FGGroundReactions Class Reference

Detailed Description

Manages ground reactions modeling.

Maintains a list of landing gear and ground contact points, all instances of FGLGear. Sums their forces and moments so that these may be provided to FGPropagate. Parses the <ground_reactions> section of the aircraft configuration file.

Configuration File Format of <ground_reactions> Section:

<ground_reactions>
    <contact>
       ... {see FGLGear for specifics of this format}
    </contact>
    ... {more contacts}
</ground_reactions>

Definition at line 79 of file FGGroundReactions.h.

#include <FGGroundReactions.h>

Inheritance diagram for FGGroundReactions:

Collaboration diagram for FGGroundReactions:

Public Member Functions
	FGGroundReactions (FGFDMExec *)
double	GetDsCmd (void) const
	Gets the steering command. More...
double	GetForces (int idx) const
const FGColumnVector3 &	GetForces (void) const
FGLGear *	GetGearUnit (int gear) const
	Gets a gear instance. More...
std::string	GetGroundReactionStrings (std::string delimeter) const
std::string	GetGroundReactionValues (std::string delimeter) const
double	GetMoments (int idx) const
const FGColumnVector3 &	GetMoments (void) const
std::vector< LagrangeMultiplier * > *	GetMultipliersList (void)
int	GetNumGearUnits (void) const
	Gets the number of gears. More...
bool	GetWOW (void) const
bool	InitModel (void) override
bool	Load (Element *el) override
void	RegisterLagrangeMultiplier (LagrangeMultiplier *lmult)
bool	Run (bool Holding) override
	Runs the Ground Reactions model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold. More...
void	SetDsCmd (double cmd)
	Sets the steering command. More...
Public Member Functions inherited from FGModel
	FGModel (FGFDMExec *)
	Constructor.
	~FGModel () override
	Destructor.
virtual SGPath	FindFullPathName (const SGPath &path) const
FGFDMExec *	GetExec (void)
const std::string &	GetName (void)
unsigned int	GetRate (void)
	Get the output rate for the model in frames.
bool	InitModel (void) override
void	SetPropertyManager (FGPropertyManager *fgpm)
void	SetRate (unsigned int tt)
	Set the ouput rate for the model in frames.
Public Member Functions inherited from FGModelFunctions
std::string	GetFunctionStrings (const std::string &delimeter) const
	Gets the strings for the current set of functions. More...
std::string	GetFunctionValues (const std::string &delimeter) const
	Gets the function values. More...
FGFunction *	GetPreFunction (const std::string &name)
	Get one of the "pre" function. More...
bool	Load (Element *el, FGFDMExec *fdmex, std::string prefix="")
void	PostLoad (Element *el, FGFDMExec *fdmex, std::string prefix="")
void	PreLoad (Element *el, FGFDMExec *fdmex, std::string prefix="")
void	RunPostFunctions (void)
void	RunPreFunctions (void)
Public Member Functions inherited from FGJSBBase
	FGJSBBase ()
	Constructor for FGJSBBase.
virtual	~FGJSBBase ()
	Destructor for FGJSBBase.
void	PutMessage (const Message &msg)
	Places a Message structure on the Message queue. More...
void	PutMessage (const std::string &text)
	Creates a message with the given text and places it on the queue. More...
void	PutMessage (const std::string &text, bool bVal)
	Creates a message with the given text and boolean value and places it on the queue. More...
void	PutMessage (const std::string &text, int iVal)
	Creates a message with the given text and integer value and places it on the queue. More...
void	PutMessage (const std::string &text, double dVal)
	Creates a message with the given text and double value and places it on the queue. More...
int	SomeMessages (void) const
	Reads the message on the queue (but does not delete it). More...
void	ProcessMessage (void)
	Reads the message on the queue and removes it from the queue. More...
Message *	ProcessNextMessage (void)
	Reads the next message on the queue and removes it from the queue. More...
void	disableHighLighting (void)
	Disables highlighting in the console output.
Public Member Functions inherited from FGSurface
	FGSurface (FGFDMExec *fdmex, int number=-1)
	Constructor.
	~FGSurface ()
	Destructor.
void	bind (void)
float	GetBumpHeight ()
	Returns the height of the bump at the provided offset.
double	GetBumpiness (void)
	Gets the normalized bumpiness factor associated with the surface.
double	GetMaximumForce (void)
	Gets the maximum force of the surface area.
double	GetRollingFFactor (void)
	Gets the rolling friction factor of the surface area.
bool	GetSolid (void)
	Gets the surface is a solid flag value.
double	GetStaticFFactor (void)
	Gets the static friction factor of the surface area.
std::string	GetSurfaceStrings (std::string delimeter) const
std::string	GetSurfaceValues (std::string delimeter) const
void	resetValues (void)
	Reset all surface values to a default.
void	SetBumpiness (double bump)
	Sets the normalized bumpiness factor associated with the surface.
void	SetMaximumForce (double force)
	Sets the maximum force for the surface area.
void	SetPosition (const double pt[3])
	Set the currect position for bumpiness calulcation.
void	SetRollingFFactor (double friction)
	Sets the rolling friction factor of the surface area.
void	SetSolid (bool solid)
	Sets the surface is a solid flag value.
void	SetStaticFFactor (double friction)
	Sets the static friction factor of the surface area.

