The Anti Lock Braking System or ABS has taken its place as one of the most popular vehicle safety equipment for the past 2-3 decades.  Safety is always a major concern whenever you are in a vehicle. Regardless of how high your skill level is, there is always a risk of coming face to face with a disastrous situation no matter how careful you are. To mitigate this, manufacturers started implementing their vehicles with electronic driver aids to ensure a safer driving experience. The ABS system also falls into the same category. In this article, we will take a look at how the Anti Lock Braking System performs its duty and how it can potentially save your life.

The Concept Of Wheel Lock:

When you are driving at a decent speed and suddenly a jaywalker decides to cross the road in front of you, your instant reflex action is to slam on the brakes. At maximum pedal effort on the brakes, the wheels are jammed shut, i.e they can’t move at all. So when you are at a speed of say 80 kmph on the road and you slam the brake pedal out of panic, the wheels instead of slowing down, straight away get jammed shut or experience the phenomena of “locking up”.

When locked up, the wheels are incapable of rotating and become the equivalent of a block of rubber being dragged down the road at high speed. This means they will immediately skid, you will have no control over the steering and the direction you will be skidding towards is in God’s hand. If you release your brake pedal, this will effectively stop the speed from decreasing which will bring you even closer to the peril ahead. So what can be done in such a situation?

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Enter, ABS

Before ABS became mainstream, expert drivers used a technique called cadence braking or threshold braking. Now as obvious as it sounds, the braking effort of the vehicle is maximum at the point just before the amount of effort required to cause wheel lock.

So drivers used to release the brake pedal by a small amount at the when the wheels locked and re-applied the pressure the moment they start rotating again till they locked up and this cycle was repeated. But now you have the advanced electronics of the ABS system to do the exact same thing for you and with exponential precision.

How does Anti Lock Braking System work?

The ABS system comprises of 4 main components namely, 4 wheel speed sensors ( one for each wheel), a hydraulic motor, pressure release valves and an electronic module that is embedded into the car’s ECU (Engine Control Unit).

When your wheels lock up, their rotational speed becomes zero and the sensor immediately detects that sudden decrease in speed and sends a signal to the control module. The control module processes the decrease in speed as a wheel lock and orders the pump to release some braking pressure through the release valves. This, in turn, decreases the braking effort on that wheel.

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Once the wheel regains rotational speed and stops skidding the sensors pick up that increase in speed and send another signal to the control module. This time the module orders the pump to shut off the release valves to stop the pressure decrease and increase the braking effort.

Now if you are thinking that this can be done by humans itself and ABS is an unnecessary expense, a human can probably do this correctional action once every 4-5 seconds. Even an entry level-ABS system will perform this action almost 15-17 times a second. Moreover, the driver needs to devote his mental attention to other things like the road ahead, the steering, judging the distance available to stop to name a few than to put it all in pumping the brakes.

How this helps?

Apart from just mitigating the occurrence of wheel lock, the most salient advantage of the Anti Lock Braking System is that it lets the driver have control even when he/she is slamming the brakes at full force. Unlike in the situation of a wheel lock, the driver will be able to steer the car easily even in full brake effort with the ABS system, as the wheels will still be rotating.

ABS is most useful in slippery road conditions. If you’re on a slippery or wet road surface, even the mildest touch to the brake pedal could commence the wheel lock cycle. In such conditions, the occurrence of a wheel lock can be most disastrous as the severe lack of frictional force between the wet road and tyres can cause the car to spin out with almost no resistance force to decrease the velocity till you reach a dry patch. But with the help of the ABS system, you will be able to brake effectively despite the wetness of the surface.

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Disadvantages of Anti Lock Braking System

As such the Anti Lock Braking System has no functional disadvantages. The only notable one is that on dirt or gravel or any non-tarmac surface, ABS will increase the braking distance. On such loose surfaces, the locking up process is necessary to come to a stop as a locked tyre will dig into the surface and help in anchoring the vehicle.

One must also be wary to not give excessive steering output to veer away from the hazards up ahead just because the ABS is there. Remember that ABS only modulates the brakes and not the steering so the latter will still behave in the same manner with or without the ABS.

Another issue with the ABS system is the cost. Usually, manufacturers only incorporate ABS systems into their topmost variants leaving the mid and base variants aside. However, this trend is changing as nowadays the newer cars are getting fitted with ABS as standard across all the variants.

To Sum it Up

The Anti Lock Braking System is one of the finest technological developments that has emerged in the field of vehicle safety in the past few decades. It truly can make the difference between life and death situations. In a welcome move, The Ministry of Road Transport and Highways has made it mandatory for manufacturers to incorporate ABS as standard in every new vehicle starting 2018 and from 2019 even their existing models will have to be equipped with ABS compulsorily if they wish to continue to sell those models.