/****************************************************************************
*
* Copyright (c) 2013 PX4 Development Team. All rights reserved.
* Author: Lorenz Meier
*
* 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
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file fw_pos_control_l1_main.c
* Implementation of a generic position controller based on the L1 norm. Outputs a bank / roll
* angle, equivalent to a lateral motion (for copters and rovers).
*
* Original publication for horizontal control class:
* S. Park, J. Deyst, and J. P. How, "A New Nonlinear Guidance Logic for Trajectory Tracking,"
* Proceedings of the AIAA Guidance, Navigation and Control
* Conference, Aug 2004. AIAA-2004-4900.
*
* Original implementation for total energy control class:
* Paul Riseborough and Andrew Tridgell, 2013 (code in lib/external_lgpl)
*
* More details and acknowledgements in the referenced library headers.
*
* @author Lorenz Meier <lm@inf.ethz.ch>
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <math.h>
#include <poll.h>
#include <time.h>
#include <drivers/drv_hrt.h>
#include <drivers/drv_accel.h>
#include <arch/board/board.h>
#include <uORB/uORB.h>
#include <uORB/topics/airspeed.h>
#include <uORB/topics/vehicle_global_position.h>
#include <uORB/topics/vehicle_global_position_set_triplet.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/vehicle_rates_setpoint.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_control_mode.h>
#include <uORB/topics/parameter_update.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>
#include <systemlib/pid/pid.h>
#include <geo/geo.h>
#include <systemlib/perf_counter.h>
#include <systemlib/systemlib.h>
#include <mathlib/mathlib.h>
#include <ecl/l1/ecl_l1_pos_control.h>
#include <external_lgpl/tecs/tecs.h>
/**
* L1 control app start / stop handling function
*
* @ingroup apps
*/
extern "C" __EXPORT int fw_pos_control_l1_main(int argc, char *argv[]);
class FixedwingPositionControl
{
public:
/**
* Constructor
*/
FixedwingPositionControl();
/**
* Destructor, also kills the sensors task.
*/
~FixedwingPositionControl();
/**
* Start the sensors task.
*
* @return OK on success.
*/
int start();
private:
bool _task_should_exit; /**< if true, sensor task should exit */
int _control_task; /**< task handle for sensor task */
int _global_pos_sub;
int _global_set_triplet_sub;
int _att_sub; /**< vehicle attitude subscription */
int _attitude_sub; /**< raw rc channels data subscription */
int _airspeed_sub; /**< airspeed subscription */
int _control_mode_sub; /**< vehicle status subscription */
int _params_sub; /**< notification of parameter updates */
int _manual_control_sub; /**< notification of manual control updates */
int _accel_sub; /**< body frame accelerations */
orb_advert_t _attitude_sp_pub; /**< attitude setpoint */
struct vehicle_attitude_s _att; /**< vehicle attitude */
struct vehicle_attitude_setpoint_s _att_sp; /**< vehicle attitude setpoint */
struct manual_control_setpoint_s _manual; /**< r/c channel data */
struct airspeed_s _airspeed; /**< airspeed */
struct vehicle_control_mode_s _control_mode; /**< vehicle status */
struct vehicle_global_position_s _global_pos; /**< global vehicle position */
