FlightGear next
JSBSim::FGAccelerations Class Reference

#include <FGAccelerations.h>

Inherits JSBSim::FGModel.

Classes

struct  Inputs
 

Public Member Functions

 FGAccelerations (FGFDMExec *Executive)
 Constructor.
 
 ~FGAccelerations ()
 Destructor.
 
bool InitModel (void) override
 Initializes the FGAccelerations class after instantiation and prior to first execution.
 
bool Run (bool Holding) override
 Runs the state propagation model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.
 
const FGColumnVector3GetUVWdot (void) const
 Retrieves the body axis acceleration.
 
const FGColumnVector3GetUVWidot (void) const
 Retrieves the body axis acceleration in the ECI frame.
 
const FGColumnVector3GetPQRdot (void) const
 Retrieves the body axis angular acceleration vector.
 
const FGColumnVector3GetPQRidot (void) const
 Retrieves the axis angular acceleration vector in the ECI frame.
 
double GetUVWdot (int idx) const
 Retrieves a body frame acceleration component.
 
const FGColumnVector3GetBodyAccel (void) const
 Retrieves the acceleration resulting from the applied forces.
 
double GetGravAccelMagnitude (void) const
 
double GetBodyAccel (int idx) const
 Retrieves a component of the acceleration resulting from the applied forces.
 
double GetPQRdot (int axis) const
 Retrieves a body frame angular acceleration component.
 
double GetMoments (int idx) const
 Retrieves a component of the total moments applied on the body.
 
FGColumnVector3 GetMoments (void) const
 
double GetForces (int idx) const
 Retrieves the total forces applied on the body.
 
FGColumnVector3 GetForces (void) const
 
double GetGroundMoments (int idx) const
 Retrieves the ground moments applied on the body.
 
FGColumnVector3 GetGroundMoments (void) const
 
double GetGroundForces (int idx) const
 Retrieves the ground forces applied on the body.
 
FGColumnVector3 GetGroundForces (void) const
 
double GetWeight (int idx) const
 Retrieves the weight applied on the body.
 
FGColumnVector3 GetWeight (void) const
 
void InitializeDerivatives (void)
 Initializes the FGAccelerations class prior to a new execution.
 
void SetHoldDown (bool hd)
 Sets the property forces/hold-down.
 
- 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.
 
FGFDMExecGetExec (void)
 
void SetPropertyManager (FGPropertyManager *fgpm)
 
virtual SGPath FindFullPathName (const SGPath &path) const
 
const std::string & GetName (void)
 
virtual bool Load (Element *el)
 
- 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.
 
FGFunctionGetPreFunction (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.
 
MessageProcessNextMessage (void)
 Reads the next message on the queue and removes it from the queue.
 
void disableHighLighting (void)
 Disables highlighting in the console output.
 

Public Attributes

struct JSBSim::FGAccelerations::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...
 
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
 
FGFDMExecFDMExec
 
FGPropertyManagerPropertyManager
 
- Protected Attributes inherited from JSBSim::FGModelFunctions
std::vector< FGFunction * > PreFunctions
 
std::vector< FGFunction * > PostFunctions
 
FGPropertyReader LocalProperties
 
static Message localMsg
 
static std::queue< MessageMessages
 
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/(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.
 
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

Definition at line 95 of file FGAccelerations.h.

Constructor & Destructor Documentation

◆ FGAccelerations()

JSBSim::FGAccelerations::FGAccelerations ( FGFDMExec * Executive)
explicit

Constructor.

Parameters
Executivea pointer to the parent executive object

Definition at line 67 of file FGAccelerations.cpp.

◆ ~FGAccelerations()

JSBSim::FGAccelerations::~FGAccelerations ( void )

Destructor.

Definition at line 85 of file FGAccelerations.cpp.

Member Function Documentation

◆ GetBodyAccel() [1/2]

double JSBSim::FGAccelerations::GetBodyAccel ( int idx) const
inline

Retrieves a component of the acceleration resulting from the applied forces.

Retrieves a component of the ratio between the sum of all forces applied on the craft to its mass. The value returned is extracted from the vBodyAccel vector (an FGColumnVector3). The vector for the acceleration in Body frame is organized (Ax, Ay, Az). The vector is 1-based. In other words, GetBodyAccel(1) returns Ax. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eX=1, eY=2, eZ=3. units ft/sec^2

Parameters
idxthe index of the acceleration component desired (1-based).
Returns
The component of the acceleration resulting from the applied forces.

Definition at line 219 of file FGAccelerations.h.

◆ GetBodyAccel() [2/2]

const FGColumnVector3 & JSBSim::FGAccelerations::GetBodyAccel ( void ) const
inline

Retrieves the acceleration resulting from the applied forces.

Retrieves the ratio of the sum of all forces applied on the craft to its mass. This does include the friction forces but not the gravity. The vector returned is represented by an FGColumnVector3 reference. The vector for the acceleration in Body frame is organized (Ax, Ay, Az). The vector is 1-based, so that the first element can be retrieved using the "()" operator. In other words, vBodyAccel(1) is Ax. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eX=1, eY=2, eZ=3. units ft/sec^2

Returns
The acceleration resulting from the applied forces.

