On Thu, Feb 9, 2012 at 8:36 PM, Avinash Rao <
address@hidden> wrote:
> Hi all,
>
> I'm new to the mailing list and just wondering if anyone can help me with
> understanding how ACC_AMP is calculated in
> booz2_filter_attitude_cmpl_euler.c?
>
> In the code, the following formula is used:
>
> /*
> * ACC_AMP
> * 9.81 * 2^10 * sin(pi/4) * ACC_AMP = pi/4 * 2^12 * F_UPDATE
> *
> */
>
> and I understand from a previous thread
> (
http://lists.gnu.org/archive/html/paparazzi-devel/2010-06/msg00014.html)
> that this is a linearization for the euler angle formulae:
>
> phi = -atan(ay/az)
> theta = asin(ax/|a|)
>
> which is where the pi/4 / sin(pi/4) part would come from, however I'm unsure
> of where the other terms (2^10, 2^12, 9.81 (obviously gravity in some way!))
> come from. Can anyone show me how this is derived?
>
> Thanks very much in advance to anyone who can help.
>
> Regards,
>
> Avinash.
>
>
> --
> Avinash Rao
>
>