-/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-\r
- Module: FGLGear.cpp\r
- Author: Jon S. Berndt\r
- Norman H. Princen\r
- Date started: 11/18/99\r
- Purpose: Encapsulates the landing gear elements\r
- Called by: FGAircraft\r
-\r
- ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------\r
-\r
- This program is free software; you can redistribute it and/or modify it under\r
- the terms of the GNU General Public License as published by the Free Software\r
- Foundation; either version 2 of the License, or (at your option) any later\r
- version.\r
-\r
- This program is distributed in the hope that it will be useful, but WITHOUT\r
- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS\r
- FOR A PARTICULAR PURPOSE. See the GNU General Public License for more\r
- details.\r
-\r
- You should have received a copy of the GNU General Public License along with\r
- this program; if not, write to the Free Software Foundation, Inc., 59 Temple\r
- Place - Suite 330, Boston, MA 02111-1307, USA.\r
-\r
- Further information about the GNU General Public License can also be found on\r
- the world wide web at http://www.gnu.org.\r
-\r
-FUNCTIONAL DESCRIPTION\r
---------------------------------------------------------------------------------\r
-\r
-HISTORY\r
---------------------------------------------------------------------------------\r
-11/18/99 JSB Created\r
-01/30/01 NHP Extended gear model to properly simulate steering and braking\r
-\r
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-INCLUDES\r
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/\r
-\r
-#include "FGLGear.h"\r
-\r
-namespace JSBSim {\r
-\r
-/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-DEFINITIONS\r
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/\r
-\r
-/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-GLOBAL DATA\r
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/\r
-\r
-static const char *IdSrc = "$Id$";\r
-static const char *IdHdr = ID_LGEAR;\r
-\r
-/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-CLASS IMPLEMENTATION\r
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/\r
-\r
-FGLGear::FGLGear(FGConfigFile* AC_cfg, FGFDMExec* fdmex) : Exec(fdmex)\r
-{\r
- string tmp;\r
- \r
- *AC_cfg >> tmp >> name >> vXYZ(1) >> vXYZ(2) >> vXYZ(3)\r
- >> kSpring >> bDamp>> dynamicFCoeff >> staticFCoeff\r
- >> rollingFCoeff >> sSteerType >> sBrakeGroup \r
- >> maxSteerAngle >> sRetractable;\r
-\r
- if (sBrakeGroup == "LEFT" ) eBrakeGrp = bgLeft;\r
- else if (sBrakeGroup == "RIGHT" ) eBrakeGrp = bgRight;\r
- else if (sBrakeGroup == "CENTER") eBrakeGrp = bgCenter;\r
- else if (sBrakeGroup == "NOSE" ) eBrakeGrp = bgNose;\r
- else if (sBrakeGroup == "TAIL" ) eBrakeGrp = bgTail;\r
- else if (sBrakeGroup == "NONE" ) eBrakeGrp = bgNone;\r
- else {\r
- cerr << "Improper braking group specification in config file: "\r
- << sBrakeGroup << " is undefined." << endl;\r
- }\r
-\r
- if (sSteerType == "STEERABLE") eSteerType = stSteer;\r
- else if (sSteerType == "FIXED" ) eSteerType = stFixed;\r
- else if (sSteerType == "CASTERED" ) eSteerType = stCaster;\r
- else {\r
- cerr << "Improper steering type specification in config file: "\r
- << sSteerType << " is undefined." << endl;\r
- }\r
- \r
- if ( sRetractable == "RETRACT" ) {\r
- isRetractable = true;\r
- } else {\r
- isRetractable = false;\r
- } \r
- \r
- GearUp = false;\r
- GearDown = true;\r
- Servicable = true;\r
-\r
-// Add some AI here to determine if gear is located properly according to its\r
-// brake group type ??\r
-\r
- State = Exec->GetState();\r
- Aircraft = Exec->GetAircraft();\r
- Position = Exec->GetPosition();\r
- Rotation = Exec->GetRotation();\r
- FCS = Exec->GetFCS();\r
- MassBalance = Exec->GetMassBalance();\r
-\r
- WOW = lastWOW = true; // should the value be initialized to true?\r
- ReportEnable = true;\r
- FirstContact = false;\r