Public Attributes
FGLGear::Inputs	in

Additional Inherited Members
Public Types inherited from FGJSBBase
enum	{ eL = 1, eM, eN }
	Moments L, M, N.
enum	{ eP = 1, eQ, eR }
	Rates P, Q, R.
enum	{ eU = 1, eV, eW }
	Velocities U, V, W.
enum	{ eX = 1, eY, eZ }
	Positions X, Y, Z.
enum	{ ePhi = 1, eTht, ePsi }
	Euler angles Phi, Theta, Psi.
enum	{ eDrag = 1, eSide, eLift }
	Stability axis forces, Drag, Side force, Lift.
enum	{ eRoll = 1, ePitch, eYaw }
	Local frame orientation Roll, Pitch, Yaw.
enum	{ eNorth = 1, eEast, eDown }
	Local frame position North, East, Down.
enum	{ eLat = 1, eLong, eRad }
	Locations Radius, Latitude, Longitude.
enum	{   inNone = 0, inDegrees, inRadians, inMeters,   inFeet }
	Conversion specifiers.
Public Types inherited from FGSurface
enum	ContactType { ctBOGEY, ctSTRUCTURE, ctGROUND }
Static Public Member Functions inherited from FGJSBBase
static const std::string &	GetVersion (void)
	Returns the version number of JSBSim. More...
static constexpr double	KelvinToFahrenheit (double kelvin)
	Converts from degrees Kelvin to degrees Fahrenheit. More...
static constexpr double	CelsiusToRankine (double celsius)
	Converts from degrees Celsius to degrees Rankine. More...
static constexpr double	RankineToCelsius (double rankine)
	Converts from degrees Rankine to degrees Celsius. More...
static constexpr double	KelvinToRankine (double kelvin)
	Converts from degrees Kelvin to degrees Rankine. More...
static constexpr double	RankineToKelvin (double rankine)
	Converts from degrees Rankine to degrees Kelvin. More...
static constexpr double	FahrenheitToCelsius (double fahrenheit)
	Converts from degrees Fahrenheit to degrees Celsius. More...
static constexpr double	CelsiusToFahrenheit (double celsius)
	Converts from degrees Celsius to degrees Fahrenheit. More...
static constexpr double	CelsiusToKelvin (double celsius)
	Converts from degrees Celsius to degrees Kelvin. More...
static constexpr double	KelvinToCelsius (double kelvin)
	Converts from degrees Kelvin to degrees Celsius. More...
static constexpr double	FeetToMeters (double measure)
	Converts from feet to meters. More...
static double	PitotTotalPressure (double mach, double p)
	Compute the total pressure in front of the Pitot tube. More...
static double	MachFromImpactPressure (double qc, double p)
	Compute the Mach number from the differential pressure (qc) and the static pressure. More...
static double	VcalibratedFromMach (double mach, double p)
	Calculate the calibrated airspeed from the Mach number. More...
static double	MachFromVcalibrated (double vcas, double p)
	Calculate the Mach number from the calibrated airspeed.Based on the formulas in the US Air Force Aircraft Performance Flight Testing Manual (AFFTC-TIH-99-01). More...
static bool	EqualToRoundoff (double a, double b)
	Finite precision comparison. More...
static bool	EqualToRoundoff (float a, float b)
	Finite precision comparison. More...
static bool	EqualToRoundoff (float a, double b)
	Finite precision comparison. More...
static bool	EqualToRoundoff (double a, float b)
	Finite precision comparison. More...
static constexpr double	Constrain (double min, double value, double max)
	Constrain a value between a minimum and a maximum value.
static constexpr double	sign (double num)
static double	GaussianRandomNumber (void)
Static Public Attributes inherited from FGJSBBase
static char	highint [5] = {27, '[', '1', 'm', '\0' }
	highlights text
static char	halfint [5] = {27, '[', '2', 'm', '\0' }
	low intensity text
static char	normint [6] = {27, '[', '2', '2', 'm', '\0' }
	normal intensity text
static char	reset [5] = {27, '[', '0', 'm', '\0' }
	resets text properties
static char	underon [5] = {27, '[', '4', 'm', '\0' }
	underlines text
static char	underoff [6] = {27, '[', '2', '4', 'm', '\0' }
	underline off
static char	fgblue [6] = {27, '[', '3', '4', 'm', '\0' }
	blue text
static char	fgcyan [6] = {27, '[', '3', '6', 'm', '\0' }
	cyan text
static char	fgred [6] = {27, '[', '3', '1', 'm', '\0' }
	red text
static char	fggreen [6] = {27, '[', '3', '2', 'm', '\0' }
	green text
static char	fgdef [6] = {27, '[', '3', '9', 'm', '\0' }
	default text
static short	debug_lvl = 1
Protected Member Functions inherited from FGModel
bool	Upload (Element *el, bool preLoad)
	Uploads this model in memory. More...
Static Protected Member Functions inherited from FGJSBBase
static std::string	CreateIndexedPropertyName (const std::string &Property, int index)
Protected Attributes inherited from FGModel
unsigned int	exe_ctr
FGFDMExec *	FDMExec
std::string	Name
FGPropertyManager *	PropertyManager
unsigned int	rate
Protected Attributes inherited from FGModelFunctions
FGPropertyReader	LocalProperties
std::vector< FGFunction * >	PostFunctions
std::vector< FGFunction * >	PreFunctions
Protected Attributes inherited from FGSurface
double	bumpiness
double	dynamicFCoeff
ContactType	eSurfaceType
bool	isSolid
double	maximumForce
double	rollingFFactor
double	staticFCoeff
double	staticFFactor
Static Protected Attributes inherited from FGJSBBase
static Message	localMsg
static std::queue< Message >	Messages
static unsigned int	messageId = 0
static constexpr double	radtodeg = 180. / M_PI
static constexpr double	degtorad = M_PI / 180.
static constexpr double	hptoftlbssec = 550.0
static constexpr double	psftoinhg = 0.014138
static constexpr double	psftopa = 47.88
static constexpr double	ktstofps = 1.68781
static constexpr double	fpstokts = 1.0 / ktstofps
static constexpr double	inchtoft = 1.0/12.0
static constexpr double	fttom = 0.3048
static constexpr double	m3toft3 = 1.0/(fttom*fttom*fttom)
static constexpr double	in3tom3 = inchtoft*inchtoft*inchtoft/m3toft3
static constexpr double	inhgtopa = 3386.38
static constexpr double	slugtolb = 32.174049
	Note that definition of lbtoslug by the inverse of slugtolb and not to a different constant you can also get from some tables will make lbtoslug*slugtolb == 1 up to the magnitude of roundoff. More...
static constexpr double	lbtoslug = 1.0/slugtolb
static constexpr double	kgtolb = 2.20462
static constexpr double	kgtoslug = 0.06852168
static const std::string	needed_cfg_version = "2.0"
static const std::string	JSBSim_version = JSBSIM_VERSION " " __DATE__ " " __TIME__
static int	gaussian_random_number_phase = 0

