mirror of https://github.com/ArduPilot/ardupilot
559 lines
32 KiB
C++
559 lines
32 KiB
C++
/*
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24 state EKF based on the derivation in https://github.com/PX4/ecl/
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blob/master/matlab/scripts/Inertial%20Nav%20EKF/GenerateNavFilterEquations.m
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Converted from Matlab to C++ by Paul Riseborough
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include <AP_Common/Location.h>
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#include <AP_Math/AP_Math.h>
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#include <AP_Param/AP_Param.h>
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#include <AP_NavEKF/AP_Nav_Common.h>
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#include <AP_NavEKF/AP_NavEKF_Source.h>
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class NavEKF3_core;
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class EKFGSF_yaw;
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class NavEKF3 {
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friend class NavEKF3_core;
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public:
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NavEKF3();
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/* Do not allow copies */
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NavEKF3(const NavEKF3 &other) = delete;
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NavEKF3 &operator=(const NavEKF3&) = delete;
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static const struct AP_Param::GroupInfo var_info[];
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static const struct AP_Param::GroupInfo var_info2[];
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// allow logging to determine the number of active cores
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uint8_t activeCores(void) const {
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return num_cores;
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}
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// Initialise the filter
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bool InitialiseFilter(void);
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// Update Filter States - this should be called whenever new IMU data is available
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void UpdateFilter(void);
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// Check basic filter health metrics and return a consolidated health status
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bool healthy(void) const;
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// returns false if we fail arming checks, in which case the buffer will be populated with a failure message
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// requires_position should be true if horizontal position configuration should be checked
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bool pre_arm_check(bool requires_position, char *failure_msg, uint8_t failure_msg_len) const;
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// returns the index of the primary core
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// return -1 if no primary core selected
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int8_t getPrimaryCoreIndex(void) const;
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// returns the index of the IMU of the primary core
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// return -1 if no primary core selected
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int8_t getPrimaryCoreIMUIndex(void) const;
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// Write the last calculated NE position relative to the reference point (m)
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// If a calculated solution is not available, use the best available data and return false
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// If false returned, do not use for flight control
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bool getPosNE(Vector2f &posNE) const;
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// Write the last calculated D position relative to the reference point (m)
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// If a calculated solution is not available, use the best available data and return false
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// If false returned, do not use for flight control
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bool getPosD(float &posD) const;
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// return NED velocity in m/s
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void getVelNED(Vector3f &vel) const;
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// return estimate of true airspeed vector in body frame in m/s
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// returns false if estimate is unavailable
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bool getAirSpdVec(Vector3f &vel) const;
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// return the innovation in m/s, innovation variance in (m/s)^2 and age in msec of the last TAS measurement processed
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// returns false if the data is unavilable
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bool getAirSpdHealthData(float &innovation, float &innovationVariance, uint32_t &age_ms) const;
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// Return the rate of change of vertical position in the down direction (dPosD/dt) in m/s
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// 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
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// but will always be kinematically consistent with the z component of the EKF position state
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float getPosDownDerivative() const;
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// return body axis gyro bias estimates in rad/sec for the specified instance
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// An out of range instance (eg -1) returns data for the primary instance
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void getGyroBias(int8_t instance, Vector3f &gyroBias) const;
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// return accelerometer bias estimate in m/s/s
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// An out of range instance (eg -1) returns data for the primary instance
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void getAccelBias(int8_t instance, Vector3f &accelBias) const;
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//returns index of the active source set used
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uint8_t get_active_source_set() const;
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// reset body axis gyro bias estimates
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void resetGyroBias(void);
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// Resets the baro so that it reads zero at the current height
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// Resets the EKF height to zero
