15:17. Anti-blocking system of brakes (ABS)
Anti-blocking system of brakes
The anti-blocking system of brakes (ABS) operates pressure in the hydraulic drive of brakes of each wheel separately and reduces liquid pressure in that wheel brake mechanism which wheel begins to be blocked.
ABS performs the following functions:
- Improvement of stability of driving at a detour of obstacles even in the course of braking.
- Reduction of a brake way at intensive braking at preservation of stability and controllability of the car even when passing turns.
The anti-blocking system of brakes works at information basis from four sensors transferred to the ABS block. The system operates each wheel separately and reduces liquid pressure in that wheel brake mechanism which wheel begins to be blocked.
Under normal conditions the standard brake system carries out braking until blocking of the wheel found by the ABS control unit. When the ABS control unit finds blocking of a wheel, it operates each valve for increase or reduction of pressure.
The ABS control unit determines the frequency of rotation and norm of delay of each wheel on the basis of information from sensors of frequency of rotation of a wheel. When braking the frequency of rotation of a wheel decreases and the ABS block defines a difference between the speed of the car and frequency of rotation of a wheel. If delay of some wheels exceeds the expected value, the ABS block defines the beginning of blocking and opens the corresponding electromagnetic valves to reduce pressure of brake fluid. At the same time the frequency of rotation of a wheel increases and the electromagnetic valve of dumping of pressure is closed and there is an increase in pressure of brake fluid in the working brake cylinder of the corresponding wheel.
EBD (Electronic distribution of brake effort)
EBD is in addition applied instead of pressure regulator ideally to distribute pressure to forward and back brakes, for prevention of blocking of back wheels at intensive braking.