struct vehicle_global_position_set_triplet_s _global_triplet; /**< triplet of global setpoints */
struct accel_report _accel; /**< body frame accelerations */
perf_counter_t _loop_perf; /**< loop performance counter */
bool _setpoint_valid; /**< flag if the position control setpoint is valid */
/** manual control states */
float _seatbelt_hold_heading; /**< heading the system should hold in seatbelt mode */
float _loiter_hold_lat;
float _loiter_hold_lon;
float _loiter_hold_alt;
bool _loiter_hold;
float _launch_lat;
float _launch_lon;
float _launch_alt;
bool _launch_valid;
/* throttle and airspeed states */
float _airspeed_error; ///< airspeed error to setpoint in m/s
bool _airspeed_valid; ///< flag if a valid airspeed estimate exists
uint64_t _airspeed_last_valid; ///< last time airspeed was valid. Used to detect sensor failures
float _groundspeed_undershoot; ///< ground speed error to min. speed in m/s
bool _global_pos_valid; ///< global position is valid
math::Dcm _R_nb; ///< current attitude
ECL_L1_Pos_Control _l1_control;
TECS _tecs;
struct {
float l1_period;
float l1_damping;
float time_const;
float min_sink_rate;
float max_sink_rate;
float max_climb_rate;
float throttle_damp;
float integrator_gain;
float vertical_accel_limit;
float height_comp_filter_omega;
float speed_comp_filter_omega;
float roll_throttle_compensation;
float speed_weight;
float pitch_damping;
float airspeed_min;
float airspeed_trim;
float airspeed_max;
float pitch_limit_min;
float pitch_limit_max;
float throttle_min;
float throttle_max;
float throttle_cruise;
float loiter_hold_radius;
} _parameters; /**< local copies of interesting parameters */
struct {
param_t l1_period;
param_t l1_damping;
param_t time_const;
param_t min_sink_rate;
param_t max_sink_rate;
param_t max_climb_rate;
param_t throttle_damp;
param_t integrator_gain;
param_t vertical_accel_limit;
param_t height_comp_filter_omega;
param_t speed_comp_filter_omega;
param_t roll_throttle_compensation;
param_t speed_weight;
param_t pitch_damping;
param_t airspeed_min;
param_t airspeed_trim;
param_t airspeed_max;
param_t pitch_limit_min;
param_t pitch_limit_max;
param_t throttle_min;
param_t throttle_max;
param_t throttle_cruise;
param_t loiter_hold_radius;
} _parameter_handles; /**< handles for interesting parameters */
/**
* Update our local parameter cache.
*/
int parameters_update();
/**
* Update control outputs
*
*/
void control_update();
/**
* Check for changes in vehicle status.
*/
void vehicle_control_mode_poll();
/**
* Check for airspeed updates.
*/
bool vehicle_airspeed_poll();
/**
* Check for position updates.
*/
void vehicle_attitude_poll();
/**
* Check for accel updates.
*/
void vehicle_accel_poll();
/**
* Check for set triplet updates.
*/
void vehicle_setpoint_poll();
/**
* Control position.
*/
bool control_position(const math::Vector2f &global_pos, const math::Vector2f &ground_speed,
const struct vehicle_global_position_set_triplet_s &global_triplet);
float calculate_target_airspeed(float airspeed_demand);
void calculate_gndspeed_undershoot();
/**
* Shim for calling task_main from task_create.
*/
static void task_main_trampoline(int argc, char *argv[]);
/**
* Main sensor collection task.
