Detailed Description

Encapsulates a magnetometer component for the flight control system.

Syntax:

<magnetometer name="name">
  <axis> {X|Y|Z} </axis>
  <lag> number </lag>
  <orientation unit=DEG">
    <x> number </x>
    <y> number </y>
    <z> number </z>
  </orientation>
  <noise variation="PERCENT|ABSOLUTE"> number </noise>
  <quantization name="name">
    <bits> number </bits>
    <min> number </min>
    <max> number </max>
  </quantization>
  <drift_rate> number </drift_rate>
  <bias> number </bias>
  <gain> number </gain>
</magnetometer>

Example:

<magnetometer name="aero/magnetometer/X">
  <axis> X </axis>
  <lag> 0.5 </lag>
  <noise variation="PERCENT"> 2 </noise>
  <quantization name="aero/magnetometer/quantized/qbar">
    <bits> 12 </bits>
    <min> 0 </min>
    <max> 400 </max>
  </quantization>
  <bias> 0.5 </bias>
  <gain> 0.5 </gain>
</magnetometer>

The only required element in the magnetometer definition is the axis element. In the default case, no degradation would be modeled, and the output would simply be the input.

For noise, if the type is PERCENT, then the value supplied is understood to be a percentage variance. That is, if the number given is 0.05, the the variance is understood to be +/-0.05 percent maximum variance. So, the actual value for the magnetometer will be anywhere from 0.95 to 1.05 of the actual "perfect" value at any time - even varying all the way from 0.95 to 1.05 in adjacent frames - whatever the delta time.

Author: Jon S. Berndt

Version

Revision: 1.5

Definition at line 121 of file FGMagnetometer.h.

#include <FGMagnetometer.h>

Inheritance diagram for FGMagnetometer:

Collaboration diagram for FGMagnetometer:

Public Member Functions
	FGMagnetometer (FGFCS fcs, Element element)

void	ResetPastStates (void) override

bool	Run (void) override

Public Member Functions inherited from FGSensor
	FGSensor (FGFCS fcs, Element element)

double	GetFailHigh (void) const

double	GetFailLow (void) const

double	GetFailStuck (void) const

int	GetQuantized (void) const

void	ResetPastStates (void) override

bool	Run (void) override

void	SetFailHigh (double val)

void	SetFailLow (double val)

void	SetFailStuck (double val)

Public Member Functions inherited from FGFCSComponent
	FGFCSComponent (FGFCS fcs, Element el)
	Constructor.

virtual	~FGFCSComponent ()
	Destructor.

std::string	GetName (void) const

double	GetOutput (void) const

virtual double	GetOutputPct (void) const

std::string	GetType (void) const

virtual void	SetOutput (void)

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

virtual	~FGJSBBase ()
	Destructor for FGJSBBase.

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

Public Member Functions inherited from FGSensorOrientation
	FGSensorOrientation (Element *element)

Additional Inherited Members
Public Types inherited from 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...

Static Public Member Functions inherited from FGJSBBase
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 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 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 Types inherited from FGSensor
enum	eDistributionType { eUniform =0 , eGaussian }

enum	eNoiseType { ePercent =0 , eAbsolute }

Protected Member Functions inherited from FGSensor
void	Bias (void)

void	bind (Element el, FGPropertyManager pm) override

void	Drift (void)

void	Gain (void)

void	Lag (void)

void	Noise (void)

void	ProcessSensorSignal (void)

void	Quantize (void)

Protected Member Functions inherited from FGFCSComponent
void	CheckInputNodes (size_t MinNodes, size_t MaxNodes, Element *el)

void	Clip (void)

void	Delay (void)

Protected Member Functions inherited from FGSensorOrientation
void	CalculateTransformMatrix (void)

Static Protected Member Functions inherited from FGJSBBase
static std::string	CreateIndexedPropertyName (const std::string &Property, int index)

