nonlinearanalyticconditionalgaussianodo.cpp

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// Copyright (C) 2008 Wim Meeussen <meeussen at willowgarage com>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//

#include <iri_robot_pose_ekf/nonlinearanalyticconditionalgaussianodo.h>
#include <wrappers/rng/rng.h> // Wrapper around several rng
                              // libraries
#define NUMCONDARGUMENTS_MOBILE 2

namespace BFL
{
  using namespace MatrixWrapper;


  NonLinearAnalyticConditionalGaussianOdo::NonLinearAnalyticConditionalGaussianOdo(const Gaussian& additiveNoise)
    : AnalyticConditionalGaussianAdditiveNoise(additiveNoise,NUMCONDARGUMENTS_MOBILE),
      df(6,6)
  {
    // initialize df matrix
    for (unsigned int i=1; i<=6; i++){
      for (unsigned int j=1; j<=6; j++){
        if (i==j) df(i,j) = 1;
        else df(i,j) = 0;
      }
    }
  }


  NonLinearAnalyticConditionalGaussianOdo::~NonLinearAnalyticConditionalGaussianOdo(){}

  ColumnVector NonLinearAnalyticConditionalGaussianOdo::ExpectedValueGet() const
  {
    ColumnVector state = ConditionalArgumentGet(0);
    ColumnVector vel  = ConditionalArgumentGet(1);

    // state = 1:x, 2:y, 3:z, 4:roll, 5:pitch, 6:yaw
    // vel = 1:v-x, 2:v-roll, 3:v-pitch, 4:v-yaw

    state(1) += cos(state(6)) * cos(state(5)) * vel(1); // state 1 = x
    state(2) += sin(state(6)) * cos(state(4)) * vel(1); // state 2 = y
    state(3) += sin(state(5)) * sin(state(4)) * vel(1); // state 3 = z
    state(4) += vel(2);                                 // state 4 = roll = phi
    state(5) += vel(3);                                 // state 5 = pitch = psi
    state(6) += vel(4);                                 // state 6 = yaw = theta
    return state + AdditiveNoiseMuGet();
  }

  Matrix NonLinearAnalyticConditionalGaussianOdo::dfGet(unsigned int i) const
  {
    if (i==0)//derivative to the first conditional argument (x)
    {
      double v = ConditionalArgumentGet(1)(1);
      double r = ConditionalArgumentGet(0)(4); // state 4 roll
      double p = ConditionalArgumentGet(0)(5); // state 5 pitch
      double y = ConditionalArgumentGet(0)(6); // state 6 yaw

      df(1,5)= -v * cos(y) * sin (p); // state 1 = x derived by state 5 pitch
      df(1,6)= -v * sin(y) * cos (p); //                              6 yaw
      df(2,4)= -v * sin(y) * sin (r); // state 2 = y derived by state 4 roll
      df(2,6)=  v * cos(y) * cos (r); //                              6 yaw
      df(3,4)=  v * sin(p) * cos (r); // state 3 = z derived by state 4 roll
      df(3,5)=  v * cos(p) * sin (r); //                              5 pitch

      return df;
    }
    else
    {
      if (i >= NumConditionalArgumentsGet())
      {
        cerr << "This pdf Only has " << NumConditionalArgumentsGet() << " conditional arguments\n";
        exit(-BFL_ERRMISUSE);
      }
      else{
        cerr << "The df is not implemented for the" <<i << "th conditional argument\n";
        exit(-BFL_ERRMISUSE);
      }
    }
  }

}//namespace BFL