static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_LGEAR;
-extern short debug_lvl;
-
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : vXYZ(3),
- vMoment(3),
- vWhlBodyVec(3),
- Exec(fdmex)
+FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : Exec(fdmex)
{
string tmp;
+
*AC_cfg >> tmp >> name >> vXYZ(1) >> vXYZ(2) >> vXYZ(3)
>> kSpring >> bDamp>> dynamicFCoeff >> staticFCoeff
- >> rollingFCoeff >> sSteerType >> sBrakeGroup >> 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 << " Rolling Friction: " << rollingFCoeff << endl;
- cout << " Steering Type: " << sSteerType << endl;
- cout << " Grouping: " << sBrakeGroup << endl;
- cout << " Max Steer Angle: " << maxSteerAngle << endl;
+ >> rollingFCoeff >> sSteerType >> sBrakeGroup
+ >> maxSteerAngle >> sRetractable;
if (sBrakeGroup == "LEFT" ) eBrakeGrp = bgLeft;
else if (sBrakeGroup == "RIGHT" ) eBrakeGrp = bgRight;
cerr << "Improper steering type specification in config file: "
<< sSteerType << " is undefined." << endl;
}
+
+ if ( sRetractable == "RETRACT" ) {
+ isRetractable = true;
+ } else {
+ isRetractable = false;
+ }
+
+ GearUp = false;
+ GearDown = true;
// Add some AI here to determine if gear is located properly according to its
// brake group type ??
Position = Exec->GetPosition();
Rotation = Exec->GetRotation();
FCS = Exec->GetFCS();
+ MassBalance = Exec->GetMassBalance();
- WOW = false;
+ WOW = lastWOW = false;
ReportEnable = true;
FirstContact = false;
Reported = false;
DistanceTraveled = 0.0;
MaximumStrutForce = MaximumStrutTravel = 0.0;
+ SinkRate = GroundSpeed = 0.0;
- vWhlBodyVec = (vXYZ - Aircraft->GetXYZcg()) / 12.0;
+ vWhlBodyVec = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
vWhlBodyVec(eX) = -vWhlBodyVec(eX);
vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
vLocalGear = State->GetTb2l() * vWhlBodyVec;
- if (debug_lvl & 2) cout << "Instantiated: FGLGear" << endl;
+ compressLength = 0.0;
+ compressSpeed = 0.0;
+ brakePct = 0.0;
+ maxCompLen = 0.0;
+
+ Debug(0);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Rotation = lgear.Rotation;
Exec = lgear.Exec;
FCS = lgear.FCS;
+ MassBalance = lgear.MassBalance;
vXYZ = lgear.vXYZ;
vMoment = lgear.vMoment;
vLocalGear = lgear.vLocalGear;
WOW = lgear.WOW;
+ lastWOW = lgear.lastWOW;
ReportEnable = lgear.ReportEnable;
FirstContact = lgear.FirstContact;
DistanceTraveled = lgear.DistanceTraveled;
Reported = lgear.Reported;
name = lgear.name;
sSteerType = lgear.sSteerType;
+ sRetractable = lgear.sRetractable;
eSteerType = lgear.eSteerType;
sBrakeGroup = lgear.sBrakeGroup;
eBrakeGrp = lgear.eBrakeGrp;
maxSteerAngle = lgear.maxSteerAngle;
+ isRetractable = lgear.isRetractable;
+ GearUp = lgear.GearUp;
+ GearDown = lgear.GearDown;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGLGear::~FGLGear()
{
- if (debug_lvl & 2) cout << "Destroyed: FGLGear" << endl;
+ Debug(1);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-FGColumnVector FGLGear::Force(void)
+FGColumnVector3& FGLGear::Force(void)
{
- float SteerGain, SteerAngle, BrakeFCoeff;
- float SinWheel, CosWheel, SideWhlVel, RollingWhlVel;
- float RudderPedal, RollingForce, SideForce, FCoeff;
- float WheelSlip;
-
- FGColumnVector vForce(3);
- FGColumnVector vLocalForce(3);
- FGColumnVector vWhlVelVec(3); // Velocity of this wheel (Local)
+ double SteerGain = 0;
+ double SinWheel, CosWheel;
+
+ vForce.InitMatrix();
+ vMoment.InitMatrix();
+
+ if (isRetractable) {
+ if (FCS->GetGearPos() < 0.01) {
+ GearUp = true;
+ GearDown = false;
+ } else if (FCS->GetGearPos() > 0.99) {
+ GearDown = true;
+ GearUp = false;
+ } else {
+ GearUp = false;
+ GearDown = false;
+ }
+ } else {
+ GearUp = false;
+ GearDown = true;
+ }
+
+ if (GearDown) {
- vWhlBodyVec = (vXYZ - Aircraft->GetXYZcg()) / 12.0;
- vWhlBodyVec(eX) = -vWhlBodyVec(eX);
- vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
+ vWhlBodyVec = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
+ vWhlBodyVec(eX) = -vWhlBodyVec(eX);
+ vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
// vWhlBodyVec now stores the vector from the cg to this wheel
- vLocalGear = State->GetTb2l() * vWhlBodyVec;
+ vLocalGear = State->GetTb2l() * vWhlBodyVec;
// vLocalGear now stores the vector from the cg to the wheel in local coords.
