Package com.irurueta.navigation.inertial.calibration.accelerometer

Class MSACRobustKnownFrameAccelerometerCalibrator

java.lang.Object

com.irurueta.navigation.inertial.calibration.accelerometer.RobustKnownFrameAccelerometerCalibrator

com.irurueta.navigation.inertial.calibration.accelerometer.MSACRobustKnownFrameAccelerometerCalibrator

All Implemented Interfaces:

AccelerometerCalibrator, AccelerometerNonLinearCalibrator, OrderedStandardDeviationFrameBodyKinematicsAccelerometerCalibrator, QualityScoredAccelerometerCalibrator, UnknownBiasAccelerometerCalibrator, UnknownBiasNonLinearAccelerometerCalibrator, AccelerometerBiasUncertaintySource, AccelerometerCalibrationSource

public class MSACRobustKnownFrameAccelerometerCalibrator
extends RobustKnownFrameAccelerometerCalibrator

Robustly estimates accelerometer biases, cross couplings and scaling factors using a MSAC algorithm to discard outliers.

To use this calibrator at least 4 measurements at different known frames must be provided. In other words, accelerometer samples must be obtained at 4 different positions, orientations and velocities (although typically velocities are always zero).

Measured specific force is assumed to follow the model shown below:

     fmeas = ba + (I + Ma) * ftrue + w
 

Where: - fmeas is the measured specific force. This is a 3x1 vector. - ba is accelerometer bias. Ideally, on a perfect accelerometer, this should be a 3x1 zero vector. - I is the 3x3 identity matrix. - Ma is the 3x3 matrix containing cross-couplings and scaling factors. Ideally, on a perfect accelerometer, this should be a 3x3 zero matrix. - ftrue is ground-truth specific force. - w is measurement noise.

Nested Class Summary

Nested classes/interfaces inherited from class com.irurueta.navigation.inertial.calibration.accelerometer.RobustKnownFrameAccelerometerCalibrator

RobustKnownFrameAccelerometerCalibrator.PreliminaryResult

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.accelerometer.RobustKnownFrameAccelerometerCalibrator

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
MSACRobustKnownFrameAccelerometerCalibrator()	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(boolean commonAxisUsed)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(boolean commonAxisUsed, RobustKnownFrameAccelerometerCalibratorListener listener)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(RobustKnownFrameAccelerometerCalibratorListener listener)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements, boolean commonAxisUsed)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements, boolean commonAxisUsed, RobustKnownFrameAccelerometerCalibratorListener listener)	Constructor.
MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements, RobustKnownFrameAccelerometerCalibratorListener listener)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	calibrate()	Estimates accelerometer calibration parameters containing bias, 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.accelerometer.RobustKnownFrameAccelerometerCalibrator

