 printable version
ABS / EBV / EDS / ASR / MSR
Driving brake system
1 - Switch ASR;
2 - the stoplight switch;
3 - speed sensor rear
left wheel;
4 - speed sensor rear
right wheel;
5 - speed sensor right front wheel;
6 - the gauge of speed of rotation of the left front wheel; | 7 - Control unit ABS / EBV / EDS / ASR / MSR;
8 - a control lamp ABS / EDS;
9 - a control lamp ASR / ESP;
10 - a control lamp of brake fluid;
11 - brake master cylinder, brake servo and the brake pedal;
12 - the hydraulic unit |
Braking performance is greatest when the grip of the tire with the road surface is greatest. During braking, tire slips on the circumferential surface and the wheel speed becomes less than the vehicle speed.
Sliding minimum (0%), when the wheel is rolling freely and the maximum (100%), when the wheel is locked. The maximum braking efficiency is achieved when the slip is 15%. This value also allows you to maintain the stability and handling.
The role of the anti-lock system is to limit the pressure generated in the hydraulic brake system, so that the value of the slip was kept near the optimal value (15%). The effect of this system should be immediate and separate for each wheel. The system should respond immediately to each change of the surface (coefficient of friction), and the load on the car.
The anti-lock system performs the functions of energy, drive and brake servo and control anti-lock wheels. The hydraulic unit is installed instead of the vacuum booster is fitted as standard with a built-in brake master cylinder. Installation ABS is only possible in the factory in the manufacture of the car and can not be installed separately. Anti-lock braking system prevents the wheels from locking under heavy braking. This reduces the braking distance, especially under low grip in the rain and snow. The adhesive force between the wheels and the road in this case is greater when the braking wheel continues to rotate. In addition, even if full braking the vehicle remains controllable. Speed sensor, one for each wheel is measured by the speed of rotation of the wheel. According to signals from the sensor wheel revolutions in electronic control unit calculates the average speed approximately corresponding to the vehicle speed. Comparing the speed of each individual wheel from the average speed calculation, the electronic unit determines individual wheel slip state, and thus determines which wheel is in predblokirovochnom condition.
When one of the four speed sensors transmit a signal to block the respective wheels, once the electronic control unit sends a signal to the appropriate closing the inlet solenoid valve, which immediately shuts off the brake fluid through the brake line to the brake of the wheel - braking force remains constant. If you still slide continues, the exhaust valve opens and the pressure in the hydraulic system of the brake is reduced - the wheel is not braked (surplus brake fluid back into the tank). Once again, the wheel starts to spin, then immediately comes the opening of the inlet valve and closing the exhaust valve. Circuit pressure increases, and the wheel is braked again.
This cycle of braking and free-wheel speed is very fast (several times per second) and continues until the car stops or until you release the brake pedal.
This process is repeated when braking for each wheel as long as the brake pedal is released or when the vehicle speed decreases to 2-3 km / h. The driver determines the ABS operation of the brake pedal pulsation.
Emergency shutdown system will disable the ABS for any failure or low voltage in the electric vehicle network (below 10V).
The electronic control unit also performs auto-diagnostic function to alert the driver fire of a control bulb of the registration failure of electrical circuits or elements of an anti-lock system. When a faulty ABS system brake, however, intact and functioning as if the system is not in the car.
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