Definition at line 203 of file FGAccelerations.h.

◆ GetForces() [1/2]

double JSBSim::FGAccelerations::GetForces ( int idx) const
inline

Retrieves the total forces applied on the body.

Retrieves the total forces applied on the body. This does include the friction forces but not the gravity. The vector for the total forces in the body frame is organized (Fx, Fy , Fz). The vector is 1-based. In other words, GetForces(1) returns Fx. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the forces returned by this call are, eX=1, eY=2, eZ=3. units lbs

Parameters
idxthe index of the forces component desired (1-based).
Returns
The total forces applied on the body.

Definition at line 261 of file FGAccelerations.h.

◆ GetForces() [2/2]

FGColumnVector3 JSBSim::FGAccelerations::GetForces ( void ) const
inline

Definition at line 262 of file FGAccelerations.h.

◆ GetGravAccelMagnitude()

double JSBSim::FGAccelerations::GetGravAccelMagnitude ( void ) const
inline

Definition at line 205 of file FGAccelerations.h.

◆ GetGroundForces() [1/2]

double JSBSim::FGAccelerations::GetGroundForces ( int idx) const
inline

Retrieves the ground forces applied on the body.

Retrieves the ground forces applied on the body. This does include the ground normal reaction and friction forces. The vector for the ground forces in the body frame is organized (Fx, Fy , Fz). The vector is 1-based. In other words, GetGroundForces(1) returns Fx. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the forces returned by this call are, eX=1, eY=2, eZ=3. units lbs.

Parameters
idxthe index of the forces component desired (1-based).
Returns
The ground forces applied on the body.

Definition at line 289 of file FGAccelerations.h.

◆ GetGroundForces() [2/2]

FGColumnVector3 JSBSim::FGAccelerations::GetGroundForces ( void ) const
inline

Definition at line 290 of file FGAccelerations.h.

◆ GetGroundMoments() [1/2]

double JSBSim::FGAccelerations::GetGroundMoments ( int idx) const
inline

Retrieves the ground moments applied on the body.

Retrieves the ground moments applied on the body. This does include the ground normal reaction and friction moments. The vector for the ground moments in the body frame is organized (Mx, My , Mz). The vector is 1-based. In other words, GetGroundMoments(1) returns Mx. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the moments returned by this call are, eX=1, eY=2, eZ=3. units lbs*ft

Parameters
idxthe index of the moments component desired (1-based).
Returns
The ground moments applied on the body.

Definition at line 275 of file FGAccelerations.h.

◆ GetGroundMoments() [2/2]

FGColumnVector3 JSBSim::FGAccelerations::GetGroundMoments ( void ) const
inline

Definition at line 276 of file FGAccelerations.h.

◆ GetMoments() [1/2]

double JSBSim::FGAccelerations::GetMoments ( int idx) const
inline

Retrieves a component of the total moments applied on the body.

Retrieves a component of the total moments applied on the body. This does include the moments generated by friction forces and the gravitational torque (if the property simulation/gravitational-torque is set to true). The vector for the total moments in the body frame is organized (Mx, My , Mz). The vector is 1-based. In other words, GetMoments(1) returns Mx. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the moments returned by this call are, eX=1, eY=2, eZ=3. units lbs*ft

Parameters
idxthe index of the moments component desired (1-based).
Returns
The total moments applied on the body.

Definition at line 247 of file FGAccelerations.h.

◆ GetMoments() [2/2]

FGColumnVector3 JSBSim::FGAccelerations::GetMoments ( void ) const
inline

Definition at line 248 of file FGAccelerations.h.

◆ GetPQRdot() [1/2]

double JSBSim::FGAccelerations::GetPQRdot ( int axis) const
inline

Retrieves a body frame angular acceleration component.

Retrieves a body frame angular acceleration component. The angular acceleration returned is extracted from the vPQRdot vector (an FGColumnVector3). The vector for the angular acceleration in Body frame is organized (Pdot, Qdot, Rdot). The vector is 1-based. In other words, GetPQRdot(1) returns Pdot (roll acceleration). Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the angular acceleration returned by this call are, eP=1, eQ=2, eR=3. units rad/sec^2

Parameters
axisthe index of the angular acceleration component desired (1-based).
Returns
The body frame angular acceleration component.

Definition at line 233 of file FGAccelerations.h.

◆ GetPQRdot() [2/2]

const FGColumnVector3 & JSBSim::FGAccelerations::GetPQRdot ( void ) const
inline

Retrieves the body axis angular acceleration vector.

Retrieves the body axis angular acceleration vector in rad/sec^2. The angular acceleration vector is determined from the applied moments and accounts for a rotating frame. The vector returned is represented by an FGColumnVector3 reference. The vector for the angular acceleration in Body frame is organized (Pdot, Qdot, Rdot). The vector is 1-based, so that the first element can be retrieved using the "()" operator. In other words, vPQRdot(1) is Pdot. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eP=1, eQ=2, eR=3. units rad/sec^2

Returns
The angular acceleration vector.

Definition at line 161 of file FGAccelerations.h.