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// Adjusts the EKF origin height so that the EKF height + origin height is the same as before
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// Returns true if the height datum reset has been performed
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// If using a range finder for height no reset is performed and it returns false
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bool resetHeightDatum(void);
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// return the horizontal speed limit in m/s set by optical flow sensor limits
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// return the scale factor to be applied to navigation velocity gains to compensate for increase in velocity noise with height when using optical flow
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void getEkfControlLimits(float &ekfGndSpdLimit, float &ekfNavVelGainScaler) const;
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// return the NED wind speed estimates in m/s (positive is air
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// moving in the direction of the axis) returns true if wind state
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// estimation is active
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bool getWind(Vector3f &wind) const;
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// return earth magnetic field estimates in measurement units / 1000
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void getMagNED(Vector3f &magNED) const;
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// return body magnetic field estimates in measurement units / 1000
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void getMagXYZ(Vector3f &magXYZ) const;
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// return the airspeed sensor in use
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uint8_t getActiveAirspeed() const;
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// Return estimated magnetometer offsets
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// Return true if magnetometer offsets are valid
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bool getMagOffsets(uint8_t mag_idx, Vector3f &magOffsets) const;
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// Return the last calculated latitude, longitude and height in WGS-84
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// If a calculated location isn't available, return a raw GPS measurement
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// The status will return true if a calculation or raw measurement is available
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// The getFilterStatus() function provides a more detailed description of data health and must be checked if data is to be used for flight control
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bool getLLH(struct Location &loc) const;
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// Return the latitude and longitude and height used to set the NED origin
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// All NED positions calculated by the filter are relative to this location
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// Returns false if the origin has not been set
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bool getOriginLLH(struct Location &loc) const;
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// set the latitude and longitude and height used to set the NED origin
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// All NED positions calculated by the filter will be relative to this location
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// The origin cannot be set if the filter is in a flight mode (eg vehicle armed)
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// Returns false if the filter has rejected the attempt to set the origin
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bool setOriginLLH(const Location &loc);
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// return estimated height above ground level
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// return false if ground height is not being estimated.
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bool getHAGL(float &HAGL) const;
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// return the Euler roll, pitch and yaw angle in radians
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void getEulerAngles(Vector3f &eulers) const;
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// return the transformation matrix from XYZ (body) to NED axes
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void getRotationBodyToNED(Matrix3f &mat) const;
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// return the quaternions defining the rotation from XYZ (body) to NED axes
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void getQuaternionBodyToNED(int8_t instance, Quaternion &quat) const;
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// return the quaternions defining the rotation from NED to XYZ (autopilot) axes
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void getQuaternion(Quaternion &quat) const;
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// return the innovations
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bool getInnovations(Vector3f &velInnov, Vector3f &posInnov, Vector3f &magInnov, float &tasInnov, float &yawInnov) const;
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// return the innovation consistency test ratios
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bool getVariances(float &velVar, float &posVar, float &hgtVar, Vector3f &magVar, float &tasVar, Vector2f &offset) const;
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// get a source's velocity innovations
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// returns true on success and results are placed in innovations and variances arguments
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bool getVelInnovationsAndVariancesForSource(AP_NavEKF_Source::SourceXY source, Vector3f &innovations, Vector3f &variances) const WARN_IF_UNUSED;
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// should we use the compass? This is public so it can be used for
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// reporting via ahrs.use_compass()
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bool use_compass(void) const;
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// write the raw optical flow measurements
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// rawFlowQuality is a measured of quality between 0 and 255, with 255 being the best quality
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// rawFlowRates are the optical flow rates in rad/sec about the X and Y sensor axes.
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// rawGyroRates are the sensor rotation rates in rad/sec measured by the sensors internal gyro
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// The sign convention is that a RH physical rotation of the sensor about an axis produces both a positive flow and gyro rate
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// msecFlowMeas is the scheduler time in msec when the optical flow data was received from the sensor.
