forked from Archive/PX4-Autopilot
640 lines
31 KiB
C++
640 lines
31 KiB
C++
/****************************************************************************
|
|
*
|
|
* Copyright (c) 2015 Estimation and Control Library (ECL). All rights reserved.
|
|
*
|
|
* 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 ECL 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 ekf.h
|
|
* Class for core functions for ekf attitude and position estimator.
|
|
*
|
|
* @author Roman Bast <bapstroman@gmail.com>
|
|
* @author Paul Riseborough <p_riseborough@live.com.au>
|
|
*
|
|
*/
|
|
|
|
#include "estimator_interface.h"
|
|
#include "geo.h"
|
|
|
|
class Ekf : public EstimatorInterface
|
|
{
|
|
public:
|
|
|
|
Ekf() = default;
|
|
~Ekf() = default;
|
|
|
|
// initialise variables to sane values (also interface class)
|
|
bool init(uint64_t timestamp);
|
|
|
|
// should be called every time new data is pushed into the filter
|
|
bool update();
|
|
|
|
// gets the innovations of velocity and position measurements
|
|
// 0-2 vel, 3-5 pos
|
|
void get_vel_pos_innov(float vel_pos_innov[6]);
|
|
|
|
// gets the innovations for of the NE auxiliary velocity measurement
|
|
void get_aux_vel_innov(float aux_vel_innov[2]);
|
|
|
|
// gets the innovations of the earth magnetic field measurements
|
|
void get_mag_innov(float mag_innov[3]);
|
|
|
|
// gets the innovations of the heading measurement
|
|
void get_heading_innov(float *heading_innov);
|
|
|
|
// gets the innovation variances of velocity and position measurements
|
|
// 0-2 vel, 3-5 pos
|
|
void get_vel_pos_innov_var(float vel_pos_innov_var[6]);
|
|
|
|
// gets the innovation variances of the earth magnetic field measurements
|
|
void get_mag_innov_var(float mag_innov_var[3]);
|
|
|
|
// gets the innovations of airspeed measurement
|
|
void get_airspeed_innov(float *airspeed_innov);
|
|
|
|
// gets the innovation variance of the airspeed measurement
|
|
void get_airspeed_innov_var(float *airspeed_innov_var);
|
|
|
|
// gets the innovations of synthetic sideslip measurement
|
|
void get_beta_innov(float *beta_innov);
|
|
|
|
// gets the innovation variance of the synthetic sideslip measurement
|
|
void get_beta_innov_var(float *beta_innov_var);
|
|
|
|
// gets the innovation variance of the heading measurement
|
|
void get_heading_innov_var(float *heading_innov_var);
|
|
|
|
// gets the innovation variance of the flow measurement
|
|
void get_flow_innov_var(float flow_innov_var[2]);
|
|
|
|
// gets the innovation of the flow measurement
|
|
void get_flow_innov(float flow_innov[2]);
|
|
|
|
// gets the innovation variance of the drag specific force measurement
|
|
void get_drag_innov_var(float drag_innov_var[2]);
|
|
|
|
// gets the innovation of the drag specific force measurement
|
|
void get_drag_innov(float drag_innov[2]);
|
|
|
|
// gets the innovation variance of the HAGL measurement
|
|
void get_hagl_innov_var(float *hagl_innov_var);
|
|
|
|
// gets the innovation of the HAGL measurement
|
|
void get_hagl_innov(float *hagl_innov);
|
|
|
|
// get the state vector at the delayed time horizon
|
|
void get_state_delayed(float *state);
|
|
|
|
// get the wind velocity in m/s
|
|
void get_wind_velocity(float *wind);
|
|
|
|
// get the wind velocity var
|
|
void get_wind_velocity_var(float *wind_var);
|
|
|
|
// get the true airspeed in m/s
|
|
void get_true_airspeed(float *tas);
|
|
|
|
// get the diagonal elements of the covariance matrix
|
|
void get_covariances(float *covariances);
|
|
|
|
// ask estimator for sensor data collection decision and do any preprocessing if required, returns true if not defined
|
|
bool collect_gps(uint64_t time_usec, struct gps_message *gps);
|
|
bool collect_imu(imuSample &imu);
|
|
|
|
// get the ekf WGS-84 origin position and height and the system time it was last set
|
|
// return true if the origin is valid
|
|
bool get_ekf_origin(uint64_t *origin_time, map_projection_reference_s *origin_pos, float *origin_alt);
|
|
|
|
// get the 1-sigma horizontal and vertical position uncertainty of the ekf WGS-84 position
|
|
void get_ekf_gpos_accuracy(float *ekf_eph, float *ekf_epv, bool *dead_reckoning);
|
|
|
|
// get the 1-sigma horizontal and vertical position uncertainty of the ekf local position
|
|
void get_ekf_lpos_accuracy(float *ekf_eph, float *ekf_epv, bool *dead_reckoning);
|
|
|
|
// get the 1-sigma horizontal and vertical velocity uncertainty
|
|
void get_ekf_vel_accuracy(float *ekf_evh, float *ekf_evv, bool *dead_reckoning);
|
|
|
|
/*
|
|
Returns the following vehicle control limits required by the estimator.
