fly316/PX4-Autopilot
7
0
Fork 0
mirror of https://gitee.com/mirrors_PX4/PX4-Autopilot.git synced 2026-10-26 01:53:34 +08:00
Code Issues Packages Projects Releases Wiki Activity

Move GPS blending from ekf2 to sensors module

Browse Source 
- new sensors work item that subscribes to N x sensor_gps and publishes vehicle_gps_position
 - blending is now configurable with SENS_GPS_MASK and SENS_GPS_TAU

Co-authored-by: Jacob Crabill <jacob@volans-i.com>
Co-authored-by: Jacob Dahl <dahl.jakejacob@gmail.com>
This commit is contained in:
Jacob Dahl
2020-09-25 23:28:31 -04:00
committed by GitHub
co-authored by Jacob Crabill Jacob Dahl
parent e792c46f20
commit a24488328f
27 changed files with 1147 additions and 861 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/modules/ekf2/EKF2.hpp
+5 -79
View File
@@ -60,7 +60,6 @@
#include <uORB/topics/distance_sensor.h>
#include <uORB/topics/ekf2_timestamps.h>
#include <uORB/topics/ekf_gps_drift.h>
#include <uORB/topics/ekf_gps_position.h>
#include <uORB/topics/estimator_innovations.h>
#include <uORB/topics/estimator_sensor_bias.h>
#include <uORB/topics/estimator_states.h>
@@ -85,15 +84,6 @@
#include "Utility/PreFlightChecker.hpp"
// defines used to specify the mask position for use of different accuracy metrics in the GPS blending algorithm
#define BLEND_MASK_USE_SPD_ACC 1
#define BLEND_MASK_USE_HPOS_ACC 2
#define BLEND_MASK_USE_VPOS_ACC 4
// define max number of GPS receivers supported and 0 base instance used to access virtual 'blended' GPS solution
#define GPS_MAX_RECEIVERS 2
#define GPS_BLENDED_INSTANCE 2
class EKF2 final : public ModuleBase<EKF2>, public ModuleParams, public px4::ScheduledWorkItem
{
public:
@@ -135,38 +125,6 @@ private:
void publish_wind_estimate(const hrt_abstime &timestamp);
void publish_yaw_estimator_status(const hrt_abstime &timestamp);
/*
* Update the internal state estimate for a blended GPS solution that is a weighted average of the phsyical
* receiver solutions. This internal state cannot be used directly by estimators because if physical receivers
* have significant position differences, variation in receiver estimated accuracy will cause undesirable
* variation in the position solution.
*/
bool blend_gps_data();
/*
* Calculate internal states used to blend GPS data from multiple receivers using weightings calculated
* by calc_blend_weights()
* States are written to _gps_state and _gps_blended_state class variables
*/
void update_gps_blend_states();
/*
* The location in _gps_blended_state will move around as the relative accuracy changes.
* To mitigate this effect a low-pass filtered offset from each GPS location to the blended location is
* calculated.
*/
void update_gps_offsets();
/*
* Apply the steady state physical receiver offsets calculated by update_gps_offsets().
*/
void apply_gps_offsets();
/*
Calculate GPS output that is a blend of the offset corrected physical receiver data
*/
void calc_gps_blend_output();
/*
* Calculate filtered WGS84 height from estimated AMSL height
*/
@@ -197,34 +155,11 @@ private:
// Used to control saving of mag declination to be used on next startup
bool _mag_decl_saved = false; ///< true when the magnetic declination has been saved
// set pose/velocity as invalid if standard deviation is bigger than max_std_dev
// TODO: the user should be allowed to set these values by a parameter
static constexpr float ep_max_std_dev = 100.0f; ///< Maximum permissible standard deviation for estimated position
static constexpr float eo_max_std_dev = 100.0f; ///< Maximum permissible standard deviation for estimated orientation
//static constexpr float ev_max_std_dev = 100.0f; ///< Maximum permissible standard deviation for estimated velocity
bool _had_valid_terrain{false}; ///< true if at any time there was a valid terrain estimate
// GPS blending and switching
gps_message _gps_state[GPS_MAX_RECEIVERS] {}; ///< internal state data for the physical GPS
gps_message _gps_blended_state{}; ///< internal state data for the blended GPS
gps_message _gps_output[GPS_MAX_RECEIVERS + 1] {}; ///< output state data for the physical and blended GPS
Vector2f _NE_pos_offset_m[GPS_MAX_RECEIVERS] = {}; ///< Filtered North,East position offset from GPS instance to blended solution in _output_state.location (m)
