Automatic brake control system

Claim 1

An automatic brake control system comprising: a distance sensor for detecting the distance between a front obstacle and a vehicle to be controlled: a brake pressure controller for controlling the application of pressure, holding of pressure and reduction of pressure for a hydraulic brake fluid in a wheel cylinder of said vehicle; and a control section which inputs a signal from said distance sensor, performs an arithmetic processing and outputs a control signal to said brake pressure controller, said control section calculating a distance X between said vehicle and said obstacle on the basis of the signal provided from said distance sensor, calculating a relative velocity Vs with respect to said obstacle from changes of X with time, determining an estimated time Tx which will be taken until contact with said obstacle, from both Vs and X, and outputting a control signal for the execution of braking in accordance with the value of the estimated time Tx; said control section storing reference times T 0 and T 1 (T 0 >T 1 ), actuating said brake pressure controller to pressurize the wheel cylinder for applying the brake when said estimated time Tx is smaller than both reference times T 0 and T 1 , and calling a driver's attention by blinking a lamp or issuing a warning sound when said estimated time Tx is smaller than the reference time T 0 and larger than the reference time T 1 ; said control section pre-pressurizing the wheel cylinder to create a light drag state of the brake when said estimated time Tx is smaller than the reference time T 0 and larger than the reference time T 1 .