|
|
vxy_max : Maximum ground relative horizontal speed (metres/sec). NaN when no limiting required.
|
|
tilt_rate_max : maximum allowed tilt rate against the direction of travel (rad/sec). NaN when no limiting required.
|
|
*/
|
|
void get_ekf_ctrl_limits(float *vxy_max, bool *limit_hagl);
|
|
|
|
/*
|
|
Reset all IMU bias states and covariances to initial alignment values.
|
|
Use when the IMU sensor has changed.
|
|
Returns true if reset performed, false if rejected due to less than 10 seconds lapsed since last reset.
|
|
*/
|
|
bool reset_imu_bias();
|
|
|
|
void get_vel_var(Vector3f &vel_var);
|
|
|
|
void get_pos_var(Vector3f &pos_var);
|
|
|
|
// return an array containing the output predictor angular, velocity and position tracking
|
|
// error magnitudes (rad), (m/sec), (m)
|
|
void get_output_tracking_error(float error[3]);
|
|
|
|
/*
|
|
Returns following IMU vibration metrics in the following array locations
|
|
0 : Gyro delta angle coning metric = filtered length of (delta_angle x prev_delta_angle)
|
|
1 : Gyro high frequency vibe = filtered length of (delta_angle - prev_delta_angle)
|
|
2 : Accel high frequency vibe = filtered length of (delta_velocity - prev_delta_velocity)
|
|
*/
|
|
void get_imu_vibe_metrics(float vibe[3]);
|
|
|
|
// return true if the global position estimate is valid
|
|
bool global_position_is_valid();
|
|
|
|
// return true if the EKF is dead reckoning the position using inertial data only
|
|
bool inertial_dead_reckoning();
|
|
|
|
// return true if the terrain estimate is valid
|
|
bool get_terrain_valid();
|
|
|
|
// get the estimated terrain vertical position relative to the NED origin
|
|
void get_terrain_vert_pos(float *ret);
|
|
|
|
// get the accerometer bias in m/s/s
|
|
void get_accel_bias(float bias[3]);
|
|
|
|
// get the gyroscope bias in rad/s
|
|
void get_gyro_bias(float bias[3]);
|
|
|
|
// get GPS check status
|
|
void get_gps_check_status(uint16_t *val);
|
|
|
|
// return the amount the local vertical position changed in the last reset and the number of reset events
|
|
void get_posD_reset(float *delta, uint8_t *counter) {*delta = _state_reset_status.posD_change; *counter = _state_reset_status.posD_counter;}
|
|
|
|
// return the amount the local vertical velocity changed in the last reset and the number of reset events
|
|
void get_velD_reset(float *delta, uint8_t *counter) {*delta = _state_reset_status.velD_change; *counter = _state_reset_status.velD_counter;}
|
|
|
|
// return the amount the local horizontal position changed in the last reset and the number of reset events
|
|
void get_posNE_reset(float delta[2], uint8_t *counter)
|
|
{
|
|
memcpy(delta, &_state_reset_status.posNE_change._data[0], sizeof(_state_reset_status.posNE_change._data));
|
|
*counter = _state_reset_status.posNE_counter;
|
|
}
|
|
|
|
// return the amount the local horizontal velocity changed in the last reset and the number of reset events
|
|
void get_velNE_reset(float delta[2], uint8_t *counter)
|
|
{
|
|
memcpy(delta, &_state_reset_status.velNE_change._data[0], sizeof(_state_reset_status.velNE_change._data));
|
|
*counter = _state_reset_status.velNE_counter;
|
|
}
|
|
|
|
// return the amount the quaternion has changed in the last reset and the number of reset events
|
|
void get_quat_reset(float delta_quat[4], uint8_t *counter)
|
|
{
|
|
memcpy(delta_quat, &_state_reset_status.quat_change._data[0], sizeof(_state_reset_status.quat_change._data));
|
|
*counter = _state_reset_status.quat_counter;
|
|
}
|
|
|
|
// get EKF innovation consistency check status information comprising of:
|
|
// status - a bitmask integer containing the pass/fail status for each EKF measurement innovation consistency check
|
|
// Innovation Test Ratios - these are the ratio of the innovation to the acceptance threshold.
