Akebono Brake Industry Co., Ltd.

Fujitsu Corporation

Yuji Matsubara

Hideo Akima

Akira Hoashi

Katsuya Miyake

Haruki Shimanuki

Isao Yamaki

Toshifumi Maehara

Hiroshi Ikegami

Naoyuki Hagiya

Takao Maki

An anti-lock control system for motor vehicles is designed to have its computed vehicle speed modified as the motor vehicle is braked. In this invention, the computed vehicle speed persists along a reference deceleration gradient line representing a predetermined acceleration follow-up limit measured with respect to the wheel speed for a predetermined period of time from a point of time when the deceleration of the computed vehicle speed reaches the reference deceleration gradient line for the first time after the motor vehicle was braked. Thereafter, the computed vehicle speed is modified to follow a deceleration gradient line with a gradient that is gentler than that of the reference deceleration gradient line, until a threshold speed is reached, which is lower by a predetermined amount than and follows the computed vehicle speed with such a speed difference.

Anti-lock control system for motor vehicles

An anti-skid brake control system for a motor vehicle comprising: a wheel speed sensor which is disposed for each wheel of a vehicle and generates a pulse signal having a pulse cycle which corresponds to a revolution speed of each wheel; a pulse cycle measuring circuit for detecting the cycle of the pulses of the pulse signal from the wheel speed sensor; and, condition setting means for setting anti-skid brake control condition factors in accordance with the wheel speed. The anti-skid brake system is controlled in accordance with the condition factors set by the condition setting means.

Anti-skid brake control system

An anti-skid control system for motor vehicles is provided wherein a computed vehicle speed is set up on the basis of respective wheel speeds of the motor vehicle; a reference speed which is lower than the computed vehicle speed by a predetermined amout and follows the computed vehicle speed with such a speed difference, is calculated on the basis of the computed vehicle speed; a high peak of the wheel speed is compared with the reference speed; when the high peak of the wheel speed is equal to or higher than the reference speed, the brake pressure is increased; and when the high peak of the wheel speed is lower than the reference speed, the brake pressure is reduced again.

Anti-skid control system for motor vehicles

In an anti-skid control system for motor vehicles of the type that the drive system thereof is switchable between two-wheel drive (2WD) and four wheel drive (4WD), the design is made such that when the drive system of the motor vehicle is switched, the anti-skid control system is changed such that under 2WD condition, it operates as a three-channel system wherein the front wheels of the motor vehicle are controlled independently and the rear wheels thereof are controlled on the basis of the lower one of the rear wheel speeds, while under 4WD condition, the anti-skid control system operates as cross or X-type two channel system wherein the wheels associated with each of the two channels are controlled on the basis of the lower one of the two wheel speeds.

Anti-skid control system for motor vehicles of the type switchable

In an anti-skid control system for a motor vehicle, brake fluid pressure reduction-control mode and brake fluid pressure buildup-control mode occurs cyclically; in the reduction-control mode, reduction of the brake fluid pressure is started on the basis of detection of an abrupt drop in wheel speed which occurs when the wheel is braked; and in buildup-control mode, a valve is repetitively opened and closed so that brake fluid pressure buildup and holding operations are performed alternatley and repetitively, whereby the brake fluid pressure is caused to build up gradually. The length of time period for the first buildup operation in the buildup-control mode is determined on the basis of variation in the wheel speed occurring between a low peak point and a high peak point; and the length of time period for at least one of each pressure holding operation and each of the second and succeeding pressure buildup operations in the abovementioned buildup-control mode, is determined on the basis of variation in the wheel speed occurring immediately before the pressure holding or buildup operation is started.

Anti-skid control system for motor vehicle

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.

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Kazo, Japan

Yuji Matsubara