gtsam/gtsam/slam/RotateFactor.h

120 lines
3.5 KiB
C++

/*
* @file RotateFactor.cpp
* @brief RotateFactor class
* @author Frank Dellaert
* @date December 17, 2013
*/
#pragma once
#include <gtsam/nonlinear/NonlinearFactor.h>
#include <gtsam/geometry/Rot3.h>
namespace gtsam {
/**
* Factor on unknown rotation iRC that relates two incremental rotations
* c1Rc2 = iRc' * i1Ri2 * iRc
* Which we can write (see doc/math.lyx)
* e^[z] = iRc' * e^[p] * iRc = e^([iRc'*p])
* with z and p measured and predicted angular velocities, and hence
* p = iRc * z
*/
class RotateFactor: public NoiseModelFactorN<Rot3> {
Point3 p_, z_; ///< Predicted and measured directions, p = iRc * z
typedef NoiseModelFactorN<Rot3> Base;
typedef RotateFactor This;
public:
/// Constructor
RotateFactor(Key key, const Rot3& P, const Rot3& Z,
const SharedNoiseModel& model) :
Base(model, key), p_(Rot3::Logmap(P)), z_(Rot3::Logmap(Z)) {
}
/// @return a deep copy of this factor
gtsam::NonlinearFactor::shared_ptr clone() const override {
return boost::static_pointer_cast<gtsam::NonlinearFactor>(
gtsam::NonlinearFactor::shared_ptr(new This(*this))); }
/// print
void print(const std::string& s = "",
const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
Base::print(s);
std::cout << "RotateFactor:]\n";
std::cout << "p: " << p_.transpose() << std::endl;
std::cout << "z: " << z_.transpose() << std::endl;
}
/// vector of errors returns 2D vector
Vector evaluateError(const Rot3& R,
OptionalMatrixType H = OptionalNone) const override {
// predict p_ as q = R*z_, derivative H will be filled if not none
Point3 q = R.rotate(z_,H);
// error is just difference, and note derivative of that wrpt q is I3
return (Vector(3) << q.x()-p_.x(), q.y()-p_.y(), q.z()-p_.z()).finished();
}
};
/**
* Factor on unknown rotation iRc that relates two directions c
* Directions provide less constraints than a full rotation
*/
class RotateDirectionsFactor: public NoiseModelFactorN<Rot3> {
Unit3 i_p_, c_z_; ///< Predicted and measured directions, i_p = iRc * c_z
typedef NoiseModelFactorN<Rot3> Base;
typedef RotateDirectionsFactor This;
public:
/// Constructor
RotateDirectionsFactor(Key key, const Unit3& i_p, const Unit3& c_z,
const SharedNoiseModel& model) :
Base(model, key), i_p_(i_p), c_z_(c_z) {
}
/// Initialize rotation iRc such that i_p = iRc * c_z
static Rot3 Initialize(const Unit3& i_p, const Unit3& c_z) {
gtsam::Quaternion iRc;
// setFromTwoVectors sets iRc to (a) quaternion which transform c_z into i_p
iRc.setFromTwoVectors(c_z.unitVector(), i_p.unitVector());
return Rot3(iRc);
}
/// @return a deep copy of this factor
gtsam::NonlinearFactor::shared_ptr clone() const override {
return boost::static_pointer_cast<gtsam::NonlinearFactor>(
gtsam::NonlinearFactor::shared_ptr(new This(*this))); }
/// print
void print(const std::string& s = "",
const KeyFormatter& keyFormatter = DefaultKeyFormatter) const override {
Base::print(s);
std::cout << "RotateDirectionsFactor:" << std::endl;
i_p_.print("p");
c_z_.print("z");
}
/// vector of errors returns 2D vector
Vector evaluateError(const Rot3& iRc, OptionalMatrixType H = OptionalNone) const override {
Unit3 i_q = iRc * c_z_;
Vector error = i_p_.error(i_q, H);
if (H) {
Matrix DR;
iRc.rotate(c_z_, DR);
*H = (*H) * DR;
}
return error;
}
GTSAM_MAKE_ALIGNED_OPERATOR_NEW
};
} // namespace gtsam