|
|
// A value > 1 indicates that the sensor measurement has exceeded the maximum acceptable level and has been rejected by the EKF
|
|
// Where a measurement type is a vector quantity, eg magnetoemter, GPS position, etc, the maximum value is returned.
|
|
void get_innovation_test_status(uint16_t *status, float *mag, float *vel, float *pos, float *hgt, float *tas, float *hagl, float *beta);
|
|
|
|
// return a bitmask integer that describes which state estimates can be used for flight control
|
|
void get_ekf_soln_status(uint16_t *status);
|
|
|
|
// return the quaternion defining the rotation from the EKF to the External Vision reference frame
|
|
void get_ekf2ev_quaternion(float *quat);
|
|
|
|
private:
|
|
|
|
static constexpr uint8_t _k_num_states{24}; ///< number of EKF states
|
|
static constexpr float _k_earth_rate{0.000072921f}; ///< earth spin rate (rad/sec)
|
|
static constexpr float _gravity_mss{9.80665f}; ///< average earth gravity at sea level (m/sec**2)
|
|
|
|
struct {
|
|
uint8_t velNE_counter; ///< number of horizontal position reset events (allow to wrap if count exceeds 255)
|
|
uint8_t velD_counter; ///< number of vertical velocity reset events (allow to wrap if count exceeds 255)
|
|
uint8_t posNE_counter; ///< number of horizontal position reset events (allow to wrap if count exceeds 255)
|
|
uint8_t posD_counter; ///< number of vertical position reset events (allow to wrap if count exceeds 255)
|
|
uint8_t quat_counter; ///< number of quaternion reset events (allow to wrap if count exceeds 255)
|
|
Vector2f velNE_change; ///< North East velocity change due to last reset (m)
|
|
float velD_change; ///< Down velocity change due to last reset (m/sec)
|
|
Vector2f posNE_change; ///< North, East position change due to last reset (m)
|
|
float posD_change; ///< Down position change due to last reset (m)
|
|
Quatf quat_change; ///< quaternion delta due to last reset - multiply pre-reset quaternion by this to get post-reset quaternion
|
|
} _state_reset_status{}; ///< reset event monitoring structure containing velocity, position, height and yaw reset information
|
|
|
|
float _dt_ekf_avg{0.001f * FILTER_UPDATE_PERIOD_MS}; ///< average update rate of the ekf
|
|
float _dt_update{0.01f}; ///< delta time since last ekf update. This time can be used for filters which run at the same rate as the Ekf::update() function. (sec)
|
|
|
|
stateSample _state{}; ///< state struct of the ekf running at the delayed time horizon
|
|
|
|
bool _filter_initialised{false}; ///< true when the EKF sttes and covariances been initialised
|
|
bool _earth_rate_initialised{false}; ///< true when we know the earth rotatin rate (requires GPS)
|
|
|
|
bool _fuse_height{false}; ///< true when baro height data should be fused
|
|
bool _fuse_pos{false}; ///< true when gps position data should be fused
|
|
bool _fuse_hor_vel{false}; ///< true when gps horizontal velocity measurement should be fused
|
|
bool _fuse_vert_vel{false}; ///< true when gps vertical velocity measurement should be fused
|
|
bool _fuse_hor_vel_aux{false}; ///< true when auxiliary horizontal velocity measurement should be fused
|
|
|
|
float _posObsNoiseNE{0.0f}; ///< 1-STD observtion noise used for the fusion of NE position data (m)
|
|
float _posInnovGateNE{1.0f}; ///< Number of standard deviations used for the NE position fusion innovation consistency check
|
|
|
|
Vector2f _velObsVarNE; ///< 1-STD observation noise variance used for the fusion of NE velocity data (m/sec)**2
|
|
float _hvelInnovGate{1.0f}; ///< Number of standard deviations used for the horizontal velocity fusion innovation consistency check
|
|
|
|
// variables used when position data is being fused using a relative position odometry model
|
