void
FixedwingAttitudeControl::task_main()
{
/*
* do subscriptions
*/
_att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
_att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
_vcontrol_mode_sub = orb_subscribe(ORB_ID(vehicle_control_mode));
_params_sub = orb_subscribe(ORB_ID(parameter_update));
_manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
_global_pos_sub = orb_subscribe(ORB_ID(vehicle_global_position));
_vehicle_status_sub = orb_subscribe(ORB_ID(vehicle_status));
_vehicle_land_detected_sub = orb_subscribe(ORB_ID(vehicle_land_detected));
_battery_status_sub = orb_subscribe(ORB_ID(battery_status));
parameters_update();
/* get an initial update for all sensor and status data */
vehicle_setpoint_poll();
vehicle_control_mode_poll();
vehicle_manual_poll();
vehicle_status_poll();
vehicle_land_detected_poll();
battery_status_poll();
_sub_airspeed.update();
/* wakeup source */
px4_pollfd_struct_t fds[1];
/* Setup of loop */
fds[0].fd = _att_sub;
fds[0].events = POLLIN;
_task_running = true;
while (!_task_should_exit) {
static int loop_counter = 0;
/* wait for up to 500ms for data */
int pret = px4_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) {
PX4_WARN("poll error %d, %d", pret, errno);
continue;
}
perf_begin(_loop_perf);
/* only update parameters if they changed */
bool params_updated = false;
orb_check(_params_sub, ¶ms_updated);
if (params_updated) {
/* read from param to clear updated flag */
parameter_update_s update;
orb_copy(ORB_ID(parameter_update), _params_sub, &update);
/* update parameters from storage */
parameters_update();
}
/* only run controller if attitude changed */
if (fds[0].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_attitude), _att_sub, &_att);
/* get current rotation matrix and euler angles from control state quaternions */
math::Quaternion q_att(_att.q[0], _att.q[1], _att.q[2], _att.q[3]);
_R = q_att.to_dcm();
math::Vector<3> euler_angles;
euler_angles = _R.to_euler();
_roll = euler_angles(0);
_pitch = euler_angles(1);
_yaw = euler_angles(2);
if (_vehicle_status.is_vtol && _parameters.vtol_type == vtol_type::TAILSITTER) {
/* vehicle is a tailsitter, we need to modify the estimated attitude for fw mode
*
* Since the VTOL airframe is initialized as a multicopter we need to
* modify the estimated attitude for the fixed wing operation.
* Since the neutral position of the vehicle in fixed wing mode is -90 degrees rotated around
* the pitch axis compared to the neutral position of the vehicle in multicopter mode
* we need to swap the roll and the yaw axis (1st and 3rd column) in the rotation matrix.
* Additionally, in order to get the correct sign of the pitch, we need to multiply
* the new x axis of the rotation matrix with -1
*
* original: modified:
*
* Rxx Ryx Rzx -Rzx Ryx Rxx
* Rxy Ryy Rzy -Rzy Ryy Rxy
* Rxz Ryz Rzz -Rzz Ryz Rxz
* */
math::Matrix<3, 3> R_adapted = _R; //modified rotation matrix
/* move z to x */
R_adapted(0, 0) = _R(0, 2);
R_adapted(1, 0) = _R(1, 2);
R_adapted(2, 0) = _R(2, 2);
/* move x to z */
R_adapted(0, 2) = _R(0, 0);
R_adapted(1, 2) = _R(1, 0);
R_adapted(2, 2) = _R(2, 0);
/* change direction of pitch (convert to right handed system) */
R_adapted(0, 0) = -R_adapted(0, 0);
R_adapted(1, 0) = -R_adapted(1, 0);
R_adapted(2, 0) = -R_adapted(2, 0);
euler_angles = R_adapted.to_euler(); //adapted euler angles for fixed wing operation
/* fill in new attitude data */
_R = R_adapted;
_roll = euler_angles(0);
_pitch = euler_angles(1);
_yaw = euler_angles(2);
/* lastly, roll- and yawspeed have to be swaped */
float helper = _att.rollspeed;
_att.rollspeed = -_att.yawspeed;
_att.yawspeed = helper;
}
_sub_airspeed.update();
vehicle_setpoint_poll();
vehicle_control_mode_poll();
vehicle_manual_poll();
global_pos_poll();
vehicle_status_poll();
vehicle_land_detected_poll();
