ignore resets for now because every z/Z key press would trigger a call to NOAA. We...

[flightgear.git] / src / Autopilot / newauto.cxx

diff --git a/src/Autopilot/newauto.cxx b/src/Autopilot/newauto.cxx
index 81708ff2aac6a7f2326267087dfce59d29b058c6..b699c8c9d8e4bee1806a728192512f38381b6efb 100644 (file)
--- a/src/Autopilot/newauto.cxx
+++ b/src/Autopilot/newauto.cxx
@@ -756,15 +756,23 @@ FGAutopilot::update (double dt)
            double current_angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
 
            double target_angle = current_radiostack->get_navcom1()->get_nav_target_gs();
-
            double gs_diff = target_angle - current_angle;
 
            // convert desired vertical path angle into a climb rate
            double des_angle = current_angle - 10 * gs_diff;
 
-           // convert to meter/min
-           double horiz_vel = cur_fdm_state->get_V_ground_speed()
-               * SG_FEET_TO_METER * 60.0;
+            // estimate horizontal speed towards ILS in meters per minute
+            static double horiz_vel = 0.0;
+            static double last_x = 0.0;
+            double dist = last_x - x;
+            last_x = x;
+            double new_vel = ( dist / dt ) * 60.0;
+            horiz_vel = 0.75 * horiz_vel + 0.25 * new_vel;
+           // double horiz_vel = cur_fdm_state->get_V_ground_speed()
+            //    * SG_FEET_TO_METER * 60.0;
+            // double horiz_vel = airspeed_node->getFloatValue()
+            //    * SG_FEET_TO_METER * 60.0;
+
            climb_rate = -sin( des_angle * SGD_DEGREES_TO_RADIANS ) * horiz_vel;
            /* climb_error_accum += gs_diff * 2.0; */
            /* climb_rate = gs_diff * 200.0 + climb_error_accum; */