Description of the ABS device

Therefore:

• Creeeping (skidding) 0% = if the wheel is free to roll
• Creeeping (skidding) 100% = if the wheel is locked and the vehicle is still moving

During braking, friction increases greatly due to the low skid coefficient values and then decreases as the wheel slows down too much in relation to the speed of the vehicle. The greatest braking efficiency has therefore, skid coefficient values between 5% and 15% with a maximum value of 20% depending on the conditions of the tyres and road surface. The ABS system regulates braking pressure so that the skid coefficient is kept within optimal limits. This ensures that the maximum degree of friction is employed to brake the vehicle and that the vehicle stops in the shortest distance possible permitted by the road surface and the condition of the tyres.

DESCRIPTION OF THE ABS DEVICE

The electrohydraulic control unit, after receiving signals from the electronic control unit, varies the pressure of the brake fluid on the brake calipers in three phases:

1. Pressure increase phase
2. Pressure decrease phase
3. Constant pressure phase