paparazzi/paparazzi — comment on commit 8b2892c0052ac9b4da597e400e490fa117c44577
File:  line 0
By martinmm:

Hi,

have not looked into the pull-request so I am not really sure what the code does. I think it is important to emphasize that there are three separate things that we need to look at:

a) the servo/control surface mis-alignment, handled by changing the servo neutrals with the actuators messages
b) the imu mis-alignment, handled by the ins_neutral
c) general aircraft tuning, e.g. fixing a changed center of gravity, usually also done by ins_neutral today

The persistent memory that was introduced some months ago should be usable for this, it works for both lpc21 and stm32.

Martin

----- original Nachricht --------

Betreff: Re: [paparazzi] Trim Fixedwing Inflight: Stop abusing ins_neutral/ir_neutral (8b2892c)
Gesendet: Do, 03. Nov 2011
Von: Christophe De Wagter

> @Gautier: "Isn't that what you do ?"
>
> Now I need to land the plane, read and store the values of the actuator
> message and remember the values from last time, edit xml, do some
> computations, compile, flash, reset the RC transmitter trims, take-off
> again. This is what I hoped to simplify with this merge request.
>
> @Gautier: "hide an (estimation) error with an other (control) error"
>
> If you trim in auto2, then this might happen indeed. But right now, people
> hide a control error (trim) by adding an estimation error (ins_neutral).
> Hopefully the ability to do airborne trimming will make it easier to have
> both right: switch back to manual, trim (not on the RC but direct in the
> airframe file), switch back to auto2 trim the rest with ahrs_neutral [in a
> single flight ;-) ].
>
> -Christophe
>
>
>
> On Thu, Nov 3, 2011 at 12:50 PM, Gautier Hattenberger <
> reply@reply.github.com>wrote:
>
> > "Ideally you would TRIM your plane in manual, then align your IMU2BODY in
> > AUTO1 with the trimmed plane and then auto2 should be perfect right
> away."
> >
> > Isn't that what you do ? Because it is exactly the way we trim new
> > aircrafts, and most of the time it flies in auto2 at the first or second
> > flight.
> >
> > For the first point, I agree it might be easier to just add an offset to
> > the command, but this way we might hide an (estimation) error with an
> other
> > (control) error. Isn't it better to fine tune aerodynamicaly with the
> servo
> > neutrals, then set estimation neutrals in level flight, and in the end
> the
> > control should not need (manual) trim ?
> > For the pitch trim on fixedwing, the vertical control loop is not nice
> > anyway, but the pitch_neutral is clearly a bad workaround.
> >
> > --
> > Reply to this email directly or view it on GitHub:
> >
> >
> https://github.com/paparazzi/paparazzi/commit/8b2892c0052ac9b4da597e400e490f
> a117c44577#commitcomment-692692
> >
>
> --
> Reply to this email directly or view it on GitHub:
> https://github.com/paparazzi/paparazzi/commit/8b2892c0052ac9b4da597e400e490f
> a117c44577#commitcomment-692776
>

--- original Nachricht Ende ----