battery_status_poll();
// the position controller will not emit attitude setpoints in some modes
// we need to make sure that this flag is reset
_att_sp.fw_control_yaw = _att_sp.fw_control_yaw && _vcontrol_mode.flag_control_auto_enabled;
/* lock integrator until control is started */
bool lock_integrator = !(_vcontrol_mode.flag_control_rates_enabled && !_vehicle_status.is_rotary_wing);
/* Simple handling of failsafe: deploy parachute if failsafe is on */
if (_vcontrol_mode.flag_control_termination_enabled) {
_actuators_airframe.control[7] = 1.0f;
//warnx("_actuators_airframe.control[1] = 1.0f;");
} else {
_actuators_airframe.control[7] = 0.0f;
//warnx("_actuators_airframe.control[1] = -1.0f;");
}
/* if we are in rotary wing mode, do nothing */
if (_vehicle_status.is_rotary_wing && !_vehicle_status.is_vtol) {
continue;
}
/* default flaps to center */
float flap_control = 0.0f;
/* map flaps by default to manual if valid */
if (PX4_ISFINITE(_manual.flaps) && _vcontrol_mode.flag_control_manual_enabled
&& fabsf(_parameters.flaps_scale) > 0.01f) {
flap_control = 0.5f * (_manual.flaps + 1.0f) * _parameters.flaps_scale;
} else if (_vcontrol_mode.flag_control_auto_enabled
&& fabsf(_parameters.flaps_scale) > 0.01f) {
flap_control = _att_sp.apply_flaps ? 1.0f * _parameters.flaps_scale : 0.0f;
}
// move the actual control value continuous with time, full flap travel in 1sec
if (fabsf(_flaps_applied - flap_control) > 0.01f) {
_flaps_applied += (_flaps_applied - flap_control) < 0 ? deltaT : -deltaT;
} else {
_flaps_applied = flap_control;
}
/* default flaperon to center */
float flaperon_control = 0.0f;
/* map flaperons by default to manual if valid */
if (PX4_ISFINITE(_manual.aux2) && _vcontrol_mode.flag_control_manual_enabled
&& fabsf(_parameters.flaperon_scale) > 0.01f) {
flaperon_control = 0.5f * (_manual.aux2 + 1.0f) * _parameters.flaperon_scale;
} else if (_vcontrol_mode.flag_control_auto_enabled
&& fabsf(_parameters.flaperon_scale) > 0.01f) {
flaperon_control = _att_sp.apply_flaps ? 1.0f * _parameters.flaperon_scale : 0.0f;
}
// move the actual control value continuous with time, full flap travel in 1sec
if (fabsf(_flaperons_applied - flaperon_control) > 0.01f) {
_flaperons_applied += (_flaperons_applied - flaperon_control) < 0 ? deltaT : -deltaT;
} else {
_flaperons_applied = flaperon_control;
}
// Check if we are in rattitude mode and the pilot is above the threshold on pitch
if (_vcontrol_mode.flag_control_rattitude_enabled) {
if (fabsf(_manual.y) > _parameters.rattitude_thres ||
fabsf(_manual.x) > _parameters.rattitude_thres) {
_vcontrol_mode.flag_control_attitude_enabled = false;
}
}
/* decide if in stabilized or full manual control */
if (_vcontrol_mode.flag_control_rates_enabled) {
/* scale around tuning airspeed */
float airspeed;
/* if airspeed is non-finite or not valid or if we are asked not to control it, we assume the normal average speed */
const bool airspeed_valid = PX4_ISFINITE(_sub_airspeed.get().indicated_airspeed_m_s)
&& ((_sub_airspeed.get().timestamp - hrt_absolute_time()) < 1e6);
if (airspeed_valid) {
/* prevent numerical drama by requiring 0.5 m/s minimal speed */
airspeed = math::max(0.5f, _sub_airspeed.get().indicated_airspeed_m_s);
} else {
airspeed = _parameters.airspeed_trim;
perf_count(_nonfinite_input_perf);
}
/*
* For scaling our actuators using anything less than the min (close to stall)
* speed doesn't make any sense - its the strongest reasonable deflection we
* want to do in flight and its the baseline a human pilot would choose.
*
* Forcing the scaling to this value allows reasonable handheld tests.
*/
float airspeed_scaling = _parameters.airspeed_trim / ((airspeed < _parameters.airspeed_min) ? _parameters.airspeed_min :
airspeed);
/* Use min airspeed to calculate ground speed scaling region.