*/
void task_main() __attribute__((noreturn));
};
namespace l1_control
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;
FixedwingPositionControl *g_control;
}
FixedwingPositionControl::FixedwingPositionControl() :
_task_should_exit(false),
_control_task(-1),
/* subscriptions */
_global_pos_sub(-1),
_global_set_triplet_sub(-1),
_att_sub(-1),
_airspeed_sub(-1),
_control_mode_sub(-1),
_params_sub(-1),
_manual_control_sub(-1),
/* publications */
_attitude_sp_pub(-1),
/* performance counters */
_loop_perf(perf_alloc(PC_ELAPSED, "fw l1 control")),
/* states */
_setpoint_valid(false),
_loiter_hold(false),
_airspeed_error(0.0f),
_airspeed_valid(false),
_groundspeed_undershoot(0.0f),
_global_pos_valid(false)
{
_parameter_handles.l1_period = param_find("FW_L1_PERIOD");
_parameter_handles.l1_damping = param_find("FW_L1_DAMPING");
_parameter_handles.loiter_hold_radius = param_find("FW_LOITER_R");
_parameter_handles.airspeed_min = param_find("FW_AIRSPD_MIN");
_parameter_handles.airspeed_trim = param_find("FW_AIRSPD_TRIM");
_parameter_handles.airspeed_max = param_find("FW_AIRSPD_MAX");
_parameter_handles.pitch_limit_min = param_find("FW_P_LIM_MIN");
_parameter_handles.pitch_limit_max = param_find("FW_P_LIM_MAX");
_parameter_handles.throttle_min = param_find("FW_THR_MIN");
_parameter_handles.throttle_max = param_find("FW_THR_MAX");
_parameter_handles.throttle_cruise = param_find("FW_THR_CRUISE");
_parameter_handles.time_const = param_find("FW_T_TIME_CONST");
_parameter_handles.min_sink_rate = param_find("FW_T_SINK_MIN");
_parameter_handles.max_sink_rate = param_find("FW_T_SINK_MAX");
_parameter_handles.max_climb_rate = param_find("FW_T_CLMB_MAX");
_parameter_handles.throttle_damp = param_find("FW_T_THR_DAMP");
_parameter_handles.integrator_gain = param_find("FW_T_INTEG_GAIN");
_parameter_handles.vertical_accel_limit = param_find("FW_T_VERT_ACC");
_parameter_handles.height_comp_filter_omega = param_find("FW_T_HGT_OMEGA");
_parameter_handles.speed_comp_filter_omega = param_find("FW_T_SPD_OMEGA");
_parameter_handles.roll_throttle_compensation = param_find("FW_T_RLL2THR");
_parameter_handles.speed_weight = param_find("FW_T_SPDWEIGHT");
_parameter_handles.pitch_damping = param_find("FW_T_PTCH_DAMP");
/* fetch initial parameter values */
parameters_update();
}
FixedwingPositionControl::~FixedwingPositionControl()
{
if (_control_task != -1) {
/* task wakes up every 100ms or so at the longest */
_task_should_exit = true;
/* wait for a second for the task to quit at our request */
unsigned i = 0;
do {
/* wait 20ms */
usleep(20000);
/* if we have given up, kill it */
if (++i > 50) {
task_delete(_control_task);
break;
}
} while (_control_task != -1);
}
l1_control::g_control = nullptr;
}
int
FixedwingPositionControl::parameters_update()
{
/* L1 control parameters */
param_get(_parameter_handles.l1_damping, &(_parameters.l1_damping));
param_get(_parameter_handles.l1_period, &(_parameters.l1_period));
param_get(_parameter_handles.loiter_hold_radius, &(_parameters.loiter_hold_radius));
param_get(_parameter_handles.airspeed_min, &(_parameters.airspeed_min));
param_get(_parameter_handles.airspeed_trim, &(_parameters.airspeed_trim));
param_get(_parameter_handles.airspeed_max, &(_parameters.airspeed_max));
param_get(_parameter_handles.pitch_limit_min, &(_parameters.pitch_limit_min));
param_get(_parameter_handles.pitch_limit_max, &(_parameters.pitch_limit_max));
param_get(_parameter_handles.throttle_min, &(_parameters.throttle_min));
param_get(_parameter_handles.throttle_max, &(_parameters.throttle_max));
param_get(_parameter_handles.throttle_cruise, &(_parameters.throttle_cruise));
param_get(_parameter_handles.time_const, &(_parameters.time_const));
