Somehow I need to incorporate distance (from the transmitter) into the the nav1 heading control, or find another way to solve the same problem. As you get closer to the target, the cone gets narrower, but more important is that the size of adjustments to correct for a give angle error become smaller.
In the old autopilot I corrected for this with the following code: // clamp closer when inside cone when beyond 5km... if (current_radiostack->get_navcom1()->get_nav_loc_dist() > 5000) { double clamp_angle = fabs(current_radiostack->get_navcom1()->get_nav_cdi_deflection()) * 3; if (clamp_angle < 30) SG_CLAMP_RANGE( adjustment, -clamp_angle, clamp_angle); } This cut down the roll angle target dramatically during the last couple minutes of the approach. This was just a hack that worked, and I suspect there is a much better solution. Basically the problem is that the large aircraft carry too much momentum and thus tend to oversteer especially in the zone where smaller and smaller corrections are required. And a given distance off course will produce larger and larger error angles. Thus the heavy aircraft will produce "S" patterns of increasing amplitude rather than actually zeroing in on the glideslope. Playing with the gain doesn't help because of the response times involved (and the fact that you don't want to shake up the passengers too much). One idea I had was to base the error not on an angle from the radial but on the distance from the center of the cone. The required response to correct this value would be consistant all the way down the cone. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel