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Diffstat (limited to 'src/modules/ekf_att_pos_estimator/estimator_21states.h')
| -rw-r--r-- | src/modules/ekf_att_pos_estimator/estimator_21states.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/modules/ekf_att_pos_estimator/estimator_21states.h b/src/modules/ekf_att_pos_estimator/estimator_21states.h new file mode 100644 index 000000000..a19ff1995 --- /dev/null +++ b/src/modules/ekf_att_pos_estimator/estimator_21states.h @@ -0,0 +1,247 @@ +#pragma once + +#include "estimator_utilities.h" + +class AttPosEKF { + +public: + + AttPosEKF(); + ~AttPosEKF(); + + /* ############################################## + * + * M A I N F I L T E R P A R A M E T E R S + * + * ########################################### */ + + /* + * parameters are defined here and initialised in + * the InitialiseParameters() (which is just 20 lines down) + */ + + float covTimeStepMax; // maximum time allowed between covariance predictions + float covDelAngMax; // maximum delta angle between covariance predictions + float rngFinderPitch; // pitch angle of laser range finder in radians. Zero is aligned with the Z body axis. Positive is RH rotation about Y body axis. + + float yawVarScale; + float windVelSigma; + float dAngBiasSigma; + float dVelBiasSigma; + float magEarthSigma; + float magBodySigma; + float gndHgtSigma; + + float vneSigma; + float vdSigma; + float posNeSigma; + float posDSigma; + float magMeasurementSigma; + float airspeedMeasurementSigma; + + float gyroProcessNoise; + float accelProcessNoise; + + float EAS2TAS; // ratio f true to equivalent airspeed + + void InitialiseParameters() + { + covTimeStepMax = 0.07f; // maximum time allowed between covariance predictions + covDelAngMax = 0.02f; // maximum delta angle between covariance predictions + rngFinderPitch = 0.0f; // pitch angle of laser range finder in radians. Zero is aligned with the Z body axis. Positive is RH rotation about Y body axis. + EAS2TAS = 1.0f; + + yawVarScale = 1.0f; + windVelSigma = 0.1f; + dAngBiasSigma = 5.0e-7f; + dVelBiasSigma = 1e-4f; + magEarthSigma = 3.0e-4f; + magBodySigma = 3.0e-4f; + gndHgtSigma = 0.02f; // assume 2% terrain gradient 1-sigma + + vneSigma = 0.2f; + vdSigma = 0.3f; + posNeSigma = 2.0f; + posDSigma = 2.0f; + + magMeasurementSigma = 0.05; + airspeedMeasurementSigma = 1.4f; + gyroProcessNoise = 1.4544411e-2f; + accelProcessNoise = 0.5f; + } + + // Global variables + float KH[n_states][n_states]; // intermediate result used for covariance updates + float KHP[n_states][n_states]; // intermediate result used for covariance updates + float P[n_states][n_states]; // covariance matrix + float Kfusion[n_states]; // Kalman gains + float states[n_states]; // state matrix + float storedStates[n_states][data_buffer_size]; // state vectors stored for the last 50 time steps + uint32_t statetimeStamp[data_buffer_size]; // time stamp for each state vector stored + + float statesAtVelTime[n_states]; // States at the effective measurement time for posNE and velNED measurements + float statesAtPosTime[n_states]; // States at the effective measurement time for posNE and velNED measurements + float statesAtHgtTime[n_states]; // States at the effective measurement time for the hgtMea measurement + float statesAtMagMeasTime[n_states]; // filter satates at the effective measurement time + float statesAtVtasMeasTime[n_states]; // filter states at the effective measurement time + + Vector3f correctedDelAng; // delta angles about the xyz body axes corrected for errors (rad) + Vector3f correctedDelVel; // delta velocities along the XYZ body axes corrected for errors (m/s) + Vector3f summedDelAng; // summed delta angles about the xyz body axes corrected for errors (rad) + Vector3f summedDelVel; // summed delta velocities along the XYZ body axes corrected for errors (m/s) + float accNavMag; // magnitude of navigation accel (- used to adjust GPS obs variance (m/s^2) + Vector3f earthRateNED; // earths angular rate vector in NED (rad/s) + Vector3f angRate; // angular rate vector in XYZ body axes measured by the IMU (rad/s) + Vector3f accel; // acceleration vector in XYZ body axes measured by the IMU (m/s^2) + Vector3f dVelIMU; + Vector3f dAngIMU; + float dtIMU; // time lapsed since the last IMU measurement or covariance update (sec) + uint8_t fusionModeGPS; // 0 = GPS outputs 3D velocity, 1 = GPS outputs 2D velocity, 2 = GPS outputs no velocity + float innovVelPos[6]; // innovation output + float varInnovVelPos[6]; // innovation variance output + + float velNED[3]; // North, East, Down