Hi, i'm working on a project and i need your help to know what is the best sensor to detect the crash?
Well i'll use an Arduino Board and a GPS Modem and wanna know what is the best sensor for my issue.
Thanks in progress.
Acceleration sensor?
If decreases rapidly crash has occurred.
Weedpharma
Investigate what sensors car makers use to deploy airbags, maybe?
weedpharma:
Acceleration sensor?If decreases rapidly crash has occurred.
These guys have a few small (dip-14) devices that might suit you.
I would suggest an accelerometer - like the device in your phone which can detect the direction. If there was an accident, it would probably move violently and could be used to trigger something.
You could also use some sort of a force sensor, or just acceleration.
It would be an interesting exercise to try to make a sensor for this, although difficult to calibrate without a fleet of vehicles to crash.
I envisage a mass in a tube or slot, with a spring in front of it. As the vehicle decelerates, the inertia keeps the mass going and it compresses the spring; some kind of limit switch arrangement could be your signal that a crash has occurred.
It's not going to be a miniature sensor though, but it would be an interesting exercise in mechanics.
Are you wanting to detect from all direction or only straight ahead?
Weedpharma
Actually i wanna detect if the crash happened from all direction not only the strait ahead one.
An accelerometer doesn't look like it fits my needs cause it's not all about the increasing or decreasing in rapid. (i need something like detecting the change happened in the car body if a harsh crash happened).
In my project, a message should be sent to a website once the crash has been detected.
So i wanna make sure if a crash has been happened or not.
I'm trying to collect the best hardware requirements before beginning the software programming process.
You could do some analysis from simple one-dimensional kinematics to determine what acceleration you could use as a threshold for indication that a crash has occurred. For example in the absence of sticky tires and banked curves on a smooth road it is hard to have accelerations greater than g, so in this world an acceleration greater than g would indicate a crash.
Now as we add potholes, bumps and similar we could have accelerations that exceed g, but they would probably not be parallel to the direction of motion of the car, so maybe you could filter out these with a 3 axis accelerometer. Accelerations caused by accidents are most likely to be in the same plane, or close to it, as your motion as the vehicle that hits you rarely drops down from above or thrusts from below you but hits you while driving on the same road as you.
This is the kind of thought process I would go through to find/build a sensor to do what you need. At the same time I would employ Google and probably reach a conclusion faster that way.
wade