mirror of https://github.com/ArduPilot/ardupilot
410 lines
23 KiB
C++
410 lines
23 KiB
C++
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
|
|
/*
|
|
24 state EKF based on https://github.com/priseborough/InertialNav
|
|
Converted from Matlab to C++ by Paul Riseborough
|
|
|
|
EKF Tuning parameters refactored by Tom Cauchois
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <AP_Math/AP_Math.h>
|
|
#include <AP_Param/AP_Param.h>
|
|
#include <GCS_MAVLink/GCS_MAVLink.h>
|
|
#include <AP_NavEKF/AP_Nav_Common.h>
|
|
#include <AP_Baro/AP_Baro.h>
|
|
#include <AP_Airspeed/AP_Airspeed.h>
|
|
#include <AP_Compass/AP_Compass.h>
|
|
#include <AP_NavEKF/AP_Nav_Common.h>
|
|
#include <AP_RangeFinder/AP_RangeFinder.h>
|
|
|
|
class NavEKF2_core;
|
|
class AP_AHRS;
|
|
|
|
class NavEKF2
|
|
{
|
|
public:
|
|
friend class NavEKF2_core;
|
|
static const struct AP_Param::GroupInfo var_info[];
|
|
|
|
NavEKF2(const AP_AHRS *ahrs, AP_Baro &baro, const RangeFinder &rng);
|
|
|
|
// allow logging to determine the number of active cores
|
|
uint8_t activeCores(void) const {
|
|
return num_cores;
|
|
}
|
|
|
|
// Initialise the filter
|
|
bool InitialiseFilter(void);
|
|
|
|
// Update Filter States - this should be called whenever new IMU data is available
|
|
void UpdateFilter(void);
|
|
|
|
// check if we should write log messages
|
|
void check_log_write(void);
|
|
|
|
// Check basic filter health metrics and return a consolidated health status
|
|
bool healthy(void) const;
|
|
|
|
// returns the index of the primary core
|
|
// return -1 if no primary core selected
|
|
int8_t getPrimaryCoreIndex(void) const;
|
|
|
|
// returns the index of the IMU of the primary core
|
|
// return -1 if no primary core selected
|
|
int8_t getPrimaryCoreIMUIndex(void) const;
|
|
|
|
// Write the last calculated NE position relative to the reference point (m) for the specified instance.
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
// If a calculated solution is not available, use the best available data and return false
|
|
// If false returned, do not use for flight control
|
|
bool getPosNE(int8_t instance, Vector2f &posNE);
|
|
|
|
// Write the last calculated D position relative to the reference point (m) for the specified instance.
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
// If a calculated solution is not available, use the best available data and return false
|
|
// If false returned, do not use for flight control
|
|
bool getPosD(int8_t instance, float &posD);
|
|
|
|
// return NED velocity in m/s for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getVelNED(int8_t instance, Vector3f &vel);
|
|
|
|
// Return the rate of change of vertical position in the down diection (dPosD/dt) in m/s for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
// This can be different to the z component of the EKF velocity state because it will fluctuate with height errors and corrections in the EKF
|
|
// but will always be kinematically consistent with the z component of the EKF position state
|
|
float getPosDownDerivative(int8_t instance);
|
|
|
|
// This returns the specific forces in the NED frame
|
|
void getAccelNED(Vector3f &accelNED) const;
|
|
|
|
// return body axis gyro bias estimates in rad/sec for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getGyroBias(int8_t instance, Vector3f &gyroBias);
|
|
|
|
// return body axis gyro scale factor error as a percentage for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getGyroScaleErrorPercentage(int8_t instance, Vector3f &gyroScale);
|
|
|
|
// return tilt error convergence metric for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getTiltError(int8_t instance, float &ang);
|
|
|
|
// reset body axis gyro bias estimates
|
|
void resetGyroBias(void);
|
|
|
|
// Resets the baro so that it reads zero at the current height
|
|
// Resets the EKF height to zero
|
|
// Adjusts the EKf origin height so that the EKF height + origin height is the same as before
|
|
// Returns true if the height datum reset has been performed
|
|
// If using a range finder for height no reset is performed and it returns false
|
|
bool resetHeightDatum(void);
|
|
|
|
// Commands the EKF to not use GPS.