|
bool _fuse_hpos_as_odom{false}; ///< true when the NE position data is being fused using an odometry assumption
|
|
Vector3f _pos_meas_prev; ///< previous value of NED position measurement fused using odometry assumption (m)
|
|
Vector2f _hpos_pred_prev; ///< previous value of NE position state used by odometry fusion (m)
|
|
bool _hpos_prev_available{false}; ///< true when previous values of the estimate and measurement are available for use
|
|
Vector3f _ev_rot_vec_filt; ///< filtered rotation vector defining the rotation from EKF to EV reference (rad)
|
|
Dcmf _ev_rot_mat; ///< transformation matrix that rotates observations from the EV to the EKF navigation frame
|
|
uint64_t _ev_rot_last_time_us{0}; ///< previous time that the calculation of the ekf to ev rotation matrix was updated (uSec)
|
|
|
|
// booleans true when fresh sensor data is available at the fusion time horizon
|
|
bool _gps_data_ready{false}; ///< true when new GPS data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _mag_data_ready{false}; ///< true when new magnetometer data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _baro_data_ready{false}; ///< true when new baro height data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _range_data_ready{false}; ///< true when new range finder data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _flow_data_ready{false}; ///< true when new optical flow data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _ev_data_ready{false}; ///< true when new external vision system data has fallen behind the fusion time horizon and is available to be fused
|
|
bool _tas_data_ready{false}; ///< true when new true airspeed data has fallen behind the fusion time horizon and is available to be fused
|
|
|
|
uint64_t _time_last_fake_gps{0}; ///< last time we faked GPS position measurements to constrain tilt errors during operation without external aiding (uSec)
|
|
|
|
uint64_t _time_last_pos_fuse{0}; ///< time the last fusion of horizontal position measurements was performed (uSec)
|
|
uint64_t _time_last_delpos_fuse{0}; ///< time the last fusion of incremental horizontal position measurements was performed (uSec)
|
|
uint64_t _time_last_vel_fuse{0}; ///< time the last fusion of velocity measurements was performed (uSec)
|
|
uint64_t _time_last_hgt_fuse{0}; ///< time the last fusion of height measurements was performed (uSec)
|
|
uint64_t _time_last_of_fuse{0}; ///< time the last fusion of optical flow measurements were performed (uSec)
|
|
uint64_t _time_last_arsp_fuse{0}; ///< time the last fusion of airspeed measurements were performed (uSec)
|
|
uint64_t _time_last_beta_fuse{0}; ///< time the last fusion of synthetic sideslip measurements were performed (uSec)
|
|
uint64_t _time_last_rng_ready{0}; ///< time the last range finder measurement was ready (uSec)
|
|
Vector2f _last_known_posNE; ///< last known local NE position vector (m)
|
|
float _last_disarmed_posD{0.0f}; ///< vertical position recorded at arming (m)
|
|
float _imu_collection_time_adj{0.0f}; ///< the amount of time the IMU collection needs to be advanced to meet the target set by FILTER_UPDATE_PERIOD_MS (sec)
|
|
|
|
uint64_t _time_acc_bias_check{0}; ///< last time the accel bias check passed (uSec)
|
|
uint64_t _delta_time_baro_us{0}; ///< delta time between two consecutive delayed baro samples from the buffer (uSec)
|
|
|
|
uint64_t _last_imu_bias_cov_reset_us{0}; ///< time the last reset of IMU delta angle and velocity state covariances was performed (uSec)
|
|
|
|
Vector3f _earth_rate_NED; ///< earth rotation vector (NED) in rad/s
|
|
|
|
Dcmf _R_to_earth; ///< transformation matrix from body frame to earth frame from last EKF predition
|
|
|
|
// used by magnetometer fusion mode selection