- StartedGroundRun = false;\r
- TakeoffReported = LandingReported = false;\r
- LandingDistanceTraveled = TakeoffDistanceTraveled = TakeoffDistanceTraveled50ft = 0.0;\r
- MaximumStrutForce = MaximumStrutTravel = 0.0;\r
- SideForce = RollingForce = 0.0;\r
- SinkRate = GroundSpeed = 0.0;\r
-\r
- vWhlBodyVec = MassBalance->StructuralToBody(vXYZ);\r
- \r
- vLocalGear = State->GetTb2l() * vWhlBodyVec;\r
-\r
- compressLength = 0.0;\r
- compressSpeed = 0.0;\r
- brakePct = 0.0;\r
- maxCompLen = 0.0;\r
-\r
- WheelSlip = lastWheelSlip = 0.0;\r
-\r
- compressLength = 0.0;\r
- compressSpeed = 0.0;\r
- brakePct = 0.0;\r
- maxCompLen = 0.0;\r
-\r
- TirePressureNorm = 1.0;\r
-\r
- Debug(0);\r
-}\r
-\r
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-\r
-FGLGear::FGLGear(const FGLGear& lgear)\r
-{\r
- State = lgear.State;\r
- Aircraft = lgear.Aircraft;\r
- Position = lgear.Position;\r
- Rotation = lgear.Rotation;\r
- Exec = lgear.Exec;\r
- FCS = lgear.FCS;\r
- MassBalance = lgear.MassBalance;\r
-\r
- vXYZ = lgear.vXYZ;\r
- vMoment = lgear.vMoment;\r
- vWhlBodyVec = lgear.vWhlBodyVec;\r
- vLocalGear = lgear.vLocalGear;\r
-\r
- WOW = lgear.WOW;\r
- lastWOW = lgear.lastWOW;\r
- ReportEnable = lgear.ReportEnable;\r
- FirstContact = lgear.FirstContact;\r
- StartedGroundRun = lgear.StartedGroundRun;\r
- LandingDistanceTraveled = lgear.LandingDistanceTraveled;\r
- TakeoffDistanceTraveled = lgear.TakeoffDistanceTraveled;\r
- TakeoffDistanceTraveled50ft = lgear.TakeoffDistanceTraveled50ft;\r
- MaximumStrutForce = lgear.MaximumStrutForce;\r
- MaximumStrutTravel = lgear.MaximumStrutTravel;\r
- SideForce = lgear.SideForce;\r
- RollingForce = lgear.RollingForce;\r
-\r
- kSpring = lgear.kSpring;\r
- bDamp = lgear.bDamp;\r
- compressLength = lgear.compressLength;\r
- compressSpeed = lgear.compressSpeed;\r
- staticFCoeff = lgear.staticFCoeff;\r
- dynamicFCoeff = lgear.dynamicFCoeff;\r
- rollingFCoeff = lgear.rollingFCoeff;\r
- brakePct = lgear.brakePct;\r
- maxCompLen = lgear.maxCompLen;\r
- SinkRate = lgear.SinkRate;\r
- GroundSpeed = lgear.GroundSpeed;\r
- LandingReported = lgear.LandingReported;\r
- TakeoffReported = lgear.TakeoffReported;\r
- name = lgear.name;\r
- sSteerType = lgear.sSteerType;\r
- sRetractable = lgear.sRetractable;\r
- eSteerType = lgear.eSteerType;\r
- sBrakeGroup = lgear.sBrakeGroup;\r
- eBrakeGrp = lgear.eBrakeGrp;\r
- maxSteerAngle = lgear.maxSteerAngle;\r
- isRetractable = lgear.isRetractable;\r
- GearUp = lgear.GearUp;\r
- GearDown = lgear.GearDown;\r
- WheelSlip = lgear.WheelSlip;\r
- lastWheelSlip = lgear.lastWheelSlip;\r
- TirePressureNorm = lgear.TirePressureNorm;\r
- Servicable = lgear.Servicable;\r
-}\r
-\r
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-\r
-FGLGear::~FGLGear()\r
-{\r
- Debug(1);\r
-}\r
-\r
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-\r
-FGColumnVector3& FGLGear::Force(void)\r
-{\r
- double SteerGain = 0;\r
- double SinWheel, CosWheel;\r
- double deltaSlip;\r
- double deltaT = State->Getdt()*Aircraft->GetRate();\r
-\r
- vForce.InitMatrix();\r
- vMoment.InitMatrix();\r
-\r
- if (isRetractable) {\r
- if (FCS->GetGearPos() < 0.01) {\r
- GearUp = true;\r
- GearDown = false;\r
- } else if (FCS->GetGearPos() > 0.99) {\r
- GearDown = true;\r
- GearUp = false;\r
- } else {\r
- GearUp = false;\r
- GearDown = false;\r
- }\r
- } else {\r
- GearUp = false;\r
- GearDown = true;\r
- } \r
- \r
- if (GearDown) {\r
-\r
- vWhlBodyVec = MassBalance->StructuralToBody(vXYZ);\r
-\r
-// vWhlBodyVec now stores the vector from the cg to this wheel\r
-\r
- vLocalGear = State->GetTb2l() * vWhlBodyVec;\r
-\r
-// vLocalGear now stores the vector from the cg to the wheel in local coords.\r
-\r
- compressLength = vLocalGear(eZ) - Position->GetDistanceAGL();\r
-\r
-// The compression length is currently measured in the Z-axis, only, at this time.\r
