output.cpp

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/**
 * @file output.cpp
 * @author Leon Müller (thedevleon)
 * @author Beat Küng <beat-kueng@gmx.net>
 *
 */

#include "output.h"
#include <errno.h>

#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_global_position.h>
#include <uORB/topics/mount_orientation.h>
#include <px4_platform_common/defines.h>
#include <lib/ecl/geo/geo.h>
#include <math.h>
#include <mathlib/mathlib.h>
#include <matrix/math.hpp>

using matrix::wrap_pi;

namespace vmount
{

OutputBase::OutputBase(const OutputConfig &output_config)
    : _config(output_config)
{
    _last_update = hrt_absolute_time();
}

OutputBase::~OutputBase()
{
    if (_vehicle_attitude_sub >= 0) {
        orb_unsubscribe(_vehicle_attitude_sub);
    }

    if (_vehicle_global_position_sub >= 0) {
        orb_unsubscribe(_vehicle_global_position_sub);
    }

    if (_mount_orientation_pub) {
        orb_unadvertise(_mount_orientation_pub);
    }
}

int OutputBase::initialize()
{
    if ((_vehicle_attitude_sub = orb_subscribe(ORB_ID(vehicle_attitude))) < 0) {
        return -errno;
    }

    if ((_vehicle_global_position_sub = orb_subscribe(ORB_ID(vehicle_global_position))) < 0) {
        return -errno;
    }

    return 0;
}

void OutputBase::publish()
{
    int instance;
    mount_orientation_s mount_orientation;

    for (unsigned i = 0; i < 3; ++i) {
        mount_orientation.attitude_euler_angle[i] = _angle_outputs[i];
    }

    orb_publish_auto(ORB_ID(mount_orientation), &_mount_orientation_pub, &mount_orientation, &instance, ORB_PRIO_DEFAULT);
}

float OutputBase::_calculate_pitch(double lon, double lat, float altitude,
                   const vehicle_global_position_s &global_position)
{
    if (!map_projection_initialized(&_projection_reference)) {
        map_projection_init(&_projection_reference, global_position.lat, global_position.lon);
    }

    float x1, y1, x2, y2;
    map_projection_project(&_projection_reference, lat, lon, &x1, &y1);
    map_projection_project(&_projection_reference, global_position.lat, global_position.lon, &x2, &y2);
    float dx = x1 - x2, dy = y1 - y2;
    float target_distance = sqrtf(dx * dx + dy * dy);
    float z = altitude - global_position.alt;

    return atan2f(z, target_distance);
}

void OutputBase::_set_angle_setpoints(const ControlData *control_data)
{
    _cur_control_data = control_data;

    for (int i = 0; i < 3; ++i) {
        _stabilize[i] = control_data->stabilize_axis[i];
        _angle_speeds[i] = 0.f;
    }

    switch (control_data->type) {
    case ControlData::Type::Angle:
        for (int i = 0; i < 3; ++i) {
            if (control_data->type_data.angle.is_speed[i]) {
                _angle_speeds[i] = control_data->type_data.angle.angles[i];

            } else {
                _angle_setpoints[i] = control_data->type_data.angle.angles[i];
            }
        }

        break;

    case ControlData::Type::LonLat:
        _handle_position_update(true);
        break;

    case ControlData::Type::Neutral:
        _angle_setpoints[0] = 0.f;
        _angle_setpoints[1] = 0.f;
        _angle_setpoints[2] = 0.f;
        break;
    }
}

void OutputBase::_handle_position_update(bool force_update)
{
    bool need_update = force_update;

    if (!_cur_control_data || _cur_control_data->type != ControlData::Type::LonLat) {
        return;
    }

    if (!force_update) {
        orb_check(_vehicle_global_position_sub, &need_update);
    }

    if (!need_update) {
        return;
    }

    vehicle_global_position_s vehicle_global_position;
    orb_copy(ORB_ID(vehicle_global_position), _vehicle_global_position_sub, &vehicle_global_position);
    const double &vlat = vehicle_global_position.lat;
    const double &vlon = vehicle_global_position.lon;

    const double &lat = _cur_control_data->type_data.lonlat.lat;
    const double &lon = _cur_control_data->type_data.lonlat.lon;
    const float &alt = _cur_control_data->type_data.lonlat.altitude;

    _angle_setpoints[0] = _cur_control_data->type_data.lonlat.roll_angle;

    // interface: use fixed pitch value > -pi otherwise consider ROI altitude
    if (_cur_control_data->type_data.lonlat.pitch_fixed_angle >= -M_PI_F) {
        _angle_setpoints[1] = _cur_control_data->type_data.lonlat.pitch_fixed_angle;

    } else {
        _angle_setpoints[1] = _calculate_pitch(lon, lat, alt, vehicle_global_position);
    }

    _angle_setpoints[2] = get_bearing_to_next_waypoint(vlat, vlon, lat, lon) - vehicle_global_position.yaw;

    // add offsets from VEHICLE_CMD_DO_SET_ROI_WPNEXT_OFFSET
    _angle_setpoints[1] += _cur_control_data->type_data.lonlat.pitch_angle_offset;
    _angle_setpoints[2] += _cur_control_data->type_data.lonlat.yaw_angle_offset;

    // make sure yaw is wrapped correctly for the output
    _angle_setpoints[2] = wrap_pi(_angle_setpoints[2]);
}

void OutputBase::_calculate_output_angles(const hrt_abstime &t)
{
    //take speed into account
    float dt = (t - _last_update) / 1.e6f;

    for (int i = 0; i < 3; ++i) {
        _angle_setpoints[i] += dt * _angle_speeds[i];
    }

    //get the output angles and stabilize if necessary
    vehicle_attitude_s vehicle_attitude;
    matrix::Eulerf euler;

    if (_stabilize[0] || _stabilize[1] || _stabilize[2]) {
        orb_copy(ORB_ID(vehicle_attitude), _vehicle_attitude_sub, &vehicle_attitude);
        euler = matrix::Quatf(vehicle_attitude.q);
    }

    for (int i = 0; i < 3; ++i) {
        if (_stabilize[i]) {
            _angle_outputs[i] = _angle_setpoints[i] - euler(i);

        } else {
            _angle_outputs[i] = _angle_setpoints[i];
        }

        //bring angles into proper range [-pi, pi]
        while (_angle_outputs[i] > M_PI_F) { _angle_outputs[i] -= 2.f * M_PI_F; }

        while (_angle_outputs[i] < -M_PI_F) { _angle_outputs[i] += 2.f * M_PI_F; }
    }
}

} /* namespace vmount */