Patch from Jim Wilson:

This is a small patch that makes the autopilot work much better with big heavy
airliners as well as the small Cessnas.  Of course this doesn't address the
way autopilots should be modeled.

But by making a couple changes the "George" is now capable of landing either a
C172 or a 747 very close to the center line of the runway with a moderate
cross breeze (15-20kt).

The changes:
- Added turn configurability so that things like Max Aileron and Roll can be
configured per aircraft.
- Enhanced localizer routine (NAV mode) to begin lining up the aircraft as soon
as the cone is entered.  The former model is adopted for the last 5km of the
approach in order to ensure greater precision (makes a very slight difference).

[float cast added by David Megginson to keep G++ 3.0 happy]

diff --git a/src/Autopilot/newauto.cxx b/src/Autopilot/newauto.cxx
index ccbf01cb4ee324aac7f00ffa40f929f7f4806cd8..1341368d90bf2502ac8d3593a513456ec31f9d7a 100644 (file)
--- a/src/Autopilot/newauto.cxx
+++ b/src/Autopilot/newauto.cxx
@@ -216,6 +216,8 @@ void FGAutopilot::init ()
     roll_node = fgGetNode("/orientation/roll-deg", true);
     pitch_node = fgGetNode("/orientation/pitch-deg", true);
 
+
+
     // bind config property nodes...
     TargetClimbRate
         = fgGetNode("/autopilot/config/target-climb-rate-fpm", true);
@@ -231,6 +233,11 @@ void FGAutopilot::init ()
         = fgGetNode("/autopilot/config/zero-pitch-throttle", true);
     zero_pitch_trim_full_throttle
         = fgGetNode("/autopilot/config/zero-pitch-trim-full-throttle", true);
+    max_aileron_node = fgGetNode("/autopilot/config/max-aileron", true);
+    max_roll_node = fgGetNode("/autopilot/config/max-roll-deg", true);
+    roll_out_node = fgGetNode("/autopilot/config/roll-out-deg", true);
+    roll_out_smooth_node = fgGetNode("/autopilot/config/roll-out-smooth-deg", true);
+
     current_throttle = fgGetNode("/controls/throttle");
 
     // initialize config properties with defaults (in case config isn't there)
@@ -250,6 +257,14 @@ void FGAutopilot::init ()
         fgSetFloat( "/autopilot/config/zero-pitch-throttle", 0.60 );
     if ( zero_pitch_trim_full_throttle->getFloatValue() < 0.0000001 )
         fgSetFloat( "/autopilot/config/zero-pitch-trim-full-throttle", 0.15 );
+    if ( max_aileron_node->getFloatValue() < 0.0000001 )
+        fgSetFloat( "/autopilot/config/max-aileron", 0.2 );
+    if ( max_roll_node->getFloatValue() < 0.0000001 )
+        fgSetFloat( "/autopilot/config/max-roll-deg", 20 );
+    if ( roll_out_node->getFloatValue() < 0.0000001 )
+        fgSetFloat( "/autopilot/config/roll-out-deg", 20 );
+    if ( roll_out_smooth_node->getFloatValue() < 0.0000001 )
+        fgSetFloat( "/autopilot/config/roll-out-smooth-deg", 10 );
 
     /* set defaults */
     heading_hold = false ;      // turn the heading hold off
@@ -283,9 +298,6 @@ void FGAutopilot::init ()
     // the deg from heading to start rolling out at, in Deg
     RollOut = 20;
 
-    // how far can I move the aleron from center.
-    MaxAileron = .2;
-
     // Smoothing distance for alerion control
     RollOutSmooth = 10;
 
@@ -296,7 +308,7 @@ void FGAutopilot::init ()
 #if !defined( USING_SLIDER_CLASS )
     MaxRollAdjust = 2 * MaxRoll;
     RollOutAdjust = 2 * RollOut;
-    MaxAileronAdjust = 2 * MaxAileron;
+    //MaxAileronAdjust = 2 * MaxAileron;
     RollOutSmoothAdjust = 2 * RollOutSmooth;
 #endif  // !defined( USING_SLIDER_CLASS )
 
@@ -432,6 +444,12 @@ FGAutopilot::update (double dt)
     double lon = longitude_node->getDoubleValue();
     double alt = altitude_node->getDoubleValue() * SG_FEET_TO_METER;
 
+    // get config settings
+    MaxAileron = max_aileron_node->getDoubleValue();
+    MaxRoll = max_roll_node->getDoubleValue();
+    RollOut = roll_out_node->getDoubleValue();
+    RollOutSmooth = roll_out_smooth_node->getDoubleValue();
+
     SG_LOG( SG_ALL, SG_DEBUG, "FGAutopilot::run()  lat = " << lat <<
             "  lon = " << lon << "  alt = " << alt );
        
@@ -509,6 +527,13 @@ FGAutopilot::update (double dt)
                * (current_radiostack->get_nav1_loc_dist() * SG_METER_TO_NM);
            SG_CLAMP_RANGE( adjustment, -30.0, 30.0 );
 
+            // clamp closer when inside cone when beyond 5km...
+            if (current_radiostack->get_nav1_loc_dist() > 5000) {
+              double clamp_angle = fabs(current_radiostack->get_nav1_heading_needle_deflection()) * 3;
+              if (clamp_angle < 30)
+                SG_CLAMP_RANGE( adjustment, -clamp_angle, clamp_angle);
+            }
+
            // determine the target heading to fly to intercept the
            // tgt_radial
            TargetHeading = tgt_radial + adjustment; 
@@ -738,11 +763,17 @@ FGAutopilot::update (double dt)
        // calculate integral error, and adjustment amount
        int_error = alt_error_accum;
        // printf("error = %.2f  int_error = %.2f\n", error, int_error);
-       int_adj = int_error / elevator_adj_factor->getFloatValue();
+        
+        // scale elev_adj_factor by speed of aircraft in relation to min climb 
+       double elev_adj_factor = elevator_adj_factor->getFloatValue();
+        elev_adj_factor *=
+         pow(float(speed / min_climb->getFloatValue()), 3.0f);
+
+       int_adj = int_error / elev_adj_factor;
 
        // caclulate proportional error
        prop_error = error;
-       prop_adj = prop_error / elevator_adj_factor->getDoubleValue();
+       prop_adj = prop_error / elev_adj_factor;
 
        total_adj = ((double) 1.0 - (double) integral_contrib->getFloatValue()) * prop_adj
             + (double) integral_contrib->getFloatValue() * int_adj;
@@ -1367,3 +1398,4 @@ FGAutopilot::setAPThrottleControl (double value)
 }
 
 // end of newauto.cxx
+