* Don't scale below gspd_scaling_trim
*/
float groundspeed = sqrtf(_global_pos.vel_n * _global_pos.vel_n +
_global_pos.vel_e * _global_pos.vel_e);
float gspd_scaling_trim = (_parameters.airspeed_min * 0.6f);
float groundspeed_scaler = gspd_scaling_trim / ((groundspeed < gspd_scaling_trim) ? gspd_scaling_trim : groundspeed);
// in STABILIZED mode we need to generate the attitude setpoint
// from manual user inputs
if (!_vcontrol_mode.flag_control_climb_rate_enabled && !_vcontrol_mode.flag_control_offboard_enabled) {
_att_sp.timestamp = hrt_absolute_time();
_att_sp.roll_body = _manual.y * _parameters.man_roll_max + _parameters.rollsp_offset_rad;
_att_sp.roll_body = math::constrain(_att_sp.roll_body, -_parameters.man_roll_max, _parameters.man_roll_max);
_att_sp.pitch_body = -_manual.x * _parameters.man_pitch_max + _parameters.pitchsp_offset_rad;
_att_sp.pitch_body = math::constrain(_att_sp.pitch_body, -_parameters.man_pitch_max, _parameters.man_pitch_max);
_att_sp.yaw_body = 0.0f;
_att_sp.thrust = _manual.z;
Quatf q(Eulerf(_att_sp.roll_body, _att_sp.pitch_body, _att_sp.yaw_body));
q.copyTo(_att_sp.q_d);
_att_sp.q_d_valid = true;
int instance;
orb_publish_auto(_attitude_setpoint_id, &_attitude_sp_pub, &_att_sp, &instance, ORB_PRIO_DEFAULT);
}
/* reset integrals where needed */
if (_att_sp.roll_reset_integral) {
_roll_ctrl.reset_integrator();
}
if (_att_sp.pitch_reset_integral) {
_pitch_ctrl.reset_integrator();
}
if (_att_sp.yaw_reset_integral) {
_yaw_ctrl.reset_integrator();
_wheel_ctrl.reset_integrator();
}
/* Reset integrators if the aircraft is on ground
* or a multicopter (but not transitioning VTOL)
*/
if (_vehicle_land_detected.landed
|| (_vehicle_status.is_rotary_wing && !_vehicle_status.in_transition_mode)) {
_roll_ctrl.reset_integrator();
_pitch_ctrl.reset_integrator();
_yaw_ctrl.reset_integrator();
_wheel_ctrl.reset_integrator();
}
float roll_sp = _att_sp.roll_body;
float pitch_sp = _att_sp.pitch_body;
float yaw_sp = _att_sp.yaw_body;
float throttle_sp = _att_sp.thrust;
/* Prepare data for attitude controllers */
struct ECL_ControlData control_input = {};
control_input.roll = _roll;
control_input.pitch = _pitch;
control_input.yaw = _yaw;
control_input.body_x_rate = _att.rollspeed;
control_input.body_y_rate = _att.pitchspeed;
control_input.body_z_rate = _att.yawspeed;
control_input.roll_setpoint = roll_sp;
control_input.pitch_setpoint = pitch_sp;
control_input.yaw_setpoint = yaw_sp;
control_input.airspeed_min = _parameters.airspeed_min;
control_input.airspeed_max = _parameters.airspeed_max;
control_input.airspeed = airspeed;
control_input.scaler = airspeed_scaling;
control_input.lock_integrator = lock_integrator;
control_input.groundspeed = groundspeed;
control_input.groundspeed_scaler = groundspeed_scaler;
/* Run attitude controllers */
if (_vcontrol_mode.flag_control_attitude_enabled) {
if (PX4_ISFINITE(roll_sp) && PX4_ISFINITE(pitch_sp)) {
_roll_ctrl.control_attitude(control_input);
_pitch_ctrl.control_attitude(control_input);
_yaw_ctrl.control_attitude(control_input); //runs last, because is depending on output of roll and pitch attitude
_wheel_ctrl.control_attitude(control_input);
/* Update input data for rate controllers */
control_input.roll_rate_setpoint = _roll_ctrl.get_desired_rate();
control_input.pitch_rate_setpoint = _pitch_ctrl.get_desired_rate();
control_input.yaw_rate_setpoint = _yaw_ctrl.get_desired_rate();
/* Run attitude RATE controllers which need the desired attitudes from above, add trim */
