System for controlling braking of an automotive vehicle

Abstract

A braking force control system comprises a yaw rate sensor for detecting an actual yaw rate of a vehicle, a target yaw rate calculating section for detecting a vehicle speed and a steering angle to calculate a target yaw rate, a yaw-rate difference calculating section for calculating a difference in yaw rate by subtracting the target yaw rate from the actual yaw rate, and a braked-wheel discriminating section for selecting a rear-inside wheel as a braked wheel when the sign of the actual yaw rate is different from that of the difference in yaw rate, and for selecting a front-outside wheel as the braked wheel when the sign of the actual yaw rate is the same as that of the difference in yaw rate. Therefore, when the vehicle is in an under-steering tendency, the rear-inside wheel is selected, and when it is in an over-steering tendency, the front-outside wheel is selected. In addition, the system may further comprise an output discriminating section for comparing the difference in yaw rate with a discriminating threshold to discriminate as to whether the difference in yaw rate is within a control region. A first threshold is set as the discriminating threshold. After the under-steering tendency is changed to the over-steering tendency, a set period of time and a second threshold, the absolute value of which is smaller than that of the first threshold, are set. With this construction, it is possible to smoothly perform the control without giving uncomfortable feeling to a driver, and it is also possible to restrain the control by a rear wheel.