|
|
Vector2f _accel_lpf_NE; ///< Low pass filtered horizontal earth frame acceleration (m/sec**2)
|
|
float _yaw_delta_ef{0.0f}; ///< Recent change in yaw angle measured about the earth frame D axis (rad)
|
|
float _yaw_rate_lpf_ef{0.0f}; ///< Filtered angular rate about earth frame D axis (rad/sec)
|
|
bool _mag_bias_observable{false}; ///< true when there is enough rotation to make magnetometer bias errors observable
|
|
bool _yaw_angle_observable{false}; ///< true when there is enough horizontal acceleration to make yaw observable
|
|
uint64_t _time_yaw_started{0}; ///< last system time in usec that a yaw rotation moaneouvre was detected
|
|
uint8_t _num_bad_flight_yaw_events{0}; ///< number of times a bad heading has been detected in flight and required a yaw reset
|
|
|
|
float P[_k_num_states][_k_num_states] {}; ///< state covariance matrix
|
|
|
|
float _vel_pos_innov[6] {}; ///< NED velocity and position innovations: 0-2 vel (m/sec), 3-5 pos (m)
|
|
float _vel_pos_innov_var[6] {}; ///< NED velocity and position innovation variances: 0-2 vel ((m/sec)**2), 3-5 pos (m**2)
|
|
float _aux_vel_innov[2] {}; ///< NE auxiliary velocity innovations: (m/sec)
|
|
|
|
float _mag_innov[3] {}; ///< earth magnetic field innovations (Gauss)
|
|
float _mag_innov_var[3] {}; ///< earth magnetic field innovation variance (Gauss**2)
|
|
|
|
float _airspeed_innov{0.0f}; ///< airspeed measurement innovation (m/sec)
|
|
float _airspeed_innov_var{0.0f}; ///< airspeed measurement innovation variance ((m/sec)**2)
|
|
|
|
float _beta_innov{0.0f}; ///< synthetic sideslip measurement innovation (rad)
|
|
float _beta_innov_var{0.0f}; ///< synthetic sideslip measurement innovation variance (rad**2)
|
|
|
|
float _drag_innov[2] {}; ///< multirotor drag measurement innovation (m/sec**2)
|
|
float _drag_innov_var[2] {}; ///< multirotor drag measurement innovation variance ((m/sec**2)**2)
|
|
|
|
float _heading_innov{0.0f}; ///< heading measurement innovation (rad)
|
|
float _heading_innov_var{0.0f}; ///< heading measurement innovation variance (rad**2)
|
|
|
|
// optical flow processing
|
|
float _flow_innov[2] {}; ///< flow measurement innovation (rad/sec)
|
|
float _flow_innov_var[2] {}; ///< flow innovation variance ((rad/sec)**2)
|
|
Vector3f _flow_gyro_bias; ///< bias errors in optical flow sensor rate gyro outputs (rad/sec)
|
|
Vector3f _imu_del_ang_of; ///< bias corrected delta angle measurements accumulated across the same time frame as the optical flow rates (rad)
|
|
float _delta_time_of{0.0f}; ///< time in sec that _imu_del_ang_of was accumulated over (sec)
|
|
float _flow_gnd_spd_max{0.0f}; ///< maximum ground speed that the flow sensor can reliably measure (m/s)
|
|
|
|
float _mag_declination{0.0f}; ///< magnetic declination used by reset and fusion functions (rad)
|
|
|
|
// output predictor states
|
|
Vector3f _delta_angle_corr; ///< delta angle correction vector (rad)
|
|
imuSample _imu_down_sampled{}; ///< down sampled imu data (sensor rate -> filter update rate)
|
|
Quatf _q_down_sampled; ///< down sampled quaternion (tracking delta angles between ekf update steps)
|
|
Vector3f _vel_err_integ; ///< integral of velocity tracking error (m)
|
|
Vector3f _pos_err_integ; ///< integral of position tracking error (m.s)
|
|
float _output_tracking_error[3] {}; ///< contains the magnitude of the angle, velocity and position track errors (rad, m/s, m)
|
|
|
|
// variables used for the GPS quality checks
|
|
float _gpsDriftVelN{0.0f}; ///< GPS north position derivative (m/sec)
|
|
float _gpsDriftVelE{0.0f}; ///< GPS east position derivative (m/sec)
|
|
float _gps_drift_velD{0.0f}; ///< GPS down position derivative (m/sec)
|
|
float _gps_velD_diff_filt{0.0f}; ///< GPS filtered Down velocity (m/sec)
