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

Class LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

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

To use this calibrator at least 10 measurements taken at a single known position and instant must be taken at 10 different unknown orientations and zero velocity 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

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator()
      Constructor.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

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

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

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

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(WorldMagneticModel magneticModel)
      Constructor.
      Parameters:
      magneticModel - Earth's magnetic model. If null, a default model will be used instead.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

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

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.NEDPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, double[] initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, double[] initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

    • LMedSRobustKnownPositionAndInstantMagnetometerCalibrator

      public LMedSRobustKnownPositionAndInstantMagnetometerCalibrator(com.irurueta.navigation.frames.ECEFPosition position, List<StandardDeviationBodyMagneticFluxDensity> measurements, boolean commonAxisUsed, com.irurueta.algebra.Matrix initialHardIron, com.irurueta.algebra.Matrix initialMm, RobustKnownPositionAndInstantMagnetometerCalibratorListener listener)
      Constructor.
      Parameters:
      position - position where body magnetic flux density measurements have been taken.
      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.

  • 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 RobustKnownPositionAndInstantMagnetometerCalibrator
      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.