Akebono Brake Industry Co., Ltd.

Fujitsu Corporation

Haruki Shimanuki

Hideo Akima

Akira Hoashi

Katsuya Miyake

Yuji Matsubara

Takao Maki

Yoshio Takahashi

Yoshiaki Hirobe

Hiroyuki Yoshizawa

Satoru Eguchi

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

In an anti-lock control system for a motor vehicle, the design is made such that such that computed vehicle speed is prevented from remarkably departing from real vehicle speed as driving wheel slips before anti-lock control is started, thereby preventing occurrence of non-braking condition when anti-lock control is started. To this end, the manner in which the computed vehicle speed is computed, is changed between during braking operation (when anti-lock control is being effected) and non-braking operation (when no anti-lock control is being effected).

In an anti-lock control system for motor vehicle, the design is made such that the braking distance of the motor vehicle is prevented from being increased by excessive reduction of brake hydraulic pressure for a road surface of medium- or high friction coefficient, while at the same time the occurrence of vibration in the motor vehicle caused by excessive reduction of the brake hydraulic pressure is avoided.

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

In an anti-lock control system for motor vehicles, the design is made such that when the motor vehicle is running on a rough road, reduction of the brake hydraulic pressure can be prevented from being started early by detecting that the motor vehicle is running on the rough road, and such that any adverse effects can be avoided which tend to be produced in the case where a device for coping with the rough road is applied when the road surface on which the motor vehicle is running is a low-.mu. road surface or when the motor vehicle is running with a low speed.

Anti-lock brake control system for motor vehicles

In an anti-skid control system for motor vehicle, there is provided means adapted, when the motor vehicle is running on a rough road, to detect that the road on which the motor vehicle is now running is a rough one, thereby preventing reduction of brake hydraulic pressure from being started early.

Anti-skid control system for motor vehicles

An anti-skid control system for motor vehicles is provided wherein when the time period from when the wheel velocity being decreased reaches a second reference velocity to a low peak of the wheel velocity at which the reduction of the brake pressure is to be stopped, is longer than a predetermined time period, the reduction of the brake pressure is continued until the wheel velocity is increased up to a first reference velocity which is higher than the second reference velocity. In this way, even if the wheel velocity drops sharply because the coefficient of friction of the road surface suddenly changes from high to low, the wheel velocity recovers so that the wheels of the motor vehicle are prevented from locking early.

An anti-skid control system for motor vehicles is provided wherein a computed wheel speed Vv is set up on the basis of the highest one of the wheel speeds of the motor vehicle; a first reference speed VT1 and a second reference speed VT2 are set up which are lower than and follow the computed vehicle speed Vv either with a first and second predetermined speed difference respectively or with a first and a second predetermined ratio respectively, the first reference speed VT1 being higher than the second reference speed VT2 (VT1&gt;VT2); in the case where the wheel speed continues decreasing with a deceleration lower than a predetermined threshold level of deceleration, reduction of brake pressure is started at a point of time when a predetermined time period T1 elapsed from a point of time when the wheel speed reached the level of the second reference speed VT2; and the reduction of the brake pressure is stopped at a point of time when the wheel speed was increased up to the level of the first reference speed VT1 as a result of the reduction of the brake pressure.

Growing community of inventors

Kasukabe, Japan

Haruki Shimanuki