On Tue, 2002-02-26 at 10:29, David Megginson wrote: > Andy Ross writes: > > > And on that subject, would you like to pick a property tree for the > > FDM output properties? How about "/control-positions"? Adding this > > support to YASim will be quick. > > Currently, JSBSim uses an /fdm subtree to report some information, and > /engine subtree, and a /gear subtree if there is retractable gear. > I'd love to hear suggestions for making all of this more consistent > and intuitive.
Well, what are the chances that both the fdm and the 3D model will need their own set of properties for these things? If there is little chance of that then I think we should go with Andy's suggestion and either eliminate the /fdm tree or save it for special purpose fdm stuff (like the trimming routine is now) Out of my own need to distinguish between input and output, I'd rather the name uses 'surfaces' rather than 'controls'. What form would you need the surface positions in? Actual angles are the easiest thing for JSBSim to output (would those be useful for 3D models?), but I can see where normalized positions (-1..1) might be easier to deal with. > > > Some things, though, might get a little complicated. On some aircraft > > (like the 172 Curt describes) trim is implemented as a mere offset to > > the control position. On others, though, it's a change to the > > incidence angle of the whole assembly. The MD-80 works this way; > > remember the crash due to the stripped jack screw? > > That's something we have to implement model-by-model anyway, so we'll > just try to do the right thing. > > > So distinct aircraft models will require special support from the FDM. > > There's no single "elevator" output that will work for all of them. > > If the elevator angle is always reported relative to the incidence > angle of the horizontal stabilizer, we should be OK. I think that in most cases this will not be true, elevator will usually be reported relative to a body reference line. > I think that > incidence angle should be a separate property from trim, though, just > in case there's a plane somewhere that uses both. Agreed. > > > All the best, > > > David > > -- > David Megginson > [EMAIL PROTECTED] > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] We all know Linux is great ... it does infinite loops in 5 seconds. -- attributed to Linus Torvalds _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
