[Paparazzi-devel] is ALT_KALMAN really necessary?

[Zouhair Mahboubi]

Hi,
I have two questions regarding the kalman filtering in the tiny 2.1.1:

1-Do we really need the ALT_KALMAN filter? the instructions say to use 
the 4G navigation mode on the u-blox, which already has its own 
filtering subroutines.

2-When ALT_KALMAN is defined and ALT_KALMAN_ENABLED is set to true, the 
estimator.h gets compiled with:
#define EstimatorSetSpeedPol(vhmod, vhdir, vz) { \
  estimator_hspeed_mod = vhmod; \
  estimator_hspeed_dir = vhdir; \
  if (!alt_kalman_enabled) estimator_z_dot = vz; \
}
This means that the vz from the GPS is not actually passed to the 
alt_kalman function? does that mean that the GPS altitude ends being 
differentiated to obtain estimator_z_dot? I thought the entire idea 
behind filtering is to 'mix' the measurement and its derivative to 
obtain a more accurate result...

What's even more worrisome is that when the estimator_init function 
calls EstimatorSetSpeedPol(0., 0., 0.) the estimator_z_dot does not get 
initialized...

Am I missing something here?

Thanks,
Zouhair



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> Today's Topics:
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>    1. Successful auto landing (chris)
>    2. A successful auto landing (chris)
>    3. Re: A successful auto landing (Andrew S)
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> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sat, 10 Oct 2009 20:53:23 +0300
> From: chris <address@hidden>
> Subject: [Paparazzi-devel] Successful auto landing
> To: address@hidden
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Today i had a wonderful experience as i achieved a very successful auto 
> landing.
> All the parameter were correct and the glide path was spot on.
> It really landed slowly exactly on the predetermined spot.
> Chris
>  
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Sat, 10 Oct 2009 20:54:22 +0300
> From: chris <address@hidden>
> Subject: [Paparazzi-devel] A successful auto landing
> To: address@hidden
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Today i had a wonderful experience as i achieved a very successful auto 
> landing.
> All the parameter were correct and the glide path was spot on.
> It really landed slowly exactly on the predetermined spot.
> Chris
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 11 Oct 2009 14:26:46 +0400
> From: Andrew S <address@hidden>
> Subject: Re: [Paparazzi-devel] A successful auto landing
> To: address@hidden
> Message-ID: <address@hidden>
> Content-Type: text/plain; charset=koi8-r
>
> Hello Chris!
> Congratulations, this is your great step to success :)!
> Did you use the standard "basic" flight plan, or custom (your own)? Did you 
> took into account the wind?
> By the way, when I tryed to make the landing procedure with simulator, I found out that simulator dont have wind info. Is it only my bag, or this should be? 
> Andrew 
>
> 10.10.09, 21:54, "chris" <address@hidden>:
>
> > Today i had a wonderful experience as i achieved a very successful auto 
> > landing.
> > All the parameter were correct and the glide path was spot on.
> > It really landed slowly exactly on the predetermined spot.
> > Chris
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