Stopping a car in a hurry on a slippery road can be very challenging. Anti-lock braking systems (ABS) take a lot of the challenge out of this sometimes nerve-wracking event. In fact, on slippery surfaces, even professional drivers can't stop as quickly without ABS as an average driver can with ABS.
The theory behind anti-lock brakes is simple. A
skidding wheel
(where the tire contact patch is sliding relative to the road) has less
traction
than a non-skidding wheel. If you have been stuck on ice, you know that if your wheels are spinning you have no traction. This is because the contact patch is sliding relative to the ice. By keeping the wheels from skidding while you slow down, anti-lock brakes benefit you in two ways: You'll stop faster, and you'll be able to steer
while you stop.
There are four main components to an ABS system:
- Speed sensors
- Pump
- Valves
- Controller