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/* -*- c++ -*- */
/*
* Copyright 2011 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef GRI_CONTROL_LOOP
#define GRI_CONTROL_LOOP
#include <gr_core_api.h>
class GR_CORE_API gri_control_loop
{
protected:
float d_phase, d_freq;
float d_max_freq, d_min_freq;
float d_damping, d_loop_bw;
float d_alpha, d_beta;
public:
gri_control_loop(float loop_bw, float max_freq, float min_freq);
virtual ~gri_control_loop();
/*! \brief update the system gains from the loop bandwidth and damping factor
*
* This function updates the system gains based on the loop
* bandwidth and damping factor of the system.
* These two factors can be set separately through their own
* set functions.
*/
void update_gains();
/*! \brief update the system gains from the loop bandwidth and damping factor
*
* This function updates the system gains based on the loop
* bandwidth and damping factor of the system.
* These two factors can be set separately through their own
* set functions.
*/
void advance_loop(float error);
/*! \brief Keep the phase between -2pi and 2pi
*
* This function keeps the phase between -2pi and 2pi. If the phase
* is greater than 2pi by d, it wraps around to be -2pi+d; similarly if
* it is less than -2pi by d, it wraps around to 2pi-d.
*
* This function should be called after advance_loop to keep the phase
* in a good operating region. It is set as a separate method in case
* another way is desired as this is fairly heavy-handed.
*/
void phase_wrap();
/*! \brief Keep the frequency between d_min_freq and d_max_freq
*
* This function keeps the frequency between d_min_freq and d_max_freq.
* If the frequency is greater than d_max_freq, it is set to d_max_freq.
* If the frequency is less than d_min_freq, it is set to d_min_freq.
*
* This function should be called after advance_loop to keep the frequency
* in the specified region. It is set as a separate method in case
* another way is desired as this is fairly heavy-handed.
*/
void frequency_limit();
/*******************************************************************
SET FUNCTIONS
*******************************************************************/
/*!
* \brief Set the loop bandwidth
*
* Set the loop filter's bandwidth to \p bw. This should be between
* 2*pi/200 and 2*pi/100 (in rads/samp). It must also be a positive
* number.
*
* When a new damping factor is set, the gains, alpha and beta, of the loop
* are recalculated by a call to update_gains().
*
* \param bw (float) new bandwidth
*
*/
void set_loop_bandwidth(float bw);
/*!
* \brief Set the loop damping factor
*
* Set the loop filter's damping factor to \p df. The damping factor
* should be sqrt(2)/2.0 for critically damped systems.
* Set it to anything else only if you know what you are doing. It must
* be a number between 0 and 1.
*
* When a new damping factor is set, the gains, alpha and beta, of the loop
* are recalculated by a call to update_gains().
*
* \param df (float) new damping factor
*
*/
void set_damping_factor(float df);
/*!
* \brief Set the loop gain alpha
*
* Set's the loop filter's alpha gain parameter.
*
* This value should really only be set by adjusting the loop bandwidth
* and damping factor.
*
* \param alpha (float) new alpha gain
*
*/
void set_alpha(float alpha);
/*!
* \brief Set the loop gain beta
*
* Set's the loop filter's beta gain parameter.
*
* This value should really only be set by adjusting the loop bandwidth
* and damping factor.
*
* \param beta (float) new beta gain
*
*/
void set_beta(float beta);
/*!
* \brief Set the control loop's frequency.
*
* Set's the control loop's frequency. While this is normally updated by the
* inner loop of the algorithm, it could be useful to manually initialize,
* set, or reset this under certain circumstances.
*
* \param freq (float) new frequency
*
*/
void set_frequency(float freq);
/*!
* \brief Set the control loop's phase.
*
* Set's the control loop's phase. While this is normally updated by the
* inner loop of the algorithm, it could be useful to manually initialize,
* set, or reset this under certain circumstances.
*
* \param phase (float) new phase
*
*/
void set_phase(float phase);
/*!
* \brief Set the control loop's maximum frequency.
*
* Set the maximum frequency the control loop can track.
*
* \param freq (float) new max frequency
*/
void set_max_freq(float freq);
/*!
* \brief Set the control loop's minimum frequency.
*
* Set the minimum frequency the control loop can track.
*
* \param freq (float) new min frequency
*/
void set_min_freq(float freq);
/*******************************************************************
GET FUNCTIONS
*******************************************************************/
/*!
* \brief Returns the loop bandwidth
*/
float get_loop_bandwidth() const;
/*!
* \brief Returns the loop damping factor
*/
float get_damping_factor() const;
/*!
* \brief Returns the loop gain alpha
*/
float get_alpha() const;
/*!
* \brief Returns the loop gain beta
*/
float get_beta() const;
/*!
* \brief Get the control loop's frequency estimate
*/
float get_frequency() const;
/*!
* \brief Get the control loop's phase estimate
*/
float get_phase() const;
/*!
* \brief Get the control loop's maximum frequency.
*/
float get_max_freq() const;
/*!
* \brief Get the control loop's minimum frequency.
*/
float get_min_freq() const;
};
#endif /* GRI_CONTROL_LOOP */
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