tracker_particle.cpp

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/* Author: Wim Meeussen */
/* Modified by Alex Noyvirt for SRS */

#include "srs_people_tracking_filter/tracker_particle.h"
#include "srs_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(srs_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