FlightGear: JSBSim::FGGroundReactions Class Reference

Manages ground reactions modeling. More...

#include <FGGroundReactions.h>

Inherits JSBSim::FGModel, and JSBSim::FGSurface.

Public Member Functions
	FGGroundReactions (FGFDMExec *)

	~FGGroundReactions (void) override

bool	InitModel (void) override

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.

bool	Load (Element *el) override

const FGColumnVector3 &	GetForces (void) const

double	GetForces (int idx) const

const FGColumnVector3 &	GetMoments (void) const

double	GetMoments (int idx) const

std::string	GetGroundReactionStrings (std::string delimeter) const

std::string	GetGroundReactionValues (std::string delimeter) const

bool	GetWOW (void) const

int	GetNumGearUnits (void) const
	Gets the number of gears.

FGLGear *	GetGearUnit (int gear) const
	Gets a gear instance.

double	GetDsCmd (void) const
	Gets the steering command.

void	SetDsCmd (double cmd)
	Sets the steering command.

void	RegisterLagrangeMultiplier (LagrangeMultiplier *lmult)

std::vector< LagrangeMultiplier * > *	GetMultipliersList (void)

Public Member Functions inherited from JSBSim::FGModel
	FGModel (FGFDMExec *)
	Constructor.

	~FGModel () override
	Destructor.

bool	InitModel (void) override

void	SetRate (unsigned int tt)
	Set the ouput rate for the model in frames.

unsigned int	GetRate (void)
	Get the output rate for the model in frames.

FGFDMExec *	GetExec (void)

void	SetPropertyManager (FGPropertyManager *fgpm)

virtual SGPath	FindFullPathName (const SGPath &path) const

const std::string &	GetName (void)

Public Member Functions inherited from JSBSim::FGModelFunctions
virtual	~FGModelFunctions ()

void	RunPreFunctions (void)

void	RunPostFunctions (void)

bool	Load (Element el, FGFDMExec fdmex, std::string prefix="")

void	PreLoad (Element el, FGFDMExec fdmex, std::string prefix="")

void	PostLoad (Element el, FGFDMExec fdmex, std::string prefix="")

std::string	GetFunctionStrings (const std::string &delimeter) const
	Gets the strings for the current set of functions.

std::string	GetFunctionValues (const std::string &delimeter) const
	Gets the function values.

FGFunction *	GetPreFunction (const std::string &name)
	Get one of the "pre" function.

Public Member Functions inherited from JSBSim::FGJSBBase
	FGJSBBase ()
	Constructor for FGJSBBase.

virtual	~FGJSBBase ()
	Destructor for FGJSBBase.

void	PutMessage (const Message &msg)
	Places a Message structure on the Message queue.

void	PutMessage (const std::string &text)
	Creates a message with the given text and places it on the queue.

void	PutMessage (const std::string &text, bool bVal)
	Creates a message with the given text and boolean value and places it on the queue.

void	PutMessage (const std::string &text, int iVal)
	Creates a message with the given text and integer value and places it on the queue.

void	PutMessage (const std::string &text, double dVal)
	Creates a message with the given text and double value and places it on the queue.

int	SomeMessages (void) const
	Reads the message on the queue (but does not delete it).

void	ProcessMessage (void)
	Reads the message on the queue and removes it from the queue.

Message *	ProcessNextMessage (void)
	Reads the next message on the queue and removes it from the queue.

void	disableHighLighting (void)
	Disables highlighting in the console output.

Public Member Functions inherited from JSBSim::FGSurface
	FGSurface (FGFDMExec *fdmex, int number=-1)
	Constructor.

	~FGSurface ()
	Destructor.

void	bind (void)

void	resetValues (void)
	Reset all surface values to a default.

void	SetStaticFFactor (double friction)
	Sets the static friction factor of the surface area.

void	SetRollingFFactor (double friction)
	Sets the rolling friction factor of the surface area.

void	SetMaximumForce (double force)
	Sets the maximum force for the surface area.

void	SetBumpiness (double bump)
	Sets the normalized bumpiness factor associated with the surface.

void	SetSolid (bool solid)
	Sets the surface is a solid flag value.

void	SetPosition (const double pt[3])
	Set the currect position for bumpiness calulcation.

void	SetBumpHeight (float height)
	Sets the height of the bump at the provided offset.

double	GetStaticFFactor (void)
	Gets the static friction factor of the surface area.

double	GetRollingFFactor (void)
	Gets the rolling friction factor of the surface area.

double	GetMaximumForce (void)
	Gets the maximum force of the surface area.

