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

Class LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

java.lang.Object
com.irurueta.navigation.inertial.calibration.magnetometer.RobustKnownMagneticFluxDensityNormMagnetometerCalibrator
com.irurueta.navigation.inertial.calibration.magnetometer.LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator
All Implemented Interfaces:
MagnetometerCalibrator, MagnetometerNonLinearCalibrator, OrderedStandardDeviationBodyMagneticFluxDensityMagnetometerCalibrator, QualityScoredMagnetometerCalibrator, UnknownHardIronMagnetometerCalibrator, UnknownHardIronNonLinearMagnetometerCalibrator
public class LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator extends RobustKnownMagneticFluxDensityNormMagnetometerCalibrator
Robustly estimates magnetometer hard-iron biases, cross couplings and scaling factors using LMedS algorithm.

To use this calibrator at least 10 measurements with known magnetic field norm at an unknown position and instant must be taken at 10 different unknown orientations when common z-axis is assumed, otherwise at least 13 measurements are required.

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. Notice that this calibrator assumes that all measurements are taken in a short span of time, where Earth magnetic field can be assumed to be constant at provided location and instant.

  • Field Details

    • DEFAULT_STOP_THRESHOLD

      public static final double DEFAULT_STOP_THRESHOLD
      Default value to be used for stop threshold. Stop threshold can be used to avoid keeping the algorithm unnecessarily iterating in case that best estimated threshold using median of residuals is not small enough. Once a solution is found that generates a threshold below this value, the algorithm will stop. The stop threshold can be used to prevent the LMedS algorithm iterating too many times in cases where samples have a very similar accuracy. For instance, in cases where proportion of outliers is very small (close to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would iterate for a long time trying to find the best solution when indeed there is no need to do that if a reasonable threshold has already been reached. Because of this behaviour the stop threshold can be set to a value much lower than the one typically used in LMedS, and yet the algorithm could still produce even smaller thresholds in estimated results.
      See Also:

    • MIN_STOP_THRESHOLD

      public static final double MIN_STOP_THRESHOLD
      Minimum allowed stop threshold value.
      See Also:

    • stopThreshold

      private double stopThreshold
      Threshold to be used to keep the algorithm iterating in case that best estimated threshold using median of residuals is not small enough. Once a solution is found that generates a threshold below this value, the algorithm will stop. The stop threshold can be used to prevent the LMedS algorithm iterating too many times in cases where samples have a very similar accuracy. For instance, in cases where proportion of outliers is very small (close to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would iterate for a long time trying to find the best solution when indeed there is no need to do that if a reasonable threshold has already been reached. Because of this behaviour the stop threshold can be set to a value much lower than the one typically used in LMedS, and yet the algorithm could still produce even smaller thresholds in estimated results.

  • Constructor Details

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator()
      Constructor.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      listener - listener to handle events raised by this calibrator.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements)
      Constructor.
      Parameters:
      measurements - list of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(boolean commonAxisUsed)
      Constructor.
      Parameters:
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(double[] initialHardIron)
      Constructor.
      Parameters:
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - list of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      listener - listener to handle events raised by this calibrator.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different 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.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, boolean commonAxisUsed)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, double[] initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different 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.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron array does not have length 3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

    • LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator

      public LMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator(Double groundTruthMagneticFluxDensityNorm, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownMagneticFluxDensityNormMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      groundTruthMagneticFluxDensityNorm - ground truth magnetic flux density norm expressed in Teslas (T).
      measurements - collection of body magnetic flux density measurements with standard deviation of magnetometer measurements taken at the same position with zero velocity and unknown different orientations.
      commonAxisUsed - indicates whether z-axis is assumed to be common for the accelerometer, gyroscope and magnetometer.
      initialHardIron - initial hard-iron to find a solution.
      initialMm - initial soft-iron matrix containing scale factors and cross coupling errors.
      listener - listener to handle events raised by this calibrator.
      Throws:
      IllegalArgumentException - if provided magnetic flux norm value is negative, or if provided hard-iron matrix is not 3x1 or if soft-iron matrix is not 3x3.

  • Method Details

    • getStopThreshold

      public double getStopThreshold()
      Returns threshold to be used to keep the algorithm iterating in case that best estimated threshold using median of residuals is not small enough. Once a solution is found that generates a threshold below this value, the algorithm will stop. The stop threshold can be used to prevent the LMedS algorithm to iterate too many times in cases where samples have a very similar accuracy. For instance, in cases where proportion of outliers is very small (close to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would iterate for a long time trying to find the best solution when indeed there is no need to do that if a reasonable threshold has already been reached. Because of this behaviour the stop threshold can be set to a value much lower than the one typically used in RANSAC, and yet the algorithm could still produce even smaller thresholds in estimated results.
      Returns:
      stop threshold to stop the algorithm prematurely when a certain accuracy has been reached.

    • setStopThreshold

      public void setStopThreshold(double stopThreshold) throws com.irurueta.navigation.LockedException
      Sets threshold to be used to keep the algorithm iterating in case that best estimated threshold using median of residuals is not small enough. Once a solution is found that generates a threshold below this value, the algorithm will stop. The stop threshold can be used to prevent the LMedS algorithm to iterate too many times in cases where samples have a very similar accuracy. For instance, in cases where proportion of outliers is very small (close to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would iterate for a long time trying to find the best solution when indeed there is no need to do that if a reasonable threshold has already been reached. Because of this behaviour the stop threshold can be set to a value much lower than the one typically used in RANSAC, and yet the algorithm could still produce even smaller thresholds in estimated results.
      Parameters:
      stopThreshold - stop threshold to stop the algorithm prematurely when a certain accuracy has been reached.
      Throws:
      IllegalArgumentException - if provided value is zero or negative.
      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 hard-iron bias and 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 RobustKnownMagneticFluxDensityNormMagnetometerCalibrator
      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.