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// posOffset is the XYZ flow sensor position in the body frame in m
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void writeOptFlowMeas(const uint8_t rawFlowQuality, const Vector2f &rawFlowRates, const Vector2f &rawGyroRates, const uint32_t msecFlowMeas, const Vector3f &posOffset);
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// retrieve latest corrected optical flow samples (used for calibration)
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bool getOptFlowSample(uint32_t& timeStamp_ms, Vector2f& flowRate, Vector2f& bodyRate, Vector2f& losPred) const;
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/*
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* Write body frame linear and angular displacement measurements from a visual odometry sensor
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*
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* quality is a normalised confidence value from 0 to 100
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* delPos is the XYZ change in linear position measured in body frame and relative to the inertial reference at timeStamp_ms (m)
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* delAng is the XYZ angular rotation measured in body frame and relative to the inertial reference at timeStamp_ms (rad)
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* delTime is the time interval for the measurement of delPos and delAng (sec)
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* timeStamp_ms is the timestamp of the last image used to calculate delPos and delAng (msec)
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* delay_ms is the average delay of external nav system measurements relative to inertial measurements
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* posOffset is the XYZ body frame position of the camera focal point (m)
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*/
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void writeBodyFrameOdom(float quality, const Vector3f &delPos, const Vector3f &delAng, float delTime, uint32_t timeStamp_ms, uint16_t delay_ms, const Vector3f &posOffset);
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/*
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* Write odometry data from a wheel encoder. The axis of rotation is assumed to be parallel to the vehicle body axis
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*
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* delAng is the measured change in angular position from the previous measurement where a positive rotation is produced by forward motion of the vehicle (rad)
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* delTime is the time interval for the measurement of delAng (sec)
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* timeStamp_ms is the time when the rotation was last measured (msec)
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* posOffset is the XYZ body frame position of the wheel hub (m)
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* radius is the effective rolling radius of the wheel (m)
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* this should not be called at more than the EKF's update rate (50hz or 100hz)
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*/
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void writeWheelOdom(float delAng, float delTime, uint32_t timeStamp_ms, const Vector3f &posOffset, float radius);
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/*
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* Writes the measurement from a yaw angle sensor
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*
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* yawAngle: Yaw angle of the vehicle relative to true north in radians where a positive angle is
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* produced by a RH rotation about the Z body axis. The Yaw rotation is the first rotation in a
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* 321 (ZYX) or a 312 (ZXY) rotation sequence as specified by the 'type' argument.
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* yawAngleErr is the 1SD accuracy of the yaw angle measurement in radians.
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* timeStamp_ms: System time in msec when the yaw measurement was taken. This time stamp must include
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* all measurement lag and transmission delays.
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* type: An integer specifying Euler rotation order used to define the yaw angle.
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* type = 1 specifies a 312 (ZXY) rotation order, type = 2 specifies a 321 (ZYX) rotation order.
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*/
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void writeEulerYawAngle(float yawAngle, float yawAngleErr, uint32_t timeStamp_ms, uint8_t type);
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/*
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* Write position and quaternion data from an external navigation system
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*
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* pos : position in the RH navigation frame. Frame is assumed to be NED if frameIsNED is true. (m)
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* quat : quaternion desribing the rotation from navigation frame to body frame
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* posErr : 1-sigma spherical position error (m)
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* angErr : 1-sigma spherical angle error (rad)
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* timeStamp_ms : system time the measurement was taken, not the time it was received (mSec)
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* delay_ms : average delay of external nav system measurements relative to inertial measurements
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* resetTime_ms : system time of the last position reset request (mSec)
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*
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*/
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void writeExtNavData(const Vector3f &pos, const Quaternion &quat, float posErr, float angErr, uint32_t timeStamp_ms, uint16_t delay_ms, uint32_t resetTime_ms);
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/*
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* Write velocity data from an external navigation system
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*
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* vel : velocity in NED (m)
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* err : velocity error (m/s)
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* timeStamp_ms : system time the measurement was taken, not the time it was received (mSec)
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* delay_ms : average delay of external nav system measurements relative to inertial measurements
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*/
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void writeExtNavVelData(const Vector3f &vel, float err, uint32_t timeStamp_ms, uint16_t delay_ms);
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// Set to true if the terrain underneath is stable enough to be used as a height reference
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// in combination with a range finder. Set to false if the terrain underneath the vehicle
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// cannot be used as a height reference. Use to prevent range finder operation otherwise
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// enabled by the combination of EK3_RNG_USE_HGT and EK3_RNG_USE_SPD parameters.