double	GetBumpiness (void)
	Gets the normalized bumpiness factor associated with the surface.

bool	GetSolid (void)
	Gets the surface is a solid flag value.

float	GetBumpHeight ()
	Returns the height of the bump at the provided offset.

std::string	GetSurfaceStrings (std::string delimeter) const

std::string	GetSurfaceValues (std::string delimeter) const

Public Attributes
FGLGear::Inputs	in

Additional Inherited Members
Public Types inherited from JSBSim::FGJSBBase
enum	{ eL = 1 , eM , eN }
	Moments L, M, N. More...

enum	{ eP = 1 , eQ , eR }
	Rates P, Q, R. More...

enum	{ eU = 1 , eV , eW }
	Velocities U, V, W. More...

enum	{ eX = 1 , eY , eZ }
	Positions X, Y, Z. More...

enum	{ ePhi = 1 , eTht , ePsi }
	Euler angles Phi, Theta, Psi. More...

enum	{ eDrag = 1 , eSide , eLift }
	Stability axis forces, Drag, Side force, Lift. More...

enum	{ eRoll = 1 , ePitch , eYaw }
	Local frame orientation Roll, Pitch, Yaw. More...

enum	{ eNorth = 1 , eEast , eDown }
	Local frame position North, East, Down. More...

enum	{ eLat = 1 , eLong , eRad }
	Locations Radius, Latitude, Longitude. More...

enum	{ inNone = 0 , inDegrees , inRadians , inMeters , inFeet }
	Conversion specifiers. More...

Public Types inherited from JSBSim::FGSurface
enum	ContactType { ctBOGEY , ctSTRUCTURE , ctGROUND }

static const std::string &	GetVersion (void)
	Returns the version number of JSBSim.

static constexpr double	KelvinToFahrenheit (double kelvin)
	Converts from degrees Kelvin to degrees Fahrenheit.

static constexpr double	CelsiusToRankine (double celsius)
	Converts from degrees Celsius to degrees Rankine.

static constexpr double	RankineToCelsius (double rankine)
	Converts from degrees Rankine to degrees Celsius.

static constexpr double	KelvinToRankine (double kelvin)
	Converts from degrees Kelvin to degrees Rankine.

static constexpr double	RankineToKelvin (double rankine)
	Converts from degrees Rankine to degrees Kelvin.

static constexpr double	FahrenheitToCelsius (double fahrenheit)
	Converts from degrees Fahrenheit to degrees Celsius.

static constexpr double	CelsiusToFahrenheit (double celsius)
	Converts from degrees Celsius to degrees Fahrenheit.

static constexpr double	CelsiusToKelvin (double celsius)
	Converts from degrees Celsius to degrees Kelvin.

static constexpr double	KelvinToCelsius (double kelvin)
	Converts from degrees Kelvin to degrees Celsius.

static constexpr double	FeetToMeters (double measure)
	Converts from feet to meters.

static double	PitotTotalPressure (double mach, double p)
	Compute the total pressure in front of the Pitot tube.

static double	MachFromImpactPressure (double qc, double p)
	Compute the Mach number from the differential pressure (qc) and the static pressure.

static double	VcalibratedFromMach (double mach, double p)
	Calculate the calibrated airspeed from the Mach number.

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).

static bool	EqualToRoundoff (double a, double b)
	Finite precision comparison.

static bool	EqualToRoundoff (float a, float b)
	Finite precision comparison.

static bool	EqualToRoundoff (float a, double b)
	Finite precision comparison.

static bool	EqualToRoundoff (double a, float b)
	Finite precision comparison.

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 JSBSim::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 JSBSim::FGModel
bool	Upload (Element *el, bool preLoad)
	Uploads this model in memory.

static std::string	CreateIndexedPropertyName (const std::string &Property, int index)

Protected Attributes inherited from JSBSim::FGModel
unsigned int	exe_ctr

unsigned int	rate

std::string	Name

FGFDMExec *	FDMExec

FGPropertyManager *	PropertyManager

Protected Attributes inherited from JSBSim::FGModelFunctions
std::vector< FGFunction * >	PreFunctions

std::vector< FGFunction * >	PostFunctions

FGPropertyReader	LocalProperties

Protected Attributes inherited from JSBSim::FGSurface
ContactType	eSurfaceType = ctBOGEY

double	staticFFactor = 1.0

double	rollingFFactor = 1.0

double	maximumForce = DBL_MAX

double	bumpiness = 0.0

bool	isSolid = true

double	staticFCoeff = 1.0

double	dynamicFCoeff = 1.0

static Message	localMsg

static std::queue< Message >	Messages

static unsigned int	messageId = 0

static constexpr double	radtodeg = 180. / 3.14159265358979323846

static constexpr double	degtorad = 3.14159265358979323846 / 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/(fttomfttomfttom)

static constexpr double	in3tom3 = inchtoftinchtoftinchtoft/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.