velocity obs (m/s) + float posNE[2]; // North, East position obs (m) + float hgtMea; // measured height (m) + float posNED[3]; // North, East Down position (m) + + float innovMag[3]; // innovation output + float varInnovMag[3]; // innovation variance output + Vector3f magData; // magnetometer flux radings in X,Y,Z body axes + float innovVtas; // innovation output + float varInnovVtas; // innovation variance output + float VtasMeas; // true airspeed measurement (m/s) + float magDeclination; + float latRef; // WGS-84 latitude of reference point (rad) + float lonRef; // WGS-84 longitude of reference point (rad) + float hgtRef; // WGS-84 height of reference point (m) + Vector3f magBias; // states representing magnetometer bias vector in XYZ body axes + uint8_t covSkipCount; // Number of state prediction frames (IMU daya updates to skip before doing the covariance prediction + + // GPS input data variables + float gpsCourse; + float gpsVelD; + float gpsLat; + float gpsLon; + float gpsHgt; + uint8_t GPSstatus; + + // Baro input + float baroHgt; + + bool statesInitialised; + + bool fuseVelData; // this boolean causes the posNE and velNED obs to be fused + bool fusePosData; // this boolean causes the posNE and velNED obs to be fused + bool fuseHgtData; // this boolean causes the hgtMea obs to be fused + bool fuseMagData; // boolean true when magnetometer data is to be fused + bool fuseVtasData; // boolean true when airspeed data is to be fused + + bool onGround; ///< boolean true when the flight vehicle is on the ground (not flying) + bool staticMode; ///< boolean true if no position feedback is fused + bool useAirspeed; ///< boolean true if airspeed data is being used + bool useCompass; ///< boolean true if magnetometer data is being used + + struct ekf_status_report current_ekf_state; + struct ekf_status_report last_ekf_error; + + bool numericalProtection; + + unsigned storeIndex; + + +void UpdateStrapdownEquationsNED(); + +void CovariancePrediction(float dt); + +void FuseVelposNED(); + +void FuseMagnetometer(); + +void FuseAirspeed(); + +void zeroRows(float (&covMat)[n_states][n_states], uint8_t first, uint8_t last); + +void zeroCols(float (&covMat)[n_states][n_states], uint8_t first, uint8_t last); + +void quatNorm(float (&quatOut)[4], const float quatIn[4]); + +// store staes along with system time stamp in msces +void StoreStates(uint64_t timestamp_ms); + +/** + * Recall the state vector. + * + * Recalls the vector stored at closest time to the one specified by msec + * + * @return zero on success, integer indicating the number of invalid states on failure. + * Does only copy valid states, if the statesForFusion vector was initialized + * correctly by the caller, the result can be safely used, but is a mixture + * time-wise where valid states were updated and invalid remained at the old + * value. + */ +int RecallStates(float statesForFusion[n_states], uint64_t msec); + +void ResetStoredStates(); + +void quat2Tbn(Mat3f &Tbn, const float (&quat)[4]); + +void calcEarthRateNED(Vector3f &omega, float latitude); + +static void eul2quat(float (&quat)[4], const float (&eul)[3]); + +static void quat2eul(float (&eul)[3], const float (&quat)[4]); + +static void calcvelNED(float (&velNED)[3], float gpsCourse, float gpsGndSpd, float gpsVelD); + +static void calcposNED(float (&posNED)[3], float lat, float lon, float hgt, float latRef, float lonRef, float hgtRef); + +static void calcLLH(float (&posNED)[3], float lat, float lon, float hgt, float latRef, float lonRef, float hgtRef); + +static void quat2Tnb(Mat3f &Tnb, const float (&quat)[4]); + +static float sq(float valIn); + +void OnGroundCheck(); + +void CovarianceInit(); + +void InitialiseFilter(float (&initvelNED)[3], double referenceLat, double referenceLon, float referenceHgt, float declination); + +float ConstrainFloat(float val, float min, float max); + +void ConstrainVariances(); + +void ConstrainStates(); + +void ForceSymmetry(); + +int CheckAndBound(); + +void ResetPosition(); + +void ResetVelocity(); + +void ZeroVariables(); + +void GetFilterState(struct ekf_status_report *state); + +void GetLastErrorState(struct ekf_status_report *last_error); + +bool StatesNaN(struct ekf_status_report *err_report); +void FillErrorReport(struct ekf_status_report *err); + +void InitializeDynamic(float (&initvelNED)[3], float declination); + +protected: + +bool FilterHealthy(); + +void ResetHeight(void); + +void AttitudeInit(float ax, float ay, float az, float mx, float my, float mz, float declination, float *initQuat); + +}; + +uint32_t millis(); + |