EKF2 limit map reprojection (#7900)

This commit is contained in:
Daniel Agar 2017-09-05 12:56:53 -04:00 committed by GitHub
parent 201b2bd75e
commit dc18112697
2 changed files with 99 additions and 107 deletions

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@ -8,7 +8,6 @@ uint64 time_utc_usec # GPS UTC timestamp, (microseconds)
float64 lat # Latitude, (degrees)
float64 lon # Longitude, (degrees)
float32 alt # Altitude AMSL, (meters)
float64[2] delta_lat_lon # Reset delta for horizontal position coordinates
float32 delta_alt # Reset delta for altitude
uint8 lat_lon_reset_counter # Counter for reset events on horizontal position coordinates
uint8 alt_reset_counter # Counter for reset events on altitude

View File

@ -41,29 +41,18 @@
#include <px4_config.h>
#include <px4_defines.h>
#include <px4_module.h>
#include <px4_tasks.h>
#include <px4_posix.h>
#include <px4_tasks.h>
#include <px4_time.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 <float.h>
#include <arch/board/board.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>
#include <cfloat>
#include <systemlib/systemlib.h>
#include <mathlib/mathlib.h>
#include <mathlib/math/filter/LowPassFilter2p.hpp>
#include <platforms/px4_defines.h>
#include <drivers/drv_hrt.h>
#include <controllib/blocks.hpp>
#include <controllib/block/BlockParam.hpp>
#include <uORB/topics/sensor_combined.h>
#include <uORB/topics/vehicle_gps_position.h>
@ -95,8 +84,7 @@ class Ekf2 : public control::SuperBlock, public ModuleBase<Ekf2>
{
public:
Ekf2();
~Ekf2();
~Ekf2() override = default;
/** @see ModuleBase */
static int task_spawn(int argc, char *argv[]);
@ -120,16 +108,12 @@ public:
int print_status() override;
private:
static constexpr float _dt_max = 0.02; ///< minimum allowed arrival time between non-IMU sensor readings (sec)
bool _replay_mode; ///< true when we use replay data from a log
int32_t _publish_replay_mode; ///< set to 1 if we should publish replay messages for logging
float _default_ev_pos_noise = 0.05f; ///< external vision position noise used when an invalid value is supplied (m)
float _default_ev_ang_noise = 0.05f; ///< external vision angle noise used when an invalid value is supplied (rad)
bool _replay_mode = false; ///< true when we use replay data from a log
// time slip monitoring
uint64_t integrated_time_us = 0; ///< integral of gyro delta time from start (uSec)
uint64_t start_time_us = 0; ///< system time at EKF start (uSec)
uint64_t _integrated_time_us = 0; ///< integral of gyro delta time from start (uSec)
uint64_t _start_time_us = 0; ///< system time at EKF start (uSec)
uint64_t _last_time_slip_us = 0; ///< Last time slip (uSec)
// Initialise time stamps used to send sensor data to the EKF and for logging
uint64_t _timestamp_mag_us = 0; ///< magnetomer data timestamp (uSec)
@ -155,31 +139,35 @@ private:
// Used to check, save and use learned magnetometer biases
hrt_abstime _last_magcal_us = 0; ///< last time the EKF was operating a mode that estimates magnetomer biases (uSec)
hrt_abstime _total_cal_time_us = 0; ///< accumulated calibration time since the last save
hrt_abstime _last_time_slip_us = 0; ///< Last time slip (uSec)
float _last_valid_mag_cal[3] = {}; ///< last valid XYZ magnetometer bias estimates (mGauss)
bool _valid_cal_available[3] = {}; ///< true when an unsaved valid calibration for the XYZ magnetometer bias is available