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, create, create, create, create, create, create, create, create, getConfidence, getEstimatedBiasAsTriad, getEstimatedBiasAsTriad, getEstimatedBiases, getEstimatedBiases, getEstimatedBiasesAsMatrix, getEstimatedBiasesAsMatrix, getEstimatedBiasFx, getEstimatedBiasFxAsAcceleration, getEstimatedBiasFxAsAcceleration, getEstimatedBiasFxStandardDeviation, getEstimatedBiasFxStandardDeviationAsAcceleration, getEstimatedBiasFxStandardDeviationAsAcceleration, getEstimatedBiasFxVariance, getEstimatedBiasFy, getEstimatedBiasFyAsAcceleration, getEstimatedBiasFyAsAcceleration, getEstimatedBiasFyStandardDeviation, getEstimatedBiasFyStandardDeviationAsAcceleration, getEstimatedBiasFyStandardDeviationAsAcceleration, getEstimatedBiasFyVariance, getEstimatedBiasFz, getEstimatedBiasFzAsAcceleration, getEstimatedBiasFzAsAcceleration, getEstimatedBiasFzStandardDeviation, getEstimatedBiasFzStandardDeviationAsAcceleration, getEstimatedBiasFzStandardDeviationAsAcceleration, getEstimatedBiasFzVariance, getEstimatedBiasStandardDeviation, getEstimatedBiasStandardDeviation, getEstimatedBiasStandardDeviationAverage, getEstimatedBiasStandardDeviationAverageAsAcceleration, getEstimatedBiasStandardDeviationAverageAsAcceleration, getEstimatedBiasStandardDeviationNorm, getEstimatedBiasStandardDeviationNormAsAcceleration, getEstimatedBiasStandardDeviationNormAsAcceleration, getEstimatedChiSq, getEstimatedCovariance, getEstimatedMa, getEstimatedMse, getEstimatedMxy, getEstimatedMxz, getEstimatedMyx, getEstimatedMyz, getEstimatedMzx, getEstimatedMzy, getEstimatedSx, getEstimatedSy, getEstimatedSz, getInitialBias, getInitialBias, getInitialBiasAsMatrix, getInitialBiasAsMatrix, getInitialBiasAsTriad, getInitialBiasAsTriad, getInitialBiasX, getInitialBiasXAsAcceleration, getInitialBiasXAsAcceleration, getInitialBiasY, getInitialBiasYAsAcceleration, getInitialBiasYAsAcceleration, getInitialBiasZ, getInitialBiasZAsAcceleration, getInitialBiasZAsAcceleration, getInitialMa, getInitialMa, getInitialMxy, getInitialMxz, getInitialMyx, getInitialMyz, getInitialMzx, getInitialMzy, getInitialSx, getInitialSy, getInitialSz, getInliersData, getListener, getMaxIterations, getMeasurements, getMeasurementType, getMinimumRequiredMeasurements, getPreliminarySubsetSize, getProgressDelta, getQualityScores, isCommonAxisUsed, isCovarianceKept, isLinearCalibratorUsed, isOrderedMeasurementsRequired, isPreliminarySolutionRefined, isReady, isResultRefined, isRunning, setCommonAxisUsed, setConfidence, setCovarianceKept, setInitialBias, setInitialBias, setInitialBias, setInitialBias, setInitialBias, setInitialBiasX, setInitialBiasX, setInitialBiasY, setInitialBiasY, setInitialBiasZ, setInitialBiasZ, setInitialCrossCouplingErrors, setInitialMa, setInitialMxy, setInitialMxz, setInitialMyx, setInitialMyz, setInitialMzx, setInitialMzy, setInitialScalingFactors, setInitialScalingFactorsAndCrossCouplingErrors, setInitialSx, setInitialSy, setInitialSz, setLinearCalibratorUsed, setListener, setMaxIterations, setMeasurements, setPreliminarySolutionRefined, setPreliminarySubsetSize, setProgressDelta, setQualityScores, setResultRefined

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

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator()

Constructor.

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(RobustKnownFrameAccelerometerCalibratorListener listener)

Constructor.

Parameters:

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

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements)

Constructor.

Parameters:

measurements - list of body kinematics measurements with standard deviations taken at different frames (positions, orientations and velocities).

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements,
 RobustKnownFrameAccelerometerCalibratorListener listener)

Constructor.

Parameters:

measurements - list of body kinematics measurements with standard deviations taken at different frames (positions, orientations and velocities).

listener - listener to handle events raised by this calibrator.

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(boolean commonAxisUsed)

Constructor.

Parameters:

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

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(boolean commonAxisUsed,
 RobustKnownFrameAccelerometerCalibratorListener listener)

Constructor.

Parameters:

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

listener - listener to handle events raised by this calibrator.

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements,
 boolean commonAxisUsed)

Constructor.

Parameters:

measurements - list of body kinematics measurements with standard deviations taken at different frames (positions, orientations and velocities).

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

MSACRobustKnownFrameAccelerometerCalibrator

public MSACRobustKnownFrameAccelerometerCalibrator(List<StandardDeviationFrameBodyKinematics> measurements,
 boolean commonAxisUsed,
 RobustKnownFrameAccelerometerCalibratorListener listener)

Constructor.

Parameters:

measurements - list of body kinematics measurements with standard deviations taken at different frames (positions, orientations and velocities).

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

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 accelerometer calibration parameters containing bias, 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 RobustKnownFrameAccelerometerCalibrator

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.