*******************************************************************************/
#include "FGLGear.h"
-#include "FGState.h"
+#include <algorithm>
+
+static const char *IdSrc = "$Header$";
+static const char *IdHdr = ID_LGEAR;
/*******************************************************************************
************************************ CODE **************************************
*******************************************************************************/
-FGLGear::FGLGear(FGConfigFile* AC_cfg)
+FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : vXYZ(3),
+ vMoment(3),
+ vWhlBodyVec(3),
+ Exec(fdmex)
{
string tmp;
- *AC_cfg >> tmp >> name >> X >> Y >> Z >> kSpring >> bDamp >> statFCoeff >> brakeCoeff;
+ *AC_cfg >> tmp >> name >> vXYZ(1) >> vXYZ(2) >> vXYZ(3)
+ >> kSpring >> bDamp>> dynamicFCoeff >> staticFCoeff
+ >> SteerType >> BrakeType >> GroupMember >> maxSteerAngle;
+
+ cout << " Name: " << name << endl;
+ cout << " Location: " << vXYZ << endl;
+ cout << " Spring Constant: " << kSpring << endl;
+ cout << " Damping Constant: " << bDamp << endl;
+ cout << " Dynamic Friction: " << dynamicFCoeff << endl;
+ cout << " Static Friction: " << staticFCoeff << endl;
+ cout << " Brake Type: " << BrakeType << endl;
+ cout << " Grouping: " << GroupMember << endl;
+ cout << " Steering Type: " << SteerType << endl;
+ cout << " Max Steer Angle: " << maxSteerAngle << endl;
+
+ State = Exec->GetState();
+ Aircraft = Exec->GetAircraft();
+ Position = Exec->GetPosition();
+ Rotation = Exec->GetRotation();
+
+ WOW = false;
+ ReportEnable=true;
+ FirstContact = false;
+ Reported = false;
+ DistanceTraveled = 0.0;
+ MaximumStrutForce = MaximumStrutTravel = 0.0;
}
+/******************************************************************************/
+
FGLGear::~FGLGear(void)
{
+ cout << "Destructing Landing Gear ..." << endl;
}
-float FGLGear::Force(void)
+/******************************************************************************/
+
+FGColumnVector FGLGear::Force(void)
{
- return 0.0;
+ FGColumnVector vForce(3);
+ FGColumnVector vLocalForce(3);
+ FGColumnVector vLocalGear(3); // Vector: CG to this wheel (Local)
+ FGColumnVector vWhlVelVec(3); // Velocity of this wheel (Local)
+
+ vWhlBodyVec = (vXYZ - Aircraft->GetXYZcg()) / 12.0;
+ vWhlBodyVec(eX) = -vWhlBodyVec(eX);
+ vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
+
+ vLocalGear = State->GetTb2l() * vWhlBodyVec;
+
+ compressLength = vLocalGear(eZ) - Position->GetDistanceAGL();
+
+ if (compressLength > 0.00) {
+
+ WOW = true;
+ vWhlVelVec = State->GetTb2l() * (Rotation->GetPQR() * vWhlBodyVec);
+ vWhlVelVec += Position->GetVel();
+
+ compressSpeed = vWhlVelVec(eZ);
+
+ if (!FirstContact) {
+ FirstContact = true;
+ SinkRate = compressSpeed;
+ GroundSpeed = Position->GetVel().Magnitude();
+ }
+
+ // 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.
+
+ vWhlVelVec = -1.0 * vWhlVelVec.Normalize();
+ vWhlVelVec(eZ) = 0.00;
+
+// the following needs work regarding friction coefficients and braking and steering
+
+ vLocalForce(eZ) = min(-compressLength * kSpring - compressSpeed * bDamp, (float)0.0);
+ vLocalForce(eX) = fabs(vLocalForce(eZ) * staticFCoeff) * vWhlVelVec(eX);
+ vLocalForce(eY) = fabs(vLocalForce(eZ) * staticFCoeff) * vWhlVelVec(eY);
+
+ MaximumStrutForce = max(MaximumStrutForce, fabs(vLocalForce(eZ)));
+ MaximumStrutTravel = max(MaximumStrutTravel, fabs(compressLength));
+
+ vForce = State->GetTl2b() * vLocalForce ;
+ vMoment = vWhlBodyVec * vForce;
+
+ } else {
+
+ WOW = false;
+
+ if (Position->GetDistanceAGL() > 200.0) {
+ FirstContact = false;
+ Reported = false;
+ DistanceTraveled = 0.0;
+ MaximumStrutForce = MaximumStrutTravel = 0.0;
+ }
+
+ vForce.InitMatrix();
+ vMoment.InitMatrix();
+ }
+
+ if (FirstContact) {
+ DistanceTraveled += Position->GetVel().Magnitude()*State->Getdt()*Aircraft->GetRate();
+ }
+
+ if (ReportEnable && Position->GetVel().Magnitude() <= 0.05 && !Reported) {
+ Report();
+ }
+ return vForce;
}
+/******************************************************************************/
+
+void FGLGear::Report(void)
+{
+ cout << endl << "Touchdown report for " << name << endl;
+ cout << " Sink rate at contact: " << SinkRate << " fps, "
+ << SinkRate*0.3408 << " mps" << endl;
+ cout << " Contact ground speed: " << GroundSpeed*.5925 << " knots, "
+ << GroundSpeed*0.3408 << " mps" << endl;
+ cout << " Maximum contact force: " << MaximumStrutForce << " lbs, "
+ << MaximumStrutForce*4.448 << " Newtons" << endl;
+ cout << " Maximum strut travel: " << MaximumStrutTravel*12.0 << " inches, "
+ << MaximumStrutTravel*30.48 << " cm" << endl;
+ cout << " Distance traveled: " << DistanceTraveled << " ft, "
+ << DistanceTraveled*0.3408 << " meters" << endl;
+ Reported = true;
+}