Traction control system for motor vehicles

• US 5,067,578 A
• Filed: 10/03/1990
• Issued: 11/26/1991
• Est. Priority Date: 12/28/1987
• Status: Expired due to Fees

• Current Assignee: Akebono Brake Industry Company Limited (Akebono Brake Corporation), Akebono Research and Development Centre Limited (Akebono Brake Corporation), Fujitsu Limited, Isuzu Motors Limited
• Original Assignee: Akebono Brake Industry Company Limited (Akebono Brake Corporation), Akebono Research and Development Centre Limited (Akebono Brake Corporation), Fujitsu Limited, Isuzu Motors Limited
• Inventors: Watanabe, Hideaki, Ookubo, Satomi, Moride, Shigeki, Shirata, Akihiro, Hagiya, Naoyuki
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): CAMBY, RICHARD M
• Application Number:
  US07/593,494
• Time in Patent Office: 419 Days
• Field of Search: 180/197, 180/244, 364/426.03, 123/352, 123/360, 123/361, 74/857, 74/859, 74/860, 74/844, 74/872
• 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
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 35/0007 using electrical feedback F02D35/0015 takes precedence

Abstract

In a traction control system for motor vehicles, a lower limit for throttle opening degree command with respect to each gear position of transmission is set up, and when the transmission is shifted up, the throttle opening degree command is decreased down to the lower limit for throttle opening degree command corresponding to the gear position assumed through the shift-up operation.

Claims

1. A traction control system for a motor vehicle having a throttle, and a transmission;

said system comprising;

means for detecting driving wheel slip, means for changing a command value for opening the throttle depending on said driving wheel slip, means for controlling the degree of opening of the throttle in accordance with the throttle opening degree command value to restrain said driving wheel slip;

means for detecting each gear position of the transmission;

means for setting a lower limit value for the throttle opening degree command value with respect to each gear position of the transmission as detected;

said means for setting a lower limit value including means for setting a different value for each respective gear position so that each value is different from any other value and corresponds to a different degree of opening for the throttle then for any other value; and

means, for causing said throttle opening degree command value to be decreased down to the lower limit value upon a gear change of the transmission up or down.

2. A traction control system according to claim 1 wherein said means for setting a limit valve provides signals representing a lower limit value a for a throttle opening degree command value with respect to a first gear speed position of the transmission, a lower limit value b for a throttle opening degree command value with respect to a second gear speed position of the transmission, a lower limit value c for a throttle opening degree command value with respect to a third gear speed position of the transmission, a lower limit value d for a throttle opening degree command value with respect to a fourth gear speed position of the transmission and a lower limit value e for the throttle opening degree command with respect to a fifth gear speed position of the transmission where a<

b<

c<

d<

e.

3. A traction control system according to claim 1, further comprising:

means for computing a reference speed Vr on the basis of lefthand and righthand driving wheel speeds VdL and VdR;

means for setting up a control threshold value Vs by adding a predetermined value Vk to a computed vehicle speed Vv computed on the basis of lefthand and righthand non-driving wheel speeds VnL and VnR; and

means arranged, when the motor vehicle starts running, for starting throttle closing control at a point of time when said reference speed Vr exceeds said control threshold value Vs.

4. A traction control system according to claim 3, wherein said reference speed Vv is the mean value of the lefthand and righthand driving wheel speeds VdL and VdR.

5. A traction control system according to claim 3, wherein said computed vehicle speed Vv is computed on the basis of the higher one of the lefthand and righthand non-driving wheel speeds VnL and VnR.

6. A traction control system according to claim 1, wherein a notional vehicle speed EVv is set up on the basis of engine speed, and gear position of transmission without taking into account of clutch slip;

and said notional vehicle speed EVv is compared with said control threshold value Vs to effect throttle control.

7. A traction control system according to claim 1, wherein said transmission assumes first to fifth-speed gear positions;

and lower limits a, b, c, d and e for throttle opening degree command are set up with respect to the first- to fifth-speed gear positions respectively in such a relationship that a<

b<

c<

d<

e.