On Monday 12 Oct 2009, Alan Teeder wrote: > > -----Original Message----- > > For the faster and more > > > maneuverable military jets though, I found that I really needed > > guaranteed higher rates to both ensure a crisp response and > > avoid instabilities. For example, I could tune an > > altitude-hold cascade that would work fine at speeds up to > > 400kt say, but which would become unstable above that. The > > reason was that the rate of deviation increases with aircraft > > speed as the control surfaces generate more force for a given > > deflection, so for a given deflection of the control surfaces > > by the controller, it sees a greater response result in its > > next sample. Eventually, it can't help but over-correct and go > > into oscillation. Running the controller at a higher rate > > though, would mean that it would see a smaller deviation > > because the aircraft would have moved less in the shorter time > > period. > > Did you try scheduling your autoplilot´s height-error to pitch > demand gain with 1/V (speed inverse) ? > > Alan
Re-read the end of the paragraph after the one you quoted above ;-) LeeE ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
