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amcl_laser.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 laser routines
// Author: Andrew Howard
// Date: 6 Feb 2003
// CVS: $Id: amcl_laser.cc 6496 2008-06-09 22:32:57Z thjc $
//

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

#define PLAYER_ENABLE_MSG 1

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

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

// Default constructor
AMCLLaser::AMCLLaser(AdaptiveMCL & aAMCL, player_devaddr_t addr) : AMCLSensor(aAMCL)
{
  this->laser_dev = NULL;
  this->laser_addr = addr;
  
  return;
}


// Load laser settings
int AMCLLaser::Load(ConfigFile* cf, int section)
{
  // Get the map settings.  Don't error check here; we'll do it later, in
  // SetupMap().
  cf->ReadDeviceAddr(&(this->map_addr), section, "requires",
                     PLAYER_MAP_CODE, -1, "laser");
  
  this->max_beams = cf->ReadInt(section, "laser_max_beams", 6);
  this->range_var = cf->ReadLength(section, "laser_range_var", 0.10);
  this->range_bad = cf->ReadFloat(section, "laser_range_bad", 0.10);

  this->time = 0.0;

  return 0;
}


// Unload the model
int AMCLLaser::Unload(void)
{
  //laser_free(this->model);
  //this->model = NULL;
  
  return 0;
}


// Set up the laser
int AMCLLaser::Setup(void)
{
  if(this->SetupMap() < 0)
  {
    PLAYER_ERROR("failed to get laser map");
    return(-1);
  }

  // Subscribe to the Laser device
  this->laser_dev = deviceTable->GetDevice(this->laser_addr);
  if (!this->laser_dev)
  {
    PLAYER_ERROR("unable to locate suitable laser device");
    return -1;
  }
  if (this->laser_dev->Subscribe(AMCL.InQueue) != 0)
  {
    PLAYER_ERROR("unable to subscribe to laser device");
    return -1;
  }

  // Ask for the laser's geometry
  Message* msg;
  if(!(msg = laser_dev->Request(AMCL.InQueue,
                                PLAYER_MSGTYPE_REQ,
                                PLAYER_LASER_REQ_GET_GEOM,
                                NULL, 0, NULL,false)))
  {
    PLAYER_WARN("failed to get laser geometry");
    this->laser_pose.v[0] = 0.0;
    this->laser_pose.v[1] = 0.0;
    this->laser_pose.v[2] = 0.0;
  }
  else
  {
    player_laser_geom_t* geom = (player_laser_geom_t*)msg->GetPayload();
    // Set the laser pose relative to the robot
    this->laser_pose.v[0] = geom->pose.px;
    this->laser_pose.v[1] = geom->pose.py;
    this->laser_pose.v[2] = geom->pose.pyaw;
    PLAYER_MSG3(2, "laser geometry: %f,%f,%f",
                this->laser_pose.v[0],
                this->laser_pose.v[1],
                RTOD(this->laser_pose.v[2]));
    delete msg;
  }
  return 0;
}

// TODO: should Unsubscribe from the map on error returns in the function
int
AMCLLaser::SetupMap(void)
{
  Device* mapdev;

  // Subscribe to the map device
  if(!(mapdev = deviceTable->GetDevice(this->map_addr)))
  {
    PLAYER_ERROR("unable to locate suitable map device");
    return -1;
  }
  if(mapdev->Subscribe(AMCL.InQueue) != 0)
  {
    PLAYER_ERROR("unable to subscribe to map device");
    return -1;
  }

  // Create the map
  this->map = map_alloc();
  PLAYER_MSG1(2, "AMCL loading map from map:%d...", this->map_addr.index);

  // Fill in the map structure (I'm doing it here instead of in libmap, 
  // because libmap is written in C, so it'd be a pain to invoke the internal 
  // device API from there)

  // first, get the map info
  Message* msg;
  if(!(msg = mapdev->Request(AMCL.InQueue,
                             PLAYER_MSGTYPE_REQ,
                             PLAYER_MAP_REQ_GET_INFO,
                             NULL, 0, NULL, false)))
  {
    PLAYER_ERROR("failed to get map info");
    return(-1);
  }

  PLAYER_MSG1(2, "AMCL loading map from map:%d...Done", this->map_addr.index);

  player_map_info_t* info = (player_map_info_t*)msg->GetPayload();
  
