FlightGear: JSBSim::FGInertial Class Reference

Models inertial forces (e.g. More...

#include <FGInertial.h>

Classes
struct	Inputs

Public Types
enum	eGravType { gtStandard , gtWGS84 }
	These define the indices use to select the gravitation models. More...

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 Member Functions
	FGInertial (FGFDMExec *)

	~FGInertial (void)

bool	Run (bool Holding) override
	Runs the Inertial model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.

const FGColumnVector3 &	GetGravity (void) const

const FGColumnVector3 &	GetOmegaPlanet () const

void	SetOmegaPlanet (double rate)

double	GetSemimajor (void) const

double	GetSemiminor (void) const

void	SetGroundCallback (FGGroundCallback *gc)
	Sets the ground callback pointer.

int	GetGravityType (void) const
	Get the gravity type.

void	SetGravityType (int gt)
	Set the gravity type.

FGMatrix33	GetTl2ec (const FGLocation &location) const
	Transform matrix from the local horizontal frame to earth centered.

FGMatrix33	GetTec2l (const FGLocation &location) const
	Transform matrix from the earth centered to local horizontal frame.

bool	Load (Element *el) override

Functions that rely on the ground callback
The following functions allow to set and get the vehicle position above the ground. The ground level is obtained by interrogating an instance of FGGroundCallback. A ground callback must therefore be set with SetGroundCallback() before calling any of these functions.
double	GetContactPoint (const FGLocation &location, FGLocation &contact, FGColumnVector3 &normal, FGColumnVector3 &velocity, FGColumnVector3 &ang_velocity) const
	Get terrain contact point information below the current location.

double	GetAltitudeAGL (const FGLocation &location) const
	Get the altitude above ground level.

void	SetAltitudeAGL (FGLocation &location, double altitudeAGL)
	Set the altitude above ground level.

void	SetTerrainElevation (double h)
	Set the terrain elevation above sea level.

void	SetTime (double time)
	Set the simulation time.

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.

Static Public Member Functions
static constexpr double	GetStandardGravity (void)

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)

Public Attributes
struct JSBSim::FGInertial::Inputs	in

Additional Inherited Members
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

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

Models inertial forces (e.g.

centripetal and coriolis accelerations). Starting conversion to WGS84.

Definition at line 65 of file FGInertial.h.

Member Enumeration Documentation

◆ eGravType

enum JSBSim::FGInertial::eGravType

These define the indices use to select the gravitation models.

Enumerator
gtStandard	Evaluate gravity using Newton's classical formula assuming the Earth is spherical.
gtWGS84	Evaluate gravity using WGS84 formulas that take the Earth oblateness into account.

Definition at line 153 of file FGInertial.h.

Constructor & Destructor Documentation

◆ FGInertial()

JSBSim::FGInertial::FGInertial ( FGFDMExec * fgex )

explicit

Definition at line 50 of file FGInertial.cpp.

◆ ~FGInertial()

JSBSim::FGInertial::~FGInertial ( void )

Definition at line 82 of file FGInertial.cpp.

Member Function Documentation

◆ GetAltitudeAGL()

double JSBSim::FGInertial::GetAltitudeAGL ( const FGLocation & location ) const

inline

Get the altitude above ground level.

Returns: the altitude AGL in feet.

Parameters

location Location at which the AGL is evaluated.

See also: SetGroundCallback

Definition at line 114 of file FGInertial.h.

◆ GetContactPoint()

double JSBSim::FGInertial::GetContactPoint	(	const FGLocation &	location,
		FGLocation &	contact,
		FGColumnVector3 &	normal,
		FGColumnVector3 &	velocity,
		FGColumnVector3 &	ang_velocity ) const

inline

Get terrain contact point information below the current location.

Parameters

location	Location at which the contact point is evaluated.
contact	Contact point location
normal	Terrain normal vector in contact point (ECEF frame)
velocity	Terrain linear velocity in contact point (ECEF frame)
ang_velocity	Terrain angular velocity in contact point (ECEF frame)

Returns: Location altitude above contact point (AGL) in feet.

See also: SetGroundCallback

Definition at line 103 of file FGInertial.h.

◆ GetGravity()

const FGColumnVector3 & JSBSim::FGInertial::GetGravity ( void ) const

inline

Definition at line 81 of file FGInertial.h.

◆ GetGravityType()

int JSBSim::FGInertial::GetGravityType ( void ) const

inline

Get the gravity type.

Definition at line 163 of file FGInertial.h.

