%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGLGear.h"
-#include <algorithm>
+//#include <algorithm>
+
+namespace JSBSim {
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
DEFINITIONS
GLOBAL DATA
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-
static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_LGEAR;
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : vXYZ(3),
- vMoment(3),
- vWhlBodyVec(3),
- vForce(3),
- vLocalForce(3),
- vWhlVelVec(3),
- Exec(fdmex)
+FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : Exec(fdmex)
{
string tmp;
- string Retractable;
*AC_cfg >> tmp >> name >> vXYZ(1) >> vXYZ(2) >> vXYZ(3)
>> kSpring >> bDamp>> dynamicFCoeff >> staticFCoeff
>> rollingFCoeff >> sSteerType >> sBrakeGroup
- >> maxSteerAngle >> Retractable;
-
- if (debug_lvl > 0) {
- 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: " << Retractable << endl;
- }
+ >> maxSteerAngle >> sRetractable;
if (sBrakeGroup == "LEFT" ) eBrakeGrp = bgLeft;
else if (sBrakeGroup == "RIGHT" ) eBrakeGrp = bgRight;
<< sSteerType << " is undefined." << endl;
}
- if( Retractable == "RETRACT" ) {
- isRetractable=true;
+ if ( sRetractable == "RETRACT" ) {
+ isRetractable = true;
} else {
- isRetractable=false;
+ isRetractable = false;
}
- GearUp=false; GearDown=true;
+ GearUp = false;
+ GearDown = true;
+ Servicable = true;
// Add some AI here to determine if gear is located properly according to its
// brake group type ??
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;
- DistanceTraveled = 0.0;
+ StartedGroundRun = false;
+ TakeoffReported = LandingReported = false;
+ LandingDistanceTraveled = TakeoffDistanceTraveled = TakeoffDistanceTraveled50ft = 0.0;
MaximumStrutForce = MaximumStrutTravel = 0.0;
SinkRate = GroundSpeed = 0.0;
- vWhlBodyVec = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
- vWhlBodyVec(eX) = -vWhlBodyVec(eX);
- vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
-
+ vWhlBodyVec = MassBalance->StructuralToBody(vXYZ);
+
vLocalGear = State->GetTb2l() * vWhlBodyVec;
- if (debug_lvl & 2) cout << "Instantiated: FGLGear" << endl;
+ 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;
+
+ TirePressureNorm = 1.0;
+
+ Debug(0);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
lastWOW = lgear.lastWOW;
ReportEnable = lgear.ReportEnable;
FirstContact = lgear.FirstContact;
- DistanceTraveled = lgear.DistanceTraveled;
+ StartedGroundRun = lgear.StartedGroundRun;
+ LandingDistanceTraveled = lgear.LandingDistanceTraveled;
+ TakeoffDistanceTraveled = lgear.TakeoffDistanceTraveled;
+ TakeoffDistanceTraveled50ft = lgear.TakeoffDistanceTraveled50ft;
MaximumStrutForce = lgear.MaximumStrutForce;
MaximumStrutTravel = lgear.MaximumStrutTravel;
maxCompLen = lgear.maxCompLen;
SinkRate = lgear.SinkRate;
GroundSpeed = lgear.GroundSpeed;
- Reported = lgear.Reported;
+ LandingReported = lgear.LandingReported;
+ TakeoffReported = lgear.TakeoffReported;
name = lgear.name;
sSteerType = lgear.sSteerType;
+ sRetractable = lgear.sRetractable;
eSteerType = lgear.eSteerType;
sBrakeGroup = lgear.sBrakeGroup;
eBrakeGrp = lgear.eBrakeGrp;
isRetractable = lgear.isRetractable;
GearUp = lgear.GearUp;
GearDown = lgear.GearDown;
+ WheelSlip = lgear.WheelSlip;
+ lastWheelSlip = lgear.lastWheelSlip;