param_get(_parameter_handles.min_sink_rate, &(_parameters.min_sink_rate));
param_get(_parameter_handles.max_sink_rate, &(_parameters.max_sink_rate));
param_get(_parameter_handles.throttle_damp, &(_parameters.throttle_damp));
param_get(_parameter_handles.integrator_gain, &(_parameters.integrator_gain));
param_get(_parameter_handles.vertical_accel_limit, &(_parameters.vertical_accel_limit));
param_get(_parameter_handles.height_comp_filter_omega, &(_parameters.height_comp_filter_omega));
param_get(_parameter_handles.speed_comp_filter_omega, &(_parameters.speed_comp_filter_omega));
param_get(_parameter_handles.roll_throttle_compensation, &(_parameters.roll_throttle_compensation));
param_get(_parameter_handles.speed_weight, &(_parameters.speed_weight));
param_get(_parameter_handles.pitch_damping, &(_parameters.pitch_damping));
param_get(_parameter_handles.max_climb_rate, &(_parameters.max_climb_rate));
_l1_control.set_l1_damping(_parameters.l1_damping);
_l1_control.set_l1_period(_parameters.l1_period);
_tecs.set_time_const(_parameters.time_const);
_tecs.set_min_sink_rate(_parameters.min_sink_rate);
_tecs.set_max_sink_rate(_parameters.max_sink_rate);
_tecs.set_throttle_damp(_parameters.throttle_damp);
_tecs.set_integrator_gain(_parameters.integrator_gain);
_tecs.set_vertical_accel_limit(_parameters.vertical_accel_limit);
_tecs.set_height_comp_filter_omega(_parameters.height_comp_filter_omega);
_tecs.set_speed_comp_filter_omega(_parameters.speed_comp_filter_omega);
_tecs.set_roll_throttle_compensation(math::radians(_parameters.roll_throttle_compensation));
_tecs.set_speed_weight(_parameters.speed_weight);
_tecs.set_pitch_damping(_parameters.pitch_damping);
_tecs.set_indicated_airspeed_min(_parameters.airspeed_min);
_tecs.set_indicated_airspeed_max(_parameters.airspeed_min);
_tecs.set_max_climb_rate(_parameters.max_climb_rate);
/* sanity check parameters */
if (_parameters.airspeed_max < _parameters.airspeed_min ||
_parameters.airspeed_max < 5.0f ||
_parameters.airspeed_min > 100.0f ||
_parameters.airspeed_trim < _parameters.airspeed_min ||
_parameters.airspeed_trim > _parameters.airspeed_max) {
warnx("error: airspeed parameters invalid");
return 1;
}
return OK;
}
void
FixedwingPositionControl::vehicle_control_mode_poll()
{
bool vstatus_updated;
/* Check HIL state if vehicle status has changed */
orb_check(_control_mode_sub, &vstatus_updated);
if (vstatus_updated) {
bool was_armed = _control_mode.flag_armed;
orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
if (!was_armed && _control_mode.flag_armed) {
_launch_lat = _global_pos.lat / 1e7f;
_launch_lon = _global_pos.lon / 1e7f;
_launch_alt = _global_pos.alt;
_launch_valid = true;
}
}
}
bool
FixedwingPositionControl::vehicle_airspeed_poll()
{
/* check if there is an airspeed update or if it timed out */
bool airspeed_updated;
orb_check(_airspeed_sub, &airspeed_updated);
if (airspeed_updated) {
orb_copy(ORB_ID(airspeed), _airspeed_sub, &_airspeed);
_airspeed_valid = true;
_airspeed_last_valid = hrt_absolute_time();
return true;
} else {
/* no airspeed updates for one second */
if (_airspeed_valid && (hrt_absolute_time() - _airspeed_last_valid) > 1e6) {
_airspeed_valid = false;
}
}
/* update TECS state */
_tecs.enable_airspeed(_airspeed_valid);
return false;
}
void
FixedwingPositionControl::vehicle_attitude_poll()
{
/* check if there is a new position */
bool att_updated;
orb_check(_att_sub, &att_updated);
if (att_updated) {
orb_copy(ORB_ID(vehicle_attitude), _att_sub, &_att);
/* set rotation matrix */
for (int i = 0; i < 3; i++) for (int j = 0; j < 3; j++)
_R_nb(i, j) = _att.R[i][j];
}
}
void
FixedwingPositionControl::vehicle_accel_poll()
{
/* check if there is a new position */
bool accel_updated;
orb_check(_accel_sub, &accel_updated);