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void setTerrainHgtStable(bool val);
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/*
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return the filter fault status as a bitmasked integer
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0 = quaternions are NaN
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1 = velocities are NaN
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2 = badly conditioned X magnetometer fusion
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3 = badly conditioned Y magnetometer fusion
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4 = badly conditioned Z magnetometer fusion
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5 = badly conditioned airspeed fusion
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6 = badly conditioned synthetic sideslip fusion
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7 = filter is not initialised
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*/
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void getFilterFaults(uint16_t &faults) const;
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/*
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return filter status flags
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*/
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void getFilterStatus(nav_filter_status &status) const;
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// send an EKF_STATUS_REPORT message to GCS
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void send_status_report(class GCS_MAVLINK &link) const;
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// provides the height limit to be observed by the control loops
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// returns false if no height limiting is required
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// this is needed to ensure the vehicle does not fly too high when using optical flow navigation
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bool getHeightControlLimit(float &height) const;
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// return the amount of yaw angle change (in radians) due to the last yaw angle reset or core selection switch
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// returns the time of the last yaw angle reset or 0 if no reset has ever occurred
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uint32_t getLastYawResetAngle(float &yawAngDelta);
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// return the amount of NE position change due to the last position reset in metres
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// returns the time of the last reset or 0 if no reset has ever occurred
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uint32_t getLastPosNorthEastReset(Vector2f &posDelta);
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// return the amount of NE velocity change due to the last velocity reset in metres/sec
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// returns the time of the last reset or 0 if no reset has ever occurred
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uint32_t getLastVelNorthEastReset(Vector2f &vel) const;
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// return the amount of vertical position change due to the last reset in metres
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// returns the time of the last reset or 0 if no reset has ever occurred
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uint32_t getLastPosDownReset(float &posDelta);
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// set and save the _baroAltNoise parameter
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void set_baro_alt_noise(float noise) { _baroAltNoise.set_and_save(noise); };
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// allow the enable flag to be set by Replay
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void set_enable(bool enable) { _enable.set_enable(enable); }
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/*
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check if switching lanes will reduce the normalised
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innovations. This is called when the vehicle code is about to
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trigger an EKF failsafe, and it would like to avoid that by
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using a different EKF lane
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*/
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void checkLaneSwitch(void);
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/*
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Request a reset of the EKF yaw. This is called when the vehicle code is about to
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trigger an EKF failsafe, and it would like to avoid that.
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*/
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void requestYawReset(void);
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// set position, velocity and yaw sources to either 0=primary, 1=secondary, 2=tertiary
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void setPosVelYawSourceSet(uint8_t source_set_idx);
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// write EKF information to on-board logs
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void Log_Write();
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// are we using (aka fusing) a non-compass yaw?
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bool using_noncompass_for_yaw() const;
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// are we using (aka fusing) external nav for yaw?
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bool using_extnav_for_yaw() const;
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// check if configured to use GPS for horizontal position estimation
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bool configuredToUseGPSForPosXY(void) const;
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// Writes the default equivalent airspeed and 1-sigma uncertainty in m/s to be used in forward flight if a measured airspeed is required and not available.
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void writeDefaultAirSpeed(float airspeed, float uncertainty);
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// parameter conversion
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void convert_parameters();
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// returns true when the yaw angle has been aligned
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bool yawAlignmentComplete(void) const;
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// returns true when the state estimates are significantly
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// degraded by vibration
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bool isVibrationAffected() const;
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// get a yaw estimator instance
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const EKFGSF_yaw *get_yawEstimator(void) const;
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private:
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uint8_t num_cores; // number of allocated cores
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uint8_t primary; // current primary core
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NavEKF3_core *core = nullptr;
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uint32_t _frameTimeUsec; // time per IMU frame
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uint8_t _framesPerPrediction; // expected number of IMU frames per prediction
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// values for EK3_LOG_LEVEL
