ardupilot/libraries/AP_NavEKF2/AP_NavEKF2.h

346 lines
20 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/>.
*/
#ifndef AP_NavEKF2_Tuning
#define AP_NavEKF2_Tuning
#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 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;
// Return the last calculated NED 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 getPosNED(int8_t instance, Vector3f &pos);
// 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(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);
// 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);
/*
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, uint8_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 due to the last yaw angle reset in radians
// returns the time of the last yaw angle reset or 0 if no reset has ever occurred
uint32_t getLastYawResetAngle(float &yawAng) const;
// 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 &pos) const;
// 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); }
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 _magProcessNoise; // 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 _noaidHorizVelNoise; // horizontal velocity measurement noise assuned when synthesised zero velocity measurements are used to constrain attitude drift : m/s
// 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
};
#endif //AP_NavEKF2