On 1/24/07, Gabriel Ambuehl <[EMAIL PROTECTED]> wrote:
On Wednesday 24 January 2007 12:33, Sean Moss-Pultz wrote:
> On 1/24/07 11:41 AM, "kkr" <[EMAIL PROTECTED]> wrote:
> > Does anybody know more about price and precision of the accelerometers's
> > chips on the market now?
>
> About US$3.
Are they good enough to twice integrate the acceleration data (which obviously
puts quite some demand onto accuracy) to get a better estimate of where a car
would be after entering a tunnel? If so, there's your killer app.
Here:
http://www.analog.com/en/subCat/0,2879,764%255F800%255F0%255F%255F0%255F,00.html
and here:
http://www.freescale.com/webapp/sps/site/taxonomy.jsp?nodeId=01126911184209
Yes, they are. You just need a "fast enough" sampling rate.... the
problem is: how fast, and the other problem: filter out gravity in
order to avoid integrating it. Thus, you need to "follow gravity", or
high-pass filter the thing, and you will lose ALL constant
accelerations.
Another issue is the "fast acceleration scenarios", where your
accelerometer would be "saturated", and you could need a less-precise,
higher-acceleration accelerometer in order
to "still know" where are you moving.
I have been working on a device like this (blind navigation system,
please don't steal the idea, if you wanna work in something like that,
we could work together, I just want it to be free)... just for fun.
If, someday, I finish it, I'll post it somewhere for everybody to
build it and use it!.
c-ya!
Ildefonso Camargo
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