ABS Anti Lock Braking System.
Why it is effictive ?
When we apply brake, we are pushing brake pads (in case of disk brake) or brake shoe (in case of drum brakes) against Rotor (Disk) or drum lining. Which causes friction between them and transfer that force to tyres and making vheicle stop. And due to friction forces between tyres and road car stops when brakes are applied.
Friction forces are of two types.
Kinetic Friction and static Friction.
Static Friction is always greater than kinetic friction .(there is a mathematical formula for that which i cannot write here)
Cutting long story short. When wheel is rotating on ground there is static friction between road and tyres and when wheels are locked (under full braking) there is kinetic friction between road and tyres (when car is in motion).
Friction is what helps stick car on road and when we try to steer it, it turns accordingly.(physics law , a object in motion will remain in motion in straight line unless any external force is applied. In case of car that force is friction between car and tyres. )
When car is moving and we apply brakes suddenly what happens is wheels get locked and there is kinetic friction between road and tyres . and the drictional forces are lost and car goes straight with locked wheels.
But what ABS DO is that it does not allow wheels to get locked at the same time applies max force possible to stop the car without locking the tyre (maintaining static friction between tyre and road). In this condition under hard braking the braking distance is reduced and at the same time you are able to steer the car as well.
for more understanding try Searching Bosch ABS video on Youtube
I have tried my level best to explain in short . Its a very long thing to explain in writing , as it consist of many other things like wheel speed sensor, ABS ECU, how it governs to distribute the different brake force to each wheel depending upon traction condition.
BOTTON LINE IS IF YOU CAN BUY A CAR WITH ABS , I SAY GO FOR IT WITHOUT SECOND THOUGHT. I SUGGEST LIKE IN WESTERN COUNTRIES WHERE CARS ARE 50% CHEAPER THAN WHAT WE PAY HERE , NEED(GOVT. RULES) TO HAVE ABS, TRACTION CONTROL, STABILITY CONTROL, ATLEAST 8 AIR BAGS STANDARD. HERE IN INDIA ALSO THESE SHOULD BE COMPULSARY