if (accel_updated) {
orb_copy(ORB_ID(sensor_accel), _accel_sub, &_accel);
}
}
void
FixedwingPositionControl::vehicle_setpoint_poll()
{
/* check if there is a new setpoint */
bool global_sp_updated;
orb_check(_global_set_triplet_sub, &global_sp_updated);
if (global_sp_updated) {
orb_copy(ORB_ID(vehicle_global_position_set_triplet), _global_set_triplet_sub, &_global_triplet);
_setpoint_valid = true;
}
}
void
FixedwingPositionControl::task_main_trampoline(int argc, char *argv[])
{
l1_control::g_control->task_main();
}
float
FixedwingPositionControl::calculate_target_airspeed(float airspeed_demand)
{
float airspeed;
if (_airspeed_valid) {
airspeed = _airspeed.true_airspeed_m_s;
} else {
airspeed = _parameters.airspeed_min + (_parameters.airspeed_max - _parameters.airspeed_min) / 2.0f;
}
/* cruise airspeed for all modes unless modified below */
float target_airspeed = airspeed_demand;
/* add minimum ground speed undershoot (only non-zero in presence of sufficient wind) */
target_airspeed += _groundspeed_undershoot;
if (0/* throttle nudging enabled */) {
//target_airspeed += nudge term.
}
/* sanity check: limit to range */
target_airspeed = math::constrain(target_airspeed, _parameters.airspeed_min, _parameters.airspeed_max);
/* plain airspeed error */
_airspeed_error = target_airspeed - airspeed;
return target_airspeed;
}
void
FixedwingPositionControl::calculate_gndspeed_undershoot()
{
if (_global_pos_valid) {
/* get ground speed vector */
math::Vector2f ground_speed_vector(_global_pos.vx, _global_pos.vy);
/* rotate with current attitude */
math::Vector2f yaw_vector(_R_nb(0, 0), _R_nb(1, 0));
yaw_vector.normalize();
float ground_speed_body = yaw_vector * ground_speed_vector;
/*
* Ground speed undershoot is the amount of ground velocity not reached
* by the plane. Consequently it is zero if airspeed is >= min ground speed
* and positive if airspeed < min ground speed.
*
* This error value ensures that a plane (as long as its throttle capability is
* not exceeded) travels towards a waypoint (and is not pushed more and more away
* by wind). Not countering this would lead to a fly-away.
*/
_groundspeed_undershoot = math::max(_parameters.airspeed_min - ground_speed_body, 0.0f);
} else {
_groundspeed_undershoot = 0;
}
}
bool
FixedwingPositionControl::control_position(const math::Vector2f ¤t_position, const math::Vector2f &ground_speed,
const struct vehicle_global_position_set_triplet_s &global_triplet)
{
bool setpoint = true;
calculate_gndspeed_undershoot();
float eas2tas = 1.0f; // XXX calculate actual number based on current measurements
// XXX re-visit
float baro_altitude = _global_pos.alt;
/* filter speed and altitude for controller */
math::Vector3 accel_body(_accel.x, _accel.y, _accel.z);
math::Vector3 accel_earth = _R_nb.transpose() * accel_body;
_tecs.update_50hz(baro_altitude, _airspeed.indicated_airspeed_m_s, _R_nb, accel_body, accel_earth);
float altitude_error = _global_triplet.current.altitude - _global_pos.alt;
/* AUTONOMOUS FLIGHT */
// XXX this should only execute if auto AND safety off (actuators active),
// else integrators should be constantly reset.
if (_control_mode.flag_control_position_enabled) {
/* execute navigation once we have a setpoint */
if (_setpoint_valid) {
float altitude_error = _global_triplet.current.altitude - _global_pos.alt;
/* current waypoint (the one currently heading for) */
math::Vector2f next_wp(global_triplet.current.lat / 1e7f, global_triplet.current.lon / 1e7f);
/* previous waypoint */
math::Vector2f prev_wp;
if (global_triplet.previous_valid) {
prev_wp.setX(global_triplet.previous.lat / 1e7f);
prev_wp.setY(global_triplet.previous.lon / 1e7f);
} else {
/*
* No valid next waypoint, go for heading hold.