-// It should be measured along the strut axis. If the local-frame gear position\r
-// "hangs down" below the CG greater than the altitude, then the compressLength\r
-// will be positive - i.e. the gear will have made contact.\r
-\r
- if (compressLength > 0.00) {\r
-\r
- WOW = true; // Weight-On-Wheels is true\r
-\r
-// The next equation should really use the vector to the contact patch of the tire\r
-// including the strut compression and not vWhlBodyVec. Will fix this later.\r
-// As it stands, now, the following equation takes the aircraft body-frame\r
-// rotational rate and calculates the cross-product with the vector from the CG\r
-// to the wheel, thus producing the instantaneous velocity vector of the tire\r
-// in Body coords. The frame is also converted to local coordinates. When the\r
-// aircraft local-frame velocity is added to this quantity, the total velocity of\r
-// the wheel in local frame is then known. Subsequently, the compression speed\r
-// (used for calculating damping force) is found by taking the Z-component of the\r
-// wheel velocity.\r
-\r
- vWhlVelVec = State->GetTb2l() * (Rotation->GetPQR() * vWhlBodyVec);\r
- vWhlVelVec += Position->GetVel();\r
- compressSpeed = vWhlVelVec(eZ);\r
-\r
-// If this is the first time the wheel has made contact, remember some values\r
-// for later printout.\r
-\r
- if (!FirstContact) {\r
- FirstContact = true;\r
- SinkRate = compressSpeed;\r
- GroundSpeed = Position->GetVel().Magnitude();\r
- TakeoffReported = false;\r
- }\r
-\r
-// If the takeoff run is starting, initialize.\r
-\r
- if ((Position->GetVel().Magnitude() > 0.1) &&\r
- (FCS->GetBrake(bgLeft) == 0) &&\r
- (FCS->GetBrake(bgRight) == 0) &&\r
- (FCS->GetThrottlePos(0) == 1) && !StartedGroundRun)\r
- {\r
- TakeoffDistanceTraveled = 0;\r
- TakeoffDistanceTraveled50ft = 0;\r
- StartedGroundRun = true;\r
- }\r
-\r
-// The following needs work regarding friction coefficients and braking and\r
-// steering The BrakeFCoeff formula assumes that an anti-skid system is used.\r
-// It also assumes that we won't be turning and braking at the same time.\r
-// Will fix this later.\r
-// [JSB] The braking force coefficients include normal rolling coefficient +\r
-// a percentage of the static friction coefficient based on braking applied.\r
-\r
- switch (eBrakeGrp) {\r
- case bgLeft:\r
- BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +\r
- staticFCoeff*FCS->GetBrake(bgLeft) );\r
- break;\r
- case bgRight:\r
- BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgRight)) +\r
- staticFCoeff*FCS->GetBrake(bgRight) );\r
- break;\r
- case bgCenter:\r
- BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +\r
- staticFCoeff*FCS->GetBrake(bgCenter) );\r
- break;\r
- case bgNose:\r
- BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +\r
- staticFCoeff*FCS->GetBrake(bgCenter) );\r
- break;\r
- case bgTail:\r
- BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +\r
- staticFCoeff*FCS->GetBrake(bgCenter) );\r
- break;\r
- case bgNone:\r
- BrakeFCoeff = rollingFCoeff;\r
- break;\r
- default:\r
- cerr << "Improper brake group membership detected for this gear." << endl;\r
- break;\r
- }\r
-\r
- switch (eSteerType) {\r
- case stSteer:\r
- SteerAngle = -maxSteerAngle * FCS->GetDrCmd() * 0.01745; \r
- break;\r
- case stFixed:\r
- SteerAngle = 0.0;\r
- break;\r
- case stCaster:\r
-// Note to Jon: This is not correct for castering gear. I'll fix it later.\r
- SteerAngle = 0.0;\r
- break;\r
- default:\r
- cerr << "Improper steering type membership detected for this gear." << endl;\r
- break;\r
- }\r
-\r
-// Transform the wheel velocities from the local axis system to the wheel axis system.\r
-// For now, steering angle is assumed to happen in the Local Z axis,\r
-// not the strut axis as it should be. Will fix this later.\r
-\r
- SinWheel = sin(Rotation->Getpsi() + SteerAngle);\r
- CosWheel = cos(Rotation->Getpsi() + SteerAngle);\r