float _last_valid_variance[3] = {}; ///< variances for the last valid magnetometer XYZ bias estimates (mGauss**2)
// Used to filter velocity innovations during pre-flight checks
bool _vel_innov_preflt_fail = false; ///< true if the norm of the filtered innovation vector is too large before flight
Vector3f _vel_innov_lpf_ned = {}; ///< Preflight low pass filtered velocity innovations (m/sec)
float _hgt_innov_lpf = 0.0f; ///< Preflight low pass filtered height innovation (m)
const float _innov_lpf_tau_inv = 0.2f; ///< Preflight low pass filter time constant inverse (1/sec)
const float _vel_innov_test_lim = 0.5f; ///< Maximum permissible velocity innovation to pass pre-flight checks (m/sec)
const float _hgt_innov_test_lim = 1.5f; ///< Maximum permissible height innovation to pass pre-flight checks (m)
static constexpr float _innov_lpf_tau_inv = 0.2f; ///< Preflight low pass filter time constant inverse (1/sec)
static constexpr float _vel_innov_test_lim =
0.5f; ///< Maximum permissible velocity innovation to pass pre-flight checks (m/sec)
static constexpr float _hgt_innov_test_lim =
1.5f; ///< Maximum permissible height innovation to pass pre-flight checks (m)
const float _vel_innov_spike_lim = 2.0f * _vel_innov_test_lim; ///< preflight velocity innovation spike limit (m/sec)
const float _hgt_innov_spike_lim = 2.0f * _hgt_innov_test_lim; ///< preflight position innovation spike limit (m)
bool _vel_innov_preflt_fail = false; ///< true if the norm of the filtered innovation vector is too large before flight
orb_advert_t _att_pub;
orb_advert_t _lpos_pub;
orb_advert_t _control_state_pub;
orb_advert_t _vehicle_global_position_pub;
orb_advert_t _wind_pub;
orb_advert_t _estimator_status_pub;
orb_advert_t _estimator_innovations_pub;
orb_advert_t _replay_pub;
orb_advert_t _ekf2_timestamps_pub;
uORB::Publication<vehicle_local_position_s> _vehicle_local_position_pub;
uORB::Publication<vehicle_global_position_s> _vehicle_global_position_pub;
/* Low pass filter for attitude rates */
math::LowPassFilter2p _lp_roll_rate; ///< Low pass filter applied to roll rates published on the control_state message
math::LowPassFilter2p _lp_pitch_rate; ///< Low pass filter applied to pitch rates published on the control_state message
@ -246,7 +234,8 @@ private:
control::BlockParamExtFloat _requiredGDoP; ///< maximum acceptable geometric dilution of precision
control::BlockParamExtFloat _requiredHdrift; ///< maximum acceptable horizontal drift speed (m/s)
control::BlockParamExtFloat _requiredVdrift; ///< maximum acceptable vertical drift speed (m/s)
control::BlockParamExtInt _param_record_replay_msg; ///< turns on recording of ekf2 replay messages
control::BlockParamInt _param_record_replay_msg; ///< turns on recording of ekf2 replay messages
// measurement source control
control::BlockParamExtInt
@ -267,8 +256,8 @@ private:
_rng_aid_innov_gate; ///< gate size used for innovation consistency checks for range aid fusion (STD)
// vision estimate fusion
control::BlockParamExtFloat _ev_pos_noise; ///< default position observation noise for exernal vision measurements (m)
control::BlockParamExtFloat _ev_ang_noise; ///< default angular observation noise for exernal vision measurements (rad)
control::BlockParamFloat _ev_pos_noise; ///< default position observation noise for exernal vision measurements (m)