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enum class LogLevel {
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ALL = 0,
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XKF4 = 1,
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XKF4_GSF = 2,
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NONE = 3
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};
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// EKF Mavlink Tuneable Parameters
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AP_Int8 _enable; // zero to disable EKF3
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AP_Float _gpsHorizVelNoise; // GPS horizontal velocity measurement noise : m/s
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AP_Float _gpsVertVelNoise; // GPS vertical velocity measurement noise : m/s
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AP_Float _gpsHorizPosNoise; // GPS horizontal position measurement noise m
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AP_Float _baroAltNoise; // Baro height measurement noise : m
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AP_Float _magNoise; // magnetometer measurement noise : gauss
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AP_Float _easNoise; // equivalent airspeed measurement noise : m/s
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AP_Float _windVelProcessNoise; // wind velocity state process noise : m/s^2
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AP_Float _wndVarHgtRateScale; // scale factor applied to wind process noise due to height rate
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AP_Float _magEarthProcessNoise; // Earth magnetic field process noise : gauss/sec
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AP_Float _magBodyProcessNoise; // Body magnetic field process noise : gauss/sec
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AP_Float _gyrNoise; // gyro process noise : rad/s
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AP_Float _accNoise; // accelerometer process noise : m/s^2
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AP_Float _gyroBiasProcessNoise; // gyro bias state process noise : rad/s
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AP_Float _accelBiasProcessNoise;// accel bias state process noise : m/s^2
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AP_Int16 _hgtDelay_ms; // effective average delay of Height measurements relative to inertial measurements (msec)
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AP_Int16 _gpsVelInnovGate; // Percentage number of standard deviations applied to GPS velocity innovation consistency check
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AP_Int16 _gpsPosInnovGate; // Percentage number of standard deviations applied to GPS position innovation consistency check
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AP_Int16 _hgtInnovGate; // Percentage number of standard deviations applied to height innovation consistency check
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AP_Int16 _magInnovGate; // Percentage number of standard deviations applied to magnetometer innovation consistency check
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AP_Int16 _tasInnovGate; // Percentage number of standard deviations applied to true airspeed innovation consistency check
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AP_Int8 _magCal; // Sets activation condition for in-flight magnetometer calibration
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AP_Int8 _gpsGlitchRadiusMax; // Maximum allowed discrepancy between inertial and GPS Horizontal position before GPS glitch is declared : m
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AP_Float _flowNoise; // optical flow rate measurement noise
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AP_Int16 _flowInnovGate; // Percentage number of standard deviations applied to optical flow innovation consistency check
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AP_Int8 _flowDelay_ms; // effective average delay of optical flow measurements rel to IMU (msec)
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AP_Int16 _rngInnovGate; // Percentage number of standard deviations applied to range finder innovation consistency check
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AP_Float _maxFlowRate; // Maximum flow rate magnitude that will be accepted by the filter
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AP_Float _rngNoise; // Range finder noise : m
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AP_Int8 _gpsCheck; // Bitmask controlling which preflight GPS checks are bypassed
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AP_Int8 _imuMask; // Bitmask of IMUs to instantiate EKF3 for
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AP_Int16 _gpsCheckScaler; // Percentage increase to be applied to GPS pre-flight accuracy and drift thresholds
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AP_Float _noaidHorizNoise; // horizontal position measurement noise assumed when synthesised zero position measurements are used to constrain attitude drift : m
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AP_Float _yawNoise; // magnetic yaw measurement noise : rad
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AP_Int16 _yawInnovGate; // Percentage number of standard deviations applied to magnetic yaw innovation consistency check
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AP_Int8 _tauVelPosOutput; // Time constant of output complementary filter : csec (centi-seconds)
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AP_Int8 _useRngSwHgt; // Maximum valid range of the range finder as a percentage of the maximum range specified by the sensor driver
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AP_Float _terrGradMax; // Maximum terrain gradient below the vehicle
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AP_Float _rngBcnNoise; // Range beacon measurement noise (m)
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AP_Int16 _rngBcnInnovGate; // Percentage number of standard deviations applied to range beacon innovation consistency check
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AP_Int8 _rngBcnDelay_ms; // effective average delay of range beacon measurements rel to IMU (msec)
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AP_Float _useRngSwSpd; // Maximum horizontal ground speed to use range finder as the primary height source (m/s)
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AP_Float _accBiasLim; // Accelerometer bias limit (m/s/s)
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AP_Int8 _magMask; // Bitmask forcing specific EKF core instances to use simple heading magnetometer fusion.
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AP_Int8 _originHgtMode; // Bitmask controlling post alignment correction and reporting of the EKF origin height.
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AP_Float _visOdmVelErrMax; // Observation 1-STD velocity error assumed for visual odometry sensor at lowest reported quality (m/s)
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AP_Float _visOdmVelErrMin; // Observation 1-STD velocity error assumed for visual odometry sensor at highest reported quality (m/s)
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AP_Float _wencOdmVelErr; // Observation 1-STD velocity error assumed for wheel odometry sensor (m/s)
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AP_Int8 _flowUse; // Controls if the optical flow data is fused into the main navigation estimator and/or the terrain estimator.
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AP_Float _hrt_filt_freq; // frequency of output observer height rate complementary filter in Hz
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AP_Int16 _mag_ef_limit; // limit on difference between WMM tables and learned earth field.
