ecl_controller.cpp

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/**
 * @file ecl_controller.cpp
 * Definition of base class for other controllers
 *
 * @author Lorenz Meier <lm@inf.ethz.ch>
 * @author Thomas Gubler <thomasgubler@gmail.com>
 *
 * Acknowledgements:
 *
 *   The control design is based on a design
 *   by Paul Riseborough and Andrew Tridgell, 2013,
 *   which in turn is based on initial work of
 *   Jonathan Challinger, 2012.
 */

#include "ecl_controller.h"

#include <stdio.h>
#include <mathlib/mathlib.h>

ECL_Controller::ECL_Controller() :
    _last_run(0),
    _tc(0.1f),
    _k_p(0.0f),
    _k_i(0.0f),
    _k_ff(0.0f),
    _integrator_max(0.0f),
    _max_rate(0.0f),
    _last_output(0.0f),
    _integrator(0.0f),
    _rate_error(0.0f),
    _rate_setpoint(0.0f),
    _bodyrate_setpoint(0.0f)
{
}

void ECL_Controller::reset_integrator()
{
    _integrator = 0.0f;
}

void ECL_Controller::set_time_constant(float time_constant)
{
    if (time_constant > 0.1f && time_constant < 3.0f) {
        _tc = time_constant;
    }
}

void ECL_Controller::set_k_p(float k_p)
{
    _k_p = k_p;
}

void ECL_Controller::set_k_i(float k_i)
{
    _k_i = k_i;
}

void ECL_Controller::set_k_ff(float k_ff)
{
    _k_ff = k_ff;
}

void ECL_Controller::set_integrator_max(float max)
{
    _integrator_max = max;
}

void ECL_Controller::set_max_rate(float max_rate)
{
    _max_rate = max_rate;
}

void ECL_Controller::set_bodyrate_setpoint(float rate)
{
    _bodyrate_setpoint = math::constrain(rate, -_max_rate, _max_rate);
}

float ECL_Controller::get_rate_error()
{
    return _rate_error;
}

float ECL_Controller::get_desired_rate()
{
    return _rate_setpoint;
}

float ECL_Controller::get_desired_bodyrate()
{
    return _bodyrate_setpoint;
}

float ECL_Controller::get_integrator()
{
    return _integrator;
}

float ECL_Controller::constrain_airspeed(float airspeed, float minspeed, float maxspeed)
{
    float airspeed_result = airspeed;

    if (!ISFINITE(airspeed)) {
        /* airspeed is NaN, +- INF or not available, pick center of band */
        airspeed_result = 0.5f * (minspeed + maxspeed);

    } else if (airspeed < minspeed) {
        airspeed_result = minspeed;
    }

    return airspeed_result;
}