AHRSFactor.h

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/* ----------------------------------------------------------------------------

 * GTSAM Copyright 2010, Georgia Tech Research Corporation,
 * Atlanta, Georgia 30332-0415
 * All Rights Reserved
 * Authors: Frank Dellaert, et al. (see THANKS for the full author list)

 * See LICENSE for the license information

 * -------------------------------------------------------------------------- */

#pragma once

/* GTSAM includes */
#include <gtsam/navigation/PreintegratedRotation.h>
#include <gtsam/nonlinear/NonlinearFactor.h>
#include <gtsam/geometry/Pose3.h>

#include <optional>

namespace gtsam {

class GTSAM_EXPORT PreintegratedAhrsMeasurements : public PreintegratedRotation {

 protected:

  Vector3 biasHat_; 
  Matrix3 preintMeasCov_; 

  friend class AHRSFactor;

 public:

  PreintegratedAhrsMeasurements() {}

  PreintegratedAhrsMeasurements(const std::shared_ptr<Params>& p,
      const Vector3& biasHat) :
      PreintegratedRotation(p), biasHat_(biasHat) {
    resetIntegration();
  }

  PreintegratedAhrsMeasurements(
      const std::shared_ptr<Params>& p,
      const Vector3& bias_hat,
      double deltaTij,
      const Rot3& deltaRij,
      const Matrix3& delRdelBiasOmega,
      const Matrix3& preint_meas_cov) :
      PreintegratedRotation(p, deltaTij, deltaRij, delRdelBiasOmega),
      biasHat_(bias_hat),
      preintMeasCov_(preint_meas_cov) {}

  Params& p() const { return *std::static_pointer_cast<Params>(p_);}
  const Vector3& biasHat() const { return biasHat_; }
  const Matrix3& preintMeasCov() const { return preintMeasCov_; }

  void print(const std::string& s = "Preintegrated Measurements: ") const;

  bool equals(const PreintegratedAhrsMeasurements&, double tol = 1e-9) const;

  void resetIntegration();

  void integrateMeasurement(const Vector3& measuredOmega, double deltaT);

  Vector3 predict(const Vector3& bias, OptionalJacobian<3,3> H = {}) const;

  // This function is only used for test purposes
  // (compare numerical derivatives wrt analytic ones)
  static Vector DeltaAngles(const Vector& msr_gyro_t, const double msr_dt,
      const Vector3& delta_angles);

  PreintegratedAhrsMeasurements(const Vector3& biasHat,
                                const Matrix3& measuredOmegaCovariance)
      : PreintegratedRotation(std::make_shared<Params>()), biasHat_(biasHat) {
    p_->gyroscopeCovariance = measuredOmegaCovariance;
    resetIntegration();
  }

private:

#ifdef GTSAM_ENABLE_BOOST_SERIALIZATION

  friend class boost::serialization::access;
  template<class ARCHIVE>
  void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
    ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(PreintegratedRotation);
    ar & BOOST_SERIALIZATION_NVP(p_);
    ar & BOOST_SERIALIZATION_NVP(biasHat_);
  }
#endif
};

class GTSAM_EXPORT AHRSFactor: public NoiseModelFactorN<Rot3, Rot3, Vector3> {

  typedef AHRSFactor This;
  typedef NoiseModelFactorN<Rot3, Rot3, Vector3> Base;

  PreintegratedAhrsMeasurements _PIM_;

  AHRSFactor() {}

public:

  // Provide access to the Matrix& version of evaluateError:
  using Base::evaluateError;

#if !defined(_MSC_VER) && __GNUC__ == 4 && __GNUC_MINOR__ > 5
  typedef typename std::shared_ptr<AHRSFactor> shared_ptr;
#else
  typedef std::shared_ptr<AHRSFactor> shared_ptr;
#endif

  AHRSFactor(Key rot_i, Key rot_j, Key bias,
      const PreintegratedAhrsMeasurements& preintegratedMeasurements);

  ~AHRSFactor() override {
  }

  gtsam::NonlinearFactor::shared_ptr clone() const override;

  void print(const std::string& s, const KeyFormatter& keyFormatter =
      DefaultKeyFormatter) const override;

  bool equals(const NonlinearFactor&, double tol = 1e-9) const override;

  const PreintegratedAhrsMeasurements& preintegratedMeasurements() const {
    return _PIM_;
  }

  Vector evaluateError(const Rot3& rot_i, const Rot3& rot_j,
      const Vector3& bias, OptionalMatrixType H1,
      OptionalMatrixType H2, OptionalMatrixType H3) const override;

  static Rot3 Predict(const Rot3& rot_i, const Vector3& bias,
                      const PreintegratedAhrsMeasurements& pim);

  AHRSFactor(Key rot_i, Key rot_j, Key bias,
             const PreintegratedAhrsMeasurements& pim,
             const Vector3& omegaCoriolis,
             const std::optional<Pose3>& body_P_sensor = {});

  static Rot3 predict(
      const Rot3& rot_i, const Vector3& bias,
      const PreintegratedAhrsMeasurements& pim, const Vector3& omegaCoriolis,
      const std::optional<Pose3>& body_P_sensor = {});

private:

#ifdef GTSAM_ENABLE_BOOST_SERIALIZATION

  friend class boost::serialization::access;
  template<class ARCHIVE>
  void serialize(ARCHIVE & ar, const unsigned int /*version*/) {
    // NoiseModelFactor3 instead of NoiseModelFactorN for backward compatibility
    ar
        & boost::serialization::make_nvp("NoiseModelFactor3",
            boost::serialization::base_object<Base>(*this));
    ar & BOOST_SERIALIZATION_NVP(_PIM_);
  }
#endif

};
// AHRSFactor

} //namespace gtsam