On Sun, 2003-06-08 at 17:43, Norman Vine wrote: > Tony Peden writes: > > On Sun, 2003-06-08 at 16:50, David Megginson wrote: > > > Norman Vine writes: > > > > > > > Try flying with the HUD not the Panel and engage the AP when > > > > at cruising altitude then use the arrow keys to increase the desired > > > > altitude under AP control by 1000 ft or so and note the > > elevator_trim > > > > and elevator control positions on the HUD > > > > > > > > This should highlite the what the initial 'complaint' was about > > > > > > It's not all that obvious to me, except that (as far as I can tell) > > > the AP moves the trim. > > > > > > In real life, changing the trim actually causes the elevator or > > > stabilator to move -- our summing up of the two is simply a kludge. > > > > The implementation of the c172 in JSBSim is such that the elevator > > *does* move. It just doesn't feedback into the elevator command that's > > displayed on the panel. > > Exactly ! > > OK - This is what I am trying to feret out > > How should this feedback be modeled ?? > > Or asked another way given the lack of feedback should the AP be > operating on the Elevator Control directly rather then the elevator trim > And the trim left as a mechanism that allows setting the offset from the > 'neutral' position of the Elevator with respect to the standard positioning
In the case of JSBSim, just look at elevator-pos rather than what's fed into elevator-cmd. There may be some details to work out, but once that's done the trim indicator should show the neutral (or hands-off) position of the elevator. Also, this would be model specific so that the indicators would once again be independent if the trim doesn't drive the elevator. > > i.e. if this were a mechanical linkage the 'trim' would be a turnbuckle that > could adjust the lenght of a piece of the linkage. > > Cheers > > Norman > > > > _______________________________________________ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden <[EMAIL PROTECTED]> _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
