float ECL_PitchController::control_attitude(const struct ECL_ControlData &ctl_data)
{
/* Do not calculate control signal with bad inputs */
if (!(ISFINITE(ctl_data.pitch_setpoint) &&
ISFINITE(ctl_data.roll) &&
ISFINITE(ctl_data.pitch) &&
ISFINITE(ctl_data.airspeed))) {
ECL_WARN("not controlling pitch");
return _rate_setpoint;
}
/* Calculate the error */
float pitch_error = ctl_data.pitch_setpoint - ctl_data.pitch;
/* Apply P controller: rate setpoint from current error and time constant */
_rate_setpoint = pitch_error / _tc;
return _rate_setpoint;
}
void Ekf::controlGpsFusion()
{
// Check for new GPS data that has fallen behind the fusion time horizon
if (_gps_data_ready) {
// Determine if we should use GPS aiding for velocity and horizontal position
// To start using GPS we need angular alignment completed, the local NED origin set and GPS data that has not failed checks recently
if ((_params.fusion_mode & MASK_USE_GPS) && !_control_status.flags.gps) {
if (_control_status.flags.tilt_align && _NED_origin_initialised && (_time_last_imu - _last_gps_fail_us > 5e6)) {
// If the heading is not aligned, reset the yaw and magnetic field states
if (!_control_status.flags.yaw_align) {
_control_status.flags.yaw_align = resetMagHeading(_mag_sample_delayed.mag);
}
// If the heading is valid start using gps aiding
if (_control_status.flags.yaw_align) {
_control_status.flags.gps = true;
_time_last_gps = _time_last_imu;
// if we are not already aiding with optical flow, then we need to reset the position and velocity
if (!_control_status.flags.opt_flow) {
if (resetPosition() && resetVelocity()) {
_control_status.flags.gps = true;
} else {
_control_status.flags.gps = false;
}
}
if (_control_status.flags.gps) {
ECL_INFO("EKF commencing GPS aiding");
}
}
}
} else if (!(_params.fusion_mode & MASK_USE_GPS)) {
_control_status.flags.gps = false;
}
// handle the case when we are relying on GPS fusion and lose it
if (_control_status.flags.gps && !_control_status.flags.opt_flow) {
// We are relying on GPS aiding to constrain attitude drift so after 10 seconds without aiding we need to do something
if ((_time_last_imu - _time_last_pos_fuse > 10e6) && (_time_last_imu - _time_last_vel_fuse > 10e6)) {
if (_time_last_imu - _time_last_gps > 5e5) {
// if we don't have gps then we need to switch to the non-aiding mode, zero the velocity states
// and set the synthetic GPS position to the current estimate
_control_status.flags.gps = false;
_last_known_posNE(0) = _state.pos(0);
_last_known_posNE(1) = _state.pos(1);
_state.vel.setZero();
ECL_WARN("EKF GPS fusion timout - stopping GPS aiding");
} else {
// Reset states to the last GPS measurement
resetPosition();
resetVelocity();
ECL_WARN("EKF GPS fusion timout - resetting to GPS");
// Reset the timeout counters
_time_last_pos_fuse = _time_last_imu;
_time_last_vel_fuse = _time_last_imu;
}
}
}
// Only use GPS data for position and velocity aiding if enabled
if (_control_status.flags.gps) {
_fuse_pos = true;
_fuse_vert_vel = true;
_fuse_hor_vel = true;
// correct velocity for offset relative to IMU
Vector3f ang_rate = _imu_sample_delayed.delta_ang * (1.0f/_imu_sample_delayed.delta_ang_dt);
Vector3f pos_offset_body = _params.gps_pos_body - _params.imu_pos_body;
Vector3f vel_offset_body = cross_product(ang_rate,pos_offset_body);
Vector3f vel_offset_earth = _R_to_earth * vel_offset_body;
_gps_sample_delayed.vel -= vel_offset_earth;
// correct position and height for offset relative to IMU
Vector3f pos_offset_earth = _R_to_earth * pos_offset_body;
_gps_sample_delayed.pos(0) -= pos_offset_earth(0);
_gps_sample_delayed.pos(1) -= pos_offset_earth(1);
_gps_sample_delayed.hgt += pos_offset_earth(2);
}
// Determine if GPS should be used as the height source
if (((_params.vdist_sensor_type == VDIST_SENSOR_GPS)) && !_gps_hgt_faulty) {
_control_status.flags.baro_hgt = false;
_control_status.flags.gps_hgt = true;
_control_status.flags.rng_hgt = false;
_control_status.flags.ev_hgt = false;
_fuse_height = true;
}
}
}