|
|
// This command must be sent prior to arming as it will only be actioned when the filter is in static mode
|
|
// This command is forgotten by the EKF each time it goes back into static mode (eg the vehicle disarms)
|
|
// Returns 0 if command rejected
|
|
// Returns 1 if attitude, vertical velocity and vertical position will be provided
|
|
// Returns 2 if attitude, 3D-velocity, vertical position and relative horizontal position will be provided
|
|
uint8_t setInhibitGPS(void);
|
|
|
|
// return the horizontal speed limit in m/s set by optical flow sensor limits
|
|
// return the scale factor to be applied to navigation velocity gains to compensate for increase in velocity noise with height when using optical flow
|
|
void getEkfControlLimits(float &ekfGndSpdLimit, float &ekfNavVelGainScaler) const;
|
|
|
|
// return the Z-accel bias estimate in m/s^2 for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getAccelZBias(int8_t instance, float &zbias);
|
|
|
|
// return the NED wind speed estimates in m/s (positive is air moving in the direction of the axis)
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getWind(int8_t instance, Vector3f &wind);
|
|
|
|
// return earth magnetic field estimates in measurement units / 1000 for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getMagNED(int8_t instance, Vector3f &magNED);
|
|
|
|
// return body magnetic field estimates in measurement units / 1000 for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getMagXYZ(int8_t instance, Vector3f &magXYZ);
|
|
|
|
// return the magnetometer in use for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
uint8_t getActiveMag(int8_t instance);
|
|
|
|
// Return estimated magnetometer offsets
|
|
// Return true if magnetometer offsets are valid
|
|
bool getMagOffsets(uint8_t mag_idx, Vector3f &magOffsets) const;
|
|
|
|
// Return the last calculated latitude, longitude and height in WGS-84
|
|
// If a calculated location isn't available, return a raw GPS measurement
|
|
// The status will return true if a calculation or raw measurement is available
|
|
// The getFilterStatus() function provides a more detailed description of data health and must be checked if data is to be used for flight control
|
|
bool getLLH(struct Location &loc) const;
|
|
|
|
// return the latitude and longitude and height used to set the NED origin
|
|
// All NED positions calculated by the filter are relative to this location
|
|
// Returns false if the origin has not been set
|
|
bool getOriginLLH(struct Location &loc) const;
|
|
|
|
// set the latitude and longitude and height used to set the NED origin
|
|
// All NED positions calcualted by the filter will be relative to this location
|
|
// The origin cannot be set if the filter is in a flight mode (eg vehicle armed)
|
|
// Returns false if the filter has rejected the attempt to set the origin
|
|
bool setOriginLLH(struct Location &loc);
|
|
|
|
// return estimated height above ground level
|
|
// return false if ground height is not being estimated.
|
|
bool getHAGL(float &HAGL) const;
|
|
|
|
// return the Euler roll, pitch and yaw angle in radians for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getEulerAngles(int8_t instance, Vector3f &eulers);
|
|
|
|
// return the transformation matrix from XYZ (body) to NED axes
|
|
void getRotationBodyToNED(Matrix3f &mat) const;
|
|
|
|
// return the quaternions defining the rotation from NED to XYZ (body) axes
|
|
void getQuaternion(Quaternion &quat) const;
|
|
|
|
// return the innovations for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getInnovations(int8_t index, Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov);
|
|
|
|
// publish output observer angular, velocity and position tracking error
|
|
void getOutputTrackingError(int8_t instance, Vector3f &error) const;
|
|
|
|
// return the innovation consistency test ratios for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getVariances(int8_t instance, float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset);
|
|
|
|
// should we use the compass? This is public so it can be used for
|
|
// reporting via ahrs.use_compass()
|
|
bool use_compass(void) const;
|
|
|
|
// write the raw optical flow measurements
|
|
// rawFlowQuality is a measured of quality between 0 and 255, with 255 being the best quality
|
|
// rawFlowRates are the optical flow rates in rad/sec about the X and Y sensor axes.
|
|
// rawGyroRates are the sensor rotation rates in rad/sec measured by the sensors internal gyro
|
|
// The sign convention is that a RH physical rotation of the sensor about an axis produces both a positive flow and gyro rate
|
|
// msecFlowMeas is the scheduler time in msec when the optical flow data was received from the sensor.
