Controller for an acceleration slip on a driving wheel

• US 4,866,623 A
• Filed: 12/08/1987
• Issued: 09/12/1989
• Est. Priority Date: 12/13/1986
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Matsumoto, Shinichi, Miyazaki, Hiroharu, Ise, Kiyotaka
• Primary Examiner(s): Gruber, Felix D.
• Application Number:
  US07/130,170
• Time in Patent Office: 644 Days
• Field of Search: 364/426.07, 364/426.03, 364/426.02, 364/148, 364/150, 364/426.04, 123/336, 303/103, 303/106, 303/108, 303/109, 180/197
• US Class Current: 701/85
• 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
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 30/18172 Preventing, or responsive to skidding of wheels
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links

Abstract

A controller for controlling an acceleration slip on a driving wheel of a vehicle comprising a vehicle speed detector, a driving wheel speed detector, a reference speed setting device for setting low and high reference speeds both higher than the detected vehicle speed, and engine output controller for executing a feedback control of an output of the engine of the vehicle so that the detected speed of the driving wheel approximates the low reference speed, a brake controller for executing a feedback control of a brake system of the driving wheel after the detected speed of the driving wheel exceeds the high reference speed, a brake monitor for detecting whether the brake control is executed, and a gain adjustor for making a feedback gain of the engine output control lower at a time when the brake control is detected as being executed than at a time when the brake control is detected as not being executed.

Claims

1. A controller for controlling an acceleration slip on a driving wheel of a vehicle comprising:

vehicle speed detection means for detecting a speed of the vehicle;

driving wheel speed detection means for detecting a speed of the driving wheel;

processor means for controlling the acceleration slip, said processor means including

reference speed setting means responsive to the detected vehicle speed for setting a low reference speed and a high reference speed both higher than the detected vehicle speed;

engine output control means for executing a feedback control of an output of the engine of the vehicle so that the detected speed of the driving wheel approximates the low reference speed;

brake control means for executing a feedback control of a brake system of the driving wheel after the detected speed of the driving wheel exceeds the high reference speed;

brake monitoring means for detecting whether the brake control is executed; and

gain adjusting means for making a feedback gain of the engine output control means lower at a time when the brake control is detected to be executed than at a time when the brake control is detected not to be executed.

2. The acceleration slip controller according to claim 1 wherein the vehicle speed detection means comprises a speed detector provided on a non-driving wheel.

3. The acceleration slip controller according to claim 1 wherein the reference speed setting means sets the low and high reference speeds by multiplying the detected vehicle speed by predetermined values greater than unity.

4. The acceleration slip controller according to claim 1 wherein the reference speed setting means sets the low and high reference speeds by adding predetermined values to the detected vehicle speed.

5. The acceleration slip controller according to claim 1 wherein the low reference speed is set at a value at which friction between the driving wheel and the road surface is a maximum.

6. The acceleration slip controller according to claim 1 wherein the engine of the vehicle comprises a sub-throttle valve provided in series with a normally provided throttle valve, and the engine output control means controls the opening of the sub-throttle valve.

7. The acceleration slip controller according to claim 6 wherein the brake monitoring means determines that the brake control means is not executed when an accumulated hydraulic pressure control signal to the brake system becomes equal to or less than zero.

8. The acceleration slip controller according to claim 1 wherein the engine output control means controls the opening of a throttle valve of the engine.

9. The acceleration slip controller according to claim 8 wherein an opening/closing speed θ

s of the throttle valve is controlled according to a formula

space="preserve" listing-type="equation">θ

s=K(α

·

Δ

V+β

·

Δ

V),

where K is a coefficient depending on the engine conditions, α and

β

are coefficients depending on the braking control condition, Δ

V=VS-VR, Δ

V is a change rate of Δ

V, VR is an actual speed of the driven wheel and VS is a target speed.

10. The acceleration slip controller according to claim 9 wherein the coefficients α

and β

are set at lower values at a time when the brake control is detected to be executed than at a time when the brake control is detected not to be executed.

11. The acceleration slip controller according to claim 9 wherein the coefficient β

is set at zero when the brake control is detected to be executed.

12. A method for controlling an acceleration slip on a driving wheel of a vehicle having steps of:

detecting a speed of the vehicle;

detecting a speed of the driving wheel;

setting a low reference speed and a high reference speed both higher than the detected vehicle speed;

executing a feedback control of an output of the engine of the vehicle so that the detected speed of the driving wheel approximates the low reference speed;

executing a feedback control of a brake system of the driving wheel after the detected speed of the driving wheel exceeds the high reference speed; and

controlling the feedback gain of the engine output control so as to lower at a time when the brake control is executed than at a time when the brake control is not executed.