- RollingWhlVel = vWhlVelVec(eX)*CosWheel + vWhlVelVec(eY)*SinWheel;\r
- SideWhlVel = vWhlVelVec(eY)*CosWheel - vWhlVelVec(eX)*SinWheel;\r
-\r
-// Calculate tire slip angle.\r
-\r
- if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {\r
- WheelSlip = 0.0;\r
- } else if (fabs(RollingWhlVel) < 1.0) {\r
- WheelSlip = 0.05*radtodeg*atan2(SideWhlVel, RollingWhlVel) + 0.95*WheelSlip;\r
- } else {\r
- WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);\r
- }\r
-/*\r
- double maxdeltaSlip = 0.5*deltaT;\r
-\r
- if (RollingWhlVel == 0.0 && SideWhlVel == 0.0) {\r
- WheelSlip = 0.0;\r
- } else if (RollingWhlVel < 1.0) {\r
- WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);\r
- deltaSlip = WheelSlip - lastWheelSlip;\r
- if (fabs(deltaSlip) > maxdeltaSlip) {\r
- if (WheelSlip > lastWheelSlip) {\r
- WheelSlip = lastWheelSlip + maxdeltaSlip;\r
- } else if (WheelSlip < lastWheelSlip) {\r
- WheelSlip = lastWheelSlip - maxdeltaSlip;\r
- }\r
- }\r
- } else {\r
- WheelSlip = radtodeg*atan2(SideWhlVel, RollingWhlVel);\r
- }\r
-\r
- if ((WheelSlip < 0.0 && lastWheelSlip > 0.0) ||\r
- (WheelSlip > 0.0 && lastWheelSlip < 0.0))\r
- {\r
- WheelSlip = 0.0;\r
- }\r
-*/ \r
- lastWheelSlip = WheelSlip;\r
-\r
-// Compute the sideforce coefficients using similar assumptions to LaRCSim for now.\r
-// Allow a maximum of 10 degrees tire slip angle before wheel slides. At that point,\r
-// transition from static to dynamic friction. There are more complicated formulations\r
-// of this that avoid the discrete jump. Will fix this later.\r
-\r
- if (fabs(WheelSlip) <= 20.0) {\r
- FCoeff = staticFCoeff*WheelSlip/20.0;\r
- } else if (fabs(WheelSlip) <= 40.0) {\r
-// FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;\r
- FCoeff = (dynamicFCoeff*(fabs(WheelSlip) - 20.0)/20.0 + \r
- staticFCoeff*(40.0 - fabs(WheelSlip))/20.0)*fabs(WheelSlip)/WheelSlip;\r
- } else {\r
- FCoeff = dynamicFCoeff*fabs(WheelSlip)/WheelSlip;\r
- }\r
-\r
-// Compute the vertical force on the wheel using square-law damping (per comment\r
-// in paper AIAA-2000-4303 - see header prologue comments). We might consider\r
-// allowing for both square and linear damping force calculation. Also need to\r
-// possibly give a "rebound damping factor" that differs from the compression\r
-// case.\r
-\r
- vLocalForce(eZ) = min(-compressLength * kSpring\r
- - compressSpeed * bDamp, (double)0.0);\r
-\r
- MaximumStrutForce = max(MaximumStrutForce, fabs(vLocalForce(eZ)));\r
- MaximumStrutTravel = max(MaximumStrutTravel, fabs(compressLength));\r
-\r
-// Compute the forces in the wheel ground plane.\r
-\r
- RollingForce = 0;\r
- if (fabs(RollingWhlVel) > 1E-3) {\r
- RollingForce = (1.0 - TirePressureNorm) * 30\r
- + vLocalForce(eZ) * BrakeFCoeff\r
- * fabs(RollingWhlVel)/RollingWhlVel;\r
- }\r
- SideForce = vLocalForce(eZ) * FCoeff;\r
-\r
-// Transform these forces back to the local reference frame.\r
-\r
- vLocalForce(eX) = RollingForce*CosWheel - SideForce*SinWheel;\r
- vLocalForce(eY) = SideForce*CosWheel + RollingForce*SinWheel;\r
-\r
-// Note to Jon: At this point the forces will be too big when the airplane is\r
-// stopped or rolling to a stop. We need to make sure that the gear forces just\r
-// balance out the non-gear forces when the airplane is stopped. That way the\r
-// airplane won't start to accelerate until the non-gear/ forces are larger than\r
-// the gear forces. I think that the proper fix should go into FGAircraft::FMGear.\r
-// This routine would only compute the local strut forces and return them to\r
-// FMGear. All of the gear forces would get adjusted in FMGear using the total\r
-// non-gear forces. Then the gear moments would be calculated. If strange things\r
-// start happening to the airplane during testing as it rolls to a stop, then we\r
-// need to implement this change. I ran out of time to do it now but have the\r
