gtsam/gtsam_unstable/dynamics/ImuBias.h

185 lines
5.5 KiB
C++

/* ----------------------------------------------------------------------------
* 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
* -------------------------------------------------------------------------- */
/**
* @file ImuBias.h
* @date Feb 2, 2012
* @author Vadim Indelman, Stephen Williams
*/
#pragma once
#include <boost/serialization/nvp.hpp>
#include <gtsam/base/Matrix.h>
#include <gtsam/base/Vector.h>
#include <gtsam/base/DerivedValue.h>
#include <gtsam/geometry/Pose3.h>
/*
* NOTES:
* - Earth-rate correction:
* + Currently the user should supply R_ECEF_to_G, which is the rotation from ECEF to Local-Level system (NED or ENU as defened by the user).
* + R_ECEF_to_G can be calculated by approximated values of latitude and longitude of the system.
* + A relatively small distance is traveled w.r.t. to initial pose is assumed, since R_ECEF_to_G is constant.
* Otherwise, R_ECEF_to_G should be updated each time using the current lat-lon.
*
* - Currently, an empty constructed is not enabled so that the user is forced to specify R_ECEF_to_G.
*/
namespace gtsam {
/// All noise models live in the noiseModel namespace
namespace imuBias {
class ConstantBias : public DerivedValue<ConstantBias> {
private:
Vector bias_acc_;
Vector bias_gyro_;
public:
ConstantBias():
bias_acc_(Vector_(3, 0.0, 0.0, 0.0)), bias_gyro_(Vector_(3, 0.0, 0.0, 0.0)) {
}
ConstantBias(const Vector& bias_acc, const Vector& bias_gyro):
bias_acc_(bias_acc), bias_gyro_(bias_gyro) {
}
Vector CorrectAcc(Vector measurment, boost::optional<Matrix&> H=boost::none) const {
if (H){
Matrix zeros3_3(zeros(3,3));
Matrix m_eye3(-eye(3));
*H = collect(2, &m_eye3, &zeros3_3);
}
return measurment - bias_acc_;
}
Vector CorrectGyro(Vector measurment, boost::optional<Matrix&> H=boost::none) const {
if (H){
Matrix zeros3_3(zeros(3,3));
Matrix m_eye3(-eye(3));
*H = collect(2, &zeros3_3, &m_eye3);
}
return measurment - bias_gyro_;
}
// H1: Jacobian w.r.t. IMUBias
// H2: Jacobian w.r.t. pose
Vector CorrectGyroWithEarthRotRate(Vector measurement, const Pose3& pose, const Vector& w_earth_rate_G,
boost::optional<Matrix&> H1=boost::none, boost::optional<Matrix&> H2=boost::none) const {
Matrix R_G_to_I( pose.rotation().matrix().transpose() );
Vector w_earth_rate_I = R_G_to_I * w_earth_rate_G;
if (H1){
Matrix zeros3_3(zeros(3,3));
Matrix m_eye3(-eye(3));
*H1 = collect(2, &zeros3_3, &m_eye3);
}
if (H2){
Matrix zeros3_3(zeros(3,3));
Matrix H = -skewSymmetric(w_earth_rate_I);
*H2 = collect(2, &H, &zeros3_3);
}
//TODO: Make sure H2 is correct.
return measurement - bias_gyro_ - w_earth_rate_I;
// Vector bias_gyro_temp(Vector_(3, -bias_gyro_(0), bias_gyro_(1), bias_gyro_(2)));
// return measurement - bias_gyro_temp - R_G_to_I * w_earth_rate_G;
}
/** Expmap around identity */
static inline ConstantBias Expmap(const Vector& v) { return ConstantBias(v.head(3), v.tail(3)); }
/** Logmap around identity - just returns with default cast back */
static inline Vector Logmap(const ConstantBias& p) { return concatVectors(2, &p.bias_acc_, &p.bias_gyro_); }
/** Update the LieVector with a tangent space update */
inline ConstantBias retract(const Vector& v) const { return ConstantBias(bias_acc_ + v.head(3), bias_gyro_ + v.tail(3)); }
/** @return the local coordinates of another object */
inline Vector localCoordinates(const ConstantBias& t2) const {
Vector delta_acc(t2.bias_acc_ - bias_acc_);
Vector delta_gyro(t2.bias_gyro_ - bias_gyro_);
return concatVectors(2, &delta_acc, &delta_gyro);
}
/** Returns dimensionality of the tangent space */
inline size_t dim() const { return this->bias_acc_.size() + this->bias_gyro_.size(); }
/// print with optional string
void print(const std::string& s = "") const {
// explicit printing for now.
std::cout << s + ".bias_acc [" << bias_acc_.transpose() << "]" << std::endl;
std::cout << s + ".bias_gyro [" << bias_gyro_.transpose() << "]" << std::endl;
}
/** equality up to tolerance */
inline bool equals(const ConstantBias& expected, double tol=1e-5) const {
return gtsam::equal(bias_acc_, expected.bias_acc_, tol) && gtsam::equal(bias_gyro_, expected.bias_gyro_, tol);
}
/** get bias_acc */
const Vector& bias_acc() const { return bias_acc_; }
/** get bias_gyro */
const Vector& bias_gyro() const { return bias_gyro_; }
ConstantBias compose(const ConstantBias& b2,
boost::optional<gtsam::Matrix&> H1=boost::none,
boost::optional<gtsam::Matrix&> H2=boost::none) const {
if(H1) *H1 = eye(dim());
if(H2) *H2 = eye(b2.dim());
return ConstantBias(bias_acc_ + b2.bias_acc_, bias_gyro_ + b2.bias_gyro_);
}
/** between operation */
ConstantBias between(const ConstantBias& b2,
boost::optional<gtsam::Matrix&> H1=boost::none,
boost::optional<gtsam::Matrix&> H2=boost::none) const {
if(H1) *H1 = -eye(dim());
if(H2) *H2 = eye(b2.dim());
return ConstantBias(b2.bias_acc_ - bias_acc_, b2.bias_gyro_ - bias_gyro_);
}
/** invert the object and yield a new one */
inline ConstantBias inverse(boost::optional<gtsam::Matrix&> H=boost::none) const {
if(H) *H = -eye(dim());
return ConstantBias(-1.0 * bias_acc_, -1.0 * bias_gyro_);
}
}; // ConstantBias class
} // namespace ImuBias
} // namespace gtsam