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mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-06-25 22:43:14 +00:00

Add tracking lib for cubature kalman filter

This commit is contained in:
Gerald LaMountain 2019-05-17 12:56:43 -04:00
parent d4d849c83d
commit 8cc141341b
3 changed files with 258 additions and 0 deletions

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@ -33,6 +33,7 @@ set(TRACKING_LIB_SOURCES
cpu_multicorrelator.cc
cpu_multicorrelator_real_codes.cc
cpu_multicorrelator_16sc.cc
cubature_filter.cc
lock_detectors.cc
tcp_communication.cc
tcp_packet_data.cc
@ -50,6 +51,7 @@ set(TRACKING_LIB_HEADERS
cpu_multicorrelator.h
cpu_multicorrelator_real_codes.h
cpu_multicorrelator_16sc.h
cubature_filter.h
lock_detectors.h
tcp_communication.h
tcp_packet_data.h

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@ -0,0 +1,182 @@
/*!
* \file cubature_filter.cc
* \brief Interface of a library with Bayesian noise statistic estimation
*
* Cubature_Filter implements the functionality of the Cubature Kalman
* Filter, which uses multidimensional cubature rules to estimate the
* time evolution of a nonlinear system.
*
* [1] TODO: Refs
*
* \authors <ul>
* <li> Gerald LaMountain, 2019. gerald(at)ece.neu.edu
* <li> Jordi Vila-Valls 2019. jvila(at)cttc.es
* </ul>
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR 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 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR 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 GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "cubature_filter.h"
Cubature_filter::Cubature_filter()
{
int nx = 1;
x_pred_out = arma::zeros(nx, 1);
P_x_pred_out = arma::eye(nx, nx) * (nx + 1);
x_est = x_pred_out;
P_x_est = P_x_pred_out;
}
Cubature_filter::Cubature_filter(int nx)
{
x_pred_out = arma::zeros(nx, 1);
P_x_pred_out = arma::eye(nx, nx) * (nx + 1);
x_est = x_pred_out;
P_x_est = P_x_pred_out;
}
Cubature_filter::Cubature_filter(const arma::vec& x_pred_0, const arma::mat& P_x_pred_0)
{
x_pred_out = x_pred_0;
P_x_pred_out = P_x_pred_0;
x_est = x_pred_out;
P_x_est = P_x_pred_out;
}
Cubature_filter::~Cubature_filter() = default;
void Cubature_filter::init(const arma::mat& x_pred_0, const arma::mat& P_x_pred_0)
{
x_pred_out = x_pred_0;
P_x_pred_out = P_x_pred_0;
x_est = x_pred_out;
P_x_est = P_x_pred_out;
}
/*
* Perform the prediction step of the cubature Kalman filter
*/
void Cubature_filter::predict_sequential(const arma::vec& x_post, const arma::mat& P_x_post, arma::vec (*transition_fcn)(const arma::mat&), const arma::mat& noise_covariance)
{
// Compute number of cubature points
int nx = x_post.n_elem;
int np = 2 * nx;
// Initialize predicted mean and covariance
arma::vec x_pred = arma::zeros(nx,1);
arma::mat P_x_pred = arma::zeros(nx,nx);
// Factorize posterior covariance
arma::mat Sm_post = arma::chol(P_x_post);
// Propagate and evaluate cubature points
arma::vec Xi_post;
arma::vec Xi_pred;
for (int32_t i = 0; i < np; i++)
{
Xi_post = Sm_post*std::sqrt(((float) np) / 2.0)*arma::ones(nx,1) + x_post;
Xi_pred = (*transition_fcn)(Xi_post);
x_pred = x_post + Xi_pred;
P_x_pred = P_x_post + Xi_pred*Xi_pred.t();
}
// Estimate predicted state and error covariance
x_pred = x_pred / ((float) np);
P_x_pred = P_x_pred / ((float) np) - x_pred*x_pred.t() + noise_covariance;
// Store predicted state and error covariance
x_pred_out = x_pred;
P_x_pred_out = P_x_pred;
}
/*
* Perform the update step of the cubature Kalman filter
*/
void Cubature_filter::update_sequential(const arma::vec& z_upd, const arma::vec& x_pred, const arma::mat& P_x_pred, arma::vec (*measurement_fcn)(const arma::mat&), const arma::mat& noise_covariance)
{
// Compute number of cubature points
int nx = x_pred.n_elem;
int nz = z_upd.n_elem;
int np = 2 * nx;
// Evaluate predicted measurement and covariances
arma::mat z_pred = arma::zeros(nx,1);
arma::mat P_zz_pred = arma::zeros(nz,nz);
arma::mat P_xz_pred = arma::zeros(nx,nz);
// Factorize predicted covariance
arma::mat Sm_pred = arma::chol(P_x_pred);
// Propagate and evaluate cubature points
arma::vec Xi_pred;
arma::vec Zi_pred;
for (int32_t i = 0; i < np; i++)
{
Xi_pred = Sm_pred*std::sqrt(((float) np) / 2.0)*arma::ones(nx,1) + x_pred;
Zi_pred = (*measurement_fcn)(Xi_pred);
z_pred = z_pred + Zi_pred;
P_zz_pred = P_zz_pred + Zi_pred*Zi_pred.t();
P_xz_pred = P_xz_pred + Xi_pred*Zi_pred.t();
}
// Estimate measurement covariance and cross covariances
z_pred = z_pred / ((float) np);
P_zz_pred = P_zz_pred / ((float) np) - z_pred*z_pred.t() + noise_covariance;
P_xz_pred = P_xz_pred / ((float) np) - x_pred*z_pred.t();
// Estimate cubature Kalman gain
arma::mat W_k = P_xz_pred*arma::inv(P_zz_pred);
// Estimate and store the updated state and error covariance
x_est = x_pred + W_k*(z_upd - z_pred);
P_x_est = P_x_pred - W_k*P_zz_pred*W_k.t();
}
arma::mat Cubature_filter::get_x_pred() const
{
return x_pred_out;
}
arma::mat Cubature_filter::get_P_x_pred() const
{
return P_x_pred_out;
}
arma::mat Cubature_filter::get_x_est() const
{
return x_est;
}
arma::mat Cubature_filter::get_P_x_est() const
{
return P_x_est;
}