-// equations.\r
-\r
-// Transform the forces back to the body frame and compute the moment.\r
-\r
- vForce = State->GetTl2b() * vLocalForce;\r
- vMoment = vWhlBodyVec * vForce;\r
-\r
- } else { // Gear is NOT compressed\r
-\r
- WOW = false;\r
-\r
- if (Position->GetDistanceAGL() > 200.0) {\r
- FirstContact = false;\r
- StartedGroundRun = false;\r
- LandingReported = false;\r
- LandingDistanceTraveled = 0.0;\r
- MaximumStrutForce = MaximumStrutTravel = 0.0;\r
- }\r
-\r
- compressLength = 0.0; // reset compressLength to zero for data output validity\r
- }\r
-\r
- if (FirstContact) LandingDistanceTraveled += Position->GetVground()*deltaT;\r
- \r
- if (StartedGroundRun) {\r
- TakeoffDistanceTraveled50ft += Position->GetVground()*deltaT;\r
- if (WOW) TakeoffDistanceTraveled += Position->GetVground()*deltaT;\r
- }\r
-\r
- if (ReportEnable && Position->GetVground() <= 0.05 && !LandingReported) {\r
- if (debug_lvl > 0) Report(erLand);\r
- }\r
-\r
- if (ReportEnable && !TakeoffReported &&\r
- (vLocalGear(eZ) - Position->GetDistanceAGL()) < -50.0)\r
- {\r
- if (debug_lvl > 0) Report(erTakeoff);\r
- }\r
-\r
- if (lastWOW != WOW) {\r
- PutMessage("GEAR_CONTACT: " + name, WOW);\r
- }\r
-\r
- lastWOW = WOW;\r
-\r
-// Crash detection logic (really out-of-bounds detection)\r
-\r
- if (compressLength > 500.0 ||\r
- vForce.Magnitude() > 100000000.0 ||\r
- vMoment.Magnitude() > 5000000000.0 ||\r
- SinkRate > 1.4666*30)\r
- {\r
- PutMessage("Crash Detected: Simulation FREEZE.");\r
- Exec->Freeze();\r
- }\r
- } \r
- return vForce; \r
-}\r
-\r
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-\r
-void FGLGear::Report(ReportType repType)\r
-{\r
- switch(repType) {\r
- case erLand:\r
- cout << endl << "Touchdown report for " << name << endl;\r
- cout << " Sink rate at contact: " << SinkRate << " fps, "\r
- << SinkRate*0.3048 << " mps" << endl;\r
- cout << " Contact ground speed: " << GroundSpeed*.5925 << " knots, "\r
- << GroundSpeed*0.3048 << " mps" << endl;\r
- cout << " Maximum contact force: " << MaximumStrutForce << " lbs, "\r
- << MaximumStrutForce*4.448 << " Newtons" << endl;\r
- cout << " Maximum strut travel: " << MaximumStrutTravel*12.0 << " inches, "\r
- << MaximumStrutTravel*30.48 << " cm" << endl;\r
- cout << " Distance traveled: " << LandingDistanceTraveled << " ft, "\r
- << LandingDistanceTraveled*0.3048 << " meters" << endl;\r
- LandingReported = true;\r
- break;\r
- case erTakeoff:\r
- cout << endl << "Takeoff report for " << name << endl;\r
- cout << " Distance traveled: " << TakeoffDistanceTraveled\r
- << " ft, " << TakeoffDistanceTraveled*0.3048 << " meters" << endl;\r
- cout << " Distance traveled (over 50'): " << TakeoffDistanceTraveled50ft\r
- << " ft, " << TakeoffDistanceTraveled50ft*0.3048 << " meters" << endl;\r
- TakeoffReported = true;\r
- break;\r
- }\r
-}\r
-\r
-//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
-// The bitmasked value choices are as follows:\r
-// unset: In this case (the default) JSBSim would only print\r
-// out the normally expected messages, essentially echoing\r
-// the config files as they are read. If the environment\r
-// variable is not set, debug_lvl is set to 1 internally\r
-// 0: This requests JSBSim not to output any messages\r
-// whatsoever.\r
-// 1: This value explicity requests the normal JSBSim\r
-// startup messages\r
-// 2: This value asks for a message to be printed out when\r
-// a class is instantiated\r
-// 4: When this value is set, a message is displayed when a\r
-// FGModel object executes its Run() method\r
-// 8: When this value is set, various runtime state variables\r
-// are printed out periodically\r
-// 16: When set various parameters are sanity checked and\r
-// a message is printed out when they go out of bounds\r
-\r
-void FGLGear::Debug(int from)\r
-{\r
- if (debug_lvl <= 0) return;\r
-\r
