Package com.irurueta.navigation.inertial.calibration.magnetometer

Class MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

java.lang.Object

com.irurueta.navigation.inertial.calibration.magnetometer.RobustKnownHardIronAndFrameMagnetometerCalibrator

com.irurueta.navigation.inertial.calibration.magnetometer.MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

All Implemented Interfaces:

KnownHardIronMagnetometerCalibrator, MagnetometerCalibrator, MagnetometerNonLinearCalibrator, OrderedStandardDeviationFrameBodyMagneticFluxDensityMagnetometerCalibrator, QualityScoredMagnetometerCalibrator

public class MSACRobustKnownHardIronAndFrameMagnetometerCalibrator
extends RobustKnownHardIronAndFrameMagnetometerCalibrator

Robustly estimates magnetometer soft-iron cross couplings and scaling factors using MSAC algorithm.

To use this calibrator at least 4 measurements at different known frames must be provided. In other words, magnetometer samples must be obtained at 4 different positions or orientations. Notice that frame velocities are ignored by this calibrator.

Measured magnetic flux density is assumed to follow the model shown below:

     mBmeas = bm + (I + Mm) * mBtrue + w
 

Where: - mBmeas is the measured magnetic flux density. This is a 3x1 vector. - bm is magnetometer hard-iron bias. Ideally, on a perfect magnetometer, this should be a 3x1 zero vector. - I is the 3x3 identity matrix. - Mm is the 3x3 soft-iron matrix containing cross-couplings and scaling factors. Ideally, on a perfect magnetometer, this should be a 3x3 zero matrix. - mBtrue is ground-truth magnetic flux density. This is a 3x1 vector. - w is measurement noise. This is a 3x1 vector.

Field Summary

Fields

Modifier and Type	Field	Description
static final double	DEFAULT_THRESHOLD	Constant defining default threshold to determine whether samples are inliers or not.
static final double	MIN_THRESHOLD	Minimum value that can be set as threshold.
private double	threshold	Threshold to determine whether samples are inliers or not when testing possible estimation solutions.

Fields inherited from class com.irurueta.navigation.inertial.calibration.magnetometer.RobustKnownHardIronAndFrameMagnetometerCalibrator

confidence, DEFAULT_CONFIDENCE, DEFAULT_KEEP_COVARIANCE, DEFAULT_MAX_ITERATIONS, DEFAULT_PROGRESS_DELTA, DEFAULT_REFINE_PRELIMINARY_SOLUTIONS, DEFAULT_REFINE_RESULT, DEFAULT_ROBUST_METHOD, DEFAULT_USE_COMMON_Z_AXIS, DEFAULT_USE_LINEAR_CALIBRATOR, inliersData, listener, MAX_CONFIDENCE, MAX_PROGRESS_DELTA, maxIterations, measurements, MIN_CONFIDENCE, MIN_ITERATIONS, MIN_PROGRESS_DELTA, MINIMUM_MEASUREMENTS, preliminarySubsetSize, progressDelta, refineResult, running

Constructor Summary

Constructors

Constructor	Description
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator()	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(boolean commonAxisUsed)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(boolean commonAxisUsed, RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements, boolean commonAxisUsed)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)	Constructor.
MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements, RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	calibrate()	Estimates magnetometer calibration parameters containing soft-iron scale factors and cross-coupling errors.
com.irurueta.numerical.robust.RobustEstimatorMethod	getMethod()	Returns method being used for robust estimation.
double	getThreshold()	Returns threshold to determine whether samples are inliers or not.
boolean	isQualityScoresRequired()	Indicates whether this calibrator requires quality scores for each measurement or not.
void	setThreshold(double threshold)	Sets threshold to determine whether samples are inliers or not.

Methods inherited from class com.irurueta.navigation.inertial.calibration.magnetometer.RobustKnownHardIronAndFrameMagnetometerCalibrator

