AttitudeModels.cpp

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//////////////////////////////////////////////////////////////////////////////////////////////////
/*! \file AttitudeModels.cpp
 *  \brief Class for various spacecraft attitude models
 *  \author $Author: jayhawk_hokie $
 *  \version $Revision: 1.2 $
 *  \date    $Date: 2007/07/24 08:37:59 $
*//////////////////////////////////////////////////////////////////////////////////////////////////
/*!
*/
//////////////////////////////////////////////////////////////////////////////////////////////////


#include "AttitudeModels.h"

using namespace std;
using namespace O_SESSAME;

                
/* Constructors */
AttitudeModels::AttitudeModels( )
{ 
}
                
/* Destructor */
AttitudeModels::~AttitudeModels( )
{

}

void AttitudeModels::MRPKinematic( ModifiedRodriguezParameters _mrp, Vector _angularVelocity, ModifiedRodriguezParameters &_mrpRate )
{ 
        Vector mrpRate = ( ( (1-pow(norm2(_mrp),2))*eye(3) + 2*skew(_mrp) + 2*_mrp*(~_mrp) )*_angularVelocity/4 );
        _mrpRate = ModifiedRodriguezParameters( mrpRate );
        return; 
}

void AttitudeModels::QuaternionKinematic( Quaternion _quaternion, Vector _angularVelocity, Quaternion &_quaternionRate )
{
        /* quaternion kinematic differential equation (vector form) */
        _quaternionRate( _(1,3) ) =  0.5 * ( _quaternion(4) * _angularVelocity - skew( _angularVelocity ) * _quaternion( _(1,3) ) );
        _quaternionRate( _(4,4) ) = (-0.5 * ~_angularVelocity * _quaternion( _(1,3) ) ) ;

        /* Euler Equation */
        //Matrix invInertiaMatrix = matrixInv3x3( inertiaMatrix );
        //stateDot( _(5,7) ) =  invInertiaMatrix*( - skew(angularRate) * inertiaMatrix * angularRate );
        return;
}



// Do not change the comments below - they will be added automatically by CVS
/*****************************************************************************
*       $Log: AttitudeModels.cpp,v $
*       Revision 1.2  2007/07/24 08:37:59  jayhawk_hokie
*       Modified Kinematic Equations.
*
*       Revision 1.1  2007/06/19 19:55:08  jayhawk_hokie
*       Initial submission. Added MRP and Quaternion Kinematic Equations.
*
*
*
*
******************************************************************************/

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