Member Function Documentation

GetDsCmd()

double GetDsCmd ( void  ) const

inline

Gets the steering command.

Returns

steering command in range from -1.0 - 1.0

Definition at line 114 of file FGGroundReactions.h.

{ return DsCmd; }

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GetGearUnit()

FGLGear* GetGearUnit ( int  gear ) const

inline

Gets a gear instance.

Parameters

gear	index of gear instance

Returns

a pointer to the FGLGear instance of the gear unit requested

Definition at line 110 of file FGGroundReactions.h.

{ return lGear[gear]; }

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GetNumGearUnits()

int GetNumGearUnits ( void  ) const

inline

Gets the number of gears.

Returns

the number of gears of the aircraft.

Definition at line 105 of file FGGroundReactions.h.

{ return (int)lGear.size(); }

Run()

bool Run ( bool  Holding )

overridevirtual

Runs the Ground Reactions model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.

Parameters

Holding

if true, the executive has been directed to hold the sim from advancing time. Some models may ignore this flag, such as the Input model, which may need to be active to listen on a socket for the "Resume" command to be given.

Returns

false if no error

Reimplemented from FGModel.

Definition at line 94 of file FGGroundReactions.cpp.

{
  if (FGModel::Run(Holding)) return true;
  if (Holding) return false;
 
  RunPreFunctions();
 
  vForces.InitMatrix();
  vMoments.InitMatrix();
 
  multipliers.clear();
 
  // Sum forces and moments for all gear, here.
  // Some optimizations may be made here - or rather in the gear code itself.
  // The gear ::Run() method is called several times - once for each gear.
  // Perhaps there is some commonality for things which only need to be
  // calculated once.
  for (unsigned int i=0; i<lGear.size(); i++) {
    vForces  += lGear[i]->GetBodyForces(this);
    vMoments += lGear[i]->GetMoments();
  }
 
  RunPostFunctions();
 
  return false;
}

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SetDsCmd()

void SetDsCmd

(

double

cmd

)

Sets the steering command.

Parameters

cmd	steering command in percent

Definition at line 137 of file FGGroundReactions.cpp.

{
  DsCmd = cmd;
  for (unsigned int i=0; i<lGear.size(); ++i)
    lGear[i]->SetSteerCmd(cmd);
}

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---

The documentation for this class was generated from the following files:

• FGGroundReactions.h
• FGGroundReactions.cpp