Akebono Brake Industry Co., Ltd.

Fujitsu Corporation

Akebono Research and Developement Centre Ltd.

Isuzu Motors Limited

Naoyuki Hagiya

Hideo Akima

Akira Hoashi

Shigeki Moride

Akihiro Shirata

Toshifumi Maehara

Katsuya Miyake

Isao Yamaki

Yuji Matsubara

Atsushi Hirako

Satomi Ookubo

Yoshiaki Yabe

Hideaki Watanabe

A traction control system for motor vehicles in which the occurrence of on-driving wheel speed is monitored during a time interval which begins when the traction control starts to a predetermined time period which elapses therefrom. In the event that no occurrence of no-driving wheel speed is detected during the aforementioned time interval, the throttle opening degree command value prevailing at the end of the time interval is decreased to a predetermined lower limit value in response thereto, while at the same time the control is changed to a low friction coefficient control mode.

Traction control system for motor vehicles

A method of controlling a traction of a vehicle, comprising the steps of reading a value determining a throttle opening and closing speed from a first throttle control map from which said throttle opening and closing speed are determined on the basis of a difference in speed between a driving and non-driving wheel speeds and of an acceleration of the driving wheel, and converting said value to an actual throttle opening and closing speed with a conversion rate corresponding to an acceleration of the non-driving wheel thereby controlling the throttle of the vehicle.

Traction control method and apparatus for a vehicle

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.

A method of computing the rotating speed of a rotating body includes the steps of setting speed computation reference time periods with respect to a pulse train signal obtained from the output of a rotating speed sensor; measuring time length from the last pulse edge in the previous speed computation reference time period to the last pulse edge in the current speed computation reference time period; and computing the rotating speed of the rotating body on the basis of the result of the time length measurement. The time point when the previous procedure of speed computation terminated corresponds to the time point when the current procedure of speed computation starts, thus making it possible to achieve continuous speed computation. In this way, an enhanced accuracy can be achieved in speed measurement for low speed range, which leads to improved control performance in anti-lock control and traction control for the low speed range.

Method of computing the rotating speed of a rotating body based upon

In a traction control system for motor vehicles, a plurality of threshold values which are higher than the vehicle speed (equal to the non-driving wheel speed) are set up; the wheel speed as increasing or decreasing is compared with the above-mentioned plurality of threshold values to effect buildup or reduction of the brake fluid pressure; and holding of the brake fluid pressure is effected on the basis of a variation in the acceleration/deceleration of the driving wheel; in the case where the holding control mode in which the brake fluid pressure is held, persists for a predetermined time period or longer when the driving wheel speed is higher than a specific one of the above-mentioned plurality of threshold values, the holding control mode is switched to buildup control mode.

An anti-skid control system for motor vehicles is disclosed wherein in case the wheel speed is equal to or lower than a minimum speed which is detectable by a microcomputer, the wheel speed is set at a predetermined threshold speed level between the minimum speed and zero, thereby preventing reduction of brake pressure from being started when the wheel is lower than the threshold speed. The anti-skid control system may also be designed such that a computed vehicle speed is set up which is approximate to the real vehicle speed; a reference speed is also set up on the basis of the computed vehicle speed in such a manner that it is lower by a predetermined amount than and follows the computed vehicle speed with such a speed difference; when the wheel speed becomes equal to or lower than a minimum speed which is detectable by a microcomputer, the wheel speed is set at a predetermined threshold speed level between the minimum speed and zero; and if a brake pressure reducing condition is prevailing at a point of time when the reference speed becomes equal to the threshold speed, then such a condition is released.

Anti-skid control system for motor vehicles

An anti-skid control system for motor vehicles is provided wherein the higher one of the lefthand and righthand rear wheels is selected as a first computed speed; the lower one of the above two wheel speeds is selected as a second computed speed; the lower one of the first computed speed and lefthand front wheel speed is selected as a third computed speed; the lower one of the first computed speed and righthand front wheel speed is selected as a fourth computed speed; and a reference speed is set up on the basis of the first computed speed in such a manner that it is lower than the first computed speed by a predetermined amount and follows the first computed speed with such a speed difference. Reduction of brake pressure which has been increased, is started on the basis of the third or fourth computed speed; and in the case where the second computed speed being decelerated, goes below the reference speed, the reduction of the brake hydraulic pressure is stopped at time when the second computed speed which is now being increased as the result of the brake pressure reduction goes above the reference speed, and thereupon buildup of the brake pressure is started.

Growing community of inventors

Ageo, Japan

Naoyuki Hagiya