Safety Devices in Cars
Created | Updated Jul 19, 2002
During the 1950’s no automotive manufacturer even thought of
safety of the passengers. In the 21st century cars are
becoming highly sophisticated and safer. Features like
airbags, anti lock braking system (ABS), safety belts, and
traction control system etc. are becoming standard in all
the cars. There has been deep transition in the nature of
these devices in the due course of time. It started with the
devices which protect the passenger in the case of an
accident such as safety belts. The devices which help in
preventing the occurrence of accidents such as ABS were next
on the list. Even then the number of accidents are escalating
so maybe the control of the vehicle will be taken away from
Homo sapiens and will be given to the computers in future.
AIRBAGS
During the crash of a car, the passenger’s speed falls to
zero from high value in very less time. Rate of change of
momentum therefore is very high, so huge forces act on the
body causing sometimes fatal injury. The purpose of the
airbag is to lengthen the time of the travel of a person
towards the dashboard and also to prevent him from hitting
it.
Basically airbag consists of three components:
1. Sensor: Sensor tells the airbag to inflate during a
collision. It senses the rapid deceleration which occurs
during the crash it can differentiate rapid braking and a
crash. Moreover inflation of the airbag starts at a precise
time calculated by a microchip depending upon the intensity
of the collision.
2. Bag: The bag is made of a nylon fabric having minute,
which maybe placed in the steering wheel, dashboard, seat
and the door. Recently VOLVO added the airbags to prevent
injury to the pedestrian, which inflates at the windshield.
The bag has tiny holes to deflate the airbag.
3. Inflation System: The inflation system produces
nitrogen gas, which fills the airbag during collision. The
inflation system ignites a solid propellant, which burns
very rapidly to produce a huge volume of gas to inflate the
airbag.
Working:
During the collision there is very rapid
deceleration and the sensor calculates the magnitude of the
impact. Then sensor ignites the propellant to produces
Nitrogen gas which inflates the airbag.
Manufactures are now designing the airbags which will not
deflate to prevent injuries to the passengers in case of the
occurrence of secondary crashes.
ANTILOCK BRAKING SYSTEM
ABS helps stopping the vehicle quickly in the low traction
or slippery conditions.
When the car is moving the friction between the tyres is
rolling friction and when the brakes are applied and wheel
stops spinning, the friction that comes into play is sliding
friction.
In the low traction conditions a
locked up tyres off very low friction and thus less braking
power. In an ABS system there are sensors to detect locking
of each individual tyre. If a sensor senses locking of a
wheel it releases brake fluid pressure and the wheel starts
spinning again, as soon the wheel starts spinning it again
increases pressure to stop the wheel. In the slippery
conditions if we apply brakes and try to steer, we lose the
control of the car easily this is due to very less kinetic
friction.
Advantages of Anti Lock Braking System:
1. ABS system prevents locking up and hence helps in
steering the car while applying the brakes.
2. By applying correctly the brakes the ABS system make
vehicle stop in shortest possible distance.
TRACTION CONTROL SYSTEM
Traction Control System is opposite to the Antilock Braking
System as it also applies brakes on the selective wheel
which start slipping and its power is transmitted to the
other wheels. Traction Control System utilizes sensors which
determine the speed at which wheels are rotating. A slipping
tyre rotates faster than other tyres so brakes are applied
automatically.
This helps achieve the following:
1. The power from slipping tyre is transferred to the rest
of the tyres and is very helpful in situations in which one
or two wheels get struck.
2. Maximum traction available to each tyre is utilized
which is very useful in the low traction and off road
conditions.
3. TCS prevents the vehicle from going of out control at
high speed as the slipping one tyre may cause the vehicle to
be steered incorrectly.
Rohit Handa ( etymologist )
safety of the passengers. In the 21st century cars are
becoming highly sophisticated and safer. Features like
airbags, anti lock braking system (ABS), safety belts, and
traction control system etc. are becoming standard in all
the cars. There has been deep transition in the nature of
these devices in the due course of time. It started with the
devices which protect the passenger in the case of an
accident such as safety belts. The devices which help in
preventing the occurrence of accidents such as ABS were next
on the list. Even then the number of accidents are escalating
so maybe the control of the vehicle will be taken away from
Homo sapiens and will be given to the computers in future.
AIRBAGS
During the crash of a car, the passenger’s speed falls to
zero from high value in very less time. Rate of change of
momentum therefore is very high, so huge forces act on the
body causing sometimes fatal injury. The purpose of the
airbag is to lengthen the time of the travel of a person
towards the dashboard and also to prevent him from hitting
it.
Basically airbag consists of three components:
1. Sensor: Sensor tells the airbag to inflate during a
collision. It senses the rapid deceleration which occurs
during the crash it can differentiate rapid braking and a
crash. Moreover inflation of the airbag starts at a precise
time calculated by a microchip depending upon the intensity
of the collision.
2. Bag: The bag is made of a nylon fabric having minute,
which maybe placed in the steering wheel, dashboard, seat
and the door. Recently VOLVO added the airbags to prevent
injury to the pedestrian, which inflates at the windshield.
The bag has tiny holes to deflate the airbag.
3. Inflation System: The inflation system produces
nitrogen gas, which fills the airbag during collision. The
inflation system ignites a solid propellant, which burns
very rapidly to produce a huge volume of gas to inflate the
airbag.
Working:
During the collision there is very rapid
deceleration and the sensor calculates the magnitude of the
impact. Then sensor ignites the propellant to produces
Nitrogen gas which inflates the airbag.
Manufactures are now designing the airbags which will not
deflate to prevent injuries to the passengers in case of the
occurrence of secondary crashes.
ANTILOCK BRAKING SYSTEM
ABS helps stopping the vehicle quickly in the low traction
or slippery conditions.
When the car is moving the friction between the tyres is
rolling friction and when the brakes are applied and wheel
stops spinning, the friction that comes into play is sliding
friction.
In the low traction conditions a
locked up tyres off very low friction and thus less braking
power. In an ABS system there are sensors to detect locking
of each individual tyre. If a sensor senses locking of a
wheel it releases brake fluid pressure and the wheel starts
spinning again, as soon the wheel starts spinning it again
increases pressure to stop the wheel. In the slippery
conditions if we apply brakes and try to steer, we lose the
control of the car easily this is due to very less kinetic
friction.
Advantages of Anti Lock Braking System:
1. ABS system prevents locking up and hence helps in
steering the car while applying the brakes.
2. By applying correctly the brakes the ABS system make
vehicle stop in shortest possible distance.
TRACTION CONTROL SYSTEM
Traction Control System is opposite to the Antilock Braking
System as it also applies brakes on the selective wheel
which start slipping and its power is transmitted to the
other wheels. Traction Control System utilizes sensors which
determine the speed at which wheels are rotating. A slipping
tyre rotates faster than other tyres so brakes are applied
automatically.
This helps achieve the following:
1. The power from slipping tyre is transferred to the rest
of the tyres and is very helpful in situations in which one
or two wheels get struck.
2. Maximum traction available to each tyre is utilized
which is very useful in the low traction and off road
conditions.
3. TCS prevents the vehicle from going of out control at
high speed as the slipping one tyre may cause the vehicle to
be steered incorrectly.
Rohit Handa ( etymologist )