* This is automatically handled by the L1 library.
*/
prev_wp.setX(global_triplet.current.lat / 1e7f);
prev_wp.setY(global_triplet.current.lon / 1e7f);
}
// XXX add RTL switch
if (global_triplet.current.nav_cmd == NAV_CMD_RETURN_TO_LAUNCH && _launch_valid) {
math::Vector2f rtl_pos(_launch_lat, _launch_lon);
_l1_control.navigate_waypoints(rtl_pos, rtl_pos, current_position, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _launch_alt, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
false, math::radians(_parameters.pitch_limit_min),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
// XXX handle case when having arrived at home (loiter)
} else if (global_triplet.current.nav_cmd == NAV_CMD_WAYPOINT) {
/* waypoint is a plain navigation waypoint */
_l1_control.navigate_waypoints(prev_wp, next_wp, current_position, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
false, math::radians(_parameters.pitch_limit_min),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
} else if (global_triplet.current.nav_cmd == NAV_CMD_LOITER_TURN_COUNT ||
global_triplet.current.nav_cmd == NAV_CMD_LOITER_TIME_LIMIT ||
global_triplet.current.nav_cmd == NAV_CMD_LOITER_UNLIMITED) {
/* waypoint is a loiter waypoint */
_l1_control.navigate_loiter(next_wp, current_position, global_triplet.current.loiter_radius,
global_triplet.current.loiter_direction, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
false, math::radians(_parameters.pitch_limit_min),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
} else if (global_triplet.current.nav_cmd == NAV_CMD_LAND) {
_l1_control.navigate_waypoints(prev_wp, next_wp, current_position, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
/* apply minimum pitch (flare) and limit roll if close to touch down, altitude error is negative (going down) */
// XXX this could make a great param
if (altitude_error > -20.0f) {
float flare_angle_rad = math::radians(15.0f);//math::radians(global_triplet.current.param1)
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_min),
_airspeed.indicated_airspeed_m_s, eas2tas,
true, flare_angle_rad,
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
/* limit roll motion to prevent wings from touching the ground first */
_att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-20.0f), math::radians(20.0f));
} else {
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
false, math::radians(_parameters.pitch_limit_min),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
}
} else if (global_triplet.current.nav_cmd == NAV_CMD_TAKEOFF) {
_l1_control.navigate_waypoints(prev_wp, next_wp, current_position, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
/* apply minimum pitch and limit roll if target altitude is not within 10 meters */
if (altitude_error > 10.0f) {
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_min),
_airspeed.indicated_airspeed_m_s, eas2tas,
true, math::radians(global_triplet.current.param1),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
/* limit roll motion to ensure enough lift */
_att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-15.0f), math::radians(15.0f));
} else {
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_triplet.current.altitude, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
false, math::radians(_parameters.pitch_limit_min),
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
}
}
// warnx("nav bearing: %8.4f bearing err: %8.4f target bearing: %8.4f", (double)_l1_control.nav_bearing(),
// (double)_l1_control.bearing_error(), (double)_l1_control.target_bearing());
// warnx("prev wp: %8.4f/%8.4f, next wp: %8.4f/%8.4f prev:%s", (double)prev_wp.getX(), (double)prev_wp.getY(),
