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amcl_odom.cc

/*
 *  Player - One Hell of a Robot Server
 *  Copyright (C) 2000  Brian Gerkey   &  Kasper Stoy
 *                      gerkey@usc.edu    kaspers@robotics.usc.edu
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU 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
 *
 */
//
// Desc: AMCL odometry routines
// Author: Andrew Howard
// Date: 6 Feb 2003
// CVS: $Id: amcl_odom.cc 4135 2007-08-23 19:58:48Z gerkey $
//

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/types.h> // required by Darwin
#include <math.h>

#include <libplayercore/playercore.h>
#include <libplayercore/error.h>
#include "amcl_odom.h"

// Default constructor
AMCLOdom::AMCLOdom(AdaptiveMCL & aAMCL, player_devaddr_t addr) : AMCLSensor(aAMCL)
{
  this->odom_dev = NULL;
  this->action_pdf = NULL;
  this->odom_addr = addr;
  
  return;
}


// Load settings
int AMCLOdom::Load(ConfigFile* cf, int section)
{
  this->time = 0.0;

  this->drift = pf_matrix_zero();

  this->drift.m[0][0] = cf->ReadTupleFloat(section, "odom_drift[0]", 0, 0.20);
  this->drift.m[0][1] = cf->ReadTupleFloat(section, "odom_drift[0]", 1, 0.00);
  this->drift.m[0][2] = cf->ReadTupleFloat(section, "odom_drift[0]", 2, 0.00); 

  this->drift.m[1][0] = cf->ReadTupleFloat(section, "odom_drift[1]", 0, 0.00);
  this->drift.m[1][1] = cf->ReadTupleFloat(section, "odom_drift[1]", 1, 0.20);
  this->drift.m[1][2] = cf->ReadTupleFloat(section, "odom_drift[1]", 2, 0.00);

  this->drift.m[2][0] = cf->ReadTupleFloat(section, "odom_drift[2]", 0, 0.20);
  this->drift.m[2][1] = cf->ReadTupleFloat(section, "odom_drift[2]", 1, 0.00);
  this->drift.m[2][2] = cf->ReadTupleFloat(section, "odom_drift[2]", 2, 0.20);

  return 0;
}


// Unload the model
int AMCLOdom::Unload(void)
{  
  return 0;
}


// Set up the underlying odom driver.
int AMCLOdom::Setup(void)
{
  // Subscribe to the odometry driver
  this->odom_dev = deviceTable->GetDevice(this->odom_addr);
  if (!this->odom_dev)
  {
    PLAYER_ERROR("unable to locate suitable position driver");
    return -1;
  }
  if (this->odom_dev->Subscribe(AMCL.InQueue) != 0)
  {
    PLAYER_ERROR("unable to subscribe to position device");
    return -1;
  }
  
  return 0;
}


// Shutdown the underlying odom device.
int AMCLOdom::Shutdown(void)
{
  // Unsubscribe from device
  this->odom_dev->Unsubscribe(AMCL.InQueue);
  this->odom_dev = NULL;
  
  return 0;
}


// Get the current odometry reading
//AMCLSensorData *AMCLOdom::GetData(void)
// Process message for this interface
int AMCLOdom::ProcessMessage(QueuePointer &resp_queue, 
                                     player_msghdr * hdr, 
                                     void * idata)
{
  pf_vector_t pose;
  AMCLOdomData *ndata;

  if(!Message::MatchMessage(hdr, PLAYER_MSGTYPE_DATA,
                            PLAYER_POSITION2D_DATA_STATE, this->odom_addr))
  {
    return -1;
  }

  player_position2d_data_t* data = reinterpret_cast<player_position2d_data_t*> (idata);

  // Compute new robot pose
  pose.v[0] = data->pos.px;
  pose.v[1] = data->pos.py;
  pose.v[2] = data->pos.pa;

  //printf("getdata %.3f %.3f %.3f\n", 
         //pose.v[0], pose.v[1], pose.v[2]);

  ndata = new AMCLOdomData;

  ndata->sensor = this;
  ndata->time = hdr->timestamp;

  ndata->pose = pose;
  ndata->delta = pf_vector_zero();

  this->time = hdr->timestamp;

  AMCL.Push(ndata);
    
  return 0;
}


// Apply the action model
bool AMCLOdom::UpdateAction(pf_t *pf, AMCLSensorData *data)
{
  AMCLOdomData *ndata;
  pf_vector_t x;
  pf_matrix_t cx;
  double ux, uy, ua;
  ndata = (AMCLOdomData*) data;

  /*
  printf("odom: %f %f %f : %f %f %f\n",
         ndata->pose.v[0], ndata->pose.v[1], ndata->pose.v[2],
         ndata->delta.v[0], ndata->delta.v[1], ndata->delta.v[2]);
  */
         
  // See how far the robot has moved
  x = ndata->delta;
  
  // Odometric drift model
  // This could probably be improved
  ux = this->drift.m[0][0] * x.v[0];
  uy = this->drift.m[1][1] * x.v[1];
  ua = this->drift.m[2][0] * fabs(x.v[0])
    + this->drift.m[2][1] * fabs(x.v[1])
    + this->drift.m[2][2] * fabs(x.v[2]);

  cx = pf_matrix_zero();
  cx.m[0][0] = ux * ux;
  cx.m[1][1] = uy * uy;
  cx.m[2][2] = ua * ua;

  //printf("x = %f %f %f\n", x.v[0], x.v[1], x.v[2]);
  
  // Create a pdf with suitable characterisitics
  this->action_pdf = pf_pdf_gaussian_alloc(x, cx); 

  // Update the filter
  pf_update_action(pf, (pf_action_model_fn_t) ActionModel, this);  

  // Delete the pdf
  pf_pdf_gaussian_free(this->action_pdf);
  this->action_pdf = NULL;
  
  return true;
}


// The action model function (static method)
void 
AMCLOdom::ActionModel(AMCLOdom *self, pf_sample_set_t* set)
{
  int i;
  pf_vector_t z;
  pf_sample_t *sample;

  // Compute the new sample poses
  for (i = 0; i < set->sample_count; i++)
  {
    sample = set->samples + i;
    z = pf_pdf_gaussian_sample(self->action_pdf);
    sample->pose = pf_vector_coord_add(z, sample->pose);
    sample->weight = 1.0 / set->sample_count;
  }
}


#ifdef INCLUDE_RTKGUI

// Setup the GUI
void AMCLOdom::SetupGUI(rtk_canvas_t *canvas, rtk_fig_t *robot_fig)
{
  return;
}


// Shutdown the GUI
void AMCLOdom::ShutdownGUI(rtk_canvas_t *canvas, rtk_fig_t *robot_fig)
{
  return;
}

#endif

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Last updated 12 September 2005 21:38:45