- if (debug_lvl & 1) { // Standard console startup message output\r
- if (from == 0) { // Constructor\r
- cout << " Name: " << name << endl;\r
- cout << " Location: " << vXYZ << endl;\r
- cout << " Spring Constant: " << kSpring << endl;\r
- cout << " Damping Constant: " << bDamp << endl;\r
- cout << " Dynamic Friction: " << dynamicFCoeff << endl;\r
- cout << " Static Friction: " << staticFCoeff << endl;\r
- cout << " Rolling Friction: " << rollingFCoeff << endl;\r
- cout << " Steering Type: " << sSteerType << endl;\r
- cout << " Grouping: " << sBrakeGroup << endl;\r
- cout << " Max Steer Angle: " << maxSteerAngle << endl;\r
- cout << " Retractable: " << sRetractable << endl;\r
- }\r
- }\r
- if (debug_lvl & 2 ) { // Instantiation/Destruction notification\r
- if (from == 0) cout << "Instantiated: FGLGear" << endl;\r
- if (from == 1) cout << "Destroyed: FGLGear" << endl;\r
- }\r
- if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects\r
- }\r
- if (debug_lvl & 8 ) { // Runtime state variables\r
- }\r
- if (debug_lvl & 16) { // Sanity checking\r
- }\r
- if (debug_lvl & 64) {\r
- if (from == 0) { // Constructor\r
- cout << IdSrc << endl;\r
- cout << IdHdr << endl;\r
- }\r
- }\r
-}\r
-\r
-} // namespace JSBSim\r
-\r
+/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+ Module: FGLGear.cpp
+ Author: Jon S. Berndt
+ Norman H. Princen
+ Date started: 11/18/99
+ Purpose: Encapsulates the landing gear elements
+ Called by: FGAircraft
+
+ ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------
+
+ This program is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License as published by the Free Software
+ Foundation; either version 2 of the License, or (at your option) any later
+ version.
+
+ This program is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ details.
+
+ You should have received a copy of the GNU General Public License along with
+ this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ Place - Suite 330, Boston, MA 02111-1307, USA.
+
+ Further information about the GNU General Public License can also be found on
+ the world wide web at http://www.gnu.org.
+
+FUNCTIONAL DESCRIPTION
+--------------------------------------------------------------------------------
+
+HISTORY
+--------------------------------------------------------------------------------
+11/18/99 JSB Created
+01/30/01 NHP Extended gear model to properly simulate steering and braking
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+INCLUDES
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
+
+#include "FGLGear.h"
+
+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) : Exec(fdmex)
+{
+ string tmp;
+
+ *AC_cfg >> tmp >> name >> vXYZ(1) >> vXYZ(2) >> vXYZ(3)
+ >> kSpring >> bDamp>> dynamicFCoeff >> staticFCoeff
+ >> rollingFCoeff >> sSteerType >> sBrakeGroup
+ >> maxSteerAngle >> sRetractable;
+
+ if (sBrakeGroup == "LEFT" ) eBrakeGrp = bgLeft;
+ else if (sBrakeGroup == "RIGHT" ) eBrakeGrp = bgRight;
+ else if (sBrakeGroup == "CENTER") eBrakeGrp = bgCenter;
+ else if (sBrakeGroup == "NOSE" ) eBrakeGrp = bgNose;
+ else if (sBrakeGroup == "TAIL" ) eBrakeGrp = bgTail;
+ else if (sBrakeGroup == "NONE" ) eBrakeGrp = bgNone;
+ else {
+ cerr << "Improper braking group specification in config file: "
+ << sBrakeGroup << " is undefined." << endl;
+ }
+
+ if (sSteerType == "STEERABLE") eSteerType = stSteer;
+ else if (sSteerType == "FIXED" ) eSteerType = stFixed;
+ else if (sSteerType == "CASTERED" ) eSteerType = stCaster;
+ else {
+ cerr << "Improper steering type specification in config file: "
+ << sSteerType << " is undefined." << endl;
+ }
+
+ if ( sRetractable == "RETRACT" ) {
+ isRetractable = true;
+ } else {
+ isRetractable = false;
+ }
+
+ GearUp = false;
+ GearDown = true;
+ Servicable = true;
+
+// Add some AI here to determine if gear is located properly according to its
+// brake group type ??
