digital compass modules
fmgrotepass at yahoo.co.uk
Wed Jan 23 23:22:41 CET 2008
On Wednesday 23 January 2008, Denis wrote:
> I think the accelerometers don't provide enough accuracy.
For INS you need both 3d axial as rotational accelerometers. For a quick check
how it works, check out the wikipedia.
One of the first big uses was Nautilus under the Polar ice cap. The combo
could work, if you have enough info, but two (or three) axial meters can not
do rotation. You could do it with 2 axial meters on each plane. The
difference between the two is the moment on the device. So with 6
accelerometers you might give it a shot. If they are accurate enough, you
might be able to remove the GPS "jitter".
> 2008/1/23, joerg <joerg.twinklephone at gmx.de>:
> > Am Mi 23. Januar 2008 schrieb Tilman Baumann:
> > > François TOURDE wrote:
> > > > Maybe the 3D accels can do that. And the GPS can be used as a bearing
> > > > indicator, when you move. No magnetic device needed in this case.
> > As stated in prev posting, GPS _can_not_ deliver bearing of device at
> > all. Imagine having the GTA in your pocket while moving - there's not the
> > faintest
> > relation between movement vector as seen by GPS and bearing of GTA.
> > > Gyroscopes is what you look for. ;)
> > > Accelerameters don't see rotational movings.
> > Though gyro won't help here at all, i think TWO 3D-accelerometers placed
> > some
> > distance from each other in a system make a nice gyro with the aid of
> > some mathematics in driver. IIRC there was mentioned more than one
> > acc-meter for the GTA. I thought that's exactly for this purpose.
> > jOERG
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