Here is a wrap-up of the latest changes to JSBSim. It still is flaky, but

much less so due to returning the aero reference point stuff to the config
files. Don't know what happened there ...

Additionally, I have added a new field to the config file: CFG_VERSION. A
version number, currently 1.1, is assigned to the config file and a matching
definition is found in FGDefs.h. The two need to match. Tony has also added
code into FGAircraft.cpp to handle if aero reference point is not specified.

diff --git a/src/FDM/JSBSim/FGAircraft.cpp b/src/FDM/JSBSim/FGAircraft.cpp
index f49e9dd98877db0717f63a95c87c68dea513f93e..b45efcbbeefcf821174ad7b1051d133ecb0958bf 100644 (file)
--- a/src/FDM/JSBSim/FGAircraft.cpp
+++ b/src/FDM/JSBSim/FGAircraft.cpp
@@ -159,6 +159,7 @@ bool FGAircraft::LoadAircraft(string aircraft_path, string engine_path, string f
   streampos gpos;
   int axis;
   string axis_descript;
+  bool readAeroRp=false;
 
   axis = -1;
   aircraftDef = aircraft_path + "/" + fname + "/" + fname + ".cfg";
@@ -169,6 +170,8 @@ bool FGAircraft::LoadAircraft(string aircraft_path, string engine_path, string f
   numTanks = numEngines = 0;
   numSelectedOxiTanks = numSelectedFuelTanks = 0;
 
+  Xcg=Ycg=Zcg=0; //protection for no cg specified in file
+
   while (!aircraftfile.fail()) {
     holding_string.erase();
     aircraftfile >> holding_string;
@@ -218,6 +221,7 @@ bool FGAircraft::LoadAircraft(string aircraft_path, string engine_path, string f
         cout << "Aircraft Empty Weight: " << EmptyWeight << endl;
       } else if (holding_string == "AC_AERORP") {
         aircraftfile >> Xrp >> Yrp >> Zrp;
+        readAeroRp=true;
         cout << "Aerodynamic Reference Point: " << Xrp << " " << Yrp << " " << Zrp << endl;
       } else if (holding_string == "AC_CGLOC") {
         aircraftfile >> baseXcg >> baseYcg >> baseZcg;
@@ -310,8 +314,15 @@ bool FGAircraft::LoadAircraft(string aircraft_path, string engine_path, string f
       aircraftfile.getline(scratch, 127);
     }
   }
-  cout << "End of Configuration File Parsing." << endl;
+  
+    if(!readAeroRp) {
+    Xrp = Xcg;
+    Yrp = Ycg;
+    Zrp = Zcg;
+    cout << "Aerodynamic reference point not found, set to empty weight cg location" << endl;
+  }    
 
+  cout << "End of Configuration File Parsing." << endl;
   return true;
 }
 
@@ -431,32 +442,31 @@ void FGAircraft::MassChange()
 void FGAircraft::FMAero(void)
 {
   float F[3];
-  float Fxaero,Fyaero,Fzaero;
   float dxcg,dycg,dzcg;
+  float ca, cb, sa, sb;
   int axis_ctr,ctr;
   F[0] = F[1] = F[2] = 0.0;
 
-  for (axis_ctr = 0; axis_ctr < 3; axis_ctr++)
-    for (ctr=0; ctr < coeff_ctr[axis_ctr]; ctr++)
+  for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
+    for (ctr=0; ctr < coeff_ctr[axis_ctr]; ctr++) {
       F[axis_ctr] += Coeff[axis_ctr][ctr]->TotalValue();
+      Coeff[axis_ctr][ctr]->DumpSD();
+    }
+  }
+
+  ca = cos(alpha);
+  sa = sin(alpha);
+  cb = cos(beta);
+  sb = sin(beta);
 