  // copy in the map info
  this->map->origin_x = info->origin.px + (info->scale * info->width) / 2.0;
  this->map->origin_y = info->origin.py + (info->scale * info->height) / 2.0;
  this->map->scale = info->scale;
  this->map->size_x = info->width;
  this->map->size_y = info->height;

  delete msg;

  // allocate space for map cells
  this->map->cells = (map_cell_t*)malloc(sizeof(map_cell_t) *
                                                  this->map->size_x *
                                                  this->map->size_y);
  assert(this->map->cells);

  // now, get the map data
  player_map_data_t* data_req;
  int i,j;
  int oi,oj;
  int sx,sy;
  int si,sj;

  data_req = (player_map_data_t*) malloc(sizeof(player_map_data_t));
  assert(data_req);

  // Tile size, limit to sensible maximum of 640x640 tiles
  sy = sx = 640;
  oi=oj=0;
  while((oi < this->map->size_x) && (oj < this->map->size_y))
  {
    si = MIN(sx, this->map->size_x - oi);
    sj = MIN(sy, this->map->size_y - oj);

    data_req->col = oi;
    data_req->row = oj;
    data_req->width = si;
    data_req->height = sj;
    data_req->data_count = 0;

    if(!(msg = mapdev->Request(AMCL.InQueue,
                               PLAYER_MSGTYPE_REQ,
                               PLAYER_MAP_REQ_GET_DATA,
                               (void*)data_req,0,NULL,false)))
    {
      PLAYER_ERROR("failed to get map info");
      free(data_req);
      free(this->map->cells);
      return(-1);
    }

    player_map_data_t* mapdata = (player_map_data_t*)msg->GetPayload();

    // copy the map data
    for(j=0;j<sj;j++)
    {
      for(i=0;i<si;i++)
      {
        this->map->cells[MAP_INDEX(this->map,oi+i,oj+j)].occ_state = 
                mapdata->data[j*si + i];
        this->map->cells[MAP_INDEX(this->map,oi+i,oj+j)].occ_dist = 0;
      }
    }

    delete msg;

    oi += si;
    if(oi >= this->map->size_x)
    {
      oi = 0;
      oj += sj;
    }
  }

  free(data_req);

  // we're done with the map device now
  if(mapdev->Unsubscribe(AMCL.InQueue) != 0)
    PLAYER_WARN("unable to unsubscribe from map device");

  PLAYER_MSG0(2, "Done");

  return(0);
}


// Shut down the laser
int AMCLLaser::Shutdown(void)
{  
  this->laser_dev->Unsubscribe(AMCL.InQueue);
  this->laser_dev = NULL;
  map_free(this->map);

  return 0;
}


// Get the current laser reading
//AMCLSensorData *AMCLLaser::GetData(void)
// Process message for this interface
int AMCLLaser::ProcessMessage(QueuePointer &resp_queue, 
                                     player_msghdr * hdr, 
                                     void * idata)
{
  int i;
  double r, b, db;
  AMCLLaserData *ndata;

  if(!Message::MatchMessage(hdr, PLAYER_MSGTYPE_DATA,
                            PLAYER_LASER_DATA_SCAN, this->laser_addr))
        return -1;

  this->time = hdr->timestamp;
  player_laser_data_t* data = reinterpret_cast<player_laser_data_t*> (idata);
  
  b = data->min_angle;
  db = data->resolution;
  
  ndata = new AMCLLaserData;

  ndata->sensor = this;
  ndata->time = hdr->timestamp;
  
  ndata->range_count = data->ranges_count;
  ndata->range_max = data->max_range;
  ndata->ranges = new double [ndata->range_count][2];

  // Read the range data
  for (i = 0; i < ndata->range_count; i++)
  {
    r = data->ranges[i];
    ndata->ranges[i][0] = r;
    ndata->ranges[i][1] = b;
    b += db;
  }

  AMCL.Push(ndata);
  
  return 0;
}


// Apply the laser sensor model
bool AMCLLaser::UpdateSensor(pf_t *pf, AMCLSensorData *data)
{
  AMCLLaserData *ndata;
  
  ndata = (AMCLLaserData*) data;
  if (this->max_beams < 2)
    return false;