- compressLength = vLocalGear(eZ) - Position->GetDistanceAGL();
+ compressLength = vLocalGear(eZ) - Position->GetDistanceAGL();
// The compression length is currently measured in the Z-axis, only, at this time.
// It should be measured along the strut axis. If the local-frame gear position
// "hangs down" below the CG greater than the altitude, then the compressLength
// will be positive - i.e. the gear will have made contact.
- if (compressLength > 0.00) {
+ if (compressLength > 0.00) {
- WOW = true; // Weight-On-Wheels is true
+ WOW = true;// Weight-On-Wheels is true
// The next equation should really use the vector to the contact patch of the tire
// including the strut compression and not vWhlBodyVec. Will fix this later.
// (used for calculating damping force) is found by taking the Z-component of the
// wheel velocity.
- vWhlVelVec = State->GetTb2l() * (Rotation->GetPQR() * vWhlBodyVec);
- vWhlVelVec += Position->GetVel();
+ vWhlVelVec = State->GetTb2l() * (Rotation->GetPQR() * vWhlBodyVec);
+
+ vWhlVelVec += Position->GetVel();
- compressSpeed = vWhlVelVec(eZ);
+ compressSpeed = vWhlVelVec(eZ);
// If this is the first time the wheel has made contact, remember some values
// for later printout.
- if (!FirstContact) {
- FirstContact = true;
- SinkRate = compressSpeed;
- GroundSpeed = Position->GetVel().Magnitude();
- }
+ if (!FirstContact) {
+ FirstContact = true;
+ SinkRate = compressSpeed;
+ GroundSpeed = Position->GetVel().Magnitude();
+ }
// The following needs work regarding friction coefficients and braking and
// steering The BrakeFCoeff formula assumes that an anti-skid system is used.
// [JSB] The braking force coefficients include normal rolling coefficient +
// a percentage of the static friction coefficient based on braking applied.
- switch (eBrakeGrp) {
- case bgLeft:
- SteerGain = -maxSteerAngle;
- BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +
- staticFCoeff*FCS->GetBrake(bgLeft);
- break;
- case bgRight:
- SteerGain = -maxSteerAngle;
- BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgRight)) +
- staticFCoeff*FCS->GetBrake(bgRight);
- break;
- case bgCenter:
- SteerGain = -maxSteerAngle;
- BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
- staticFCoeff*FCS->GetBrake(bgCenter);
- break;
- case bgNose:
- SteerGain = maxSteerAngle;
- BrakeFCoeff = rollingFCoeff;
- break;
- case bgTail:
- SteerGain = -maxSteerAngle;
- BrakeFCoeff = rollingFCoeff;
- break;
- case bgNone:
- SteerGain = -maxSteerAngle;
- BrakeFCoeff = rollingFCoeff;
- break;
- default:
- cerr << "Improper brake group membership detected for this gear." << endl;
- break;
- }
-
- switch (eSteerType) {
- case stSteer:
- SteerAngle = SteerGain*FCS->GetDrCmd();
- break;
- case stFixed:
- SteerAngle = 0.0;
- break;
- case stCaster:
- // Note to Jon: This is not correct for castering gear. I'll fix it later.