control::BlockParamFloat _ev_ang_noise; ///< default angular observation noise for exernal vision measurements (rad)
control::BlockParamExtFloat _ev_innov_gate; ///< external vision position innovation consistency gate size (STD)
// optical flow fusion
@ -345,16 +334,15 @@ private:
Ekf2::Ekf2():
SuperBlock(nullptr, "EKF"),
_replay_mode(false),
_publish_replay_mode(0),
_att_pub(nullptr),
_lpos_pub(nullptr),
_control_state_pub(nullptr),
_vehicle_global_position_pub(nullptr),
_wind_pub(nullptr),
_estimator_status_pub(nullptr),
_estimator_innovations_pub(nullptr),
_replay_pub(nullptr),
_ekf2_timestamps_pub(nullptr),
_vehicle_local_position_pub(ORB_ID(vehicle_local_position), -1, &getPublications()),
_vehicle_global_position_pub(ORB_ID(vehicle_global_position), -1, &getPublications()),
_lp_roll_rate(250.0f, 30.0f),
_lp_pitch_rate(250.0f, 30.0f),
_lp_yaw_rate(250.0f, 20.0f),
@ -403,7 +391,7 @@ Ekf2::Ekf2():
_requiredGDoP(this, "EKF2_REQ_GDOP", false, _params->req_gdop),
_requiredHdrift(this, "EKF2_REQ_HDRIFT", false, _params->req_hdrift),
_requiredVdrift(this, "EKF2_REQ_VDRIFT", false, _params->req_vdrift),
_param_record_replay_msg(this, "EKF2_REC_RPL", false, _publish_replay_mode),
_param_record_replay_msg(this, "EKF2_REC_RPL", false),
_fusion_mode(this, "EKF2_AID_MASK", false, _params->fusion_mode),
_vdist_sensor_type(this, "EKF2_HGT_MODE", false, _params->vdist_sensor_type),
_range_noise(this, "EKF2_RNG_NOISE", false, _params->range_noise),
@ -415,8 +403,8 @@ Ekf2::Ekf2():
_rng_aid_hor_vel_max(this, "EKF2_RNG_A_VMAX", false, _params->max_vel_for_range_aid),
_rng_aid_height_max(this, "EKF2_RNG_A_HMAX", false, _params->max_hagl_for_range_aid),
_rng_aid_innov_gate(this, "EKF2_RNG_A_IGATE", false, _params->range_aid_innov_gate),
_ev_pos_noise(this, "EKF2_EVP_NOISE", false, _default_ev_pos_noise),
_ev_ang_noise(this, "EKF2_EVA_NOISE", false, _default_ev_ang_noise),
_ev_pos_noise(this, "EKF2_EVP_NOISE", false),
_ev_ang_noise(this, "EKF2_EVA_NOISE", false),
_ev_innov_gate(this, "EKF2_EV_GATE", false, _params->ev_innov_gate),
_flow_noise(this, "EKF2_OF_N_MIN", false, _params->flow_noise),
_flow_noise_qual_min(this, "EKF2_OF_N_MAX", false, _params->flow_noise_qual_min),
@ -461,12 +449,6 @@ Ekf2::Ekf2():
_K_pstatic_coef_y(this, "EKF2_PCOEF_Y", false),
_K_pstatic_coef_z(this, "EKF2_PCOEF_Z", false)
{
}
Ekf2::~Ekf2()
{
}
int Ekf2::print_status()
@ -546,6 +528,8 @@ void Ekf2::run()
bool gps_updated = false;
bool airspeed_updated = false;
bool baro_updated = false;
bool sensor_selection_updated = false;
bool optical_flow_updated = false;
bool range_finder_updated = false;
bool vehicle_land_detected_updated = false;
@ -574,6 +558,18 @@ void Ekf2::run()
orb_copy(ORB_ID(airspeed), airspeed_sub, &airspeed);
}
orb_check(sensor_baro_sub, &baro_updated);
if (baro_updated) {
orb_copy(ORB_ID(sensor_baro), sensor_baro_sub, &sensor_baro);
}
orb_check(sensor_selection_sub, &sensor_selection_updated);
if (sensor_selection_updated) {
orb_copy(ORB_ID(sensor_selection), sensor_selection_sub, &sensor_selection);
}
orb_check(optical_flow_sub, &optical_flow_updated);
if (optical_flow_updated) {
@ -619,13 +615,14 @@ void Ekf2::run()
gyro_integral[0] = sensors.gyro_rad[0] * gyro_dt;
gyro_integral[1] = sensors.gyro_rad[1] * gyro_dt;
gyro_integral[2] = sensors.gyro_rad[2] * gyro_dt;
