What is Anti-lock Braking System?
Principle of Working
It works on the principle of threshold braking and cadence braking. Cadence braking and threshold braking is a technique in which a driver applies the brakes and releases it before locking up the wheel and then applies the brakes and releases it again before locking. This process of applying and releasing the brakes on the wheel is done in pulse form to prevent it from locking and stop skidding of the vehicle. The driver practices this technique to achieve better control over the vehicle during instant braking and stop skidding of the vehicle. The ABS system automatically does this cadence braking to prevent locking of wheel and skidding of vehicle when brakes are applied.
Why Anti-lock Braking System (ABS) is essential in vehicles?
Let’s us take another situation, now you are driving a car which is equipped with anti-lock braking system. When you encounter with an obstacle on the road and suddenly apply the brakes. But this time the ABS system of your car prevent the locking of the wheel and avoid skidding. At this time you can control your steering and can stops your car hitting from the obstacle. This is how the abs system prevents the skidding of the vehicle and provides greater control over it and prevents accidents.
Main Components of ABS System
1. Speed Sensors
- In position one, the valve remains open; and pressure from the master cylinder passed through it to the brake.
- In position two, the valve blocks the line and separates the brake from the master cylinder. And this prevents the further rise of the pressure to the brakes. Valve operates in second position when the driver applies the brake harder.
- In position three, some of the pressure from the brake is released by the valve.
The controller used in the ABS system is of ECU type. Its main function is to receives information from each individual wheel speed sensors and if a wheel loses its traction with the ground, a signal is sent to the controller, the controller than limit the brake force (EBD) and activate the ABS modulator. The activated ABS modulator actuates the braking valves on and off and varies the pressure to the brakes.
Working of Anti-lock Braking System (ABS)
- The controller (ECU-Electronic Control Unit) reads the signal from each of the speed sensors of the wheel.
- As the brakes are suddenly applied by the driver, this makes the wheel to decelerate at faster rate and may cause the wheel to Lock.
- As the ECU reads the signal which indicates the rapid decrease in the speed of the wheel, it sends signal to the valve which makes the valve close and the pressure to the brake pad reduces and prevents the wheel from locking.
- The wheel again starts to accelerate, again the signal sends to the controller, this time it opens the valve, increasing the pressure to the brake pad and brakes are applied, this again reduces the speed of the wheel and tries to make it stop.
- This process of applying brakes and releasing it happens 15 times in a second when a driver suddenly applies the brake harder. Due to this the locking of the wheel is prevented and the skidding of the vehicle eliminated. During braking with ABS system, the driver can steer the vehicle and reduces the risk of vehicle collision.
For Better Explanation about Anti-lock Braking System Watch the Video Given Below:
How Would you Know that the ABS System is in Operation?
When the ABS in operation, it can be felt by the driver through pulsation in the brake pedal; this happens because of the rapid opening and closing of the valves. The pulsing action of the pedal tells the driver that ABS system is in operation. Any fault in the ABS system is indicated on the instrument panel of the vehicle and it will work when the fault is completely removed.
- It prevents the locking of the wheel and thus eliminates the chance of skidding.
- The skidding of the vehicle is completely removed, which results in excellent control during braking?
- A better steering control is obtained with the ABS system.
- It reduces the chance of collision by 30 %.