|
|
float _gps_velN_filt{0.0f}; ///< GPS filtered North velocity (m/sec)
|
|
float _gps_velE_filt{0.0f}; ///< GPS filtered East velocity (m/sec)
|
|
uint64_t _last_gps_fail_us{0}; ///< last system time in usec that the GPS failed it's checks
|
|
|
|
// Variables used to publish the WGS-84 location of the EKF local NED origin
|
|
uint64_t _last_gps_origin_time_us{0}; ///< time the origin was last set (uSec)
|
|
float _gps_alt_ref{0.0f}; ///< WGS-84 height (m)
|
|
|
|
// Variables used to initialise the filter states
|
|
uint32_t _hgt_counter{0}; ///< number of height samples read during initialisation
|
|
float _rng_filt_state{0.0f}; ///< filtered height measurement (m)
|
|
uint32_t _mag_counter{0}; ///< number of magnetometer samples read during initialisation
|
|
uint32_t _ev_counter{0}; ///< number of external vision samples read during initialisation
|
|
uint64_t _time_last_mag{0}; ///< measurement time of last magnetomter sample (uSec)
|
|
Vector3f _mag_filt_state; ///< filtered magnetometer measurement (Gauss)
|
|
Vector3f _delVel_sum; ///< summed delta velocity (m/sec)
|
|
float _hgt_sensor_offset{0.0f}; ///< set as necessary if desired to maintain the same height after a height reset (m)
|
|
float _baro_hgt_offset{0.0f}; ///< baro height reading at the local NED origin (m)
|
|
|
|
// Variables used to control activation of post takeoff functionality
|
|
float _last_on_ground_posD{0.0f}; ///< last vertical position when the in_air status was false (m)
|
|
bool _flt_mag_align_complete{false}; ///< true when the in-flight mag field alignment has been completed
|
|
bool _flt_mag_align_converging{false}; ///< true when the in-flight mag field post alignment convergence is being performd
|
|
uint64_t _flt_mag_align_start_time{0}; ///< time that inflight magnetic field alignment started (uSec)
|
|
uint64_t _time_last_movement{0}; ///< last system time that sufficient movement to use 3-axis magnetometer fusion was detected (uSec)
|
|
float _saved_mag_variance[6] {}; ///< magnetic field state variances that have been saved for use at the next initialisation (Gauss**2)
|
|
bool _velpos_reset_request{false}; ///< true when a large yaw error has been fixed and a velocity and position state reset is required
|
|
|
|
gps_check_fail_status_u _gps_check_fail_status{};
|
|
|
|
// variables used to inhibit accel bias learning
|
|
bool _accel_bias_inhibit{false}; ///< true when the accel bias learning is being inhibited
|
|
float _accel_mag_filt{0.0f}; ///< acceleration magnitude after application of a decaying envelope filter (m/sec**2)
|
|
float _ang_rate_mag_filt{0.0f}; ///< angular rate magnitude after application of a decaying envelope filter (rad/sec)
|
|
Vector3f _prev_dvel_bias_var; ///< saved delta velocity XYZ bias variances (m/sec)**2
|
|
|
|
// Terrain height state estimation
|
|
float _terrain_vpos{0.0f}; ///< estimated vertical position of the terrain underneath the vehicle in local NED frame (m)
|
|
float _terrain_var{1e4f}; ///< variance of terrain position estimate (m**2)
|
|
float _hagl_innov{0.0f}; ///< innovation of the last height above terrain measurement (m)
|
|
float _hagl_innov_var{0.0f}; ///< innovation variance for the last height above terrain measurement (m**2)
|
|
uint64_t _time_last_hagl_fuse{0}; ///< last system time that the hagl measurement failed it's checks (uSec)
|
|
bool _terrain_initialised{false}; ///< true when the terrain estimator has been intialised
|
|
float _sin_tilt_rng{0.0f}; ///< sine of the range finder tilt rotation about the Y body axis
|
|
float _cos_tilt_rng{0.0f}; ///< cosine of the range finder tilt rotation about the Y body axis
|
|
float _R_rng_to_earth_2_2{0.0f}; ///< 2,2 element of the rotation matrix from sensor frame to earth frame