◆ GetPQRidot()

const FGColumnVector3 & JSBSim::FGAccelerations::GetPQRidot ( void ) const
inline

Retrieves the axis angular acceleration vector in the ECI frame.

Retrieves the body axis angular acceleration vector measured in the ECI frame and expressed in the body frame. The angular acceleration vector is determined from the applied moments. The vector returned is represented by an FGColumnVector3 reference. The vector for the angular acceleration in Body frame is organized (Pidot, Qidot, Ridot). The vector is 1-based, so that the first element can be retrieved using the "()" operator. In other words, vPQRidot(1) is Pidot. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eP=1, eQ=2, eR=3. units rad/sec^2

Returns
The angular acceleration vector.

Definition at line 176 of file FGAccelerations.h.

◆ GetUVWdot() [1/2]

double JSBSim::FGAccelerations::GetUVWdot ( int idx) const
inline

Retrieves a body frame acceleration component.

Retrieves a body frame acceleration component. The acceleration returned is extracted from the vUVWdot vector (an FGColumnVector3). The vector for the acceleration in Body frame is organized (Ax, Ay, Az). The vector is 1-based. In other words, GetUVWdot(1) returns Ax. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the acceleration returned by this call are, eX=1, eY=2, eZ=3. units ft/sec^2

Parameters
idxthe index of the acceleration component desired (1-based).
Returns
The body frame acceleration component.

Definition at line 189 of file FGAccelerations.h.

◆ GetUVWdot() [2/2]

const FGColumnVector3 & JSBSim::FGAccelerations::GetUVWdot ( void ) const
inline

Retrieves the body axis acceleration.

Retrieves the computed body axis accelerations based on the applied forces and accounting for a rotating body frame. The vector returned is represented by an FGColumnVector3 reference. The vector for the acceleration in Body frame is organized (Ax, Ay, Az). The vector is 1-based, so that the first element can be retrieved using the "()" operator. In other words, vUVWdot(1) is Ax. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eX=1, eY=2, eZ=3. units ft/sec^2

Returns
Body axis translational acceleration in ft/sec^2.

Definition at line 130 of file FGAccelerations.h.

◆ GetUVWidot()

const FGColumnVector3 & JSBSim::FGAccelerations::GetUVWidot ( void ) const
inline

Retrieves the body axis acceleration in the ECI frame.

Retrieves the computed body axis accelerations based on the applied forces. The ECI frame being an inertial frame this vector does not contain the Coriolis and centripetal accelerations. The vector is expressed in the Body frame. The vector returned is represented by an FGColumnVector3 reference. The vector for the acceleration in Body frame is organized (Aix, Aiy, Aiz). The vector is 1-based, so that the first element can be retrieved using the "()" operator. In other words, vUVWidot(1) is Aix. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the vector returned by this call are, eX=1, eY=2, eZ=3. units ft/sec^2

Returns
Body axis translational acceleration in ft/sec^2.

Definition at line 146 of file FGAccelerations.h.

◆ GetWeight() [1/2]

double JSBSim::FGAccelerations::GetWeight ( int idx) const
inline

Retrieves the weight applied on the body.

Retrieves the weight applied on the body i.e. the force that results from the gravity applied to the body mass. The vector for the weight forces in the body frame is organized (Fx, Fy , Fz). The vector is 1-based. In other words, GetWeight(1) returns Fx. Various convenience enumerators are defined in FGJSBBase. The relevant enumerators for the forces returned by this call are, eX=1, eY=2, eZ=3. units lbs.

Parameters
idxthe index of the forces component desired (1-based).
Returns
The ground forces applied on the body.

Definition at line 303 of file FGAccelerations.h.

◆ GetWeight() [2/2]

FGColumnVector3 JSBSim::FGAccelerations::GetWeight ( void ) const
inline

Definition at line 304 of file FGAccelerations.h.

◆ InitializeDerivatives()

void JSBSim::FGAccelerations::InitializeDerivatives ( void )

Initializes the FGAccelerations class prior to a new execution.

Initializes the class prior to a new execution when the input data stored in the Inputs structure have been set to their initial values.

Definition at line 334 of file FGAccelerations.cpp.

◆ InitModel()

bool JSBSim::FGAccelerations::InitModel ( void )
overridevirtual

Initializes the FGAccelerations class after instantiation and prior to first execution.

The base class FGModel::InitModel is called first, initializing pointers to the other FGModel objects (and others).

Reimplemented from JSBSim::FGModelFunctions.

Definition at line 92 of file FGAccelerations.cpp.

◆ Run()

bool JSBSim::FGAccelerations::Run ( bool Holding)
overridevirtual

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

Parameters
Holdingif 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 109 of file FGAccelerations.cpp.

◆ SetHoldDown()

void JSBSim::FGAccelerations::SetHoldDown ( bool hd)

Sets the property forces/hold-down.

This allows to do hard 'hold-down' such as for rockets on a launch pad with engines ignited.

Parameters
hdenables the 'hold-down' function if non-zero

Definition at line 209 of file FGAccelerations.cpp.

Member Data Documentation

◆ in

struct JSBSim::FGAccelerations::Inputs JSBSim::FGAccelerations::in

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