float accel_integral[3];
float accel_dt = sensors.accelerometer_integral_dt / 1.e6f;
accel_integral[0] = sensors.accelerometer_m_s2[0] * accel_dt;
accel_integral[1] = sensors.accelerometer_m_s2[1] * accel_dt;
accel_integral[2] = sensors.accelerometer_m_s2[2] * accel_dt;
_ekf.setIMUData(now, sensors.gyro_integral_dt, sensors.accelerometer_integral_dt,
gyro_integral, accel_integral);
_ekf.setIMUData(now, sensors.gyro_integral_dt, sensors.accelerometer_integral_dt, gyro_integral, accel_integral);
// read mag data
if (sensors.magnetometer_timestamp_relative == sensor_combined_s::RELATIVE_TIMESTAMP_INVALID) {
@ -640,8 +637,6 @@ void Ekf2::run()
// Do not reset parmameters when armed to prevent potential time slips casued by parameter set
// and notification events
// Check if there has been a persistant change in magnetometer ID
orb_copy(ORB_ID(sensor_selection), sensor_selection_sub, &sensor_selection);
if (sensor_selection.mag_device_id != 0 && sensor_selection.mag_device_id != _mag_bias_id.get()) {
if (_invalid_mag_id_count < 200) {
_invalid_mag_id_count++;
@ -718,7 +713,6 @@ void Ekf2::run()
float balt_data_avg = _balt_data_sum / (float)_balt_sample_count;
// estimate air density assuming typical 20degC ambient temperature
orb_copy(ORB_ID(sensor_baro), sensor_baro_sub, &sensor_baro);
const float pressure_to_density = 100.0f / (CONSTANTS_AIR_GAS_CONST * (20.0f - CONSTANTS_ABSOLUTE_NULL_CELSIUS));
float rho = pressure_to_density * sensor_baro.pressure;
_ekf.set_air_density(rho);
@ -741,7 +735,7 @@ void Ekf2::run()
_K_pstatic_coef_z.get() * fminf(_vel_body_wind(2) * _vel_body_wind(2), max_airspeed_sq));
// correct baro measurement using pressure error estimate and assuming sea level gravity
balt_data_avg += pstatic_err / (rho * 9.80665f);
balt_data_avg += pstatic_err / (rho * CONSTANTS_ONE_G);
// push to estimator
_ekf.setBaroData(1000 * (uint64_t)balt_time_ms, balt_data_avg);
@ -756,7 +750,7 @@ void Ekf2::run()
// read gps data if available
if (gps_updated) {
struct gps_message gps_msg = {};
struct gps_message gps_msg;
gps_msg.time_usec = gps.timestamp;
gps_msg.lat = gps.lat;
gps_msg.lon = gps.lon;
@ -780,19 +774,22 @@ void Ekf2::run()
// only set airspeed data if condition for airspeed fusion are met
bool fuse_airspeed = airspeed_updated && !vehicle_status.is_rotary_wing
&& _arspFusionThreshold.get() <= airspeed.true_airspeed_m_s && _arspFusionThreshold.get() >= 0.1f;
&& (_arspFusionThreshold.get() > FLT_EPSILON)
&& (airspeed.true_airspeed_m_s > _arspFusionThreshold.get());
if (fuse_airspeed) {
float eas2tas = airspeed.true_airspeed_m_s / airspeed.indicated_airspeed_m_s;
_ekf.setAirspeedData(airspeed.timestamp, airspeed.true_airspeed_m_s, eas2tas);
}
if (vehicle_status_updated) {
// only fuse synthetic sideslip measurements if conditions are met
bool fuse_beta = !vehicle_status.is_rotary_wing && _fuseBeta.get();
bool fuse_beta = !vehicle_status.is_rotary_wing && (_fuseBeta.get() == 1);
_ekf.set_fuse_beta_flag(fuse_beta);
// let the EKF know if the vehicle motion is that of a fixed wing (forward flight only relative to wind)
_ekf.set_is_fixed_wing(!vehicle_status.is_rotary_wing);
}
if (optical_flow_updated) {
flow_message flow;
@ -825,8 +822,8 @@ void Ekf2::run()
ev_data.quat = q;
// position measurement error from parameters. TODO : use covariances from topic
