8.23. Anti-blocking system of brakes (ABS)
The anti-blocking system prevents blocking of wheels at sharp braking. Thanks to it the car at full braking remains operated. The system consists of the hydraulic block of the regulator and 4-wheeled sensors. The block of the regulator contains the electronic control device (ECU), hydraulic electromagnetic valves and the pump with the electric drive. Electromagnetic valves are run by the ECU block which receives signals from 4 sensors installed on each wheel of the car which control the speed of rotation of each wheel. Comparing these signals, the ECU block can determine car speed. Due to comparison of speed of separately taken wheel with the average speed of the car the control unit defines a condition of blocking of a wheel. When the wheel approaches blocking, pressure of brake fluid is too high therefore pressure in a support decreases on a control unit signal. It occurs until the wheel does not begin to accelerate again. Then the valve are closed again and pressure created by a brake pedal begins to make impact repeatedly. However value of pressure in a brake contour of this wheel not above the general pressure in system. Work of ABS at sharp braking repeats on each wheel until the effort is made for a pedal or the car does not stop.
At any malfunction in the ABS system there is its shutdown. In this case the control lamp of ABS on the dashboard lights up and the brake system works in the usual mode.