|
|
bool _range_data_continuous{false}; ///< true when we are receiving range finder data faster than a 2Hz average
|
|
float _dt_last_range_update_filt_us{0.0f}; ///< filtered value of the delta time elapsed since the last range measurement came into the filter (uSec)
|
|
|
|
// height sensor fault status
|
|
bool _baro_hgt_faulty{false}; ///< true if valid baro data is unavailable for use
|
|
bool _gps_hgt_faulty{false}; ///< true if valid gps height data is unavailable for use
|
|
bool _rng_hgt_faulty{false}; ///< true if valid rnage finder height data is unavailable for use
|
|
int _primary_hgt_source{VDIST_SENSOR_BARO}; ///< specifies primary source of height data
|
|
|
|
// imu fault status
|
|
uint64_t _time_bad_vert_accel{0}; ///< last time a bad vertical accel was detected (uSec)
|
|
uint64_t _time_good_vert_accel{0}; ///< last time a good vertical accel was detected (uSec)
|
|
bool _bad_vert_accel_detected{false}; ///< true when bad vertical accelerometer data has been detected
|
|
|
|
// variables used to control range aid functionality
|
|
bool _in_range_aid_mode{false}; ///< true when range finder is to be used as the height reference instead of the primary height sensor
|
|
|
|
// variables used to check for "stuck" rng data
|
|
bool _rng_stuck{false}; ///< true when rng data wasn't ready for more than 10s and new rng values haven't changed enough
|
|
float _rng_check_min_val{0.0f}; ///< minimum value for new rng measurement when being stuck
|
|
float _rng_check_max_val{0.0f}; ///< maximum value for new rng measurement when being stuck
|
|
|
|
// update the real time complementary filter states. This includes the prediction
|
|
// and the correction step
|
|
void calculateOutputStates();
|
|
|
|
// initialise filter states of both the delayed ekf and the real time complementary filter
|
|
bool initialiseFilter(void);
|
|
|
|
// initialise ekf covariance matrix
|
|
void initialiseCovariance();
|
|
|
|
// predict ekf state
|
|
void predictState();
|
|
|
|
// predict ekf covariance
|
|
void predictCovariance();
|
|
|
|
// ekf sequential fusion of magnetometer measurements
|
|
void fuseMag();
|
|
|
|
// fuse the first euler angle from either a 321 or 312 rotation sequence as the observation (currently measures yaw using the magnetometer)
|
|
void fuseHeading();
|
|
|
|
// fuse magnetometer declination measurement
|
|
void fuseDeclination();
|
|
|
|
// fuse airspeed measurement
|
|
void fuseAirspeed();
|
|
|
|
// fuse synthetic zero sideslip measurement
|
|
void fuseSideslip();
|
|
|
|
// fuse body frame drag specific forces for multi-rotor wind estimation
|
|
void fuseDrag();
|
|
|
|
// fuse velocity and position measurements (also barometer height)
|
|
void fuseVelPosHeight();
|
|
|
|
// reset velocity states of the ekf
|
|
bool resetVelocity();
|
|
|
|
// fuse optical flow line of sight rate measurements
|
|
void fuseOptFlow();
|
|
|
|
// calculate optical flow bias errors
|
|
void calcOptFlowBias();
|
|
|
|
// initialise the terrain vertical position estimator
|
|
// return true if the initialisation is successful
|
|
bool initHagl();
|
|
|
|
// run the terrain estimator
|
|
void runTerrainEstimator();
|
|
|
|
// update the terrain vertical position estimate using a height above ground measurement from the range finder
|
|
void fuseHagl();
|
|
|
|
// reset the heading and magnetic field states using the declination and magnetometer measurements
|
|
// return true if successful
|
|
bool resetMagHeading(Vector3f &mag_init);
|
|
|
|
// Do a forced re-alignment of the yaw angle to align with the horizontal velocity vector from the GPS.
|
|
// It is used to align the yaw angle after launch or takeoff for fixed wing vehicle.
