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Topic: Vehicle Air bag Controller Open source (Read 3790 times) previous topic - next topic


Hi All,

I started a new project. This is based on Arduino hardware. It is open source and is a Car Airbag controller for DIY. This is for vehicles that are not equipped with OEM airbags.



I started the Open Source car airbag controller project over at http://diyairbag.ning.com/

It is based on the Arduino platform and uses the IMU, Gyro and Accel's from the Ardupilot over at http://www.diydrones.com/



Frankly I don't believe that the design & implementation of a device that controls the detonation of an explosive device in front of your face is really an appropriate place for DIY activities.

It's dangerous, and probably illegal in most jurisdictions.


Agreed. I know a bit more than most about the stringent regulations and testing involved in airbag controller manufacturing. Every device is constructed in a tightly controlled environment, individually shock and vibration tested in all directions, every part of the circuit is verified by visual, electronic, and camera based systems, each board is run through many cycles of thermal testing, specially formulated coatings are applied. The components are selected to be reliable in a harsh environment for a long time.

Not something you approach in a cavalier attitude with an Arduino and sensors designed for hobby airplanes.
Unique RGB LED Modules and Arduino shields: http://www.macetech.com/store


Well, he obviously isn't a resident of the USA; many people would love to know where to get used airbag assemblies (mainly for the kevlar cloth used in them - high power model rocketry enthusiasts use it for parachute deployment shielding).

Individuals can't buy any component of an airbag system anywhere that I know of in the US - you can't even get used components from a pick-your-part place (on a similar note, you can't get catalytic converters, either). I think if you are an auto manufacturer, you have to have a license or something to buy and install them in your automobiles...

As far as whether he should be doing such a thing or not; explosives issues aside, and assuming he could get the accelerometer to work properly, homebrewing something like this really isn't that big of a deal. I don't know how he plans to test such a device as a homebrewer, but that's his problem. I think if you had a working, tested system and it was mounted properly, it probably wouldn't be any more dangerous than not having one, at least for an adult; and if you are talking about installing one in an older car for safety (ie, pre-collapsible steering column, etc), it could probably help save lives.

There are only a few countries though that I would imagine where this kind of homebrew system could have a market, though, as just about all new automobiles (and most made in the last 10-15 years) have airbags already...
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.


Feb 15, 2010, 03:14 am Last Edit: Feb 15, 2010, 03:17 am by macegr Reason: 1
Can't really agree with someone having a lashed-together airbag that could go off at any time...such as while going around a curve on a highway.

Will you call the resulting product the [size=20]Darwuino[/size]?
Unique RGB LED Modules and Arduino shields: http://www.macetech.com/store


Guys, you may or may not agree to build such a device, installing it is different tho, and designing and building it is entirely irrelevant to the subject matter at hand. Installing it is different.

As pointed out, in the US most if not all cars are equipped with air bags to begin with. No old classic, hot rod or kit car is so equipped tho.

Testing need only be done of the system, not the bags. The bags are pre tested. Steering wheel bags and bags installed in seats where the seat is so equipped from the OEM factory are all pre tested.

By installing such a seat, or steering wheel with bag, were these available ;) to be installed, there function is not altered.  It is only the controller that is different.

The idea is developing the algorithms to control any airbag and see if the DIY technology can successfully control these devices.



As to the bags being deployed when going around a corner, no they don't. A car can only generate ohhh lets say 1.3G when going around a corner, if it is a super car, and not much more when pulling away from standstill. Braking does not genereate any more than pulling away really.

The safeguard is another accelerometer, well actually more than 1, 2 to be exact that act as arming accelerometers.  Very simply they arm the system when ohh lets say about 60% of the deployment G in that particular direction has been reached.

These units are mounted in different places, on on the controller and the other with lets say the bag in the steering wheel, obviously behind the bag and not in front of it ;). So both sensors must experience a force high enough to reach the respective thresholds before the signal is sent for deployment. If only 1 sensor is triggered, no deployment.

Other sensors like speed, from embedded GPS if you cannot get to wheel speed, or don't want to use wheel speed can also be used. Brake pressure is another option.



Feb 16, 2010, 01:20 am Last Edit: Feb 16, 2010, 01:21 am by crimony Reason: 1
designing and building it is entirely irrelevant to the subject matter at hand.

Nonsense. You're proposing designing and building the deployment control system, which is equally safety critical.

As a matter of principle, design and implementation of safety critical systems is best left to well-resourced experts.

If you don't think that the control system of a device that fires pyrotechnics in close proximity to the operator of a 1500kg machine travelling at potentially 100km/h on public roads requires some very serious safety engineering, then you should think again.


If you are planning on installing this system in a car, yes I agree 100%. And no I am not implying that the control system is not a safety system, it clearly is, only that the designing of such a system is not.

Just go and read of the issues that Honda and Toyota as well as Volvo has with systems deploying when door are closed while stationary and where systems did not employ where they should have done so. Also on the many recalls that manufacturers had to do on these systems.

I don't care if you agree with me or not, that is your prerogative, designing such a system is a challenge, testing it as well, this is exactly why I am doing it. It is illegal to install such a system in the USA without it being certified. If you build it yourself and want to install it, it will, I guess, be illegal, and maybe not safe.

There is a lot we can do to build and test this, without using any airbag. We can develop the algorithms, test the sensors and show the control logic and timings to work. We can improve, even invent new ways to control and improve the technology.

Wishing you a good challenge in design.


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