Lee Elliott <[EMAIL PROTECTED]> said: > > The autopilot altitude hold seems a bit messed up though since yesterday - > quite bad porpoising - I checked that with the 747, a4, c-172 and a couple of > mine. Terrain following still seems ok though. I doubt this is due to the > replay stuff. >
Lee, It is suprising that you are finding problems with the altitude hold, that really hasn't changed. You aren't using throttle control as well are you? In anycase with the 747, I just comitted some changes to the 747 autopilot config. This addressed some problems that have been there a while. As for the others. I'm not seeing a problem with the c172p at all. The a4 does seem to have a problem. One issue that I looked into has to do with the frame rate frequency of update. At first I thought there would be an impact with the elevator-adj-factor which essentially is a gain/output adjustment (lower values increase elevator movement). There is also an integral-contribution value that has the effect of drawing the AP closer to its target altitude. It occurred to me that the integral value will probably offset any frame rate related problem with the gain so long as they were balanced. If you adjust the elevator-adj-factor so that the porposing goes away (try lowering it in 25% steps) and tweak the integral so that the aircraft hits the target (increase in very small steps). You can make these adjustments during flight using the property browser. I'd be interested in see what you come up with for numbers. Note that the integral-contribution should generally be between 0.01 and 0.002, otherwise it is probably is introducing its own problems. Also try varying the throttle to see how the AP settings perform (don't stall though :-)). Again, let me know what you get for numbers on one or two AC, and also note the frame rate. Thanks, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