attemptRefine, computeError, computePreliminarySolutions, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, create, getConfidence, getEstimatedChiSq, getEstimatedCovariance, getEstimatedMm, getEstimatedMse, getEstimatedMxy, getEstimatedMxz, getEstimatedMyx, getEstimatedMyz, getEstimatedMzx, getEstimatedMzy, getEstimatedSx, getEstimatedSy, getEstimatedSz, getHardIron, getHardIron, getHardIronAsTriad, getHardIronAsTriad, getHardIronMatrix, getHardIronMatrix, getHardIronX, getHardIronXAsMagneticFluxDensity, getHardIronXAsMagneticFluxDensity, getHardIronY, getHardIronYAsMagneticFluxDensity, getHardIronYAsMagneticFluxDensity, getHardIronZ, getHardIronZAsMagneticFluxDensity, getHardIronZAsMagneticFluxDensity, getInitialMm, getInitialMm, getInitialMxy, getInitialMxz, getInitialMyx, getInitialMyz, getInitialMzx, getInitialMzy, getInitialSx, getInitialSy, getInitialSz, getInliersData, getListener, getMagneticModel, getMaxIterations, getMeasurements, getMeasurementType, getMinimumRequiredMeasurements, getPreliminarySubsetSize, getProgressDelta, getQualityScores, isCommonAxisUsed, isCovarianceKept, isLinearCalibratorUsed, isOrderedMeasurementsRequired, isPreliminarySolutionRefined, isReady, isResultRefined, isRunning, setCommonAxisUsed, setConfidence, setCovarianceKept, setHardIron, setHardIron, setHardIron, setHardIronCoordinates, setHardIronCoordinates, setHardIronX, setHardIronX, setHardIronY, setHardIronY, setHardIronZ, setHardIronZ, setInitialCrossCouplingErrors, setInitialMm, setInitialMxy, setInitialMxz, setInitialMyx, setInitialMyz, setInitialMzx, setInitialMzy, setInitialScalingFactors, setInitialScalingFactorsAndCrossCouplingErrors, setInitialSx, setInitialSy, setInitialSz, setLinearCalibratorUsed, setListener, setMagneticModel, setMaxIterations, setMeasurements, setPreliminarySolutionRefined, setPreliminarySubsetSize, setProgressDelta, setQualityScores, setResultRefined, setupWmmEstimator

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_THRESHOLD

public static final double DEFAULT_THRESHOLD

Constant defining default threshold to determine whether samples are inliers or not.

See Also:

• Constant Field Values

MIN_THRESHOLD

public static final double MIN_THRESHOLD

Minimum value that can be set as threshold. Threshold must be strictly greater than 0.0.

See Also:

• Constant Field Values

threshold

private double threshold

Threshold to determine whether samples are inliers or not when testing possible estimation solutions.

Constructor Details

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator()

Constructor.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)

Constructor.

Parameters:

listener - listener to be notified of events such as when estimation starts, ends or its progress significantly changes.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements)

Constructor.

Parameters:

measurements - list of body magnetic flux density measurements with standard deviations taken at different frames (positions and orientations).

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements,
 RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)

Constructor.

Parameters:

measurements - list of body magnetic flux density measurements with standard deviations taken at different frames (positions and orientations).

listener - listener to handle events raised by this calibrator.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(boolean commonAxisUsed)

Constructor.

Parameters:

commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(boolean commonAxisUsed,
 RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)

Constructor.

Parameters:

commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

listener - listener to handle events raised by this calibrator.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements,
 boolean commonAxisUsed)

Constructor.

Parameters:

measurements - list of body magnetic flux density measurements with standard deviations taken at different frames (positions and orientations).

commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

MSACRobustKnownHardIronAndFrameMagnetometerCalibrator

public MSACRobustKnownHardIronAndFrameMagnetometerCalibrator(List<StandardDeviationFrameBodyMagneticFluxDensity> measurements,
 boolean commonAxisUsed,
 RobustKnownHardIronAndFrameMagnetometerCalibratorListener listener)

Constructor.

Parameters:

measurements - list of body magnetic flux density measurements with standard deviations taken at different frames (positions and orientations).

commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

listener - listener to handle events raised by this calibrator.

Method Details

getThreshold

public double getThreshold()

Returns threshold to determine whether samples are inliers or not.

Returns:

threshold to determine whether samples are inliers or not.

setThreshold

public void setThreshold(double threshold)
                  throws com.irurueta.navigation.LockedException

Sets threshold to determine whether samples are inliers or not.

Parameters:

threshold - threshold to be set.

Throws:

IllegalArgumentException - if provided value is equal or less than zero.

com.irurueta.navigation.LockedException - if calibrator is currently running.

calibrate

public void calibrate()
               throws com.irurueta.navigation.LockedException,
com.irurueta.navigation.NotReadyException,
CalibrationException

Estimates magnetometer calibration parameters containing soft-iron scale factors and cross-coupling errors.

Throws:

com.irurueta.navigation.LockedException - if calibrator is currently running.

com.irurueta.navigation.NotReadyException - if calibrator is not ready.

CalibrationException - if estimation fails for numerical reasons.

getMethod

public com.irurueta.numerical.robust.RobustEstimatorMethod getMethod()

Returns method being used for robust estimation.

Specified by:

getMethod in class RobustKnownHardIronAndFrameMagnetometerCalibrator

Returns:

method being used for robust estimation.

isQualityScoresRequired

public boolean isQualityScoresRequired()

Indicates whether this calibrator requires quality scores for each measurement or not.

Returns:

true if quality scores are required, false otherwise.