Hello steemians today i am explaining what is Antilock
Braking System (ABS) what is it and why is it necessary.
Sometimes on applying brakes too hard or applying brakes on
slippery surfaces can cause the wheels to lock and slide. Due to locking of
wheels you lose steering control and the stopping distance will be longer as
car slides on the surface due to its momentum.
The Antilock Braking System (ABS) prevents the lockdown or slipping
of wheels doesn’t matter how hardly you have applied the brakes or how much
slippery the road surface is, thus stopping distance reduces and steering
always remains in your control
Now let’s see its technical specification and working
It mainly consist of
A brake pedal: pedal which driver pushes to stop the car.
A master cylinder: technically it’s a device which is use to
convert non-hydraulic pressure to hydraulic pressure, in simple language when
you push the brake pedal it converts the mechanical force to hydraulic
A wheel speed sensor: A sensor to measure the wheel speed
The electronic control unit (ECU): The electronic control
unit is like a computer it controls many important functions of the car engine
such as proper air and fuel ratio, correct ignition timing, etc. In ABS readings
from wheel speed sensors are constantly sent to the controller and if any wheel
looses traction then controller immediately limits the braking force.
The hydraulic control
unit also called hydraulic modulator: It controls the solenoid valves though which
hydraulic fluid leads to each of the wheels.
Now let’s see how ABS works
The wheel speed sensor has a toothed rotor that rotates with
each wheel and a pickup sensor which measures the speed of the rotor.
When the wheel rotates the pickup sensor starts sending voltage
pulse signal to the electronic control unit. When the brakes are applied the
wheel speed of rotation changes this sends a new signal to ECU.
Readings from wheel speed sensors are constantly sent to ECU
and if ECU detects any condition of locking of wheels or any wheel loosing
traction it further sends an electric voltage pulse signal to the hydraulic
The hydraulic control unit is commonly a three channel size
control unit and has three solenoid valves to control brake pressure and
prevent the locking or sliding of wheels. These valves are installed in series
with master cylinder and the brake circuit. In this three one solenoid valve
controls each of thefront wheels and the second solenoid valve is used to
control each of the rear wheels.