claim 1 further including fuel control means for supplying fuel to the engine at a rate establishing a predetermined air/fuel ratio and wherein (A) the predetermined engine parameter is the rate of fuel supplied to the engine and (B) the adjustment to the predetermined engine parameter is a reduction in the rate of fuel supplied to the engine independent of the predetermined air/fuel ratio.

3. The traction control system of claim 1 further including ignition control means for ignitiong the air and fuel mixture in the combustion chambers at a predetermined ignition advance angle and wherein (A) the predetermined engine parameter is the ignition advance angle and (B) the adjustment to the predetermined engine parameter is a reduction of the ignition advance angle.

4. A traction control system for a vehicle having an internal combustion engine with combustion chambers into which an air and fuel mixture is drawn and ignited to undergo combustion, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in the event excessive torque is applied thereto by the engine, the system comprising, in combination:

air flow control means including a throttle valve for regulating mass air flow into the engine in response to a vehicle operator air flow command;

fuel control means for supplying fuel to the combustion chambers of the engine at a rate establishing a predetermined air/fuel ratio;

ignition control means for igniting the air and fuel mixture in the combustion chambers at a predetermined ignition advance angle;

means for determining driven wheel slip that is a function of the difference between the driven and undriven wheel speeds; and

means responsive to predetermined excessive values of the determined driven wheel slip for (A) adjusting the air flow control means to reduce, after an air flow control delay, the mass air flow into the engine to reduce the torque applied to the driven wheel after the air flow control delay, (B) reducing the rate of fuel supplied to the engine for a predetermined time period substantially equal to the air flow control delay independent of the predetermined air/fuel ratio and (C) reducing the ignition advance angle of the igniting of the air and fuel mixture for the predetermined time period, whereby the reduction in the fuel supplied and the ignition advance angle provide a reduction in the torque applied to the driven wheel by the engine during the air flow control delay.

5. A traction control system for a vehicle having an internal combustion engine with combustion chambers into which an air and fuel mixture is drawn and ignited to undergo combustion, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in the event excessive torque is applied thereto by the engine, the system comprising, in combination:

an accelerator pedal for operation by a vehicle operator to control the mass air flow into the engine;

air flow control means including (A) a throttle valve for regulating mass air flow into the engine, (B) means for generating a throttle position command signal in response to the operation of the accelerator pedal and (C) means for positioning the throttle valve in accord with the throttle position command signal between a closed position for minimum mass air flow into the engine and an open position for maximum mass air flow into the engine;

fuel control means for supplying fuel to the engine at a rate establishing a predetermined air/fuel ratio;

ignition control means for igniting the air and fuel mixture in the combustion chambers at a predetermined ignition advance angle;

means for determining the value of driven wheel slip that is a function of the difference between the driven and undriven wheel speeds; and

means responsive to predetermined excessive values of the determined driven wheel slip for (A) reducing the throttle position command signal by a factor related to the value of the driven wheel slip so that the throttle valve is moved, after a control delay, toward the closed position to reduce the mass air flow into the engine to reduce the torque applied to the driven wheel, (B) reducing the rate of fuel supplied to the engine by the fuel control means for a predetermined time period substantially equal to the control delay independent of the predetermined air/fuel ratio and (C) reducing the ignition advance angle of the igniting of the air and fuel mixture for the predetermined time period, whereby the reduction in the rate of fuel supplied and the ignition advance angle provide a reduction in torque applied to the driven wheel by the engine during the air flow control delay, whereby the slip of the driven wheel is limited to provide traction control.