|
|
void writeOptFlowMeas(uint8_t &rawFlowQuality, Vector2f &rawFlowRates, Vector2f &rawGyroRates, uint32_t &msecFlowMeas);
|
|
|
|
// return data for debugging optical flow fusion for the specified instance
|
|
// An out of range instance (eg -1) returns data for the the primary instance
|
|
void getFlowDebug(int8_t instance, float &varFlow, float &gndOffset, float &flowInnovX, float &flowInnovY, float &auxInnov, float &HAGL, float &rngInnov, float &range, float &gndOffsetErr);
|
|
|
|
// called by vehicle code to specify that a takeoff is happening
|
|
// causes the EKF to compensate for expected barometer errors due to ground effect
|
|
void setTakeoffExpected(bool val);
|
|
|
|
// called by vehicle code to specify that a touchdown is expected to happen
|
|
// causes the EKF to compensate for expected barometer errors due to ground effect
|
|
void setTouchdownExpected(bool val);
|
|
|
|
// Set to true if the terrain underneath is stable enough to be used as a height reference
|
|
// in combination with a range finder. Set to false if the terrain underneath the vehicle
|
|
// cannot be used as a height reference
|
|
void setTerrainHgtStable(bool val);
|
|
|
|
/*
|
|
return the filter fault status as a bitmasked integer for the specified instance
|
|
An out of range instance (eg -1) returns data for the the primary instance
|
|
0 = quaternions are NaN
|
|
1 = velocities are NaN
|
|
2 = badly conditioned X magnetometer fusion
|
|
3 = badly conditioned Y magnetometer fusion
|
|
5 = badly conditioned Z magnetometer fusion
|
|
6 = badly conditioned airspeed fusion
|
|
7 = badly conditioned synthetic sideslip fusion
|
|
7 = filter is not initialised
|
|
*/
|
|
void getFilterFaults(int8_t instance, uint16_t &faults);
|
|
|
|
/*
|
|
return filter timeout status as a bitmasked integer for the specified instance
|
|
An out of range instance (eg -1) returns data for the the primary instance
|
|
0 = position measurement timeout
|
|
1 = velocity measurement timeout
|
|
2 = height measurement timeout
|
|
3 = magnetometer measurement timeout
|
|
5 = unassigned
|
|
6 = unassigned
|
|
7 = unassigned
|
|
7 = unassigned
|
|
*/
|
|
void getFilterTimeouts(int8_t instance, uint8_t &timeouts);
|
|
|
|
/*
|
|
return filter gps quality check status for the specified instance
|
|
An out of range instance (eg -1) returns data for the the primary instance
|
|
*/
|
|
void getFilterGpsStatus(int8_t instance, nav_gps_status &faults);
|
|
|
|
/*
|
|
return filter status flags for the specified instance
|
|
An out of range instance (eg -1) returns data for the the primary instance
|
|
*/
|
|
void getFilterStatus(int8_t instance, nav_filter_status &status);
|
|
|
|
// send an EKF_STATUS_REPORT message to GCS
|
|
void send_status_report(mavlink_channel_t chan);
|
|
|
|
// provides the height limit to be observed by the control loops
|
|
// returns false if no height limiting is required
|
|
// this is needed to ensure the vehicle does not fly too high when using optical flow navigation
|
|
bool getHeightControlLimit(float &height) const;
|
|
|
|
// return the amount of yaw angle change (in radians) due to the last yaw angle reset or core selection switch
|
|
// returns the time of the last yaw angle reset or 0 if no reset has ever occurred
|
|
uint32_t getLastYawResetAngle(float &yawAngDelta);
|
|
|
|
// return the amount of NE position change due to the last position reset in metres
|
|
// returns the time of the last reset or 0 if no reset has ever occurred
|
|
uint32_t getLastPosNorthEastReset(Vector2f &posDelta);
|
|
|
|
// return the amount of NE velocity change due to the last velocity reset in metres/sec
|
|
// returns the time of the last reset or 0 if no reset has ever occurred
|
|
uint32_t getLastVelNorthEastReset(Vector2f &vel) const;
|
|
|
|
// report any reason for why the backend is refusing to initialise
|
|
const char *prearm_failure_reason(void) const;
|
|
|
|
// allow the enable flag to be set by Replay
|
|
void set_enable(bool enable) { _enable.set(enable); }
|
|
|
|
// are we doing sensor logging inside the EKF?
