Anti-lock braking systems (ABS) help prevent car wheels from locking up during heavy braking. ABS uses sensors to detect wheel lockup and pumps the brakes 100s of times per second to maintain steering control. The key components are speed sensors, valves to control brake pressure, a pump to apply pressure, and an electronic control unit. ABS is effective at reducing crashes and stopping distances compared to regular brakes, but works best on clean, dry surfaces and may not perform as well on loose surfaces like snow or ice.

1. ANTI-LOCK BRAKING
SYSTEM
AUTOMOBILE ENGINEERING
UMAIR IBRAHIM(17ME01)

2. What are Anti-Lock Braking Systems?
• Commonly known as ABS, or sometimes anti-skid braking systems, anti-lock braking systems help
prevent car and motorcycle wheels locking up and improve steering control whilst braking.
• The first primitive form of ABS was developed in the 1920's by French pioneer Gabriel Voisin, initially
to aid braking on aircraft. Although, it wasn't until the 1970's that ABS was adapted and introduced to
the commercial vehicle market on a large scale.
• Today, anti-lock braking is now standard on virtually all new cars and motorcycles and is used not only
to aid steering whilst braking but also to help with traction control.

3. MAJOR COMPONENTS OF ABS.
The four major components of a typical anti-lock braking system are:
Speed sensors -These sensors monitor how fast the wheel or wheels are rotating
Valves -Valves in the brake line allow, block and release pressure on the brakes by assuming three different positions
Pump -These pumps are filled with hydraulic fluid and apply pressure to the brake drums or callipers on demand
Controller -The electronic control unit (ECU) is the brain of the ABS and uses data from the sensors to determine whether
or not to pump the brakes

4.  How does the Anti-Lock Braking System work?
• ABS works by releasing and then reapplying or 'pumping' the brakes to a motorcycle wheel or car wheels in heavy
braking situations. Sensors on each wheel are used to detect 'locking' or when a wheel stops moving and starts to
skid. Although not all ABS systems are the same, with some only preventing wheels on the rear axle from locking up.
When a lock-up is detected, ABS pumps the brakes, 100's of times a second. This stops the wheel or wheels from
skidding and helps keep the driver in control of the vehicle. So essentially, ABS works in three stages:
1. Brake pedal is pushed
2. Wheel sensors detect skidding or 'locking'
3. ABS pumps the brakes

6.  How effective are anti-lock brakes?
It doesn’t take a genius to conclude that if the aviation industry and car manufacturers swear by
ABS, it’s probably a good thing. The fact that it’s a mandatory feature on all new cars sold
indicates the faith the government and other regulators have in the system.
Here are four benefits of ABS:
1. Cars fitted with ABS are less likely to be involved in a fatal crash.
2. ABS decreases the chance of frontal collision on wet and dry roads
3. Cars with ABS rarely stray from the road ahead.
4. In an emergency, a car with ABS tends to stop in a far shorter distance than one would without
ABS.

7. Problems with ABS
• ABS works best on clean surfaces, such as a typical tarmac
road. They tend to be less effective on surfaces that have
loose gravel, mud or snow, which is worth remembering when
driving in winter.
• This is because the ABS system may interpret data from the
sensors incorrectly and not respond in an optimum fashion.
• So, in answer to the commonly-asked question ‘does ABS
work on ice?’, the answer is ‘not to an extent that you would
want to rely on it alone’.
• Incidentally, the issue of loose or slippery road surfaces
explains why off-road vehicles tend to switch off the ABS.
• A locked wheel is likely to dig into the road surface, effectively
anchoring itself, when being raced off-road.