float _hgt_offset_mm[GPS_MAX_RECEIVERS] = {}; ///< Filtered height offset from GPS instance relative to blended solution in _output_state.location (mm)
Vector3f _blended_antenna_offset = {}; ///< blended antenna offset
float _blend_weights[GPS_MAX_RECEIVERS] = {}; ///< blend weight for each GPS. The blend weights must sum to 1.0 across all instances.
uint64_t _time_prev_us[GPS_MAX_RECEIVERS] = {}; ///< the previous value of time_us for that GPS instance - used to detect new data.
uint8_t _gps_best_index = 0; ///< index of the physical receiver with the lowest reported error
uint8_t _gps_select_index = 0; ///< 0 = GPS1, 1 = GPS2, 2 = blended
uint8_t _gps_time_ref_index =
0; ///< index of the receiver that is used as the timing reference for the blending update
uint8_t _gps_oldest_index = 0; ///< index of the physical receiver with the oldest data
uint8_t _gps_newest_index = 0; ///< index of the physical receiver with the newest data
uint8_t _gps_slowest_index = 0; ///< index of the physical receiver with the slowest update rate
float _gps_dt[GPS_MAX_RECEIVERS] = {}; ///< average time step in seconds.
bool _gps_new_output_data = false; ///< true if there is new output data for the EKF
bool _had_valid_terrain = false; ///< true if at any time there was a valid terrain estimate
int32_t _gps_alttitude_ellipsoid[GPS_MAX_RECEIVERS] {}; ///< altitude in 1E-3 meters (millimeters) above ellipsoid
uint64_t _gps_alttitude_ellipsoid_previous_timestamp[GPS_MAX_RECEIVERS] {}; ///< storage for previous timestamp to compute dt
uint64_t _gps_time_usec{0};
int32_t _gps_alttitude_ellipsoid{0}; ///< altitude in 1E-3 meters (millimeters) above ellipsoid
uint64_t _gps_alttitude_ellipsoid_previous_timestamp{0}; ///< storage for previous timestamp to compute dt
float _wgs84_hgt_offset = 0; ///< height offset between AMSL and WGS84
bool _imu_bias_reset_request{false};
@@ -242,6 +177,7 @@ private:
uORB::Subscription _parameter_update_sub{ORB_ID(parameter_update)};
uORB::Subscription _sensor_selection_sub{ORB_ID(sensor_selection)};
uORB::Subscription _status_sub{ORB_ID(vehicle_status)};
uORB::Subscription _vehicle_gps_position_sub{ORB_ID(vehicle_gps_position)};
uORB::Subscription _vehicle_land_detected_sub{ORB_ID(vehicle_land_detected)};
uORB::SubscriptionCallbackWorkItem _sensor_combined_sub{this, ORB_ID(sensor_combined)};
@@ -255,16 +191,12 @@ private:
uORB::SubscriptionMultiArray<distance_sensor_s> _distance_sensor_subs{ORB_ID::distance_sensor};
int _range_finder_sub_index = -1; // index for downward-facing range finder subscription
// because we can have multiple GPS instances
uORB::Subscription _gps_subs[GPS_MAX_RECEIVERS] {{ORB_ID(vehicle_gps_position), 0}, {ORB_ID(vehicle_gps_position), 1}};
sensor_selection_s _sensor_selection{};
vehicle_land_detected_s _vehicle_land_detected{};
vehicle_status_s _vehicle_status{};
uORB::Publication<ekf2_timestamps_s> _ekf2_timestamps_pub{ORB_ID(ekf2_timestamps)};
uORB::Publication<ekf_gps_drift_s> _ekf_gps_drift_pub{ORB_ID(ekf_gps_drift)};
uORB::Publication<ekf_gps_position_s> _blended_gps_pub{ORB_ID(ekf_gps_position)};
uORB::Publication<estimator_innovations_s> _estimator_innovation_test_ratios_pub{ORB_ID(estimator_innovation_test_ratios)};
uORB::Publication<estimator_innovations_s> _estimator_innovation_variances_pub{ORB_ID(estimator_innovation_variances)};
uORB::Publication<estimator_innovations_s> _estimator_innovations_pub{ORB_ID(estimator_innovations)};
@@ -516,12 +448,6 @@ private:
(ParamExtFloat<px4::params::EKF2_PCOEF_Z>)
_param_ekf2_pcoef_z, ///< static pressure position error coefficient along the Z body axis
// GPS blending
(ParamInt<px4::params::EKF2_GPS_MASK>)
_param_ekf2_gps_mask, ///< mask defining when GPS accuracy metrics are used to calculate the blend ratio
(ParamFloat<px4::params::EKF2_GPS_TAU>)
_param_ekf2_gps_tau, ///< time constant controlling how rapidly the offset used to bring GPS solutions together is allowed to change (sec)
// Test used to determine if the vehicle is static or moving
(ParamExtFloat<px4::params::EKF2_MOVE_TEST>)
_param_ekf2_move_test, ///< scaling applied to IMU data thresholds used to determine if the vehicle is static or moving.