|
|
bool have_ekf_logging(void) const { return logging.enabled && _logging_mask != 0; }
|
|
|
|
private:
|
|
uint8_t num_cores; // number of allocated cores
|
|
uint8_t primary; // current primary core
|
|
NavEKF2_core *core = nullptr;
|
|
const AP_AHRS *_ahrs;
|
|
AP_Baro &_baro;
|
|
const RangeFinder &_rng;
|
|
|
|
// EKF Mavlink Tuneable Parameters
|
|
AP_Int8 _enable; // zero to disable EKF2
|
|
AP_Float _gpsHorizVelNoise; // GPS horizontal velocity measurement noise : m/s
|
|
AP_Float _gpsVertVelNoise; // GPS vertical velocity measurement noise : m/s
|
|
AP_Float _gpsHorizPosNoise; // GPS horizontal position measurement noise m
|
|
AP_Float _baroAltNoise; // Baro height measurement noise : m^2
|
|
AP_Float _magNoise; // magnetometer measurement noise : gauss
|
|
AP_Float _easNoise; // equivalent airspeed measurement noise : m/s
|
|
AP_Float _windVelProcessNoise; // wind velocity state process noise : m/s^2
|
|
AP_Float _wndVarHgtRateScale; // scale factor applied to wind process noise due to height rate
|
|
AP_Float _magEarthProcessNoise; // Earth magnetic field process noise : gauss/sec
|
|
AP_Float _magBodyProcessNoise; // Body magnetic field process noise : gauss/sec
|
|
AP_Float _gyrNoise; // gyro process noise : rad/s
|
|
AP_Float _accNoise; // accelerometer process noise : m/s^2
|
|
AP_Float _gyroBiasProcessNoise; // gyro bias state process noise : rad/s
|
|
AP_Float _accelBiasProcessNoise;// accel bias state process noise : m/s^2
|
|
AP_Int16 _gpsDelay_ms; // effective average delay of GPS measurements relative to inertial measurement (msec)
|
|
AP_Int16 _hgtDelay_ms; // effective average delay of Height measurements relative to inertial measurements (msec)
|
|
AP_Int8 _fusionModeGPS; // 0 = use 3D velocity, 1 = use 2D velocity, 2 = use no velocity
|
|
AP_Int16 _gpsVelInnovGate; // Percentage number of standard deviations applied to GPS velocity innovation consistency check
|
|
AP_Int16 _gpsPosInnovGate; // Percentage number of standard deviations applied to GPS position innovation consistency check
|
|
AP_Int16 _hgtInnovGate; // Percentage number of standard deviations applied to height innovation consistency check
|
|
AP_Int16 _magInnovGate; // Percentage number of standard deviations applied to magnetometer innovation consistency check
|
|
AP_Int16 _tasInnovGate; // Percentage number of standard deviations applied to true airspeed innovation consistency check
|
|
AP_Int8 _magCal; // Sets activation condition for in-flight magnetometer calibration
|
|
AP_Int8 _gpsGlitchRadiusMax; // Maximum allowed discrepancy between inertial and GPS Horizontal position before GPS glitch is declared : m
|
|
AP_Float _flowNoise; // optical flow rate measurement noise
|
|
AP_Int16 _flowInnovGate; // Percentage number of standard deviations applied to optical flow innovation consistency check
|
|
AP_Int8 _flowDelay_ms; // effective average delay of optical flow measurements rel to IMU (msec)
|
|
AP_Int16 _rngInnovGate; // Percentage number of standard deviations applied to range finder innovation consistency check
|
|
AP_Float _maxFlowRate; // Maximum flow rate magnitude that will be accepted by the filter
|
|
AP_Int8 _altSource; // Primary alt source during optical flow navigation. 0 = use Baro, 1 = use range finder.
|
|
AP_Float _gyroScaleProcessNoise;// gyro scale factor state process noise : 1/s
|
|
AP_Float _rngNoise; // Range finder noise : m
|
|
AP_Int8 _gpsCheck; // Bitmask controlling which preflight GPS checks are bypassed
|
|
AP_Int8 _imuMask; // Bitmask of IMUs to instantiate EKF2 for
|
|
AP_Int16 _gpsCheckScaler; // Percentage increase to be applied to GPS pre-flight accuracy and drift thresholds
|
|
AP_Float _noaidHorizNoise; // horizontal position measurement noise assumed when synthesised zero position measurements are used to constrain attitude drift : m
|
|
AP_Int8 _logging_mask; // mask of IMUs to log
|
|
AP_Float _yawNoise; // magnetic yaw measurement noise : rad
|
|
AP_Int16 _yawInnovGate; // Percentage number of standard deviations applied to magnetic yaw innovation consistency check
|
|
AP_Int8 _tauVelPosOutput; // Time constant of output complementary filter : csec (centi-seconds)
|
|
AP_Int8 _useRngSwHgt; // Maximum valid range of the range finder in metres
|
|
AP_Float _terrGradMax; // Maximum terrain gradient below the vehicle
|
|
|
|
// Tuning parameters
|
|
const float gpsNEVelVarAccScale; // Scale factor applied to NE velocity measurement variance due to manoeuvre acceleration
|
|
const float gpsDVelVarAccScale; // Scale factor applied to vertical velocity measurement variance due to manoeuvre acceleration