◆ GetOmegaPlanet()

const FGColumnVector3 & JSBSim::FGInertial::GetOmegaPlanet ( ) const

inline

Definition at line 82 of file FGInertial.h.

◆ GetSemimajor()

double JSBSim::FGInertial::GetSemimajor ( void ) const

inline

Definition at line 86 of file FGInertial.h.

◆ GetSemiminor()

double JSBSim::FGInertial::GetSemiminor ( void ) const

inline

Definition at line 87 of file FGInertial.h.

◆ GetStandardGravity()

static constexpr double JSBSim::FGInertial::GetStandardGravity ( void )

inlinestaticconstexpr

Definition at line 80 of file FGInertial.h.

◆ GetTec2l()

FGMatrix33 JSBSim::FGInertial::GetTec2l ( const FGLocation & location ) const

inline

Transform matrix from the earth centered to local horizontal frame.

The local frame is the NED (North-East-Down) frame. Since the Down direction depends on the gravity so is the local frame. The East direction is tangent to the spheroid with a null component along the Z axis. The North direction is obtained from the cross product between East and Down.

Parameters

location The location at which the transform matrix must be evaluated.

Returns: a rotation matrix of the transform from the earth centered frame to the local horizontal frame.

Definition at line 194 of file FGInertial.h.

◆ GetTl2ec()

FGMatrix33 JSBSim::FGInertial::GetTl2ec ( const FGLocation & location ) const

Transform matrix from the local horizontal frame to earth centered.

Parameters

location The location at which the transform matrix must be evaluated.

Returns: a rotation matrix of the transform from the earth centered frame to the local horizontal frame.

Definition at line 151 of file FGInertial.cpp.

◆ Load()

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

overridevirtual

Reimplemented from JSBSim::FGModel.

Definition at line 89 of file FGInertial.cpp.

◆ Run()

bool JSBSim::FGInertial::Run ( bool Holding )

overridevirtual

Runs the Inertial 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 127 of file FGInertial.cpp.

◆ SetAltitudeAGL()

void JSBSim::FGInertial::SetAltitudeAGL	(	FGLocation &	location,
		double	altitudeAGL )

Set the altitude above ground level.

Parameters

location	Location at which the AGL is set.
altitudeAGL	Altitude above Ground Level in feet.

See also: SetGroundCallback

Definition at line 216 of file FGInertial.cpp.

◆ SetGravityType()

void JSBSim::FGInertial::SetGravityType ( int gt )

Set the gravity type.

Definition at line 231 of file FGInertial.cpp.

◆ SetGroundCallback()

void JSBSim::FGInertial::SetGroundCallback ( FGGroundCallback * gc )

inline

Sets the ground callback pointer.

FGInertial will take ownership of the pointer which must therefore be located in the heap.

Parameters

gc	A pointer to a ground callback object

See also: FGGroundCallback

Definition at line 150 of file FGInertial.h.

◆ SetOmegaPlanet()

void JSBSim::FGInertial::SetOmegaPlanet ( double rate )

inline

Definition at line 83 of file FGInertial.h.

◆ SetTerrainElevation()

void JSBSim::FGInertial::SetTerrainElevation ( double h )

inline

Set the terrain elevation above sea level.

Parameters

h	Terrain elevation in ft.

See also: SetGroundcallback

Definition at line 130 of file FGInertial.h.

◆ SetTime()

void JSBSim::FGInertial::SetTime ( double time )

inline

Set the simulation time.

The elapsed time can be used by the ground callbck to assess the planet rotation or the movement of objects.

Parameters

time	elapsed time in seconds since the simulation started.

Definition at line 139 of file FGInertial.h.

Member Data Documentation

◆ in

struct JSBSim::FGInertial::Inputs JSBSim::FGInertial::in

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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ eGravType

Constructor & Destructor Documentation

◆ FGInertial()

◆ ~FGInertial()

Member Function Documentation

◆ GetAltitudeAGL()

◆ GetContactPoint()

◆ GetGravity()

◆ GetGravityType()

◆ GetOmegaPlanet()

◆ GetSemimajor()

◆ GetSemiminor()

◆ GetStandardGravity()

◆ GetTec2l()

◆ GetTl2ec()

◆ Load()

◆ Run()

◆ SetAltitudeAGL()

◆ SetGravityType()

◆ SetGroundCallback()

◆ SetOmegaPlanet()

◆ SetTerrainElevation()

◆ SetTime()

Member Data Documentation

◆ in