Use of safety airbags

2. OVERVIEW OF THE TOPIC
 Introduction
 The basics of Airbags
 Development of Airbags
 Main parts of Airbags
 Sensor types
 Working of Airbags
 Future of Airbags
 Conclusion

3. INTRODUCTION
 For years, the trusty seat belt provided the sole form of passive restraint in our cars.
 There were debated about their safety, especially relating to children.
 But over time, much of the country adopted mandatory seat-belt laws.
 Statistics have shown that the use of seat belts has saved thousands of lives that might have
been lost in collisions.
 Air bags have been under development for many years.

4.  No safety device has consumed more attention and resources than the airbag.
 It is known with high confidence that when a crash occurs the presence of airbag reduces
fatality risk to drivers.
 Airbags are subject of serious government and industry research.

5. THE BASICS OF AIR BAGS
Newton’ second Law of motion:
 If objects aren’t applied any force ,they will continue moving at the speed of the moving car
even if the car is stopped by collision.
 All airbag need to do is to slow down passenger’s speed.

6. MAIN PARTS OF AIRBAG
 BAG
 SENSOR
 INFLATION SYSTEM

7. BAG
 Made of a thin, nylon fabric, which is folded into the steering wheel or dashboard or, the seat
or door.
 The powdery substance released(regular cornstarch or talcum powder) is used to keep the
bags lubricated while they’re in storage.

8. SENSORS
 The sensor is the device that tells the bag to inflate.
 It has the control module to discriminate between crash and non-crash events.
 work on the principle of detecting a decrease in acceleration of a moving vehicle and
generate an electrical impulse
TYPES
 Mass Type Sensor
 Roller Type Sensor

9. Mass Type Sensor(Impact sensor)
 Fitted to the front of the vehicle.
 This safety sensor is required to measure the intensity of the collision to determine whether
the impact is over a certain threshold to justify release of an airbag.
Structural components to an Inertia sensor. Source:
Duffy, J.E. (2001). ICar Professional Automotive Collision.
Repair. New York: Delmar, a division of Thomas Learning

10.  During a collision the sensing mass is forced forward into the gold plated contacts as a result
of change in the state of motion.
Roller Type Sensor
 It involves a weight connected to a coil spring component.
 The metal weight is forced forward which alters the tension on the coil spring to manipulate
the electrical circuit that closes off the sensor contact.
Functional principle to a typical roller type airbag sensor. Source:
Erjavec, J. (2010). Automotive Technology: A Systems Approach.
New York: Delmar, Cengage Learning.

11. INFLATION SYSTEM
 Consists of a gas generator containing a mixture of NaN3,KNO3 and SiO2.
REACTIONS
 2NaN3----2Na+3N2
 10Na+2KNO3---K2O+5Na2O+N2
 K2O+Na2O+SiO2--Na2K2SiO4(alkaline silicate glass)
 Hot Blasts of the nitrogen inflate the air bag from its storage site up to 332 Kmph.

12. INFLATOR ASSEMBLY
 Control module activates the airbag assembly.
 an electric current is sent to the detonator, which ignites the sodium azide pellets.
Center for applied technology-http://www.cast.org

13. WORKING OF AIR BAGS
 The deployment accompany activation of array of sensors.
 Air Bags are designed to inflate in frontal impacts in which the car strikes about 16 kilometres
per hour.
 ACU decides if and how to deploy the air bags.
 After collision, sensors sends an electric current to igniter system.
 The electric currents heat a filament (wire),which ignites a capsule which in turn ignites the
gas generating pellets.
 The gas expands quickly and inflation of airbags thereby takes place, which breaks through a
plastic cover in the steering wheel.
 The whole process takes about 0.04 second.

14. http://www.opelegypt.net/vehicle
s/opel-
range/cars/mokka/features/safet
y-driver-assistance.html

15. FUTURE OF AIR BAGS
SMART SYSTEMS
 Weight sensors
• Determine what type of occupant is in the seat,i.e adult or child.
 Infrared occupant detection
• To detect the distance the passenger is from the airbag.
 Capacitive Reflective Occupant sensing
• Identify the distance passenger from dashboard.
• To discriminate between a human occupant and inanimate objects.

16.  Updated sensors
• Deploy the seat belt pretensioners faster to get benefits of the airbags.
 Centralized electronic control unit
• The new sensor technology through new software.

17. CONCLUSIONS
 Air bags are of greater importance in today’s vehicles since safety of human life is of prior
importance.
 So far safe riding and for saving the precious life the safety bags must be implemented.
 Let’s hope every automobile manufacturer implement the same.

18. REFERENCE
 Leonard Evans, “Airbag benefits, airbag costs”, journal of Science Servicing Society,2003
 www.howstuff works.com
 www.scienceservicinsociety.com
 V.E.WEZEL - Airbags Systems - Actual Status and Outlook for the Future Safety
 The Vehicle and The Road Vol.2, FISITA 92 FISITA No. 925217, page no. 1
 Experience'. Frontal impact protection seat belts and airbags, 1993,SAE - SP - 947