+ TirePressureNorm = lgear.TirePressureNorm;
+ Servicable = lgear.Servicable;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGLGear::~FGLGear()
{
- if (debug_lvl & 2) cout << "Destroyed: FGLGear" << endl;
+ Debug(1);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGColumnVector3& FGLGear::Force(void)
{
+ double SteerGain = 0;
+ double SinWheel, CosWheel;
+ double deltaSlip;
+ double deltaT = State->Getdt()*Aircraft->GetRate();
+ double maxdeltaSlip = 0.5*deltaT;
+
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;
+
+ 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;
+ GearUp = false;
+ GearDown = false;
}
} else {
- GearUp=false; GearDown=true;
+ GearUp = false;
+ GearDown = true;
}
- if( GearDown ) {
- double SteerGain = 0;
- double SinWheel, CosWheel, SideWhlVel, RollingWhlVel;
- double RollingForce, SideForce, FCoeff;
- double WheelSlip;
+ if (GearDown) {
- vWhlBodyVec = (vXYZ - MassBalance->GetXYZcg()) / 12.0;
- vWhlBodyVec(eX) = -vWhlBodyVec(eX);
- vWhlBodyVec(eZ) = -vWhlBodyVec(eZ);
+ vWhlBodyVec = MassBalance->StructuralToBody(vXYZ);
// vWhlBodyVec now stores the vector from the cg to this wheel
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.
FirstContact = true;
SinkRate = compressSpeed;
GroundSpeed = Position->GetVel().Magnitude();
+ TakeoffReported = false;
+ }
+
+// If the takeoff run is starting, initialize.
+
+ if ((Position->GetVel().Magnitude() > 0.1) &&
+ (FCS->GetBrake(bgLeft) == 0) &&
+ (FCS->GetBrake(bgRight) == 0) &&
+ (FCS->GetThrottlePos(0) == 1) && !StartedGroundRun)
+ {
+ TakeoffDistanceTraveled = 0;
+ TakeoffDistanceTraveled50ft = 0;
+ StartedGroundRun = true;
}
// The following needs work regarding friction coefficients and braking and
switch (eBrakeGrp) {
case bgLeft:
- SteerGain = -0.10;
- BrakeFCoeff = rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +
- staticFCoeff*FCS->GetBrake(bgLeft);
+ 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);
+ 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);
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
break;
case bgNose:
- SteerGain = 0.10;
- BrakeFCoeff = rollingFCoeff;
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
break;
case bgTail:
- SteerGain = -0.10;
- BrakeFCoeff = rollingFCoeff;
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
break;
case bgNone:
- SteerGain = -0.10;
- BrakeFCoeff = rollingFCoeff;
+ BrakeFCoeff = rollingFCoeff;
break;
default:
cerr << "Improper brake group membership detected for this gear." << endl;
switch (eSteerType) {
case stSteer:
- SteerAngle = SteerGain*FCS->GetDrPos();
+ SteerAngle = -maxSteerAngle * FCS->GetDrCmd() * 0.01745;
break;
case stFixed:
SteerAngle = 0.0;
if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {
WheelSlip = 0.0;
+ } else if (fabs(RollingWhlVel) < 1.0) {
+ WheelSlip = 0.05*radtodeg*atan2(SideWhlVel, RollingWhlVel) + 0.95*WheelSlip;
+ } else {
+ WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);
+ }
+/*
+ if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {
+ WheelSlip = 0.0;
+ } else if (RollingWhlVel < 1.0) {
+ WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);
+ deltaSlip = WheelSlip - lastWheelSlip;
+ if (fabs(deltaSlip) > maxdeltaSlip) {
+ if (WheelSlip > lastWheelSlip) {
+ WheelSlip = lastWheelSlip + maxdeltaSlip;