float roll_u = _roll_ctrl.control_euler_rate(control_input);
_actuators.control[actuator_controls_s::INDEX_ROLL] = (PX4_ISFINITE(roll_u)) ? roll_u + _parameters.trim_roll :
_parameters.trim_roll;
if (!PX4_ISFINITE(roll_u)) {
_roll_ctrl.reset_integrator();
perf_count(_nonfinite_output_perf);
if (_debug && loop_counter % 10 == 0) {
warnx("roll_u %.4f", (double)roll_u);
}
}
float pitch_u = _pitch_ctrl.control_euler_rate(control_input);
_actuators.control[actuator_controls_s::INDEX_PITCH] = (PX4_ISFINITE(pitch_u)) ? pitch_u + _parameters.trim_pitch :
_parameters.trim_pitch;
if (!PX4_ISFINITE(pitch_u)) {
_pitch_ctrl.reset_integrator();
perf_count(_nonfinite_output_perf);
if (_debug && loop_counter % 10 == 0) {
warnx("pitch_u %.4f, _yaw_ctrl.get_desired_rate() %.4f,"
" airspeed %.4f, airspeed_scaling %.4f,"
" roll_sp %.4f, pitch_sp %.4f,"
" _roll_ctrl.get_desired_rate() %.4f,"
" _pitch_ctrl.get_desired_rate() %.4f"
" att_sp.roll_body %.4f",
(double)pitch_u, (double)_yaw_ctrl.get_desired_rate(),
(double)airspeed, (double)airspeed_scaling,
(double)roll_sp, (double)pitch_sp,
(double)_roll_ctrl.get_desired_rate(),
(double)_pitch_ctrl.get_desired_rate(),
(double)_att_sp.roll_body);
}
}
float yaw_u = 0.0f;
if (_parameters.w_en && _att_sp.fw_control_yaw) {
yaw_u = _wheel_ctrl.control_bodyrate(control_input);
} else {
yaw_u = _yaw_ctrl.control_euler_rate(control_input);
}
_actuators.control[actuator_controls_s::INDEX_YAW] = (PX4_ISFINITE(yaw_u)) ? yaw_u + _parameters.trim_yaw :
_parameters.trim_yaw;
/* add in manual rudder control in manual modes */
if (_vcontrol_mode.flag_control_manual_enabled) {
_actuators.control[actuator_controls_s::INDEX_YAW] += _manual.r;
}
if (!PX4_ISFINITE(yaw_u)) {
_yaw_ctrl.reset_integrator();
_wheel_ctrl.reset_integrator();
perf_count(_nonfinite_output_perf);
if (_debug && loop_counter % 10 == 0) {
warnx("yaw_u %.4f", (double)yaw_u);
}
}
/* throttle passed through if it is finite and if no engine failure was detected */
_actuators.control[actuator_controls_s::INDEX_THROTTLE] = (PX4_ISFINITE(throttle_sp)
&& !_vehicle_status.engine_failure) ? throttle_sp : 0.0f;
/* scale effort by battery status */
if (_parameters.bat_scale_en && _battery_status.scale > 0.0f &&
_actuators.control[actuator_controls_s::INDEX_THROTTLE] > 0.1f) {
_actuators.control[actuator_controls_s::INDEX_THROTTLE] *= _battery_status.scale;
}
if (!PX4_ISFINITE(throttle_sp)) {
if (_debug && loop_counter % 10 == 0) {
warnx("throttle_sp %.4f", (double)throttle_sp);
}
}
} else {
perf_count(_nonfinite_input_perf);
if (_debug && loop_counter % 10 == 0) {
warnx("Non-finite setpoint roll_sp: %.4f, pitch_sp %.4f", (double)roll_sp, (double)pitch_sp);
}
}
} else {
// pure rate control
_roll_ctrl.set_bodyrate_setpoint(_manual.y * _parameters.acro_max_x_rate_rad);
_pitch_ctrl.set_bodyrate_setpoint(-_manual.x * _parameters.acro_max_y_rate_rad);
_yaw_ctrl.set_bodyrate_setpoint(_manual.r * _parameters.acro_max_z_rate_rad);
float roll_u = _roll_ctrl.control_bodyrate(control_input);
_actuators.control[actuator_controls_s::INDEX_ROLL] = (PX4_ISFINITE(roll_u)) ? roll_u + _parameters.trim_roll :
_parameters.trim_roll;
float pitch_u = _pitch_ctrl.control_bodyrate(control_input);
_actuators.control[actuator_controls_s::INDEX_PITCH] = (PX4_ISFINITE(pitch_u)) ? pitch_u + _parameters.trim_pitch :
_parameters.trim_pitch;
float yaw_u = _yaw_ctrl.control_bodyrate(control_input);
_actuators.control[actuator_controls_s::INDEX_YAW] = (PX4_ISFINITE(yaw_u)) ? yaw_u + _parameters.trim_yaw :
