On Friday 04 June 2004 15:37, David Megginson wrote: > Josh Babcock wrote: > > How do real life FMS's do it? Does this generally vary? If so maybe it > > would make sense to pick this number up from the autopilot XML with a > > default defined in preferences.xml. > > At any given speed, the same bank angle will give you the same turn rate > (for a coordinated turn), no matter how big or small the plane is. I don't > know the proper equation, but the rule of thumb for a rate one turn (3 > degrees per second) is knots/10+7, so at 120 kt you will need (roughly) a > 19 degree bank for a rate-one turn; at 250 knots, you will need (roughly) a > 32 degree bank. > > I don't think that fast passenger planes typically bank much more than 20 > degrees, though, so they will be doing a turn at considerably less than > rate one. Get the proper formulas, specify the maximum allowed bank angle, > then crunch the numbers to see how far ahead the plane will have to start > turning at its current airspeed to change course by a specified number of > degrees. > > > All the best, > > > David
If I understand the problem correctly, changing the distance at which the turn is initiated won't make any difference - it's the way that the pid controller reacts to the jump in input as the waypoint is popped that's causing the abrupt change. For example, if there are two waypoints, directly north and south of each other, when one waypoint is popped the pid controller is presented with an input change of 180 deg, regardless of how far away from the waypoint it is. LeeE _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
