acceleration sensors: which one do you use ?
openmoko at mazikeen.demon.co.uk
Sat Jun 27 02:25:57 CEST 2009
On Friday 26 June 2009, Marcelo wrote:
> On Fri, Jun 26, 2009 at 14:28, Sebastian
> Krzyszkowiak<seba.dos1 at gmail.com> wrote:
> > But that would be nice if someone will explain, how that second accel
> > can be used, where the first couldn't...
> Since you have acceleration for two different points in the body and
> you know the positions of those points, you can compute the direction
> in which it's rotating wrt to some axis. You can't do that with a
> single acceleration vector without resorting to collecting samples
> over time.
In theory you can calculate angular acceleration about two axes, but in
practise the small separation of the accelerometers means this will only work
for large angular accelerations. If this is what you want you would be better
replacing one of the accelerometers with a 3 axis gyro, though a 3 axis
magnetometer may actually be more useful.
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