What is ABS?
ABS or Anti-lock Brakes are fundamental to almost every modern active safety systemAnti-lock braking systems (ABS) have been around since the late 70s and are now mandated by government legislation. The basic technology supports more advanced safety systems like traction control, emergency brake assist and stability control. Every new car sold comes with ABS, but few people realise why it's so important.
So why do we need them... and how do they work?
ABS – from the German acronym 'Antiblockiersystem' – allows the driver to maintain steering control under heavy braking by preventing wheels from locking.
Let's delve a little deeper: the only thing keeping your vehicle going where you intend it to, is the friction between your vehicle's tyres and the road surface (tyre grip).
If the wheels lock (stop rotating) on a damp road surface for example, the momentum of the vehicle causes them to slide over the road's surface in the original direction the vehicle was travelling. Turning the steering wheel at this point to avoid a collision would make no difference to the direction of travel.
To have directional control the wheels need to be rolling over the road's surface, not locked and sliding over the surface. However, we also need friction between the tyre and the road so we can stop. If we can have maximum friction (to stop the vehicle) and keep the wheels turning at varying rates of rotational speed, we can have braking performance as well as steering control of the vehicle.
The Anti-Locking Brake system monitors individual wheel speeds; if a wheel starts to slow (decelerate) sooner than the other wheels, the ABS can monitor this and ease off the hydraulic brake pressure to the wheel that is going to lock (losing grip).
Initially, if the driver applies too much pressure to the brakes (with his/her foot on the pedal) ABS will take over and reduce the brake pressure to the slowing wheel, preventing wheel lock-up and allowing the driver to gain steering control.
This ability to vary the braking pressure across all four wheels means the car can steer and brake at the same time. As the car turns, the ABS continuously monitors and readjusts brake pressure to each of the four wheels as required.
It's the magic that keeps you and your car from enjoying a close-up look at the scenery in an emergency...
Tags
Please see our Editorial Guidelines & Code of Ethics (including for more information about sponsored content and paid events). The information published on this website is of a general nature only and doesn’t consider your particular circumstances or needs.