Protected Attributes inherited from FGSensor
double	bias

int	bits

double	ca

double	cb
	lag filter coefficient "a"

enum JSBSim::FGSensor::eDistributionType	DistributionType

int	divisions

double	drift

double	drift_rate

bool	fail_high

bool	fail_low

bool	fail_stuck

double	gain

double	granularity

double	lag

double	max

double	min

int	noise_type

double	noise_variance

enum JSBSim::FGSensor::eNoiseType	NoiseType

double	PreviousInput

double	PreviousOutput
	lag filter coefficient "b"

std::string	quant_property

int	quantized

double	span

Protected Attributes inherited from FGFCSComponent
bool	clip

FGParameter_ptr	ClipMax

FGParameter_ptr	ClipMin

bool	cyclic_clip

unsigned int	delay

double	delay_time

double	dt

FGFCS *	fcs

int	index

std::vector< FGPropertyValue_ptr >	InitNodes

double	Input

std::vector< FGPropertyValue_ptr >	InputNodes

std::string	Name

double	Output

std::vector< double >	output_array

std::vector< FGPropertyNode_ptr >	OutputNodes

std::string	Type

Protected Attributes inherited from FGSensorOrientation
int	axis

FGMatrix33	mT

FGColumnVector3	vOrient

Static Protected Attributes inherited from FGJSBBase
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	fttom = 0.3048

static constexpr double	ktstofps = 1852./(3600*fttom)

static constexpr double	fpstokts = 1.0 / ktstofps

static constexpr double	inchtoft = 1.0/12.0

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__

Constructor & Destructor Documentation

◆ FGMagnetometer()

FGMagnetometer	(	FGFCS *	fcs,
		Element *	element
	)

Definition at line 54 of file FGMagnetometer.cpp.

  : FGSensor(fcs, element), FGSensorOrientation(element), counter(0),
    INERTIAL_UPDATE_RATE(1000)
{
  Propagate = fcs->GetExec()->GetPropagate();
  MassBalance = fcs->GetExec()->GetMassBalance();
  Inertial = fcs->GetExec()->GetInertial();
  
  Element* location_element = element->FindElement("location");
  if (location_element)
    vLocation = location_element->FindElementTripletConvertTo("IN");
  else {
    cerr << element->ReadFrom()
         << "No location given for magnetometer. " << endl;
    throw("Malformed magnetometer specification.");
  }
 
  vRadius = MassBalance->StructuralToBody(vLocation);
 
  //assuming date wont significantly change over a flight to affect mag field
  //would be better to get the date from the sim if its simulated...
  time_t rawtime;
  time( &rawtime );
  struct tm ptm;
  #if defined(_MSC_VER) || defined(__MINGW32__)
  gmtime_s(&ptm, &rawtime);
  #else
  gmtime_r(&rawtime, &ptm);
  #endif
 
  int year = ptm.tm_year;
  if(year>100)
  {
    year-= 100;
  }
  //the months here are zero based TODO find out if the function expects 1s based
  date = (yymmdd_to_julian_days(ptm.tm_year, ptm.tm_mon, ptm.tm_mday)); //Julian 1950-2049 yy,mm,dd
  updateInertialMag();
 
  Debug(0);
}

◆ ~FGMagnetometer()

~FGMagnetometer ( )

Definition at line 97 of file FGMagnetometer.cpp.

{
  Debug(1);
}

Member Function Documentation

◆ ResetPastStates()

void ResetPastStates ( void )

overridevirtual

Reimplemented from FGFCSComponent.

Definition at line 104 of file FGMagnetometer.cpp.

{
  FGSensor::ResetPastStates();
  counter = 0;
}

◆ Run()

bool Run ( void )

overridevirtual

Reimplemented from FGFCSComponent.

Definition at line 127 of file FGMagnetometer.cpp.

{
  // There is no input assumed. This is a dedicated magnetic field sensor.
  
  vRadius = MassBalance->StructuralToBody(vLocation);
 
  updateInertialMag();
 
  // Inertial magnetic field rotated to the body frame
  vMag = Propagate->GetTl2b() * FGColumnVector3(field[3], field[4], field[5]);
 
  // Allow for sensor orientation
  vMag = mT * vMag;
  
  Input = vMag(axis);
 
  ProcessSensorSignal();
 
  SetOutput();
 
  return true;
}

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