My observations are similar to this. However, I don't think that it's a problem with the accuracy of the calculations as such. The route manager code is relatively old and tries to set a straight course to it's next waypoint. It doesn't consider the wind blowing the aircraft off its lateral track. The autopilot tries to compensate by keeping the aircraft on a heading straight to the next waypoint. Now, as we get closer, this happens at an increasingly greater rate, until the rate of required course adjustment exceeds maximum turn-rate. I've seen a few occasions where the 747 couldn't reach the next waypoint because of this phenomenon and started flying around it in endless circles, until I manually popped it.
Cheers, Durk On Saturday 05 June 2004 03:28, Ampere K. Hardraade wrote: > The violent maneuvers I was describing occur when the plane is a few > kilometers away from the waypoint. Therefore, it should have little to do > with the way that pid controller reacts to the jump in waypoints. > > One explanation for the violent maneuvers that I thought of is this: as the > distance between the plane and the waypoint decreases, the accuracy > required in the course calculations increases. Since it takes time for the > autopilot to respond, and takes even more time for the plane itself to > respond to the commands of the autopilot, the plane will never align itself > perfectly with the waypoint. Hence, the autopilot will keep trying to > "catch" the waypoint until the very last moment, thus causing the violent > maneuvers. > > One solutions to the above problem is to pop the waypoint when the plane is > still some distance away, thereby preventing the autopilot from making all > those course adjustments. > _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel