px4-firmware/apps/multirotor_att_control/multirotor_rate_control.c

/****************************************************************************
 *
 *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
 *   Author: Tobias Naegeli <naegelit@student.ethz.ch>
 *           Lorenz Meier <lm@inf.ethz.ch>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 *
 ****************************************************************************/

/**
 * @file multirotor_rate_control.c
 *
 * Implementation of rate controller
 *
 * @author Tobias Naegeli <naegelit@student.ethz.ch>
 * @author Lorenz Meier <lm@inf.ethz.ch>
 */

#include "multirotor_rate_control.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <float.h>
#include <math.h>
#include <systemlib/pid/pid.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>
#include <drivers/drv_hrt.h>

PARAM_DEFINE_FLOAT(MC_YAWRATE_P, 0.1f); /* same on Flamewheel */
PARAM_DEFINE_FLOAT(MC_YAWRATE_D, 0.0f);
PARAM_DEFINE_FLOAT(MC_YAWRATE_I, 0.0f);
PARAM_DEFINE_FLOAT(MC_YAWRATE_AWU, 0.0f);
PARAM_DEFINE_FLOAT(MC_YAWRATE_LIM, 1.0f);

PARAM_DEFINE_FLOAT(MC_ATTRATE_P, 0.2f); /* 0.15 F405 Flamewheel */
PARAM_DEFINE_FLOAT(MC_ATTRATE_D, 0.05f);
PARAM_DEFINE_FLOAT(MC_ATTRATE_I, 0.0f);
PARAM_DEFINE_FLOAT(MC_ATTRATE_AWU, 0.05f);
PARAM_DEFINE_FLOAT(MC_ATTRATE_LIM, 1.0f);	/**< roughly < 500 deg/s limit */

struct mc_rate_control_params {

	float yawrate_p;
	float yawrate_d;
	float yawrate_i;
	float yawrate_awu;
	float yawrate_lim;

	float attrate_p;
	float attrate_d;
	float attrate_i;
	float attrate_awu;
	float attrate_lim;

	float rate_lim;
};

struct mc_rate_control_param_handles {

	param_t yawrate_p;
	param_t yawrate_i;
	param_t yawrate_d;
	param_t yawrate_awu;
	param_t yawrate_lim;

	param_t attrate_p;
	param_t attrate_i;
	param_t attrate_d;
	param_t attrate_awu;
	param_t attrate_lim;
};

/**
 * Initialize all parameter handles and values
 *
 */
static int parameters_init(struct mc_rate_control_param_handles *h);

/**
 * Update all parameters
 *
 */
static int parameters_update(const struct mc_rate_control_param_handles *h, struct mc_rate_control_params *p);


static int parameters_init(struct mc_rate_control_param_handles *h)
{
	/* PID parameters */
	h->yawrate_p 	=	param_find("MC_YAWRATE_P");
	h->yawrate_i 	=	param_find("MC_YAWRATE_I");
	h->yawrate_d 	=	param_find("MC_YAWRATE_D");
	h->yawrate_awu 	=	param_find("MC_YAWRATE_AWU");
	h->yawrate_lim 	=	param_find("MC_YAWRATE_LIM");

	h->attrate_p 	= 	param_find("MC_ATTRATE_P");
	h->attrate_i 	= 	param_find("MC_ATTRATE_I");
	h->attrate_d 	= 	param_find("MC_ATTRATE_D");
	h->attrate_awu 	= 	param_find("MC_ATTRATE_AWU");
	h->attrate_lim 	= 	param_find("MC_ATTRATE_LIM");

	return OK;
}

static int parameters_update(const struct mc_rate_control_param_handles *h, struct mc_rate_control_params *p)
{
	param_get(h->yawrate_p, &(p->yawrate_p));
	param_get(h->yawrate_i, &(p->yawrate_i));
	param_get(h->yawrate_d, &(p->yawrate_d));
	param_get(h->yawrate_awu, &(p->yawrate_awu));
	param_get(h->yawrate_lim, &(p->yawrate_lim));

	param_get(h->attrate_p, &(p->attrate_p));
	param_get(h->attrate_i, &(p->attrate_i));
	param_get(h->attrate_d, &(p->attrate_d));
	param_get(h->attrate_awu, &(p->attrate_awu));
	param_get(h->attrate_lim, &(p->attrate_lim));

	return OK;
}

void multirotor_control_rates(const struct vehicle_rates_setpoint_s *rate_sp,
	const float rates[], struct actuator_controls_s *actuators)
{
	static float roll_control_last  = 0;
	static float pitch_control_last = 0;
	static uint64_t last_run = 0;
	const float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
	static uint64_t last_input = 0;

	float dT_input = (hrt_absolute_time() - last_input) / 1000000.0f;
	if (last_input != rate_sp->timestamp) {
		last_input = rate_sp->timestamp;
	}

	last_run = hrt_absolute_time();

	static int motor_skip_counter = 0;

	static struct mc_rate_control_params p;
	static struct mc_rate_control_param_handles h;

	static bool initialized = false;

	/* initialize the pid controllers when the function is called for the first time */
	if (initialized == false) {
		parameters_init(&h);
		parameters_update(&h, &p);
		initialized = true;
	}

	/* load new parameters with lower rate */
	if (motor_skip_counter % 2500 == 0) {
		/* update parameters from storage */
		parameters_update(&h, &p);
		// warnx("rate ctrl: p.yawrate_p: %8.4f, loop: %d Hz, input: %d Hz",
		// 	(double)p.yawrate_p, (int)(1.0f/deltaT), (int)(1.0f/dT_input));
	}

	/* calculate current control outputs */
	
	/* control pitch (forward) output */
	float pitch_control = p.attrate_p * (rate_sp->pitch - rates[1]) - (p.attrate_d * pitch_control_last);
	/* increase resilience to faulty control inputs */
	if (isfinite(pitch_control)) {
		pitch_control_last = pitch_control;
	} else {
		pitch_control = 0.0f;
		warnx("rej. NaN ctrl pitch");
	}

	/* control roll (left/right) output */
	float roll_control = p.attrate_p * (rate_sp->roll - rates[0]) - (p.attrate_d * roll_control_last);
	/* increase resilience to faulty control inputs */
	if (isfinite(roll_control)) {
		roll_control_last = roll_control;
	} else {
		roll_control = 0.0f;
		warnx("rej. NaN ctrl roll");
	}

	/* control yaw rate */
	float yaw_rate_control = p.yawrate_p * (rate_sp->yaw - rates[2]);

	actuators->control[0] = roll_control;
	actuators->control[1] = pitch_control;
	actuators->control[2] = yaw_rate_control;
	actuators->control[3] = rate_sp->thrust;

	motor_skip_counter++;
}