|
|
const float gpsPosVarAccScale; // Scale factor applied to horizontal position measurement variance due to manoeuvre acceleration
|
|
const uint16_t magDelay_ms; // Magnetometer measurement delay (msec)
|
|
const uint16_t tasDelay_ms; // Airspeed measurement delay (msec)
|
|
const uint16_t gpsRetryTimeUseTAS_ms; // GPS retry time with airspeed measurements (msec)
|
|
const uint16_t gpsRetryTimeNoTAS_ms; // GPS retry time without airspeed measurements (msec)
|
|
const uint16_t gpsFailTimeWithFlow_ms; // If we have no GPs for longer than this and we have optical flow, then we will switch across to using optical flow (msec)
|
|
const uint16_t hgtRetryTimeMode0_ms; // Height retry time with vertical velocity measurement (msec)
|
|
const uint16_t hgtRetryTimeMode12_ms; // Height retry time without vertical velocity measurement (msec)
|
|
const uint16_t tasRetryTime_ms; // True airspeed timeout and retry interval (msec)
|
|
const uint32_t magFailTimeLimit_ms; // number of msec before a magnetometer failing innovation consistency checks is declared failed (msec)
|
|
const float magVarRateScale; // scale factor applied to magnetometer variance due to angular rate
|
|
const float gyroBiasNoiseScaler; // scale factor applied to gyro bias state process noise when on ground
|
|
const uint16_t hgtAvg_ms; // average number of msec between height measurements
|
|
const uint16_t betaAvg_ms; // average number of msec between synthetic sideslip measurements
|
|
const float covTimeStepMax; // maximum time (sec) between covariance prediction updates
|
|
const float covDelAngMax; // maximum delta angle between covariance prediction updates
|
|
const float DCM33FlowMin; // If Tbn(3,3) is less than this number, optical flow measurements will not be fused as tilt is too high.
|
|
const float fScaleFactorPnoise; // Process noise added to focal length scale factor state variance at each time step
|
|
const uint8_t flowTimeDeltaAvg_ms; // average interval between optical flow measurements (msec)
|
|
const uint32_t flowIntervalMax_ms; // maximum allowable time between flow fusion events
|
|
const uint16_t gndEffectTimeout_ms; // time in msec that ground effect mode is active after being activated
|
|
const float gndEffectBaroScaler; // scaler applied to the barometer observation variance when ground effect mode is active
|
|
const uint8_t gndGradientSigma; // RMS terrain gradient percentage assumed by the terrain height estimation
|
|
const uint8_t fusionTimeStep_ms; // The minimum time interval between covariance predictions and measurement fusions in msec
|
|
|
|
struct {
|
|
bool enabled:1;
|
|
bool log_compass:1;
|
|
bool log_gps:1;
|
|
bool log_baro:1;
|
|
bool log_imu:1;
|
|
} logging;
|
|
|
|
// time at start of current filter update
|
|
uint64_t imuSampleTime_us;
|
|
|
|
struct {
|
|
uint32_t last_function_call; // last time getLastYawYawResetAngle was called
|
|
bool core_changed; // true when a core change happened and hasn't been consumed, false otherwise
|
|
uint32_t last_primary_change; // last time a primary has changed
|
|
float core_delta; // the amount of yaw change between cores when a change happened
|
|
} yaw_reset_data;
|
|
|
|
struct {
|
|
uint32_t last_function_call; // last time getLastPosNorthEastReset was called
|
|
bool core_changed; // true when a core change happened and hasn't been consumed, false otherwise
|
|
uint32_t last_primary_change; // last time a primary has changed
|
|
Vector2f core_delta; // the amount of NE position change between cores when a change happened
|
|
} pos_reset_data;
|
|
|
|
// update the yaw reset data to capture changes due to a lane switch
|
|
// has_switched - true if the primary instance has already been changed during this filter update cycle
|
|
// new_primary - index of the ekf instance that we are about to switch to as the primary
|
|
// old_primary - index of the ekf instance that we are currently using as the primary
|
|
void updateLaneSwitchYawResetData(bool has_switched, uint8_t new_primary, uint8_t old_primary);
|
|
|
|
// update the position reset data to capture changes due to a lane switch
|
|
// has_switched - true if the primary instance has already been changed during this filter update cycle
|
|
// new_primary - index of the ekf instance that we are about to switch to as the primary
|
|
// old_primary - index of the ekf instance that we are currently using as the primary
|
|
void updateLaneSwitchPosResetData(bool has_switched, uint8_t new_primary, uint8_t old_primary);
|
|
};
|