Encapsulates a filter for the flight control system. More...

#include <FGFilter.h>

Inheritance diagram for FGFilter:

Collaboration diagram for FGFilter:

Public Types
enum	{ eLag, eLeadLag, eOrder2, eWashout, eIntegrator, eUnknown }

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 Member Functions
	FGFilter (FGFCS fcs, Element element)

void	ResetPastStates (void)

bool	Run (void)

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

void	SetDtForFrameCount (int FrameCount)

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.

std::string	GetVersion (void)
	Returns the version number of JSBSim. More...

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)
	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...

Public Attributes
enum JSBSim::FGFilter:: { ... }	FilterType

bool	Initialize
	When true, causes previous values to be set to current values. More...

Additional Inherited Members
Static Public Member Functions inherited from FGJSBBase
static double	CelsiusToFahrenheit (double celsius)
	Converts from degrees Celsius to degrees Fahrenheit. More...

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

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

static double	Constrain (double min, double value, double max)
	Constrain a value between a minimum and a maximum value.

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

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

static double	GaussianRandomNumber (void)

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

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

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

static double	MachFromVcalibrated (double vcas, double p, double psl, double rhosl)
	Calculate the Mach number from the calibrated airspeed. More...

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

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

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

static double	sign (double num)

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

Static Public Attributes inherited from FGJSBBase
static short	debug_lvl = 1

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

Protected Member Functions inherited from FGFCSComponent
virtual void	bind ()

void	Clip (void)

void	Delay (void)

Protected Member Functions inherited from FGJSBBase
void	Debug (int)

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

Protected Attributes inherited from FGFCSComponent
bool	clip

double	clipmax

FGPropertyNode_ptr	ClipMaxPropertyNode

float	clipMaxSign

double	clipmin

FGPropertyNode_ptr	ClipMinPropertyNode

float	clipMinSign

unsigned int	delay

double	delay_time

double	dt

FGFCS *	fcs

int	index

std::vector< std::string >	InitNames

std::vector< FGPropertyValue * >	InitNodes

std::vector< float >	InitSigns

double	Input

std::vector< std::string >	InputNames

std::vector< FGPropertyValue * >	InputNodes

std::vector< float >	InputSigns

bool	IsOutput

std::string	Name

double	Output

std::vector< double >	output_array

std::vector< FGPropertyNode_ptr >	OutputNodes

FGPropertyManager *	PropertyManager

FGPropertyNode_ptr	treenode

std::string	Type

Static Protected Attributes inherited from FGJSBBase
static const double	degtorad = 0.017453292519943295769236907684886

static const double	fpstokts = 1.0/ktstofps

static const double	fttom = 0.3048

static int	gaussian_random_number_phase = 0

static const double	hptoftlbssec = 550.0

static const double	in3tom3 = 1.638706E-5

static const double	inchtoft = 0.08333333

static const double	inhgtopa = 3386.38

static const std::string	JSBSim_version = "1.0 " __DATE__ " " __TIME__

static const double	kgtolb = 2.20462

static const double	kgtoslug = 0.06852168

static const double	ktstofps = 1.68781

static const double	lbtoslug = 1.0/slugtolb

static Message	localMsg

static const double	m3toft3 = 1.0/(fttomfttomfttom)

static double	Mair = 28.9645

static unsigned int	messageId = 0

static std::queue< Message >	Messages

static const std::string	needed_cfg_version = "2.0"

static const double	psftoinhg = 0.014138

static const double	psftopa = 47.88

static const double	radtodeg = 57.295779513082320876798154814105

static double	Reng = 1716.56

static double	Rstar = 1545.348

static const double	SHRatio = 1.40

static const double	slugtolb = 32.174049

Detailed Description

Encapsulates a filter for the flight control system.

The filter component can simulate any first or second order filter. The Tustin substitution is used to take filter definitions from LaPlace space to the time domain. The general format for a filter specification is:

<typename name="name">
  <input> property </input>
  <c1> value|property </c1>
  [<c2> value|property </c2>]
  [<c3> value|property </c3>]
  [<c4> value|property </c4>]
  [<c5> value|property </c5>]
  [<c6> value|property </c6>]
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property </output>]
</typename>

For a lag filter of the form,

  C1
------
s + C1

the corresponding filter definition is:

<lag_filter name="name">
  <input> property </input>
  <c1> value|property </c1>
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property <output>]
</lag_filter>

As an example, for the specific filter:

  600
------
s + 600

the corresponding filter definition could be:

<lag_filter name="Heading Roll Error Lag">
  <input> fcs/heading-command </input>
  <c1> 600 </c1>
</lag_filter>

For a lead-lag filter of the form:

C1*s + C2
---------
C3*s + C4

The corresponding filter definition is:

<lead_lag_filter name="name">
  <input> property </input>
  <c1> value|property <c/1>
  <c2> value|property <c/2>
  <c3> value|property <c/3>
  <c4> value|property <c/4>
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property </output>]
</lead_lag_filter>

For a washout filter of the form:

  s
------
s + C1

The corresponding filter definition is:

<washout_filter name="name">
  <input> property </input>
  <c1> value </c1>
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property </output>]
</washout_filter>

For a second order filter of the form:

C1*s^2 + C2*s + C3
------------------
C4*s^2 + C5*s + C6

The corresponding filter definition is:

<second_order_filter name="name">
  <input> property </input>
  <c1> value|property </c1>
  <c2> value|property </c2>
  <c3> value|property </c3>
  <c4> value|property </c4>
  <c5> value|property </c5>
  <c6> value|property </c6>
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property </output>]
</second_order_filter>

For an integrator of the form:

C1
---
 s

The corresponding filter definition is:

<integrator name="name">
  <input> property </input>
  <c1> value|property </c1>
  [<trigger> property </trigger>]
  [<clipto>
    <min> {[-]property name | value} </min>
    <max> {[-]property name | value} </max>
  </clipto>]
  [<output> property </output>]
</integrator>

For the integrator, the trigger features the following behavior. If the trigger property value is:

0: no action is taken - the output is calculated normally
not 0: (or simply greater than zero), all current and previous inputs will be set to 0.0

In all the filter specifications above, an <output> element is also seen. This is so that the last component in a "string" can copy its value to the appropriate output, such as the elevator, or speedbrake, etc.

Author: Jon S. Berndt

Version

Revision: 1.14

Definition at line 239 of file FGFilter.h.

Member Data Documentation

◆ Initialize

bool Initialize

When true, causes previous values to be set to current values.

This is particularly useful for first pass.

Definition at line 249 of file FGFilter.h.

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

Public Types

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Member Data Documentation

◆ Initialize