alcohol helmet

8/9/2019 Alcohol Helmet

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1.Aim: Smart Helmet for bike accident prevention

2. Abstract

Due to increase in the bike accidents because of alcohol consumption, it is necessary to developa device which will be able to effectively save life and decrease accidents. In order to achieve

this we will be developing an intelligent and smart helmet which will be able to detect alcohol

consumtion and if the level of alcohol is more then it will disable all the bike functions.

3. Introduction


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A motorcycle helmet is a type ofprotective headgearused by motorcycle riders. The primary

goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus

preventing or reducing head injury or saving the rider's life. Some helmets provide additional

conveniences, such as ventilation, face shields, ear protection, intercom etc.

The conventional motorcycle helmet has two principal protective components: a thin, hard, outer

shell typically made frompolycarbonate plastic, fiberglass, orKevlarand a soft, thick, inner liner

usually made of expanded polystyrene orpolypropylene foam. The purpose of the hard outer

shell is:

1. to prevent penetration of the helmet by a pointed object that might otherwise puncture the

skull, and

2. to provide structure to the inner liner so it does not disintegrate upon abrasive contact

with pavement. This is important because the foams used have very little resistance to

penetration and abrasion.

The purpose of the foam liner is to crush during an impact, thereby increasing the distance and

period of time over which the head stops and reducing its deceleration.

To understand the action of a helmet, it is first necessary to understand the mechanism of head

injury. The common perception that a helmet's purpose is to save the rider's head from splitting

open is misleading. Skull fractures are usually not life threatening unless the fracture is

depressed and impinges on the brain beneath and bone fractures usually heal over a relatively

short period. Brain injuries are much more serious. They frequently result in death, permanent

disability or personality change and, unlike bone, neurological tissue has very limited ability to

recover after an injury. Therefore, the primary purpose of a helmet is to prevent traumatic brain

injury while skull and face injuries are a significant secondary concern.

The most common type of head injury in motorcycle accidents is closed head injury, meaning

injury in which the skull is not broken as distinct from an open head injury like a bullet wound.

Closed head injury results from violent acceleration of the head which causes the brain to move

around inside the skull. During an impact to the front of the head, the brain lurches forwards

inside the skull, squeezing the tissue near the impact site and stretching the tissue on the opposite
http://en.wikipedia.org/wiki/Helmethttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Motorcycle_safetyhttp://en.wikipedia.org/wiki/Intercomhttp://en.wikipedia.org/wiki/Polycarbonatehttp://en.wikipedia.org/wiki/Fiberglasshttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/Polystyrenehttp://en.wikipedia.org/wiki/Polystyrenehttp://en.wikipedia.org/wiki/Polypropylenehttp://en.wikipedia.org/wiki/Traumatic_brain_injuryhttp://en.wikipedia.org/wiki/Traumatic_brain_injuryhttp://en.wikipedia.org/wiki/Helmethttp://en.wikipedia.org/wiki/Motorcyclehttp://en.wikipedia.org/wiki/Motorcycle_safetyhttp://en.wikipedia.org/wiki/Intercomhttp://en.wikipedia.org/wiki/Polycarbonatehttp://en.wikipedia.org/wiki/Fiberglasshttp://en.wikipedia.org/wiki/Kevlarhttp://en.wikipedia.org/wiki/Polystyrenehttp://en.wikipedia.org/wiki/Polypropylenehttp://en.wikipedia.org/wiki/Traumatic_brain_injuryhttp://en.wikipedia.org/wiki/Traumatic_brain_injury


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side of the head. Then the brain rebounds in the opposite direction, stretching the tissue near the

impact site and squeezing the tissue on the other side of the head. Blood vessels linking the brain

to the inside of the skull may also break during this process, causing dangerous bleeding.

Another hazard, susceptibility of the brain to shearing forces, plays a role primarily in injuries

which involve rapid and forceful movements of the head, such as in motor vehicle accidents. In

these situations rotational forces such as might occur in whiplash-type injuries are particularly

important. These forces, associated with the rapid acceleration and deceleration of the head, are

smallest at the point of rotation of the brain near the lower end of the brain stem and successively

increase at increasing distances from this point. The resulting shearing forces cause different

levels in the brain to move relative to one another. This movement produces stretching and

tearing of axons (diffuse axonal injury) and the insulating myelin sheath, injuries which are themajor cause of loss of consciousness in a head trauma. Small blood vessels are also damaged

causing bleeding (petechial hemorrhages) deep within the brain.

It is important that the liner in a motorcycle helmet is soft and thick so the head decelerates at a

gentle rate as it sinks into it. Unfortunately, there is a limit to how thick the helmet can be for the

simple reason that the helmet quickly becomes impractical if the liner is more than 12 inches

(2.55.1 cm) thick. This implies a limit to how soft the liner can be. If the liner is too soft, the

head will crush it completely upon impact without coming to a stop. Outside the liner is a hard

plastic shell and beyond that is whatever the helmet is hitting, which is usually an unyielding

surface, like concrete pavement. Consequently, the head cannot move any further, so after

crushing the liner it comes suddenly to an abrupt stop, causing high accelerations that injure the

brain.

Therefore, an ideal helmet liner is stiff enough to decelerate the impacting head to an abrupt stop

in a smooth uniform manner just before it completely crushes the liner and no stiffer. The

required stiffness depends on the impact speed of the head, which is unknown at the time of

manufacture of the helmet. The result is that the manufacturer must choose a likely speed of

impact and optimize the helmet for that impact speed. If the helmet is in a real impact that is

slower than the one for which it was designed, it will still help but the head will be decelerated a

little more violently than was actually necessary given the available space between the inside and


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outside of the helmet, although that deceleration will still be much less than what is would have

been in the absence of the helmet. If the impact is faster than the one the helmet was designed

for, the head will completely crush the liner and slow down but not stop in the process. When the

crush space of the liner runs out, the head will stop suddenly which is not ideal. However, in the

absence of the helmet, the head would have been brought to a sudden stop from a higher speed

causing more injury. Still, a helmet with a stiffer foam that stopped the head before the liner

crush space ran out would have done a better job. So helmets help most in impacts at the speeds

they were designed for, and continue to help but not as much in impacts that are at different

speeds. In practice, motorcycle helmet manufacturers choose the impact speed they will design

for based on the speed used in standard helmet tests. Most standard helmet tests use speeds

between 4 and 7 m/s (8.9 and 16 mph; 14 and 25 km/h).

4. Block Diagram

Alcohol

sensor on

helmet

HT 12E

Encoder IC

RF Transmitter

ASK modulation

433 Mhz + 5v

RF Receiver

ASK

modulation HT 12 EDecoder


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16x2 LCD

Display

Microcontroller

89s51

Power Supply +5vClock 11 Mzh

Reset

SMS system

for sending

alert

alcohol helmet

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