Vehicle traction control apparatus and method of traction control

• US 6,547,022 B2
• Filed: 06/22/2001
• Issued: 04/15/2003
• Est. Priority Date: 06/27/2000
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hosomi, Kazushi, Nagae, Akira
• Primary Examiner(s): LERNER, AVRAHAM H
• Application Number:
  US09/885,938
• Publication Number:
  US 20010054520A1
• Time in Patent Office: 662 Days
• Field of Search: 701/71, 701/78, 701/79, 701/83, 303/20, 303/113.2, 180/197
• 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 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/1005 Transmission ratio engaged

Abstract

A vehicle traction control apparatus and method where an amount of pressure change of braking pressure is based on the amount of acceleration slip and the wheel acceleration. When the traction control is being performed and the braking force is being increased, an upper limit pressure increase amount of braking pressure is based on the engine revolution speed, and the estimated braking pressure, so that the calculated value is smaller if the revolution speed or the estimated braking pressure is greater. The upper limit pressure increase amount of braking pressure is corrected so that it is greater if the speed reduction ratio of the transmission is smaller. If the amount of pressure change of requested braking pressure is excessively high, and the amount of increase in braking pressure needs to be limited, the amount of pressure change of braking pressure is limited to the corrected upper limit pressure increase amount.

Claims

1. A traction control apparatus of a vehicle for reducing a drive slip of a drive wheel by applying a braking force to the drive wheel, the apparatus comprising:

a detector that detects an engine inertia force; and

a controller that reduces a rate of increasing the braking force during a traction control if the engine inertia force is high, compared to when the engine inertia force is low.

2. The traction control apparatus according to claim 1, wherein the controller reduces the rate of increasing the braking force during the traction control so that the rate of increasing the braking force decreases with increases in the engine revolution speed.

3. The traction control apparatus according to claim 1, wherein the controller reduces the rate of increasing the braking force during the traction control if the braking force applied to the drive wheel is high, compared to a low braking force.

4. The traction control apparatus according to claim 3, wherein the controller reduces the rate of increasing the braking force during the traction control so that the rate of increasing the braking force decreases with increases in the braking force applied to the drive wheel.

5. The traction control apparatus according to claim 4, wherein the braking force applied to the drive wheel is estimated based on the rate of increasing the braking force and on a control time based on the rate of increasing the braking force.

6. The traction control apparatus according to claim 1, wherein the controller detects a speed reduction ratio of a transmission apparatus, and increases an amount of reduction of the rate of increasing the braking force during the traction control when the speed reduction ratio is great.

7. The traction control apparatus according to claim 6, wherein the controller increases the amount of reduction of the rate of increasing the braking force during the traction control with increases in the speed reduction ratio of the transmission apparatus.

8. The traction control apparatus according to claim 1, wherein the controller reduces the rate of increasing the braking force during the traction control, by reducing an upper limit of the rate of increasing the braking force.

9. The traction control apparatus according to claim 8, wherein the controller sets the upper limit of the rate of increasing the braking force, in accordance with an engine revolution speed and the drive force applied to the drive wheel.

10. The traction control apparatus according to claim 9, wherein the controller sets the upper limit of the rate of increasing the braking force, in accordance with the speed reduction ratio of the transmission apparatus.

11. A traction control method for a vehicle that reduces a drive slip of a drive wheel by applying a braking force to the drive wheel, the method comprising the steps of:

detecting an engine inertia force; and

reducing a rate of increasing the braking force during a traction control if the engine inertia force is high, compared to when the engine inertia force is low.

12. The traction control method according to claim 11, wherein the rate of increasing the braking force during the traction control is reduced so that the rate of increasing the braking force decreases with increases in the engine revolution speed.

13. The traction control method according to claim 11, wherein the rate of increasing the braking force during the traction control is reduced if the braking force applied to the drive wheel is high, compared to a low braking force.

14. The traction control method according to claim 13, wherein the rate of increasing the braking force during the traction control is reduced so that the rate of increasing the braking force decreases with increases in the braking force applied to the drive wheel.

15. The traction control method according to claim 14, wherein the braking force applied to the drive wheel is estimated based on the rate of increasing the braking force and on a control time based on the rate of increasing the braking force.

16. The traction control method according to claim 11, further comprising detecting a speed reduction ratio of a transmission apparatus, and increasing an amount of reduction of the rate of increasing the braking force during the traction control when the speed reduction ratio is great.

17. The traction control method according to claim 16, wherein the amount of reduction of the rate of increasing the braking force during the traction control increases with increases in the speed reduction ratio of the transmission apparatus.

18. The traction control method according to claim 11, wherein the rate of increasing the braking force during the traction control is reduced by reducing an upper limit of the rate of increasing the braking force.

19. The traction control method according to claim 18, wherein the upper limit of the rate of increasing the braking force is set in accordance with an engine revolution speed and the drive force applied to the drive wheel.

20. The traction control method according to claim 19, wherein the upper limit of the rate of increasing the braking force is corrected in accordance with the speed reduction ratio of the transmission apparatus.