What is Anti Lock Braking System In Cars?

The popular term seen in determining a car’s safety feature is the ABS or Anti Lock Braking System. While some of you may be wondering exactly what is Anti Lock Braking System in cars? How does the ABS function? What does ABS+EBD mean etc? Let us look at these technologies in detail.

Principle of ABS (Anti Lock Braking System)-

The ABS system works on the basic principle of braking multiple times in a second without locking the wheel. In simple terms, the moment we apply the brake the braking force is applied multiple times and released simultaneously so that there is no skidding. It is just like pushing the braked pedal several times and releasing it within seconds.

The frequency with which this happens usually lies between 10- 15 times per second or more.

Components Of ABS System-

The complete ABS setup consists of four main components:

• ABS sensor
• Valves
• Pumps
• Controllers

Each of these components has a specific role to play, let us see what it takes to set up the ABS to work in a car.

1. ABS sensors- The ABS sensors are mounted over a toothed ring commonly called ABS rings, their main job is to measure the speed of the car. Depending upon the input from the ABS sensor the controllers decide whether to use ABS functionality during braking or not.
2. Valves- The valves act as the start-stop button when ABS is working. Depending upon the wheel spin the valves release the braking force to the wheels or suppress it to prevent excessive loss of traction to avoid skidding.
3. Pumps- The pump’s main function is to restore pressure back to the hydraulic brake after brakes are applied.
4. Controller- The controller acts as the CPU in the ABS system which regulates the amount of braking force on each wheel.

Working Of Anti Lock Braking System-

Most of you might be wondering whether the ABS feature is always working in the car? The answer to this question is no. Only in the event of sudden high-speed braking ABS feature is on. Let us assume a scenario of panic braking being done by the driver. In this case when ABS is working in the vehicle then the following series of events happen within a fraction of seconds.

1. ABS sensors measure the speed of the vehicle based on the rpm of each wheel
2. Depending upon the input received from the ABS sensor the controllers send the signal to the valve to block or release the braking force. If the braking force is more then the controller sends the signal to block the excess braking force so as to avoid locking the wheels which thereby prevents the skidding of the vehicle.
3. The moment the braking force decreases and the wheel again start to move forward, the controllers send the signal to valves to release the braking force and apply brakes.
4. This cycle of events happens multiple times within a fraction of seconds. Say 10-15 times within a second to halt the vehicle without skidding.

Electronic Brake Force Distribution-

As you are driving the car at a constant speed, it may happen that all the wheels of the car are not running at the same speed. This type of scenario arises while making a turn where the inner wheel has to travel less distance as compared to the outer wheel. Therefore applying the same braking force on all the wheels will lead to skidding. This is where the need for EBD arises.

Components Of EBD-

The EBD system makes use of the components from the ABS system itself. It requires three main parts to function which are as follows:

1. Speed Sensors
2. Brake Force Modulators
3. ECU

Slip Ratio-

The difference between the speed of the car and the speed at which the tyres are rotating. Now the slip ratio on individual wheels can vary depending upon the amount of load put on to the vehicle.

Working of EBD-

The EBD system works by measuring the speed of the vehicle and the difference in the speed of rotation of each wheel. This data is then sent to the ECU or Electronic Control Unit which sends the signal to the brake force modulators/valves to modulate the amount of braking force being applied on each wheel. Hence the braking force on each wheel differs depending upon the slip ratio of each wheel.

FAQs regarding ABS and EBD-

      1. Is the ABS feature always on during the braking of the vehicle?

ANS. No, it is working only in case of high-speed sudden braking. So next time when you drive your vehicle at a lower speed be mindful to apply the required amount of braking force on your own.

      2. Does EBD increases the effectiveness of steering while turning the vehicle?

ANS. Yes, EBD helps in improving the steering angle while turning your vehicle at higher speeds.

      3. The ABS light in my car is always on, what can be the reason?

ANS. This simply doesn’t mean that the ABS feature is working continuously in the car, it can signify some fault in the ABS components in the vehicle. You should seek technical advice from the authorized service center.

      4. What are Single Channel ABS and Dual Channel ABS?

ANS. Single Channel ABS simply means that the ABS functionality is available only on a single wheel while Dual Channel ABS means ABS functionality is available on both wheels. This term is mostly used in motorbikes where the ABS feature is given only on front wheels or sometimes on both wheels.

      5. How to know whether my car is having ABS?

ANS. Usually, when you switch on the vehicle all the warning lights will glow up on the dashboard there you can find the ABS warning light also if your car is having the ABS feature. The next option is to refer to the vehicle’s brochure for confirming the same.

Summary-

ABS and EBD feature has significantly helped in improving the overall safety ratings of the car. Even a yard less traveled while braking the car can fructify the extra cost incurred in buying an ABS-equipped vehicle.