Re: [Paparazzi-devel] Paparazzi EKF- and compelmentary- filter

[Felix Ruess]

Hi,

I just didn't split up the computation yet. Also haven't measured the
time it would need. If I have time I will test the filter properly and
if everything works as expected in simulation I might split it up.

EFs with more states?

Felix

On Wed, Apr 14, 2010 at 7:00 PM, Prof. Dr.-Ing. Heinrich Warmers
<address@hidden> wrote:
> Hi Flex,
> our EKF with float has a run time of  7ms without the use of tables for
> arcosin and  arctan2.
> For a normal plane and a quadrocopter there is no problem to run the EKF all
> 25ms. There are  no timing problems with
> the feedback loops since backstepping is used.
> See our videos on  http://vimeo.com/10134857
> If you can give me the code of EFs with more states   it would help us.
>
> Cheers, Heinrich
>
>
> Felix Ruess schrieb:
>
> Hi Andrew,
>
> some (unpublished) filters are used on an external more powerful
> hardware (gumstix and atom). There is also the error state space KF I
> wrote in float for testing in simulation under
> sw/airborne/booz/ahrs/booz_ahrs_float_lkf. But you can't fly with that
> one at the moment (too long to compute in float and probably still has
> some bugs I guess).
>
> Cheers, Felix
>
> 2010/4/13 Andrew S <address@hidden>:
>
>
> Hi Felix,
> Where is the paparazzi KF?
> Andrew
>
>
> 13.04.10, 08:35, "Felix Ruess" <address@hidden>:
>
>
>
> Hi Andrew,
>
>  Whether you represent your angles in a way that they have
>  singularities (like euler angles) or not (like quaternions or dcm) has
>  nothing to do with the choice of your estimator (e.g. EKF or
>  complementary filter or your PI controller). In any case you have to
>  transform your IMU measurements from the IMU frame into the navigation
>  frame (assumed to be the same as the inertial frame considering the
>  quality of the sensors).
>  The paparazzi KF uses quaternions as angle representations (you really
>  don't want to use dcm here) but also converts the latest quaternion
>  attitude estimate to euler angle and dcm representations for ease of
>  use.
>
>  Cheers, Felix
>
>  2010/4/6 Andrew S :
>  > Hi
>  > For my view, EKF is unnecessary as it loads microcontroller. You can use
> even simple PI controller. It works worse than EKF, but quite well. For good
> results PI regulator should be adjusted for 10 seconds of correction after
> 180 degrees error. Also I can say cheap two axis gyros by ST are unusable
> because of cross axis interference and whey do not have tolerancy against
> vibration. Complementary one axis Z-gyros are better.
>  > For correct angles EKF is not a solution, you need for example
> Directional cosine matrices for calculations between body and earth frames.
> The problem is that gyros works in the body frame, but accelerometers works
> in the earth frame. In fact when pitch is near 90 degrees, the roll gyro
> indicates jaw :)  EKF will not helps for this.
>  > Andrew
>  >
>  > 02.04.10, 17:41, "Prof. Dr.-Ing. Heinrich Warmers" :
>  >
>  >> Hello,
>  >>  we made same experiments with a EKF based  on the rotomotion solution
> in
>  >>  combination with the tiny13 and a low cost analogue IMU from sparkefun.
>  >>  By the test i saw that the software is not  possible to  deal with
>  >>  pitch  angeles over  90°. So  to fly a looping is impossible.
>  >>  If  90° arrives it is  impossible to get the correct angeles by the g
>  >>  force since static  z acceleration is zero.
>  >>  If the pitch angels is more than  120°  the roll angeles rotate fast.
>  >>  What is about the  paparazzi  booz ekf and complementary filter. Can
>  >>  they deal  all angeles ?
>  >>  In the video from 2006  i saw only small  angeles.
>  >>
>  >>  Cheers
>  >>
>  >>  Heinrich
>  >>
>  >>
>  >>
>  >>
>  >>
>  >>  _______________________________________________
>  >>  Paparazzi-devel mailing list
>  >> address@hidden
>  >>  http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>  >>
>  >>
>  >
>  > --
>  > Здесь спама нет http://mail.yandex.ru/nospam/sign
>  >
>  >
>  > _______________________________________________
>  > Paparazzi-devel mailing list
>  > address@hidden
>  > http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>  >
>
>
>  _______________________________________________
>  Paparazzi-devel mailing list
> address@hidden
>  http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
>
>
> --
> Здесь спама нет http://mail.yandex.ru/nospam/sign
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>
>
> _______________________________________________
> Paparazzi-devel mailing list
> address@hidden
> http://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>
>