Anti-Lock Braking Systems

A Look at the Effectiveness of Anti-Lock Braking Systems

Anti-lock braking systems (ABS) provide a lot more control to the driver in a situation where a car has lost traction and has begun to skid off the road. Without ABS, bringing a car to a stop safely in such a situation requires skill and experience, something which the average driver lacks. However, with ABS, the process is a lot easier and the system does more than enough to compensate for the driver’s lack of ability.

The Theory behind ABS

When a car begins to skid, it has officially lost traction to the road because the surface area of the tire which is contact with the ground is not moving in the same direction as the road, but it is sliding relative to it. It would be just as sliding on ice.

This loss of traction occurs most commonly when a car is traveling at high speeds and brakes suddenly. This not only causes the wheels to skid, but they also lock in, not allowing the driver to steer. Both of these problems are solved with ABS which permits faster stops while avoiding skidding and while being able to steer.

How ABS Works

An ABS system has four components which work in conjunction with one another: speed sensors, a pump, a set of valves and a controller.

The speed sensors, as their name suggests, monitor the speed of each wheel in order to determine when one of them is about to lock up. This requires for sensors to be placed at each wheel’s location although, in some cases, the sensors can be installed in the differential instead.

The valves will be located in the brake line for each brake. When they are open, they allow pressure to pass through unimpeded. When they block the line, they separate the master cylinder from the brake. This prevents the pressure from building up due to the driver flooring the brake pedal. Lastly, in order to control the rate of braking, the valves open temporarily in order to release some of the pressure.

The pump fulfills a role which is opposite to that of the valves. While the valves release the pressure from the brakes, the pump reintroduces it back into the system when it is necessary. The last component is the controller which is simply a computer located inside the car which monitors and controls the sensors and the valves.