ev_data.posErr = _default_ev_pos_noise;
ev_data.angErr = _default_ev_ang_noise;
ev_data.posErr = _ev_pos_noise.get();
ev_data.angErr = _ev_ang_noise.get();
// use timestamp from external computer, clocks are synchronized when using MAVROS
_ekf.setExtVisionData(vision_position_updated ? ev_pos.timestamp : ev_att.timestamp, &ev_data);
@ -843,11 +840,11 @@ void Ekf2::run()
if (_ekf.update()) {
// integrate time to monitor time slippage
if (start_time_us == 0) {
start_time_us = now;
if (_start_time_us == 0) {
_start_time_us = now;
} else if (start_time_us > 0) {
integrated_time_us += sensors.gyro_integral_dt;
} else if (_start_time_us > 0) {
_integrated_time_us += sensors.gyro_integral_dt;
}
matrix::Quaternion<float> q;
@ -989,13 +986,16 @@ void Ekf2::run()
}
// generate vehicle local position data
struct vehicle_local_position_s lpos = {};
vehicle_local_position_s &lpos = _vehicle_local_position_pub.get();
float pos[3] = {};
lpos.timestamp = now;
// Position of body origin in local NED frame
_ekf.get_position(pos);
const float lpos_x_prev = lpos.x;
const float lpos_y_prev = lpos.y;
lpos.x = (_ekf.local_position_is_valid()) ? pos[0] : 0.0f;
lpos.y = (_ekf.local_position_is_valid()) ? pos[1] : 0.0f;
lpos.z = pos[2];
@ -1013,11 +1013,19 @@ void Ekf2::run()
lpos.v_z_valid = !_vel_innov_preflt_fail;
// Position of local NED origin in GPS / WGS84 frame
struct map_projection_reference_s ekf_origin = {};
map_projection_reference_s ekf_origin = {};
uint64_t origin_time = 0;
// true if position (x,y,z) has a valid WGS-84 global reference (ref_lat, ref_lon, alt)
lpos.xy_global = lpos.z_global = _ekf.get_ekf_origin(&lpos.ref_timestamp, &ekf_origin, &lpos.ref_alt);
const bool ekf_origin_valid = _ekf.get_ekf_origin(&origin_time, &ekf_origin, &lpos.ref_alt);
lpos.xy_global = ekf_origin_valid;
lpos.z_global = ekf_origin_valid;
if (ekf_origin_valid && (origin_time > lpos.ref_timestamp)) {
lpos.ref_timestamp = origin_time;
lpos.ref_lat = ekf_origin.lat_rad * 180.0 / M_PI; // Reference point latitude in degrees
lpos.ref_lon = ekf_origin.lon_rad * 180.0 / M_PI; // Reference point longitude in degrees
}
// The rotation of the tangent plane vs. geographical north
matrix::Eulerf euler(q);
@ -1047,28 +1055,19 @@ void Ekf2::run()
_ekf.get_velNE_reset(&lpos.delta_vxy[0], &lpos.vxy_reset_counter);
// publish vehicle local position data
if (_lpos_pub == nullptr) {
_lpos_pub = orb_advertise(ORB_ID(vehicle_local_position), &lpos);
} else {
orb_publish(ORB_ID(vehicle_local_position), _lpos_pub, &lpos);
}
_vehicle_local_position_pub.update();
if (_ekf.global_position_is_valid() && !_vel_innov_preflt_fail) {
// generate and publish global position data
struct vehicle_global_position_s global_pos = {};
vehicle_global_position_s &global_pos = _vehicle_global_position_pub.get();
global_pos.timestamp = now;
global_pos.time_utc_usec = gps.time_utc_usec; // GPS UTC timestamp in microseconds
double est_lat, est_lon, lat_pre_reset, lon_pre_reset;
map_projection_reproject(&ekf_origin, lpos.x, lpos.y, &est_lat, &est_lon);
global_pos.lat = est_lat; // Latitude in degrees
global_pos.lon = est_lon; // Longitude in degrees
map_projection_reproject(&ekf_origin, lpos.x - lpos.delta_xy[0], lpos.y - lpos.delta_xy[1], &lat_pre_reset,
&lon_pre_reset);
global_pos.delta_lat_lon[0] = est_lat - lat_pre_reset;