+
+ State = Exec->GetState();
+ Aircraft = Exec->GetAircraft();
+ Propagate = Exec->GetPropagate();
+ Auxiliary = Exec->GetAuxiliary();
+ FCS = Exec->GetFCS();
+ MassBalance = Exec->GetMassBalance();
+
+ WOW = lastWOW = true; // should the value be initialized to true?
+ ReportEnable = true;
+ FirstContact = false;
+ StartedGroundRun = false;
+ TakeoffReported = LandingReported = false;
+ LandingDistanceTraveled = TakeoffDistanceTraveled = TakeoffDistanceTraveled50ft = 0.0;
+ MaximumStrutForce = MaximumStrutTravel = 0.0;
+ SideForce = RollingForce = 0.0;
+ SinkRate = GroundSpeed = 0.0;
+
+ vWhlBodyVec = MassBalance->StructuralToBody(vXYZ);
+
+ vLocalGear = Propagate->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;
+
+ TirePressureNorm = 1.0;
+
+ Debug(0);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGLGear::FGLGear(const FGLGear& lgear)
+{
+ State = lgear.State;
+ Aircraft = lgear.Aircraft;
+ Propagate = lgear.Propagate;
+ Auxiliary = lgear.Auxiliary;
+ Exec = lgear.Exec;
+ FCS = lgear.FCS;
+ MassBalance = lgear.MassBalance;
+
+ vXYZ = lgear.vXYZ;
+ vMoment = lgear.vMoment;
+ vWhlBodyVec = lgear.vWhlBodyVec;
+ vLocalGear = lgear.vLocalGear;
+
+ WOW = lgear.WOW;
+ lastWOW = lgear.lastWOW;
+ ReportEnable = lgear.ReportEnable;
+ FirstContact = lgear.FirstContact;
+ StartedGroundRun = lgear.StartedGroundRun;
+ LandingDistanceTraveled = lgear.LandingDistanceTraveled;
+ TakeoffDistanceTraveled = lgear.TakeoffDistanceTraveled;
+ TakeoffDistanceTraveled50ft = lgear.TakeoffDistanceTraveled50ft;
+ MaximumStrutForce = lgear.MaximumStrutForce;
+ MaximumStrutTravel = lgear.MaximumStrutTravel;
+ SideForce = lgear.SideForce;
+ RollingForce = lgear.RollingForce;
+
+ kSpring = lgear.kSpring;
+ bDamp = lgear.bDamp;
+ compressLength = lgear.compressLength;
+ compressSpeed = lgear.compressSpeed;
+ staticFCoeff = lgear.staticFCoeff;
+ dynamicFCoeff = lgear.dynamicFCoeff;
+ rollingFCoeff = lgear.rollingFCoeff;
+ brakePct = lgear.brakePct;
+ maxCompLen = lgear.maxCompLen;
+ SinkRate = lgear.SinkRate;
+ GroundSpeed = lgear.GroundSpeed;
+ LandingReported = lgear.LandingReported;
+ TakeoffReported = lgear.TakeoffReported;
+ 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;
+ WheelSlip = lgear.WheelSlip;
+ lastWheelSlip = lgear.lastWheelSlip;
+ TirePressureNorm = lgear.TirePressureNorm;
+ Servicable = lgear.Servicable;
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGLGear::~FGLGear()
+{
+ Debug(1);
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+FGColumnVector3& FGLGear::Force(void)
+{
+ double SinWheel, CosWheel;
+ double deltaSlip;
+ double deltaT = State->Getdt()*Aircraft->GetRate();
+
+ 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 = MassBalance->StructuralToBody(vXYZ);
+
+// vWhlBodyVec now stores the vector from the cg to this wheel
+
+ vLocalGear = Propagate->GetTb2l() * vWhlBodyVec;
+
+// vLocalGear now stores the vector from the cg to the wheel in local coords.
+
+ compressLength = vLocalGear(eZ) - Propagate->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) {
+
+ 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.
+// As it stands, now, the following equation takes the aircraft body-frame
+// rotational rate and calculates the cross-product with the vector from the CG
+// to the wheel, thus producing the instantaneous velocity vector of the tire
+// in Body coords. The frame is also converted to local coordinates. When the
+// aircraft local-frame velocity is added to this quantity, the total velocity of
+// the wheel in local frame is then known. Subsequently, the compression speed
+// (used for calculating damping force) is found by taking the Z-component of the
+// wheel velocity.
