JSBSim updates. This update changes the file format, so an update of the base

[flightgear.git] / src / FDM / JSBSim / FGLGear.cpp

diff --git a/src/FDM/JSBSim/FGLGear.cpp b/src/FDM/JSBSim/FGLGear.cpp
index dcd9b1c42f32bc49ee1fbd8d904350c690fb36ea..52d834168a59cdc22c5d8cd8ca995a3baec26719 100644 (file)
--- a/src/FDM/JSBSim/FGLGear.cpp
+++ b/src/FDM/JSBSim/FGLGear.cpp
@@ -104,7 +104,7 @@ FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : Exec(fdmex)
   FCS         = Exec->GetFCS();
   MassBalance = Exec->GetMassBalance();
 
-  WOW = lastWOW = false;
+  WOW = lastWOW = true; // should the value be initialized to true?
   ReportEnable = true;
   FirstContact = false;
   Reported = false;
@@ -115,9 +115,21 @@ FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : Exec(fdmex)
   vWhlBodyVec     = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
   vWhlBodyVec(eX) = -vWhlBodyVec(eX);
   vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
-
+  
   vLocalGear = State->GetTb2l() * vWhlBodyVec;
 
+  compressLength  = 0.0;
+  compressSpeed   = 0.0;
+  brakePct        = 0.0;
+  maxCompLen      = 0.0;
+
+  WheelSlip = lastWheelSlip = 0.0;
+
+  compressLength  = 0.0;
+  compressSpeed   = 0.0;
+  brakePct        = 0.0;
+  maxCompLen      = 0.0;
+
   Debug(0);
 }
 
@@ -168,6 +180,8 @@ FGLGear::FGLGear(const FGLGear& lgear)
   isRetractable   = lgear.isRetractable;
   GearUp          = lgear.GearUp;
   GearDown        = lgear.GearDown;
+  WheelSlip       = lgear.WheelSlip;
+  lastWheelSlip   = lgear.lastWheelSlip;
 }
 
 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -181,6 +195,9 @@ FGLGear::~FGLGear()
 
 FGColumnVector3& FGLGear::Force(void)
 {
+  double SteerGain = 0;
+  double SinWheel, CosWheel;
+
   vForce.InitMatrix();
   vMoment.InitMatrix();
 
@@ -201,10 +218,6 @@ FGColumnVector3& FGLGear::Force(void)
   }         
       
   if (GearDown) {
-    double SteerGain = 0;
-    double SinWheel, CosWheel, SideWhlVel, RollingWhlVel;
-    double RollingForce, SideForce, FCoeff;
-    double WheelSlip;
 
     vWhlBodyVec     = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
     vWhlBodyVec(eX) = -vWhlBodyVec(eX);
@@ -262,22 +275,22 @@ FGColumnVector3& FGLGear::Force(void)
 
       switch (eBrakeGrp) {
       case bgLeft:
-        SteerGain = -0.10;
+        SteerGain = 0.10;
         BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +
                                               staticFCoeff*FCS->GetBrake(bgLeft);
         break;
       case bgRight:
-        SteerGain = -0.10;
+        SteerGain = 0.10;
         BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgRight)) +
                                              staticFCoeff*FCS->GetBrake(bgRight);
         break;
       case bgCenter:
-        SteerGain = -0.10;
+        SteerGain = 0.10;
         BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
                                              staticFCoeff*FCS->GetBrake(bgCenter);
         break;
       case bgNose:
-        SteerGain = 0.10;
+        SteerGain = -0.50;
         BrakeFCoeff = rollingFCoeff;
         break;
       case bgTail:
@@ -285,7 +298,7 @@ FGColumnVector3& FGLGear::Force(void)
         BrakeFCoeff = rollingFCoeff;
         break;
       case bgNone:
-        SteerGain = -0.10;
+        SteerGain = 0.0;
         BrakeFCoeff = rollingFCoeff;
         break;
       default:
@@ -322,27 +335,31 @@ FGColumnVector3& FGLGear::Force(void)
 
       if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {
         WheelSlip = 0.0;
+      } else if (fabs(RollingWhlVel) < 0.10) {
+        WheelSlip = 0.05*radtodeg*atan2(SideWhlVel, RollingWhlVel) + 0.95*WheelSlip;
       } else {
         WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);
       }
 
-// The following code normalizes the wheel velocity vector, reverses it, and zeroes out
-// the z component of the velocity. The question is, should the Z axis velocity be zeroed
-// out first before the normalization takes place or not? Subsequent to that, the Wheel
-// Velocity vector now points as a unit vector backwards and parallel to the wheel
-// velocity vector. It acts AT the wheel.
-
-// Note to Jon: I commented out this line because I wasn't sure we want to do this.
-//    vWhlVelVec      = -1.0 * vWhlVelVec.Normalize();
-//    vWhlVelVec(eZ)  =  0.00;
+      if ((WheelSlip < 0.0 && lastWheelSlip > 0.0) ||
+          (WheelSlip > 0.0 && lastWheelSlip < 0.0))
+      {
+        WheelSlip = 0.0;
+      }
+      
+      lastWheelSlip = WheelSlip;
 
 // Compute the sideforce coefficients using similar assumptions to LaRCSim for now.
 // Allow a maximum of 10 degrees tire slip angle before wheel slides.  At that point,
 // transition from static to dynamic friction.  There are more complicated formulations
 // of this that avoid the discrete jump.  Will fix this later.
 
-      if (fabs(WheelSlip) <= 10.0) {
-        FCoeff = staticFCoeff*WheelSlip/10.0;
+      if (fabs(WheelSlip) <= 20.0) {
+        FCoeff = staticFCoeff*WheelSlip/20.0;
+      } else if (fabs(WheelSlip) <= 40.0) {
+//        FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;
+        FCoeff = (dynamicFCoeff*(fabs(WheelSlip) - 20.0)/20.0 + 
+                  staticFCoeff*(40.0 - fabs(WheelSlip))/20.0)*fabs(WheelSlip)/WheelSlip;
       } else {
         FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;
       }
@@ -351,7 +368,7 @@ FGColumnVector3& FGLGear::Force(void)
 // in paper AIAA-2000-4303 - see header prologue comments). We might consider
 // allowing for both square and linear damping force calculation. Also need to
 // possibly give a "rebound damping factor" that differs from the compression
-// case. NOTE: SQUARE LAW DAMPING NO GOOD!
+// case.
 
       vLocalForce(eZ) =  min(-compressLength * kSpring
                              - compressSpeed * bDamp, (double)0.0);
@@ -412,7 +429,7 @@ FGColumnVector3& FGLGear::Force(void)
     }
 
     if (lastWOW != WOW) {
-      PutMessage("GEAR_CONTACT", WOW);
+      PutMessage("GEAR_CONTACT: " + name, WOW);
     }
 
     lastWOW = WOW;
@@ -424,7 +441,7 @@ FGColumnVector3& FGLGear::Force(void)
         vMoment.Magnitude() > 5000000000.0 ||
         SinkRate > 1.4666*30)
     {
-      PutMessage("Crash Detected");
+      PutMessage("Crash Detected: Simulation FREEZE.");
       Exec->Freeze();
     }
   } 
@@ -497,5 +514,11 @@ void FGLGear::Debug(int from)
   }
   if (debug_lvl & 16) { // Sanity checking
   }
+  if (debug_lvl & 64) {
+    if (from == 0) { // Constructor
+      cout << IdSrc << endl;
+      cout << IdHdr << endl;
+    }
+  }
 }