-  Fxaero = - F[DragCoeff]*cos(alpha)*cos(beta)
-           - F[SideCoeff]*cos(alpha)*sin(beta)
-           + F[LiftCoeff]*sin(alpha);
-  Fyaero =   F[DragCoeff]*sin(beta)
-             + F[SideCoeff]*cos(beta);
-  Fzaero = - F[DragCoeff]*sin(alpha)*cos(beta)
-           - F[SideCoeff]*sin(alpha)*sin(beta)
-           - F[LiftCoeff]*cos(alpha);
-
-  Forces[0] += - F[DragCoeff]*cos(alpha)*cos(beta)
-               - F[SideCoeff]*cos(alpha)*sin(beta)
-               + F[LiftCoeff]*sin(alpha);
-  Forces[1] +=   F[DragCoeff]*sin(beta)
-                 + F[SideCoeff]*cos(beta);
-  Forces[2] += - F[DragCoeff]*sin(alpha)*cos(beta)
-               - F[SideCoeff]*sin(alpha)*sin(beta)
-               - F[LiftCoeff]*cos(alpha);
+  Forces[0] += - F[DragCoeff]*ca*cb
+               - F[SideCoeff]*ca*sb
+               + F[LiftCoeff]*sa;
+  Forces[1] +=   F[DragCoeff]*sb
+                 + F[SideCoeff]*cb;
+  Forces[2] += - F[DragCoeff]*sa*cb
+               - F[SideCoeff]*sa*sb
+               - F[LiftCoeff]*ca;
 
   // The d*cg distances below, given in inches, are the distances FROM the c.g.
   // TO the reference point. Since the c.g. and ref point are given in inches in
@@ -468,13 +478,14 @@ void FGAircraft::FMAero(void)
   dycg =  (Yrp - Ycg)/12;
   dzcg = -(Zrp - Zcg)/12;
 
-  Moments[0] +=  Fzaero*dycg - Fyaero*dzcg; //rolling moment
-  Moments[1] +=  Fxaero*dzcg - Fzaero*dxcg; //pitching moment
-  Moments[2] += -Fxaero*dycg + Fyaero*dxcg; //yawing moment
+  Moments[0] +=  Forces[2]*dycg - Forces[1]*dzcg; //rolling moment
+  Moments[1] +=  Forces[0]*dzcg - Forces[2]*dxcg; //pitching moment
+  Moments[2] += -Forces[0]*dycg + Forces[1]*dxcg; //yawing moment
 
   for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
     for (ctr = 0; ctr < coeff_ctr[axis_ctr+3]; ctr++) {
       Moments[axis_ctr] += Coeff[axis_ctr+3][ctr]->TotalValue();
+      Coeff[axis_ctr+3][ctr]->DumpSD();
     }
   }
 }

diff --git a/src/FDM/JSBSim/FGCoefficient.cpp b/src/FDM/JSBSim/FGCoefficient.cpp
index 0e69bcb75974c374a923f2ca16ce5ffdfc90ea25..2ed2d69ef9a0b6f129693b140a4a6783f0ba2c78 100644 (file)
--- a/src/FDM/JSBSim/FGCoefficient.cpp
+++ b/src/FDM/JSBSim/FGCoefficient.cpp
@@ -352,7 +352,7 @@ float FGCoefficient::Value(float rVal, float cVal)
   col1temp = rFactor*(Table3D[r][c-1] - Table3D[r-1][c-1]) + Table3D[r-1][c-1];
   col2temp = rFactor*(Table3D[r][c] - Table3D[r-1][c]) + Table3D[r-1][c];
 
-  Value = col1temp + cFactor*(col2temp - col1temp);
+  SD = Value = col1temp + cFactor*(col2temp - col1temp);
 
   for (midx=0;midx<mult_count;midx++) {
     Value *= GetCoeffVal(mult_idx[midx]);
@@ -379,7 +379,7 @@ float FGCoefficient::Value(float Val)
     Factor = 1.0;
   }
 
-  Value = Factor*(Table3D[r][1] - Table3D[r-1][1]) + Table3D[r-1][1];
+  SD = Value = Factor*(Table3D[r][1] - Table3D[r-1][1]) + Table3D[r-1][1];
 
   for (midx=0;midx<mult_count;midx++) {
     Value *= GetCoeffVal(mult_idx[midx]);
@@ -394,7 +394,7 @@ float FGCoefficient::Value(void)
        float Value;
        int midx;
        