|
|
bool realignYawGPS();
|
|
|
|
// calculate the magnetic declination to be used by the alignment and fusion processing
|
|
void calcMagDeclination();
|
|
|
|
// reset position states of the ekf (only horizontal position)
|
|
bool resetPosition();
|
|
|
|
// reset height state of the ekf
|
|
void resetHeight();
|
|
|
|
// modify output filter to match the the EKF state at the fusion time horizon
|
|
void alignOutputFilter();
|
|
|
|
// update the estimated angular misalignment vector between the EV naigration frame and the EKF navigation frame
|
|
// and update the rotation matrix which transforms EV navigation frame measurements into NED
|
|
void calcExtVisRotMat();
|
|
|
|
|
|
// reset the estimated angular misalignment vector between the EV naigration frame and the EKF navigation frame
|
|
// and reset the rotation matrix which transforms EV navigation frame measurements into NED
|
|
void resetExtVisRotMat();
|
|
|
|
// limit the diagonal of the covariance matrix
|
|
void fixCovarianceErrors();
|
|
|
|
// make ekf covariance matrix symmetric between a nominated state indexe range
|
|
void makeSymmetrical(float (&cov_mat)[_k_num_states][_k_num_states], uint8_t first, uint8_t last);
|
|
|
|
// constrain the ekf states
|
|
void constrainStates();
|
|
|
|
// generic function which will perform a fusion step given a kalman gain K
|
|
// and a scalar innovation value
|
|
void fuse(float *K, float innovation);
|
|
|
|
// calculate the earth rotation vector from a given latitude
|
|
void calcEarthRateNED(Vector3f &omega, double lat_rad) const;
|
|
|
|
// return true id the GPS quality is good enough to set an origin and start aiding
|
|
bool gps_is_good(struct gps_message *gps);
|
|
|
|
// Control the filter fusion modes
|
|
void controlFusionModes();
|
|
|
|
// control fusion of external vision observations
|
|
void controlExternalVisionFusion();
|
|
|
|
// control fusion of optical flow observtions
|
|
void controlOpticalFlowFusion();
|
|
|
|
// control fusion of GPS observations
|
|
void controlGpsFusion();
|
|
|
|
// control fusion of magnetometer observations
|
|
void controlMagFusion();
|
|
|
|
// control fusion of range finder observations
|
|
void controlRangeFinderFusion();
|
|
|
|
// control fusion of air data observations
|
|
void controlAirDataFusion();
|
|
|
|
// control fusion of synthetic sideslip observations
|
|
void controlBetaFusion();
|
|
|
|
// control fusion of multi-rotor drag specific force observations
|
|
void controlDragFusion();
|
|
|
|
// control fusion of pressure altitude observations
|
|
void controlBaroFusion();
|
|
|
|
// control fusion of velocity and position observations
|
|
void controlVelPosFusion();
|
|
|
|
// control fusion of auxiliary velocity observations
|
|
void controlAuxVelFusion();
|
|
|
|
// control for height sensor timeouts, sensor changes and state resets
|
|
void controlHeightSensorTimeouts();
|
|
|
|
// control for combined height fusion mode (implemented for switching between baro and range height)
|
|
void controlHeightFusion();
|
|
|
|
bool rangeAidConditionsMet(bool in_range_aid_mode);
|
|
|
|
// check for "stuck" range finder measurements when rng was not valid for certain period
|
|
void checkForStuckRange();
|
|
|
|
// return the square of two floating point numbers - used in auto coded sections
|
|
inline float sq(float var)
|
|
{
|
|
return var * var;
|
|
}
|
|
|
|
// set control flags to use baro height
|
|
void setControlBaroHeight();
|
|
|
|
// set control flags to use range height
|
|
void setControlRangeHeight();
|
|
|
|
// set control flags to use GPS height
|
|
void setControlGPSHeight();
|
|
|
|
// set control flags to use external vision height
|
|
void setControlEVHeight();
|
|
|
|
// zero the specified range of rows in the state covariance matrix
|
|
void zeroRows(float (&cov_mat)[_k_num_states][_k_num_states], uint8_t first, uint8_t last);
|
|
|
|
// zero the specified range of columns in the state covariance matrix
|
|
void zeroCols(float (&cov_mat)[_k_num_states][_k_num_states], uint8_t first, uint8_t last);
|
|
|
|
// zero the specified range of off diagonals in the state covariance matrix
|
|
void zeroOffDiag(float (&cov_mat)[_k_num_states][_k_num_states], uint8_t first, uint8_t last);
|
|
|
|
// zero the specified range of off diagonals in the state covariance matrix
|
|
// set the diagonals to the supplied value
|
|
void setDiag(float (&cov_mat)[_k_num_states][_k_num_states], uint8_t first, uint8_t last, float variance);
|
|
|
|
// calculate the measurement variance for the optical flow sensor
|
|
float calcOptFlowMeasVar();
|
|
|
|
// rotate quaternion covariances into variances for an equivalent rotation vector
|
|
Vector3f calcRotVecVariances();
|
|
|
|
// initialise the quaternion covariances using rotation vector variances
|
|
void initialiseQuatCovariances(Vector3f &rot_vec_var);
|
|
|
|
// perform a limited reset of the magnetic field state covariances
|
|
void resetMagCovariance();
|
|
|
|
// perform a limited reset of the wind state covariances
|
|
void resetWindCovariance();
|
|
|
|
// perform a reset of the wind states
|
|
void resetWindStates();
|
|
|
|
// check that the range finder data is continuous
|
|
void checkRangeDataContinuity();
|
|
|
|
};
|