Modify solution heuristics. Do the cruise AoA and tail incidence only

when the lift/drag are really solid.  And defer the approach trim until
the all four of the other variables are perfect.  I believe this should
fix the solution failures under gcc 2.95.2.

diff --git a/src/FDM/YASim/Airplane.cpp b/src/FDM/YASim/Airplane.cpp
index 82b10d7d144844c255759b23206c5a6867243f0e..64997d2cdcf749bc22a1944178fbd1902c97d4e3 100644 (file)
--- a/src/FDM/YASim/Airplane.cpp
+++ b/src/FDM/YASim/Airplane.cpp
@@ -8,6 +8,7 @@
 #include "Thruster.hpp"
 
 #include "Airplane.hpp"
+
 namespace yasim {
 
 // gadgets
@@ -794,6 +795,16 @@ void Airplane::solve()
     _solutionIterations = 0;
     _failureMsg = 0;
     while(1) {
+#if 0
+        printf("%d %f %f %f %f %f\n", //DEBUG
+               _solutionIterations,
+               1000*_dragFactor,
+               _liftRatio,
+               _cruiseAoA,
+               _tailIncidence,
+               _approachElevator.val);
+#endif
+
        if(_solutionIterations++ > 10000) {
             _failureMsg = "Solution failed to converge after 10000 iterations";
            return;
@@ -816,7 +827,7 @@ void Airplane::solve()
        runApproach();
 
        _model.getBody()->getAngularAccel(tmp);
-       float apitch0 = tmp[1];
+       double apitch0 = tmp[1];
 
        _model.getBody()->getAccel(tmp);
        float alift = _approachWeight * tmp[2];
@@ -846,25 +857,20 @@ void Airplane::solve()
        float tailDelta = -pitch0 * (ARCMIN/(pitch1-pitch0));
 
         // Sanity:
-        if(dragFactor <= 0) {
-            _failureMsg = "Zero or negative drag adjustment.";
-            return;
-        } else if(liftFactor <= 0) {
-            _failureMsg = "Zero or negative lift adjustment.";
-            return;
-        }
+        if(dragFactor <= 0 || liftFactor <= 0)
+            break;
 
         // And the elevator control in the approach.  This works just
         // like the tail incidence computation (it's solving for the
         // same thing -- pitching moment -- by diddling a different
         // variable).
-        const float ELEVDIDDLE = 0.0001f;
+        const float ELEVDIDDLE = 0.001f;
         _approachElevator.val += ELEVDIDDLE;
         runApproach();
         _approachElevator.val -= ELEVDIDDLE;
 
        _model.getBody()->getAngularAccel(tmp);
-       float apitch1 = tmp[1];
+       double apitch1 = tmp[1];
         float elevDelta = -apitch0 * (ELEVDIDDLE/(apitch1-apitch0));
 
         // Now apply the values we just computed.  Note that the
@@ -875,8 +881,8 @@ void Airplane::solve()
        applyLiftRatio(liftFactor);
 
        // DON'T do the following until the above are sane
-       if(normFactor(dragFactor) > 1.1
-          || normFactor(liftFactor) > 1.1)
+       if(normFactor(dragFactor) > 1.0001
+          || normFactor(liftFactor) > 1.0001)
        {
            continue;
        }
@@ -884,19 +890,25 @@ void Airplane::solve()
        // OK, now we can adjust the minor variables:
        _cruiseAoA += 0.5f*aoaDelta;
        _tailIncidence += 0.5f*tailDelta;
-        _approachElevator.val += 0.5f*elevDelta;
        
-       _cruiseAoA = clamp(_cruiseAoA, -0.174f, 0.174f);
-       _tailIncidence = clamp(_tailIncidence, -0.174f, 0.174f);
-        _approachElevator.val = clamp(_approachElevator.val, -1.f, 1.f);
+       _cruiseAoA = clamp(_cruiseAoA, -0.175f, 0.175f);
+       _tailIncidence = clamp(_tailIncidence, -0.175f, 0.175f);
 
         if(norm(dragFactor) < 1.00001 &&
            norm(liftFactor) < 1.00001 &&
            abs(aoaDelta) < .000017 &&
-           abs(tailDelta) < .000017 &&
-           abs(elevDelta) < 0.00001)
+           abs(tailDelta) < .000017)
         {
-            break;
+            // If this finaly value is OK, then we're all done
+            if(abs(elevDelta) < 0.0001)
+                break;
+
+            // Otherwise, adjust and do the next iteration
+            _approachElevator.val += 0.8 * elevDelta;
+            if(abs(_approachElevator.val) > 1) {
+                _failureMsg = "Insufficient elevator to trim for approach";
+                break;
+            }
         }
     }
 
@@ -906,10 +918,10 @@ void Airplane::solve()
     } else if(_liftRatio < 1e-04 || _liftRatio > 1e4) {
        _failureMsg = "Lift ratio beyond reasonable bounds.";
        return;
-    } else if(Math::abs(_cruiseAoA) >= .174) {
+    } else if(Math::abs(_cruiseAoA) >= .17453293) {
        _failureMsg = "Cruise AoA > 10 degrees";
        return;
-    } else if(Math::abs(_tailIncidence) >= .174) {
+    } else if(Math::abs(_tailIncidence) >= .17453293) {
        _failureMsg = "Tail incidence > 10 degrees";
        return;
     }