// (double)next_wp.getX(), (double)next_wp.getY(), (global_triplet.previous_valid) ? "valid" : "invalid");
// XXX at this point we always want no loiter hold if a
// mission is active
_loiter_hold = false;
} else if (_control_mode.flag_armed) {
/* hold position, but only if armed, climb 20m in case this is engaged on ground level */
// XXX rework with smarter state machine
if (!_loiter_hold) {
_loiter_hold_lat = _global_pos.lat / 1e7f;
_loiter_hold_lon = _global_pos.lon / 1e7f;
_loiter_hold_alt = _global_pos.alt + 25.0f;
_loiter_hold = true;
}
float altitude_error = _loiter_hold_alt - _global_pos.alt;
math::Vector2f loiter_hold_pos(_loiter_hold_lat, _loiter_hold_lon);
/* loiter around current position */
_l1_control.navigate_loiter(loiter_hold_pos, current_position, _parameters.loiter_hold_radius,
1, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
/* climb with full throttle if the altitude error is bigger than 5 meters */
bool climb_out = (altitude_error > 5);
float min_pitch;
if (climb_out) {
min_pitch = math::radians(20.0f);
} else {
min_pitch = math::radians(_parameters.pitch_limit_min);
}
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _loiter_hold_alt, calculate_target_airspeed(_parameters.airspeed_trim),
_airspeed.indicated_airspeed_m_s, eas2tas,
climb_out, min_pitch,
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
math::radians(_parameters.pitch_limit_min), math::radians(_parameters.pitch_limit_max));
if (climb_out) {
/* limit roll motion to ensure enough lift */
_att_sp.roll_body = math::constrain(_att_sp.roll_body, math::radians(-15.0f), math::radians(15.0f));
}
}
} else if (0/* seatbelt mode enabled */) {
/** SEATBELT FLIGHT **/
if (0/* switched from another mode to seatbelt */) {
_seatbelt_hold_heading = _att.yaw;
}
if (0/* seatbelt on and manual control yaw non-zero */) {
_seatbelt_hold_heading = _att.yaw + _manual.yaw;
}
/* if in seatbelt mode, set airspeed based on manual control */
// XXX check if ground speed undershoot should be applied here
float seatbelt_airspeed = _parameters.airspeed_min +
(_parameters.airspeed_max - _parameters.airspeed_min) *
_manual.throttle;
_l1_control.navigate_heading(_seatbelt_hold_heading, _att.yaw, ground_speed);
_att_sp.roll_body = _l1_control.nav_roll();
_att_sp.yaw_body = _l1_control.nav_bearing();
_tecs.update_pitch_throttle(_R_nb, _att.pitch, _global_pos.alt, _global_pos.alt + _manual.pitch * 2.0f,
seatbelt_airspeed,
_airspeed.indicated_airspeed_m_s, eas2tas,
false, _parameters.pitch_limit_min,
_parameters.throttle_min, _parameters.throttle_max, _parameters.throttle_cruise,
_parameters.pitch_limit_min, _parameters.pitch_limit_max);
} else {
/** MANUAL FLIGHT **/
/* no flight mode applies, do not publish an attitude setpoint */
setpoint = false;
}
_att_sp.pitch_body = _tecs.get_pitch_demand();
_att_sp.thrust = _tecs.get_throttle_demand();
return setpoint;
}
void
FixedwingPositionControl::task_main()
{
/* inform about start */
warnx("Initializing..");
fflush(stdout);
/*
* do subscriptions
*/
_global_pos_sub = orb_subscribe(ORB_ID(vehicle_global_position));
_global_set_triplet_sub = orb_subscribe(ORB_ID(vehicle_global_position_set_triplet));
_att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
_accel_sub = orb_subscribe(ORB_ID(sensor_accel));
_control_mode_sub = orb_subscribe(ORB_ID(vehicle_control_mode));
_airspeed_sub = orb_subscribe(ORB_ID(airspeed));
_params_sub = orb_subscribe(ORB_ID(parameter_update));
_manual_control_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
/* rate limit vehicle status updates to 5Hz */
orb_set_interval(_control_mode_sub, 200);