_parameters.trim_yaw;
_actuators.control[actuator_controls_s::INDEX_THROTTLE] = PX4_ISFINITE(throttle_sp) ? throttle_sp : 0.0f;
}
/*
* Lazily publish the rate setpoint (for analysis, the actuators are published below)
* only once available
*/
_rates_sp.roll = _roll_ctrl.get_desired_bodyrate();
_rates_sp.pitch = _pitch_ctrl.get_desired_bodyrate();
_rates_sp.yaw = _yaw_ctrl.get_desired_bodyrate();
_rates_sp.timestamp = hrt_absolute_time();
if (_rate_sp_pub != nullptr) {
/* publish the attitude rates setpoint */
orb_publish(_rates_sp_id, _rate_sp_pub, &_rates_sp);
} else if (_rates_sp_id) {
/* advertise the attitude rates setpoint */
_rate_sp_pub = orb_advertise(_rates_sp_id, &_rates_sp);
}
rate_ctrl_status_s rate_ctrl_status;
rate_ctrl_status.timestamp = hrt_absolute_time();
rate_ctrl_status.rollspeed = _att.rollspeed;
rate_ctrl_status.pitchspeed = _att.pitchspeed;
rate_ctrl_status.yawspeed = _att.yawspeed;
rate_ctrl_status.rollspeed_integ = _roll_ctrl.get_integrator();
rate_ctrl_status.pitchspeed_integ = _pitch_ctrl.get_integrator();
rate_ctrl_status.yawspeed_integ = _yaw_ctrl.get_integrator();
rate_ctrl_status.additional_integ1 = _wheel_ctrl.get_integrator();
int instance;
orb_publish_auto(ORB_ID(rate_ctrl_status), &_rate_ctrl_status_pub, &rate_ctrl_status, &instance, ORB_PRIO_DEFAULT);
} else {
/* manual/direct control */
_actuators.control[actuator_controls_s::INDEX_ROLL] = _manual.y * _parameters.man_roll_scale + _parameters.trim_roll;
_actuators.control[actuator_controls_s::INDEX_PITCH] = -_manual.x * _parameters.man_pitch_scale +
_parameters.trim_pitch;
_actuators.control[actuator_controls_s::INDEX_YAW] = _manual.r * _parameters.man_yaw_scale + _parameters.trim_yaw;
_actuators.control[actuator_controls_s::INDEX_THROTTLE] = _manual.z;
}
// Add feed-forward from roll control output to yaw control output
// This can be used to counteract the adverse yaw effect when rolling the plane
_actuators.control[actuator_controls_s::INDEX_YAW] += _parameters.roll_to_yaw_ff * math::constrain(
_actuators.control[actuator_controls_s::INDEX_ROLL], -1.0f, 1.0f);
_actuators.control[actuator_controls_s::INDEX_FLAPS] = _flaps_applied;
_actuators.control[5] = _manual.aux1;
_actuators.control[actuator_controls_s::INDEX_AIRBRAKES] = _flaperons_applied;
// FIXME: this should use _vcontrol_mode.landing_gear_pos in the future
_actuators.control[7] = _manual.aux3;
/* lazily publish the setpoint only once available */
_actuators.timestamp = hrt_absolute_time();
_actuators.timestamp_sample = _att.timestamp;
_actuators_airframe.timestamp = hrt_absolute_time();
_actuators_airframe.timestamp_sample = _att.timestamp;
/* Only publish if any of the proper modes are enabled */
if (_vcontrol_mode.flag_control_rates_enabled ||
_vcontrol_mode.flag_control_attitude_enabled ||
_vcontrol_mode.flag_control_manual_enabled) {
/* publish the actuator controls */
if (_actuators_0_pub != nullptr) {
orb_publish(_actuators_id, _actuators_0_pub, &_actuators);
} else if (_actuators_id) {
_actuators_0_pub = orb_advertise(_actuators_id, &_actuators);
}
if (_actuators_2_pub != nullptr) {
/* publish the actuator controls*/
orb_publish(ORB_ID(actuator_controls_2), _actuators_2_pub, &_actuators_airframe);
} else {
/* advertise and publish */
_actuators_2_pub = orb_advertise(ORB_ID(actuator_controls_2), &_actuators_airframe);
}
}
}
loop_counter++;
perf_end(_loop_perf);
}
warnx("exiting.\n");
_control_task = -1;
_task_running = false;
}
