tracker_particle.cpp

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/* Author: Wim Meeussen */

#include "people_tracking_filter/tracker_particle.h"
#include "people_tracking_filter/gaussian_pos_vel.h"

using namespace MatrixWrapper;
using namespace BFL;
using namespace tf;
using namespace std;
using namespace ros;




namespace estimation
{
// constructor
TrackerParticle::TrackerParticle(const string& name, unsigned int num_particles, const StatePosVel& sysnoise):
  Tracker(name),
  prior_(num_particles),
  filter_(NULL),
  sys_model_(sysnoise),
  meas_model_(tf::Vector3(0.1, 0.1, 0.1)),
  tracker_initialized_(false),
  num_particles_(num_particles)
{};



// destructor
TrackerParticle::~TrackerParticle()
{
  if (filter_) delete filter_;
};


// initialize prior density of filter
void TrackerParticle::initialize(const StatePosVel& mu, const StatePosVel& sigma, const double time)
{
  cout << "Initializing tracker with " << num_particles_ << " particles, with covariance "
       << sigma << " around " << mu << endl;


  GaussianPosVel gauss_pos_vel(mu, sigma);
  vector<Sample<StatePosVel> > prior_samples(num_particles_);
  gauss_pos_vel.SampleFrom(prior_samples, num_particles_, CHOLESKY, NULL);
  prior_.ListOfSamplesSet(prior_samples);
  filter_ = new BootstrapFilter<StatePosVel, tf::Vector3>(&prior_, &prior_, 0, num_particles_ / 4.0);

  // tracker initialized
  tracker_initialized_ = true;
  quality_ = 1;
  filter_time_ = time;
  init_time_ = time;
}




// update filter prediction
bool TrackerParticle::updatePrediction(const double time)
{
  bool res = true;
  if (time > filter_time_)
  {
    // set dt in sys model
    sys_model_.SetDt(time - filter_time_);
    filter_time_ = time;

    // update filter
    res = filter_->Update(&sys_model_);
    if (!res) quality_ = 0;
  }
  return res;
};



// update filter correction
bool TrackerParticle::updateCorrection(const tf::Vector3&  meas, const MatrixWrapper::SymmetricMatrix& cov)
{
  assert(cov.columns() == 3);

  // set covariance
  ((MeasPdfPos*)(meas_model_.MeasurementPdfGet()))->CovarianceSet(cov);

  // update filter
  bool res = filter_->Update(&meas_model_, meas);
  if (!res) quality_ = 0;

  return res;
};


// get evenly spaced particle cloud
void TrackerParticle::getParticleCloud(const tf::Vector3& step, double threshold, sensor_msgs::PointCloud& cloud) const
{
  ((MCPdfPosVel*)(filter_->PostGet()))->getParticleCloud(step, threshold, cloud);
};


// get most recent filter posterior
void TrackerParticle::getEstimate(StatePosVel& est) const
{
  est = ((MCPdfPosVel*)(filter_->PostGet()))->ExpectedValueGet();
};


void TrackerParticle::getEstimate(people_msgs::PositionMeasurement& est) const
{
  StatePosVel tmp = filter_->PostGet()->ExpectedValueGet();

  est.pos.x = tmp.pos_[0];
  est.pos.y = tmp.pos_[1];
  est.pos.z = tmp.pos_[2];

  est.header.stamp.fromSec(filter_time_);
  est.object_id = getName();
}





Matrix TrackerParticle::getHistogramPos(const tf::Vector3& min, const tf::Vector3& max, const tf::Vector3& step) const
{
  return ((MCPdfPosVel*)(filter_->PostGet()))->getHistogramPos(min, max, step);
};


Matrix TrackerParticle::getHistogramVel(const tf::Vector3& min, const tf::Vector3& max, const tf::Vector3& step) const
{
  return ((MCPdfPosVel*)(filter_->PostGet()))->getHistogramVel(min, max, step);
};


double TrackerParticle::getLifetime() const
{
  if (tracker_initialized_)
    return filter_time_ - init_time_;
  else
    return 0;
}


double TrackerParticle::getTime() const
{
  if (tracker_initialized_)
    return filter_time_;
  else
    return 0;
}
}; // namespace