  // Apply the laser sensor model
  pf_update_sensor(pf, (pf_sensor_model_fn_t) SensorModel, data);
  
  return true;
}


// Determine the probability for the given pose
double AMCLLaser::SensorModel(AMCLLaserData *data, pf_sample_set_t* set)
{
  AMCLLaser *self;
  int i, j, step;
  double z, c, pz;
  double p;
  double map_range;
  double obs_range, obs_bearing;
  double total_weight;
  pf_sample_t *sample;
  pf_vector_t pose;
  
  self = (AMCLLaser*) data->sensor;

  total_weight = 0.0;
  
  // Compute the sample weights
  for (j = 0; j < set->sample_count; j++)
  {
    sample = set->samples + j;
    pose = sample->pose;

    // Take account of the laser pose relative to the robot
    pose = pf_vector_coord_add(self->laser_pose, pose);

    p = 1.0;

    step = (data->range_count - 1) / (self->max_beams - 1);
    for (i = 0; i < data->range_count; i += step)
    {
      obs_range = data->ranges[i][0];
      obs_bearing = data->ranges[i][1];

      // Compute the range according to the map
      map_range = map_calc_range(self->map, pose.v[0], pose.v[1],
                                 pose.v[2] + obs_bearing, data->range_max + 1.0);

      if (obs_range >= data->range_max && map_range >= data->range_max)
      {
        pz = 1.0;
      }
      else
      {
        // TODO: proper sensor model (using Kolmagorov?)
        // Simple gaussian model
        c = self->range_var;
        z = obs_range - map_range;
        pz = self->range_bad + (1 - self->range_bad) * exp(-(z * z) / (2 * c * c));
      }

      /*
         if (obs->range >= 8.0 && map_range >= 8.0)
         p *= 1.0;
         else if (obs->range >= 8.0 && map_range < 8.0)
         p *= self->range_bad;
         else if (obs->range < 8.0 && map_range >= 8.0)
         p *= self->range_bad;
         else
         p *= laser_sensor_prob(self, obs->range, map_range);
       */

      p *= pz;
    }

    //printf("%e\n", p);
    //assert(p >= 0);

    sample->weight *= p;
    total_weight += sample->weight;
  }

  return(total_weight);
}



#ifdef INCLUDE_RTKGUI

// Setup the GUI
void AMCLLaser::SetupGUI(rtk_canvas_t *canvas, rtk_fig_t *robot_fig)
{  
  this->fig = rtk_fig_create(canvas, robot_fig, 0);

  // Draw the laser map
  this->map_fig = rtk_fig_create(canvas, NULL, -50);
  map_draw_occ(this->map, this->map_fig);
  
  return;
}


// Shutdown the GUI
void AMCLLaser::ShutdownGUI(rtk_canvas_t *canvas, rtk_fig_t *robot_fig)
{
  rtk_fig_destroy(this->map_fig);
  rtk_fig_destroy(this->fig);
  this->map_fig = NULL;
  this->fig = NULL;

  return;
}


// Draw the laser values
void AMCLLaser::UpdateGUI(rtk_canvas_t *canvas, rtk_fig_t *robot_fig, AMCLSensorData *data)
{
  int i, step;
  double r, b, ax, ay, bx, by;
  AMCLLaserData *ndata;

  ndata = (AMCLLaserData*) data;
  
  rtk_fig_clear(this->fig);

  // Draw the complete scan
  rtk_fig_color_rgb32(this->fig, 0x8080FF);
  for (i = 0; i < ndata->range_count; i++)
  {
    r = ndata->ranges[i][0];
    b = ndata->ranges[i][1];

    ax = 0;
    ay = 0;
    bx = ax + r * cos(b);
    by = ay + r * sin(b);

    rtk_fig_line(this->fig, ax, ay, bx, by);
  }

  if (this->max_beams < 2)
    return;

  // Draw the significant part of the scan
  step = (ndata->range_count - 1) / (this->max_beams - 1);
  for (i = 0; i < ndata->range_count; i += step)
  {
    r = ndata->ranges[i][0];
    b = ndata->ranges[i][1];
    //m = map_calc_range(this->map, pose.v[0], pose.v[1], pose.v[2] + b, 8.0);

    ax = 0;
    ay = 0;

    bx = ax + r * cos(b);
    by = ay + r * sin(b);
    rtk_fig_color_rgb32(this->fig, 0xFF0000);
    rtk_fig_line(this->fig, ax, ay, bx, by);
  }

  return;
}

#endif

---

Last updated 12 September 2005 21:38:45