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@ -0,0 +1,74 @@
/*!
* \file cubature_filter.h
* \brief Interface of a library with Bayesian noise statistic estimation
*
* Cubature_Filter implements the functionality of the Cubature Kalman
* Filter, which uses multidimensional cubature rules to estimate the
* time evolution of a nonlinear system.
*
* [1] TODO: Refs
*
* \authors <ul>
* <li> Gerald LaMountain, 2019. gerald(at)ece.neu.edu
* <li> Jordi Vila-Valls 2019. jvila(at)cttc.es
* </ul>
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR 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 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR 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 GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_CUBATURE_FILTER_H_
#define GNSS_SDR_CUBATURE_FILTER_H_
#include <armadillo>
#include <gnuradio/gr_complex.h>
class Cubature_filter
{
public:
// Constructors and destructors
Cubature_filter();
Cubature_filter(int nx);
Cubature_filter(const arma::vec& x_pred_0, const arma::mat& P_x_pred_0);
~Cubature_filter();
// Reinitialization function
void init(const arma::mat& x_pred_0, const arma::mat& P_x_pred_0);
// Prediction and estimation
void predict_sequential(const arma::vec& x_post, const arma::mat& P_x_post, arma::vec (*transition_fcn)(const arma::mat&), const arma::mat& noise_covariance);
void update_sequential(const arma::vec& z_upd, const arma::vec& x_pred, const arma::mat& P_x_pred, arma::vec (*measurement_fcn)(const arma::mat&), const arma::mat& noise_covariance);
// Getters
arma::mat get_x_pred() const;
arma::mat get_P_x_pred() const;
arma::mat get_x_est() const;
arma::mat get_P_x_est() const;
private:
arma::vec x_pred_out;
arma::mat P_x_pred_out;
arma::vec x_est;
arma::mat P_x_est;
};
#endif