global_pos.delta_lat_lon[1] = est_lon - lon_pre_reset;
if (fabsf(lpos_x_prev - lpos.x) > FLT_EPSILON || fabsf(lpos_y_prev - lpos.y) > FLT_EPSILON) {
map_projection_reproject(&ekf_origin, lpos.x, lpos.y, &global_pos.lat, &global_pos.lon);
}
global_pos.lat_lon_reset_counter = lpos.xy_reset_counter;
global_pos.alt = -pos[2] + lpos.ref_alt; // Altitude AMSL in meters
@ -1100,17 +1099,12 @@ void Ekf2::run()
global_pos.pressure_alt = sensors.baro_alt_meter; // Pressure altitude AMSL (m)
if (_vehicle_global_position_pub == nullptr) {
_vehicle_global_position_pub = orb_advertise(ORB_ID(vehicle_global_position), &global_pos);
} else {
orb_publish(ORB_ID(vehicle_global_position), _vehicle_global_position_pub, &global_pos);
}
_vehicle_global_position_pub.update();
}
// publish estimator status
{
struct estimator_status_s status = {};
estimator_status_s status;
status.timestamp = now;
_ekf.get_state_delayed(status.states);
_ekf.get_covariances(status.covariances);
@ -1128,9 +1122,9 @@ void Ekf2::run()
_ekf.get_imu_vibe_metrics(status.vibe);
// monitor time slippage
if (start_time_us != 0 && now > start_time_us) {
status.time_slip = (float)(1e-6 * ((double)(now - start_time_us) - (double) integrated_time_us));
_last_time_slip_us = (now - start_time_us) - integrated_time_us;
if (_start_time_us != 0 && now > _start_time_us) {
status.time_slip = (float)(1e-6 * ((double)(now - _start_time_us) - (double) _integrated_time_us));
_last_time_slip_us = (now - _start_time_us) - _integrated_time_us;
} else {
status.time_slip = 0.0f;
@ -1218,7 +1212,7 @@ void Ekf2::run()
}
// Publish wind estimate
struct wind_estimate_s wind_estimate = {};
wind_estimate_s wind_estimate;
wind_estimate.timestamp = now;
wind_estimate.windspeed_north = status.states[22];
wind_estimate.windspeed_east = status.states[23];
@ -1235,7 +1229,7 @@ void Ekf2::run()
// publish estimator innovation data
{
struct ekf2_innovations_s innovations = {};
ekf2_innovations_s innovations;
innovations.timestamp = now;
_ekf.get_vel_pos_innov(&innovations.vel_pos_innov[0]);
_ekf.get_mag_innov(&innovations.mag_innov[0]);
@ -1362,11 +1356,8 @@ void Ekf2::run()
}
}
// publish replay message if in replay mode
bool publish_replay_message = (bool)_param_record_replay_msg.get();
if (publish_replay_message) {
if (_param_record_replay_msg.get() == 1) {
struct ekf2_replay_s replay = {};
replay.timestamp = now;
replay.gyro_integral_dt = sensors.gyro_integral_dt;
@ -1440,8 +1431,8 @@ void Ekf2::run()
replay.quat_ev[2] = ev_att.q[2];
replay.quat_ev[3] = ev_att.q[3];
// TODO: switch to covariances from topic later
replay.pos_err = _default_ev_pos_noise;
replay.ang_err = _default_ev_ang_noise;
replay.pos_err = _ev_pos_noise.get();
replay.ang_err = _ev_ang_noise.get();
} else {
replay.ev_timestamp = 0;
@ -1463,9 +1454,11 @@ void Ekf2::run()
orb_unsubscribe(optical_flow_sub);
orb_unsubscribe(range_finder_sub);
orb_unsubscribe(ev_pos_sub);
orb_unsubscribe(ev_att_sub);
orb_unsubscribe(vehicle_land_detected_sub);
orb_unsubscribe(status_sub);
orb_unsubscribe(sensor_selection_sub);
orb_unsubscribe(sensor_baro_sub);
}
Ekf2 *Ekf2::instantiate(int argc, char *argv[])
@ -1517,7 +1510,7 @@ int Ekf2::task_spawn(int argc, char *argv[])
_task_id = px4_task_spawn_cmd("ekf2",
SCHED_DEFAULT,
SCHED_PRIORITY_ESTIMATOR,
5900,
5700,
(px4_main_t)&run_trampoline,
(char *const *)argv);