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AP_Int8 _gsfRunMask; // mask controlling which EKF3 instances run a separate EKF-GSF yaw estimator
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AP_Int8 _gsfUseMask; // mask controlling which EKF3 instances will use EKF-GSF yaw estimator data to assit with yaw resets
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AP_Int8 _gsfResetMaxCount; // maximum number of times the EKF3 is allowed to reset it's yaw to the EKF-GSF estimate
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AP_Float _err_thresh; // lanes have to be consistently better than the primary by at least this threshold to reduce their overall relativeCoreError
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AP_Int32 _affinity; // bitmask of sensor affinity options
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AP_Float _dragObsNoise; // drag specific force observatoin noise (m/s/s)**2
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AP_Float _ballisticCoef_x; // ballistic coefficient measured for flow in X body frame directions
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AP_Float _ballisticCoef_y; // ballistic coefficient measured for flow in Y body frame directions
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AP_Float _momentumDragCoef; // lift rotor momentum drag coefficient
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AP_Int8 _betaMask; // Bitmask controlling when sideslip angle fusion is used to estimate non wind states
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AP_Float _ognmTestScaleFactor; // Scale factor applied to the thresholds used by the on ground not moving test
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AP_Float _baroGndEffectDeadZone;// Dead zone applied to positive baro height innovations when in ground effect (m)
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AP_Int8 _primary_core; // initial core number
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AP_Enum<LogLevel> _log_level; // log verbosity level
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AP_Float _gpsVAccThreshold; // vertical accuracy threshold to use GPS as an altitude source
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// Possible values for _flowUse
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#define FLOW_USE_NONE 0
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#define FLOW_USE_NAV 1
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#define FLOW_USE_TERRAIN 2
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// Tuning parameters
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const float gpsNEVelVarAccScale = 0.05f; // Scale factor applied to NE velocity measurement variance due to manoeuvre acceleration
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const float gpsDVelVarAccScale = 0.07f; // Scale factor applied to vertical velocity measurement variance due to manoeuvre acceleration
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const float gpsPosVarAccScale = 0.05f; // Scale factor applied to horizontal position measurement variance due to manoeuvre acceleration
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const float extNavVelVarAccScale = 0.05f; // Scale factor applied to ext nav velocity measurement variance due to manoeuvre acceleration
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const uint16_t magDelay_ms = 60; // Magnetometer measurement delay (msec)
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const uint16_t tasDelay_ms = 100; // Airspeed measurement delay (msec)
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const uint16_t tiltDriftTimeMax_ms = 15000; // Maximum number of ms allowed without any form of tilt aiding (GPS, flow, TAS, etc)
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const uint16_t posRetryTimeUseVel_ms = 10000; // Position aiding retry time with velocity measurements (msec)
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const uint16_t posRetryTimeNoVel_ms = 7000; // Position aiding retry time without velocity measurements (msec)
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const uint16_t hgtRetryTimeMode0_ms = 10000; // Height retry time with vertical velocity measurement (msec)
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const uint16_t hgtRetryTimeMode12_ms = 5000; // Height retry time without vertical velocity measurement (msec)
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const uint16_t tasRetryTime_ms = 5000; // True airspeed timeout and retry interval (msec)
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const uint16_t dragFailTimeLimit_ms = 5000; // Drag timeout (msec)
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const uint32_t magFailTimeLimit_ms = 10000; // number of msec before a magnetometer failing innovation consistency checks is declared failed (msec)
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const float magVarRateScale = 0.005f; // scale factor applied to magnetometer variance due to angular rate
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const float gyroBiasNoiseScaler = 2.0f; // scale factor applied to gyro bias state process noise when on ground
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const uint16_t hgtAvg_ms = 100; // average number of msec between height measurements
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const uint16_t betaAvg_ms = 100; // average number of msec between synthetic sideslip measurements
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const float covTimeStepMax = 0.1f; // maximum time (sec) between covariance prediction updates
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const float covDelAngMax = 0.05f; // maximum delta angle between covariance prediction updates
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const float DCM33FlowMin = 0.71f; // If Tbn(3,3) is less than this number, optical flow measurements will not be fused as tilt is too high.