/* rate limit position updates to 50 Hz */
orb_set_interval(_global_pos_sub, 20);
/* abort on a nonzero return value from the parameter init */
if (parameters_update()) {
/* parameter setup went wrong, abort */
warnx("aborting startup due to errors.");
_task_should_exit = true;
}
/* wakeup source(s) */
struct pollfd fds[2];
/* Setup of loop */
fds[0].fd = _params_sub;
fds[0].events = POLLIN;
fds[1].fd = _global_pos_sub;
fds[1].events = POLLIN;
while (!_task_should_exit) {
/* wait for up to 500ms for data */
int pret = poll(&fds[0], (sizeof(fds) / sizeof(fds[0])), 100);
/* timed out - periodic check for _task_should_exit, etc. */
if (pret == 0)
continue;
/* this is undesirable but not much we can do - might want to flag unhappy status */
if (pret < 0) {
warn("poll error %d, %d", pret, errno);
continue;
}
perf_begin(_loop_perf);
/* check vehicle status for changes to publication state */
vehicle_control_mode_poll();
/* only update parameters if they changed */
if (fds[0].revents & POLLIN) {
/* read from param to clear updated flag */
struct parameter_update_s update;
orb_copy(ORB_ID(parameter_update), _params_sub, &update);
/* update parameters from storage */
parameters_update();
}
/* only run controller if position changed */
if (fds[1].revents & POLLIN) {
static uint64_t last_run = 0;
float deltaT = (hrt_absolute_time() - last_run) / 1000000.0f;
last_run = hrt_absolute_time();
/* guard against too large deltaT's */
if (deltaT > 1.0f)
deltaT = 0.01f;
/* load local copies */
orb_copy(ORB_ID(vehicle_global_position), _global_pos_sub, &_global_pos);
// XXX add timestamp check
_global_pos_valid = true;
vehicle_attitude_poll();
vehicle_setpoint_poll();
vehicle_accel_poll();
vehicle_airspeed_poll();
// vehicle_baro_poll();
math::Vector2f ground_speed(_global_pos.vx, _global_pos.vy);
math::Vector2f current_position(_global_pos.lat / 1e7f, _global_pos.lon / 1e7f);
/*
* Attempt to control position, on success (= sensors present and not in manual mode),
* publish setpoint.
*/
if (control_position(current_position, ground_speed, _global_triplet)) {
_att_sp.timestamp = hrt_absolute_time();
/* lazily publish the setpoint only once available */
if (_attitude_sp_pub > 0) {
/* publish the attitude setpoint */
orb_publish(ORB_ID(vehicle_attitude_setpoint), _attitude_sp_pub, &_att_sp);
} else {
/* advertise and publish */
_attitude_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
}
}
}
perf_end(_loop_perf);
}
warnx("exiting.\n");
_control_task = -1;
_exit(0);
}
int
FixedwingPositionControl::start()
{
ASSERT(_control_task == -1);
/* start the task */
_control_task = task_spawn_cmd("fw_pos_control_l1",
SCHED_DEFAULT,
SCHED_PRIORITY_MAX - 5,
4048,
(main_t)&FixedwingPositionControl::task_main_trampoline,
nullptr);
if (_control_task < 0) {
warn("task start failed");
return -errno;
}
return OK;
}
int fw_pos_control_l1_main(int argc, char *argv[])
{
if (argc < 1)
errx(1, "usage: fw_pos_control_l1 {start|stop|status}");
if (!strcmp(argv[1], "start")) {
if (l1_control::g_control != nullptr)
errx(1, "already running");
l1_control::g_control = new FixedwingPositionControl;
if (l1_control::g_control == nullptr)
errx(1, "alloc failed");
if (OK != l1_control::g_control->start()) {
delete l1_control::g_control;
l1_control::g_control = nullptr;
err(1, "start failed");
}
exit(0);
}
if (!strcmp(argv[1], "stop")) {
if (l1_control::g_control == nullptr)
errx(1, "not running");
delete l1_control::g_control;
l1_control::g_control = nullptr;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (l1_control::g_control) {
errx(0, "running");
} else {
errx(1, "not running");
}
}
warnx("unrecognized command");
return 1;
}