+
+ vWhlVelVec = Propagate->GetTb2l() * (Propagate->GetPQR() * vWhlBodyVec);
+ vWhlVelVec += Propagate->GetVel();
+ 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 = Propagate->GetVel().Magnitude();
+ TakeoffReported = false;
+ }
+
+// If the takeoff run is starting, initialize.
+
+ if ((Propagate->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
+// steering The BrakeFCoeff formula assumes that an anti-skid system is used.
+// It also assumes that we won't be turning and braking at the same time.
+// Will fix this later.
+// [JSB] The braking force coefficients include normal rolling coefficient +
+// a percentage of the static friction coefficient based on braking applied.
+
+ switch (eBrakeGrp) {
+ case bgLeft:
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgLeft)) +
+ staticFCoeff*FCS->GetBrake(bgLeft) );
+ break;
+ case bgRight:
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgRight)) +
+ staticFCoeff*FCS->GetBrake(bgRight) );
+ break;
+ case bgCenter:
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
+ break;
+ case bgNose:
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
+ break;
+ case bgTail:
+ BrakeFCoeff = ( rollingFCoeff*(1.0 - FCS->GetBrake(bgCenter)) +
+ staticFCoeff*FCS->GetBrake(bgCenter) );
+ break;
+ case bgNone:
+ BrakeFCoeff = rollingFCoeff;
+ break;
+ default:
+ cerr << "Improper brake group membership detected for this gear." << endl;
+ break;
+ }
+
+ switch (eSteerType) {
+ case stSteer:
+ SteerAngle = -maxSteerAngle * FCS->GetDrCmd() * 0.01745;
+ 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(Propagate->Getpsi() + SteerAngle);
+ CosWheel = cos(Propagate->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 if (fabs(RollingWhlVel) < 1.0) {
+ WheelSlip = 0.05*radtodeg*atan2(SideWhlVel, fabs(RollingWhlVel)) + 0.95*WheelSlip;
+ } else {
+ WheelSlip = radtodeg*atan2(SideWhlVel, fabs(RollingWhlVel));
+ }
+/*
+ double maxdeltaSlip = 0.5*deltaT;
+
+ 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);
+ }
+
+ 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 (similar to Pacejka). Will fix this later.
+
+ 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;
+ }
+
+// 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.
+
+ vLocalForce(eZ) = min(-compressLength * kSpring
+ - compressSpeed * bDamp, (double)0.0);
+
+ 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 = (1.0 - TirePressureNorm) * 30
+ + 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;
+
+// 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
+// balance out the non-gear forces when the airplane is stopped. That way the
+// airplane won't start to accelerate until the non-gear/ forces are larger than
+// the gear forces. I think that the proper fix should go into FGAircraft::FMGear.
+// This routine would only compute the local strut forces and return them to
+// FMGear. All of the gear forces would get adjusted in FMGear using the total
+// non-gear forces. Then the gear moments would be calculated. If strange things
+// start happening to the airplane during testing as it rolls to a stop, then we
+// need to implement this change. I ran out of time to do it now but have the
+// equations.
+
+// Transform the forces back to the body frame and compute the moment.
+
+ vForce = Propagate->GetTl2b() * vLocalForce;
+ vMoment = vWhlBodyVec * vForce;
+
+ } else { // Gear is NOT compressed
+
+ WOW = false;
+
+ if (Propagate->GetDistanceAGL() > 200.0) {
+ FirstContact = false;
+ StartedGroundRun = false;
+ LandingReported = false;
+ LandingDistanceTraveled = 0.0;
+ MaximumStrutForce = MaximumStrutTravel = 0.0;
+ }
+
+ compressLength = 0.0; // reset compressLength to zero for data output validity
+ }
+
+ if (FirstContact) LandingDistanceTraveled += Auxiliary->GetVground()*deltaT;
+
+ if (StartedGroundRun) {
+ TakeoffDistanceTraveled50ft += Auxiliary->GetVground()*deltaT;
+ if (WOW) TakeoffDistanceTraveled += Auxiliary->GetVground()*deltaT;
+ }
+
+ if (ReportEnable && Auxiliary->GetVground() <= 0.05 && !LandingReported) {
+ if (debug_lvl > 0) Report(erLand);
+ }
+
+ if (ReportEnable && !TakeoffReported &&
+ (vLocalGear(eZ) - Propagate->GetDistanceAGL()) < -50.0)
+ {
+ if (debug_lvl > 0) Report(erTakeoff);
+ }
+
+ if (lastWOW != WOW) {
+ PutMessage("GEAR_CONTACT: " + name, WOW);
+ }
+
+ lastWOW = WOW;
+
+// 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::Report(ReportType repType)
+{
+ 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;
+ }
+}
+
+//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+// 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)
+{
+ 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
+