Research on Technology

I researched on some of the technology which allows inflation.

Air-blower

• Pros: Can be used repeatedly instead of a one-time thing.
• Cons: Weighty gears to be carried by the user. Air blower cannot be covered to not hinder the spinning of the fan, hence need to be placed near the legs or worn externally.

Cannister

• Used by many other inflatable garments such as the airbag.
• Pros: Immediate inflation. One trigger allows one episode only.
• Cons: One-time. Not sustainable.

About sensors

• Wikipedia explanation of Accelerometer – An accelerometer is a device that measures proper acceleration; proper acceleration is not the same as coordinate acceleration (rate of change of velocity). For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earth’s gravity, straight upwards (by definition) of g ≈ 9.81 m/s². By contrast, accelerometers in free fall (falling toward the center of the Earth at a rate of about 9.81 m/s²) will measure zero.
• Definition of a Gyrometer – A gyrometer is any device that measures angular speed. At present, there are many types of gyro, each functioning differently depending on their type. While gyroscopes were traditionally used for sailing ships through foggy conditions, their applications have since diversified and, today, high-tech gyros can be found in consumer goods such as cameras, drones, and smartphones or in high-end applications such as military and aerospace.
• Choice: 3 axis accelerometer to determine when to inflate the clothes.
• Sensor to use when the suit is static – to enable manual inflation: Either a switch or infra-red sensor.
• The choice for activation when the suit is placed in the museum: Infra-red sensor. Museum visitors  may not reach in to turn the hidden switch on.

For keeping the suit in place

• A mechanism which pulls the suit taut to deflate air – (As suggested by Naga)
• A small vacuum

Case Study: Dainese Air Suit for Skiers

 

 

 

 

 

 

 

 

 

 

 

Italian motorcycle gear maker Dainese is continually improving its airbag-equipped suits, which contain self-inflating compartments in critical areas, such as along the collarbone and over the shoulders. Its D-air suits, some of which retail for more than $1,000, have three accelerometers, three gyroscopes, a GPS, and onboard electronics that collect all the data and deploy the airbags before a racer crashes into the ground, according to a forthcoming article in the spring 2014 issue of Bloomberg Pursuits.

 

Case Study: Hövding Air Bag for Cyclists

Hövding Video

Researchers at Stanford University highlight the airbag for cyclists by the Swedish company Hövding, and found in a study that the thickness and stiffness of the Hövding helmet is “near perfect” in terms of protecting against concussion and head injuries caused by accidents. They conclude that there is an eight-fold reduction in the risk of concussion with the Hövding airbag compared to traditional helmets.

On sensors and algorithms:

How Hövding tells the difference between biking and accidents:

Thousands of cycling accidents were re-enacted using stunt riders and crash-test dummies to collect the specific movement patterns of cyclists in accidents. In parallel, an equal amount of normal cycling data has been collected using test cyclists wearing Hövding in everyday cycling. Based on this collected data, we have developed an algorithm that can distinguish normal cycling from accidents.

Normal cycling means all the situations and movements that usually happen in a cycling context, bending down to pick up keys, etc.

In the highly unusual category of cycling accident where no measurable movement appears within the cyclist, i.e. if an object falls from above straight down on the cyclist’s head, Hövding will not react.

Summary of Research

• Material thickness is of importance: Materials have to maintain a certain amount of stiffness when inflated to protect the body.
• Differentiation between the normal walking status and activation for my project: Using an 3-axis accelerometer to determine whether the person wearing it is experiencing high risks of danger VS low risk of danger. The acceleration when a person is static is 0ms-2. Acceleration when a person is running.
• Human acceleration according to wired.com calculation can be seen in the graph below of Usain Bolt’s speed in a 100 meter dash. WIRED Usain Bolt Calculation
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• Running acceleration of Usain Bolt (approximate from this graph) = (9.8-5.4)/(2.4-1)= 4.4/1.4 = 3.142ms-2.
• Note to self – When programming accelerometer, 0 – 2 ms-2 -> Nothing happens. 2ms-2 and more-> Air blower activated constantly.
• Identifying important parts of the body (Most important parts according to common knowledge) : Spine, upper torso, neck, skull.
• Other components needed: Transistors for vacuum and blower, wires (normal coated instead of wire thread due to low cost and higher stability and durability), batteries for the vacuum circuit (12V) and battery for the lilypad, lilypad, lilypad accelerometer.

 

UPDATED NOTES:

• Due to the machinery not working very well – vacuum is not used in the exhibited piece.
• Due to too many projects and a lack of battery resource, the accelerometer will not be programmed for the exhibition as well.