- SteerAngle = 0.0;
- break;
- default:
- cerr << "Improper steering type membership detected for this gear." << endl;
- break;
- }
+ switch (eBrakeGrp) {
+ case bgLeft:
+ SteerGain = -0.10;
+ BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +
+ staticFCoeff*FCS->GetBrake(bgLeft);
+ break;
+ case bgRight:
+ SteerGain = -0.10;
+ BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgRight)) +
+ staticFCoeff*FCS->GetBrake(bgRight);
+ break;
+ case bgCenter:
+ SteerGain = -0.10;
+ BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter);
+ break;
+ case bgNose:
+ SteerGain = -0.50;
+ BrakeFCoeff = rollingFCoeff;
+ break;
+ case bgTail:
+ SteerGain = -0.10;
+ BrakeFCoeff = rollingFCoeff;
+ break;
+ case bgNone:
+ SteerGain = -0.10;
+ BrakeFCoeff = rollingFCoeff;
+ break;
+ default:
+ cerr << "Improper brake group membership detected for this gear." << endl;
+ break;
+ }
+
+ switch (eSteerType) {
+ case stSteer:
+ SteerAngle = SteerGain*FCS->GetDrPos();
+ break;
+ case stFixed:
+ SteerAngle = 0.0;
+ break;
+ case stCaster:
+// Note to Jon: This is not correct for castering gear. I'll fix it later.
+ SteerAngle = 0.0;
+ break;
+ default:
+ cerr << "Improper steering type membership detected for this gear." << endl;
+ break;
+ }
// Transform the wheel velocities from the local axis system to the wheel axis system.
// For now, steering angle is assumed to happen in the Local Z axis,
// not the strut axis as it should be. Will fix this later.
- SinWheel = sin(Rotation->Getpsi() + SteerAngle*DEGTORAD);
- CosWheel = cos(Rotation->Getpsi() + SteerAngle*DEGTORAD);
- RollingWhlVel = vWhlVelVec(eX)*CosWheel + vWhlVelVec(eY)*SinWheel;
- SideWhlVel = vWhlVelVec(eY)*CosWheel - vWhlVelVec(eX)*SinWheel;
+ SinWheel = sin(Rotation->Getpsi() + SteerAngle);
+ CosWheel = cos(Rotation->Getpsi() + SteerAngle);
+ RollingWhlVel = vWhlVelVec(eX)*CosWheel + vWhlVelVec(eY)*SinWheel;
+ SideWhlVel = vWhlVelVec(eY)*CosWheel - vWhlVelVec(eX)*SinWheel;
// Calculate tire slip angle.
- if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {
- WheelSlip = 0.0;
- } 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 (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {
+ WheelSlip = 0.0;
+ } else {
+ WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);
+ }
// 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;
- } else {
- FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;
- }
+ if (fabs(WheelSlip) <= 10.0) {
+ FCoeff = staticFCoeff*WheelSlip/10.0;
+ } else {
+ FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;
+ }
// Compute the vertical force on the wheel using square-law damping (per comment
// 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, (float)0.0);
+ vLocalForce(eZ) = min(-compressLength * kSpring
+ - compressSpeed * bDamp, (double)0.0);
- MaximumStrutForce = max(MaximumStrutForce, fabs(vLocalForce(eZ)));
- MaximumStrutTravel = max(MaximumStrutTravel, fabs(compressLength));
+ MaximumStrutForce = max(MaximumStrutForce, fabs(vLocalForce(eZ)));
+ MaximumStrutTravel = max(MaximumStrutTravel, fabs(compressLength));
// Compute the forces in the wheel ground plane.
- RollingForce = 0;
- if (fabs(RollingWhlVel) > 1E-3) {
- RollingForce = vLocalForce(eZ) * BrakeFCoeff * fabs(RollingWhlVel)/RollingWhlVel;
- }
- SideForce = vLocalForce(eZ) * FCoeff;
+ RollingForce = 0;
+ if (fabs(RollingWhlVel) > 1E-3) {
+ RollingForce = vLocalForce(eZ) * BrakeFCoeff * fabs(RollingWhlVel)/RollingWhlVel;
+ }
+ SideForce = vLocalForce(eZ) * FCoeff;
// Transform these forces back to the local reference frame.
