[Jsbsim-devel] Position/orientation-hold

[Jon S B. <js...@ha...>]

On Sat, 29 Dec 2007 07:21:27 -0600
  David Culp <dav...@co...> wrote:
> I don't mean to highjack this thread, but this is a good time to 
>argue that we 
> could use a position freeze in JSBSim.  That is where the model goes 
>through 
> its normal iterations at each time step, but doesn't actually move 
>anywhere, 
> creating a wind-tunnel like environment.  In this case we could set 
>a model 
> up in a glide at a given speed/altitude with the engine off then 
>experiment 
> with various prop angles and take thrust and rpm data.  A single 
>button press 
> could engage/disengage the position freeze.  The implementation is 
>pretty 
> easy I think - you just ignore the final calculation of the model's 
>new 
> position.  I brought this up a few years ago, but I don't think we 
>ever did 
> it.  If not, then maybe we could now?  I'd be happy to get to it.
> 
> Dave


This sounds like a good idea. Could be that if the hold-position flag 
was set, then the final position and/or orientation of the aircraft 
would be set to its previous value, overriding any newly calculated 
value. The new "previous value" would then be set (to what it already 
is), and the position/orientation would hold.

Jon