-       Value = StaticValue;
+       SD = Value = StaticValue;
 
   for (midx=0;midx<mult_count;midx++) {
     Value *= GetCoeffVal(mult_idx[midx]);
@@ -463,3 +463,8 @@ float FGCoefficient::GetCoeffVal(int val_idx)
   return 0;
 }
 
+
+void FGCoefficient::DumpSD(void)
+{
+  cout << "   " << name << " = " << SD << endl;
+}

diff --git a/src/FDM/JSBSim/FGCoefficient.h b/src/FDM/JSBSim/FGCoefficient.h
index c937c54a657d472f48c914eebb94e970e0632ccf..a1c2ca4af9db8587debd15670a571b766996dd66 100644 (file)
--- a/src/FDM/JSBSim/FGCoefficient.h
+++ b/src/FDM/JSBSim/FGCoefficient.h
@@ -133,6 +133,9 @@ public:
   float Value(float);
   float Value(void);
   float TotalValue(void);
+  inline float GetSDValue(void) {return SD;}
+  inline void SetSDValue(float tt) {SD = tt;}
+  void DumpSD(void);
   enum Type {UNKNOWN, VALUE, VECTOR, TABLE, EQUATION};
 
 protected:
@@ -153,6 +156,7 @@ private:
   Type type;
   int multipliers;
   int mult_count;
+  float SD; // Actual stability derivative (or other coefficient) value
 
   float GetCoeffVal(int);
 

diff --git a/src/FDM/JSBSim/FGControls.cpp b/src/FDM/JSBSim/FGControls.cpp
index 8dde344658455cc319b72910f8022cf3ff449818..c8693a4f7a2d4c6dc0e2f9bbf0e13426c2e10098 100644 (file)
--- a/src/FDM/JSBSim/FGControls.cpp
+++ b/src/FDM/JSBSim/FGControls.cpp
@@ -35,13 +35,13 @@ FGControls::FGControls() :
     elevator_trim( 1.969572E-03 ),
     rudder( 0.0 )
 {
-    for ( int engine = 0; engine < MAX_ENGINES; engine++ ) {
-       throttle[engine] = 0.0;
-    }
+  for ( int engine = 0; engine < MAX_ENGINES; engine++ ) {
+    throttle[engine] = 0.0;
+  }
 
-    for ( int wheel = 0; wheel < MAX_WHEELS; wheel++ ) {
-        brake[wheel] = 0.0;
-    }
+  for ( int wheel = 0; wheel < MAX_WHEELS; wheel++ ) {
+    brake[wheel] = 0.0;
+  }
 }
 
 
@@ -51,6 +51,16 @@ FGControls::~FGControls() {
 
 
 // $Log$
+// Revision 1.7  1999/12/30 17:01:59  curt
+// Here is a wrap-up of the latest changes to JSBSim. It still is flaky, but
+// much less so due to returning the aero reference point stuff to the config
+// files. Don't know what happened there ...
+//
+// Additionally, I have added a new field to the config file: CFG_VERSION. A
+// version number, currently 1.1, is assigned to the config file and a matching
+// definition is found in FGDefs.h. The two need to match. Tony has also added
+// code into FGAircraft.cpp to handle if aero reference point is not specified.
+//
 // Revision 1.6  1999/09/07 21:15:45  curt
 // Updates to get engine working.
 //

diff --git a/src/FDM/JSBSim/FGFDMExec.cpp b/src/FDM/JSBSim/FGFDMExec.cpp
index ecfe62395b8bd49ccdd26a8fe52fcff56e97663a..4210e7de7551456be33b56ff4f8728f091ab98d3 100644 (file)
--- a/src/FDM/JSBSim/FGFDMExec.cpp
+++ b/src/FDM/JSBSim/FGFDMExec.cpp
@@ -119,7 +119,7 @@ FGFDMExec::FGFDMExec(void)
   Schedule(Translation, 1);
   Schedule(Position,    1);
   Schedule(Auxiliary,   1);
-  Schedule(Output,      120);
+  Schedule(Output,      1);
 
   terminate = false;
   frozen = false;