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const float fScaleFactorPnoise = 1e-10f; // Process noise added to focal length scale factor state variance at each time step
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const uint8_t flowTimeDeltaAvg_ms = 100; // average interval between optical flow measurements (msec)
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const uint32_t flowIntervalMax_ms = 100; // maximum allowable time between flow fusion events
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const float gndEffectBaroScaler = 4.0f; // scaler applied to the barometer observation variance when ground effect mode is active
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const uint8_t gndGradientSigma = 50; // RMS terrain gradient percentage assumed by the terrain height estimation
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const uint16_t fusionTimeStep_ms = 10; // The minimum time interval between covariance predictions and measurement fusions in msec
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const uint8_t sensorIntervalMin_ms = 50; // The minimum allowed time between measurements from any non-IMU sensor (msec)
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const uint8_t flowIntervalMin_ms = 20; // The minimum allowed time between measurements from optical flow sensors (msec)
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const uint8_t extNavIntervalMin_ms = 20; // The minimum allowed time between measurements from external navigation sensors (msec)
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const float maxYawEstVelInnov = 2.0f; // Maximum acceptable length of the velocity innovation returned by the EKF-GSF yaw estimator (m/s)
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const uint16_t deadReckonDeclare_ms = 1000; // Time without equivalent position or velocity observation to constrain drift before dead reckoning is declared (msec)
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// time at start of current filter update
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uint64_t imuSampleTime_us;
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// time of last lane switch
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uint32_t lastLaneSwitch_ms;
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// last time of Log_Write
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uint64_t lastLogWrite_us;
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struct {
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uint32_t last_function_call; // last time getLastYawResetAngle was called
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bool core_changed; // true when a core change happened and hasn't been consumed, false otherwise
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uint32_t last_primary_change; // last time a primary has changed
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float core_delta; // the amount of yaw change between cores when a change happened
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} yaw_reset_data;
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struct {
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uint32_t last_function_call; // last time getLastPosNorthEastReset was called
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bool core_changed; // true when a core change happened and hasn't been consumed, false otherwise
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uint32_t last_primary_change; // last time a primary has changed
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Vector2f core_delta; // the amount of NE position change between cores when a change happened
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} pos_reset_data;
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|
|
struct {
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uint32_t last_function_call; // last time getLastPosDownReset was called
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bool core_changed; // true when a core change happened and hasn't been consumed, false otherwise
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uint32_t last_primary_change; // last time a primary has changed
|
|
float core_delta; // the amount of D position change between cores when a change happened
|
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} pos_down_reset_data;
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|
|
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#define MAX_EKF_CORES 3 // maximum allowed EKF Cores to be instantiated
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#define CORE_ERR_LIM 1 // -LIM to LIM relative error range for a core
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#define BETTER_THRESH 0.5 // a lane should have this much relative error difference to be considered for overriding a healthy primary core
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|
|
|
bool runCoreSelection; // true when the primary core has stabilised and the core selection logic can be started
|
|
bool coreSetupRequired[MAX_EKF_CORES]; // true when this core index needs to be setup
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uint8_t coreImuIndex[MAX_EKF_CORES]; // IMU index used by this core
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|
float coreRelativeErrors[MAX_EKF_CORES]; // relative errors of cores with respect to primary
|
|
float coreErrorScores[MAX_EKF_CORES]; // the instance error values used to update relative core error
|
|
uint64_t coreLastTimePrimary_us[MAX_EKF_CORES]; // last time we were using this core as primary
|
|
|
|
// origin set by one of the cores
|
|
struct Location common_EKF_origin;
|
|
bool common_origin_valid;
|
|
|
|
// update the yaw reset data to capture changes due to a lane switch
|
|
// 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(uint8_t new_primary, uint8_t old_primary);
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|
|
|
// update the position reset data to capture changes due to a lane switch
|
|
// 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(uint8_t new_primary, uint8_t old_primary);
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|
|
|
// update the position down reset data to capture changes due to a lane switch
|
|
// 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 updateLaneSwitchPosDownResetData(uint8_t new_primary, uint8_t old_primary);
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|
|
|
// Update instance error scores for all available cores
|
|
float updateCoreErrorScores(void);
|
|
|
|
// Update relative error scores for all alternate available cores
|
|
void updateCoreRelativeErrors(void);
|
|
|
|
// Reset error scores for all available cores
|
|
void resetCoreErrors(void);
|
|
|
|
// return true if a new core has a better score than an existing core, including
|
|
// checks for alignment
|
|
bool coreBetterScore(uint8_t new_core, uint8_t current_core) const;
|
|
|
|
// position, velocity and yaw source control
|
|
AP_NavEKF_Source sources;
|
|
};
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