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

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.

Constructor & Destructor Documentation

◆ FGGroundReactions()

JSBSim::FGGroundReactions::FGGroundReactions ( FGFDMExec * fgex )

Definition at line 52 of file FGGroundReactions.cpp.

◆ ~FGGroundReactions()

JSBSim::FGGroundReactions::~FGGroundReactions ( void )

override

Definition at line 66 of file FGGroundReactions.cpp.

Member Function Documentation

◆ GetDsCmd()

double JSBSim::FGGroundReactions::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.

◆ GetForces() [1/2]

double JSBSim::FGGroundReactions::GetForces ( int idx ) const

inline

Definition at line 96 of file FGGroundReactions.h.

◆ GetForces() [2/2]

const FGColumnVector3 & JSBSim::FGGroundReactions::GetForces ( void ) const

inline

Definition at line 95 of file FGGroundReactions.h.

◆ GetGearUnit()

FGLGear * JSBSim::FGGroundReactions::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.

◆ GetGroundReactionStrings()

string JSBSim::FGGroundReactions::GetGroundReactionStrings ( std::string delimeter ) const

Definition at line 175 of file FGGroundReactions.cpp.

◆ GetGroundReactionValues()

string JSBSim::FGGroundReactions::GetGroundReactionValues ( std::string delimeter ) const

Definition at line 216 of file FGGroundReactions.cpp.

◆ GetMoments() [1/2]

double JSBSim::FGGroundReactions::GetMoments ( int idx ) const

inline

Definition at line 98 of file FGGroundReactions.h.

◆ GetMoments() [2/2]

const FGColumnVector3 & JSBSim::FGGroundReactions::GetMoments ( void ) const

inline

Definition at line 97 of file FGGroundReactions.h.

◆ GetMultipliersList()

std::vector< LagrangeMultiplier * > * JSBSim::FGGroundReactions::GetMultipliersList ( void )

inline

Definition at line 121 of file FGGroundReactions.h.

◆ GetNumGearUnits()

int JSBSim::FGGroundReactions::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.

◆ GetWOW()

bool JSBSim::FGGroundReactions::GetWOW ( void ) const

Definition at line 123 of file FGGroundReactions.cpp.

◆ InitModel()

bool JSBSim::FGGroundReactions::InitModel ( void )

overridevirtual

Reimplemented from JSBSim::FGModelFunctions.

Definition at line 76 of file FGGroundReactions.cpp.

◆ Load()

bool JSBSim::FGGroundReactions::Load ( Element * el )

overridevirtual

Reimplemented from JSBSim::FGModel.

Definition at line 146 of file FGGroundReactions.cpp.

◆ RegisterLagrangeMultiplier()

void JSBSim::FGGroundReactions::RegisterLagrangeMultiplier ( LagrangeMultiplier * lmult )

inline

Definition at line 120 of file FGGroundReactions.h.

◆ Run()

bool JSBSim::FGGroundReactions::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 JSBSim::FGModel.

Definition at line 94 of file FGGroundReactions.cpp.

◆ SetDsCmd()

void JSBSim::FGGroundReactions::SetDsCmd ( double cmd )

Sets the steering command.

Parameters

cmd	steering command in percent

Definition at line 137 of file FGGroundReactions.cpp.

Member Data Documentation

◆ in

FGLGear::Inputs JSBSim::FGGroundReactions::in

Definition at line 123 of file FGGroundReactions.h.

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

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Configuration File Format of <ground_reactions> Section:

Constructor & Destructor Documentation

◆ FGGroundReactions()

◆ ~FGGroundReactions()

Member Function Documentation

◆ GetDsCmd()

◆ GetForces() [1/2]

◆ GetForces() [2/2]

◆ GetGearUnit()

◆ GetGroundReactionStrings()

◆ GetGroundReactionValues()

◆ GetMoments() [1/2]

◆ GetMoments() [2/2]

◆ GetMultipliersList()

◆ GetNumGearUnits()

◆ GetWOW()

◆ InitModel()

◆ Load()

◆ RegisterLagrangeMultiplier()

◆ Run()

◆ SetDsCmd()

Member Data Documentation

◆ in