- vLocalForce(eX) = RollingForce*CosWheel - SideForce*SinWheel;
- vLocalForce(eY) = SideForce*CosWheel + RollingForce*SinWheel;
+ vLocalForce(eX) = RollingForce*CosWheel - SideForce*SinWheel;
+ vLocalForce(eY) = SideForce*CosWheel + RollingForce*SinWheel;
// Note to Jon: At this point the forces will be too big when the airplane is
// stopped or rolling to a stop. We need to make sure that the gear forces just
// Transform the forces back to the body frame and compute the moment.
- vForce = State->GetTl2b() * vLocalForce;
- vMoment = vWhlBodyVec * vForce;
+ vForce = State->GetTl2b() * vLocalForce;
+ vMoment = vWhlBodyVec * vForce;
- } else {
+ } else {
+
+ WOW = false;
- WOW = false;
+ if (Position->GetDistanceAGL() > 200.0) {
+ FirstContact = false;
+ Reported = false;
+ DistanceTraveled = 0.0;
+ MaximumStrutForce = MaximumStrutTravel = 0.0;
+ }
- if (Position->GetDistanceAGL() > 200.0) {
- FirstContact = false;
- Reported = false;
- DistanceTraveled = 0.0;
- MaximumStrutForce = MaximumStrutTravel = 0.0;
+ compressLength = 0.0; // reset compressLength to zero for data output validity
}
- vForce.InitMatrix();
- vMoment.InitMatrix();
- }
+ if (FirstContact) {
+ DistanceTraveled += Position->GetVel().Magnitude()*State->Getdt()*Aircraft->GetRate();
+ }
+
+ if (ReportEnable && Position->GetVel().Magnitude() <= 0.05 && !Reported) {
+ if (debug_lvl > 0) Report();
+ }
- if (FirstContact) {
- DistanceTraveled += Position->GetVel().Magnitude()*State->Getdt()*Aircraft->GetRate();
- }
+ if (lastWOW != WOW) {
+ PutMessage("GEAR_CONTACT", WOW);
+ }
- if (ReportEnable && Position->GetVel().Magnitude() <= 0.05 && !Reported) {
- Report();
- }
+ lastWOW = WOW;
- return vForce;
+// Crash detection logic (really out-of-bounds detection)
+
+ if (compressLength > 500.0 ||
+ vForce.Magnitude() > 100000000.0 ||
+ vMoment.Magnitude() > 5000000000.0 ||
+ SinkRate > 1.4666*30)
+ {
+ PutMessage("Crash Detected: Simulation FREEZE.");
+ Exec->Freeze();
+ }
+ }
+ return vForce;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-void FGLGear::Debug(void)
+// The bitmasked value choices are as follows:
+// unset: In this case (the default) JSBSim would only print
+// out the normally expected messages, essentially echoing
+// the config files as they are read. If the environment
+// variable is not set, debug_lvl is set to 1 internally
+// 0: This requests JSBSim not to output any messages
+// whatsoever.
+// 1: This value explicity requests the normal JSBSim
+// startup messages
+// 2: This value asks for a message to be printed out when
+// a class is instantiated
+// 4: When this value is set, a message is displayed when a
+// FGModel object executes its Run() method
+// 8: When this value is set, various runtime state variables
+// are printed out periodically
+// 16: When set various parameters are sanity checked and
+// a message is printed out when they go out of bounds
+
+void FGLGear::Debug(int from)
{
- // TODO: Add user code here
+ if (debug_lvl <= 0) return;
+
+ if (debug_lvl & 1) { // Standard console startup message output
+ if (from == 0) { // Constructor
+ 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 << " Rolling Friction: " << rollingFCoeff << endl;
+ cout << " Steering Type: " << sSteerType << endl;
+ cout << " Grouping: " << sBrakeGroup << endl;
+ cout << " Max Steer Angle: " << maxSteerAngle << endl;
+ cout << " Retractable: " << sRetractable << endl;
+ }
+ }
+ if (debug_lvl & 2 ) { // Instantiation/Destruction notification
+ if (from == 0) cout << "Instantiated: FGLGear" << endl;
+ if (from == 1) cout << "Destroyed: FGLGear" << endl;
+ }
+ if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
+ }
+ if (debug_lvl & 8 ) { // Runtime state variables
+ }
+ if (debug_lvl & 16) { // Sanity checking
+ }
+ if (debug_lvl & 64) {
+ if (from == 0) { // Constructor
+ cout << IdSrc << endl;
+ cout << IdHdr << endl;
+ }
+ }
}
projects / flightgear.git / blobdiff