+ } else if (WheelSlip < lastWheelSlip) {
+ WheelSlip = lastWheelSlip - maxdeltaSlip;
+ }
+ }
} 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;
}
// 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);
RollingForce = 0;
if (fabs(RollingWhlVel) > 1E-3) {
- RollingForce = vLocalForce(eZ) * BrakeFCoeff * fabs(RollingWhlVel)/RollingWhlVel;
+ RollingForce = (1.0 - TirePressureNorm) * 30
+ + vLocalForce(eZ) * BrakeFCoeff
+ * fabs(RollingWhlVel)/RollingWhlVel;
}
SideForce = vLocalForce(eZ) * FCoeff;
vForce = State->GetTl2b() * vLocalForce;
vMoment = vWhlBodyVec * vForce;
- } else {
+ } else { // Gear is NOT compressed
WOW = false;
if (Position->GetDistanceAGL() > 200.0) {
FirstContact = false;
- Reported = false;
- DistanceTraveled = 0.0;
+ StartedGroundRun = false;
+ LandingReported = false;
+ LandingDistanceTraveled = 0.0;
MaximumStrutForce = MaximumStrutTravel = 0.0;
}
- compressLength = 0.0;// reset compressLength to zero for data output validity
+ compressLength = 0.0; // reset compressLength to zero for data output validity
+ }
-
+ if (FirstContact) LandingDistanceTraveled += Position->GetVground()*deltaT;
+
+ if (StartedGroundRun) {
+ TakeoffDistanceTraveled50ft += Position->GetVground()*deltaT;
+ if (WOW) TakeoffDistanceTraveled += Position->GetVground()*deltaT;
}
- if (FirstContact) {
- DistanceTraveled += Position->GetVel().Magnitude()*State->Getdt()*Aircraft->GetRate();
+ if (ReportEnable && Position->GetVground() <= 0.05 && !LandingReported) {
+ if (debug_lvl > 0) Report(erLand);
}
-
- if (ReportEnable && Position->GetVel().Magnitude() <= 0.05 && !Reported) {
- if (debug_lvl > 0) Report();
+
+ if (ReportEnable && !TakeoffReported &&
+ (vLocalGear(eZ) - Position->GetDistanceAGL()) < -50.0)
+ {
+ if (debug_lvl > 0) Report(erTakeoff);
}
if (lastWOW != WOW) {
- PutMessage("GEAR_CONTACT", WOW);
+ PutMessage("GEAR_CONTACT: " + name, WOW);
}
lastWOW = WOW;
vMoment.Magnitude() > 5000000000.0 ||
SinkRate > 1.4666*30)
{
- PutMessage("Crash Detected");
+ PutMessage("Crash Detected: Simulation FREEZE.");
Exec->Freeze();
}
-
-
}
return vForce;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-void FGLGear::Report(void)
+void FGLGear::Report(ReportType repType)
{
- 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;
+ switch(repType) {
+ case erLand:
+ cout << endl << "Touchdown report for " << name << endl;
+ cout << " Sink rate at contact: " << SinkRate << " fps, "
+ << SinkRate*0.3048 << " mps" << endl;
+ cout << " Contact ground speed: " << GroundSpeed*.5925 << " knots, "
+ << GroundSpeed*0.3048 << " 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: " << LandingDistanceTraveled << " ft, "
+ << LandingDistanceTraveled*0.3048 << " meters" << endl;
+ LandingReported = true;
+ break;
+ case erTakeoff:
+ cout << endl << "Takeoff report for " << name << endl;
+ cout << " Distance traveled: " << TakeoffDistanceTraveled
+ << " ft, " << TakeoffDistanceTraveled*0.3048 << " meters" << endl;
+ cout << " Distance traveled (over 50'): " << TakeoffDistanceTraveled50ft
+ << " ft, " << TakeoffDistanceTraveled50ft*0.3048 << " meters" << endl;
+ TakeoffReported = true;
+ break;
+ }
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-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;
+ }
+ }
}
+} // namespace JSBSim
+