FGLinearization Class Reference

Detailed Description

Class used to create linear models from FGFDMExec instances.

Definition at line 39 of file FGLinearization.h.

#include <FGLinearization.h>

Public Member Functions
	FGLinearization (FGFDMExec *fdmPtr)
const Vector2D< double > &	GetFeedforwardMatrix () const
const std::vector< double > &	GetInitialInput () const
const std::vector< double > &	GetInitialOutput () const
const std::vector< double > &	GetInitialState () const
const Vector2D< double > &	GetInputMatrix () const
const std::vector< std::string > &	GetInputNames () const
const std::vector< std::string > &	GetInputUnits () const
const Vector2D< double > &	GetOutputMatrix () const
const std::vector< std::string > &	GetOutputNames () const
const std::vector< std::string > &	GetOutputUnits () const
const std::vector< std::string > &	GetStateNames () const
const std::vector< std::string > &	GetStateUnits () const
const Vector2D< double > &	GetSystemMatrix () const
	Get the state space model matrices.
void	WriteScicoslab () const
	Write Scicoslab source file with the state space model to a file in the current working directory.
void	WriteScicoslab (std::string &path) const
	Write Scicoslab source file with the state space model to the given path.

Constructor & Destructor Documentation

FGLinearization()

FGLinearization

(

FGFDMExec *

fdmPtr

)

Parameters

fdmPtr

Already configured FGFDMExec instance used to create the new linear model.

Definition at line 25 of file FGLinearization.cpp.

    : aircraft_name(fdm->GetAircraft()->GetAircraftName())
{
    FGStateSpace ss(fdm);
    ss.x.add(new FGStateSpace::Vt);
    ss.x.add(new FGStateSpace::Alpha);
    ss.x.add(new FGStateSpace::Theta);
    ss.x.add(new FGStateSpace::Q);
 
    // get propulsion pointer to determine type/ etc.
    auto engine0 = fdm->GetPropulsion()->GetEngine(0);
    FGThruster * thruster0 = engine0->GetThruster();
 
    if (thruster0->GetType()==FGThruster::ttPropeller)
    {
        ss.x.add(new FGStateSpace::Rpm0);
        // TODO add variable prop pitch property
        // if (variablePropPitch) ss.x.add(new FGStateSpace::PropPitch);
        int numEngines = fdm->GetPropulsion()->GetNumEngines();
        if (numEngines>1) ss.x.add(new FGStateSpace::Rpm1);
        if (numEngines>2) ss.x.add(new FGStateSpace::Rpm2);
        if (numEngines>3) ss.x.add(new FGStateSpace::Rpm3);
        if (numEngines>4) {
            std::cerr << "more than 4 engines not currently handled" << std::endl;
        }
    }
    ss.x.add(new FGStateSpace::Beta);
    ss.x.add(new FGStateSpace::Phi);
    ss.x.add(new FGStateSpace::P);
    ss.x.add(new FGStateSpace::Psi);
    ss.x.add(new FGStateSpace::R);
    ss.x.add(new FGStateSpace::Latitude);
    ss.x.add(new FGStateSpace::Longitude);
    ss.x.add(new FGStateSpace::Alt);
 
    ss.u.add(new FGStateSpace::ThrottleCmd);
    ss.u.add(new FGStateSpace::DaCmd);
    ss.u.add(new FGStateSpace::DeCmd);
    ss.u.add(new FGStateSpace::DrCmd);
 
    // state feedback
    ss.y = ss.x;
 
    x0 = ss.x.get();
    u0 = ss.u.get();
    y0 = x0; // state feedback
 
    fdm->SuspendIntegration();
    ss.linearize(x0, u0, y0, A, B, C, D);
    fdm->ResumeIntegration();
 
    x_names = ss.x.getName();
    u_names = ss.u.getName();
    y_names = ss.y.getName();
    x_units = ss.x.getUnit();
    u_units = ss.u.getUnit();
    y_units = ss.y.getUnit();
}

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Member Function Documentation

GetFeedforwardMatrix()

const Vector2D< double > & GetFeedforwardMatrix ( ) const

inline

Definition at line 75 of file FGLinearization.h.

{ return D; };

GetInitialInput()

const std::vector< double > & GetInitialInput ( ) const

inline

Definition at line 78 of file FGLinearization.h.

{ return u0; };

GetInitialOutput()

const std::vector< double > & GetInitialOutput ( ) const

inline

Definition at line 79 of file FGLinearization.h.

{ return y0; };

GetInitialState()

const std::vector< double > & GetInitialState ( ) const

inline

Definition at line 77 of file FGLinearization.h.

{ return x0; };

GetInputMatrix()

const Vector2D< double > & GetInputMatrix ( ) const

inline

Definition at line 73 of file FGLinearization.h.

{ return B; };

GetInputNames()

const std::vector< std::string > & GetInputNames ( ) const

inline

Definition at line 82 of file FGLinearization.h.

{ return u_names; };

GetInputUnits()

const std::vector< std::string > & GetInputUnits ( ) const

inline

Definition at line 86 of file FGLinearization.h.

{ return u_units; };

GetOutputMatrix()

const Vector2D< double > & GetOutputMatrix ( ) const

inline

Definition at line 74 of file FGLinearization.h.

{ return C; };

GetOutputNames()

const std::vector< std::string > & GetOutputNames ( ) const

inline

Definition at line 83 of file FGLinearization.h.

{ return y_names; };

GetOutputUnits()

const std::vector< std::string > & GetOutputUnits ( ) const

inline

Definition at line 87 of file FGLinearization.h.

{ return y_units; };

GetStateNames()

const std::vector< std::string > & GetStateNames ( ) const

inline

Definition at line 81 of file FGLinearization.h.

{ return x_names; };

GetStateUnits()

const std::vector< std::string > & GetStateUnits ( ) const

inline

Definition at line 85 of file FGLinearization.h.

{ return x_units; };

GetSystemMatrix()

const Vector2D< double > & GetSystemMatrix ( ) const

inline

Get the state space model matrices.

Parameters

A_	System matrix
B_	Input matrix
C_	Output matrix
D_	Feedforward matrix

Definition at line 72 of file FGLinearization.h.

{ return A; };

WriteScicoslab() [1/2]

void WriteScicoslab

(

)

const

Write Scicoslab source file with the state space model to a file in the current working directory.

Definition at line 84 of file FGLinearization.cpp.

                                           {
    auto path = std::string(aircraft_name+"_lin.sce");
    WriteScicoslab(path);
}

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WriteScicoslab() [2/2]

void WriteScicoslab

(

std::string &

path

)

const

Write Scicoslab source file with the state space model to the given path.

Parameters

path

Definition at line 89 of file FGLinearization.cpp.

                                                          {
    int width=20;
    int precision=10;
    std::ofstream scicos(path.c_str());
    scicos.precision(precision);
    width=20;
    scicos  << std::scientific
            << aircraft_name << ".x0=..\n" << std::setw(width) << x0 << ";\n"
            << aircraft_name << ".u0=..\n" << std::setw(width) << u0 << ";\n"
            << aircraft_name << ".sys = syslin('c',..\n"
            << std::setw(width) << A << ",..\n"
            << std::setw(width) << B << ",..\n"
            << std::setw(width) << C << ",..\n"
            << std::setw(width) << D << ");\n"
            << aircraft_name << ".tfm = ss2tf(" << aircraft_name << ".sys);\n"
            << std::endl;
    scicos.close();
 
}

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

• FGLinearization.h
• FGLinearization.cpp