gtsam/gtsam/navigation/PreintegrationBase.cpp

313 lines
13 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 PreintegrationBase.h
* @author Luca Carlone
* @author Stephen Williams
* @author Richard Roberts
* @author Vadim Indelman
* @author David Jensen
* @author Frank Dellaert
**/
#include "PreintegrationBase.h"
#include <boost/make_shared.hpp>
using namespace std;
namespace gtsam {
//------------------------------------------------------------------------------
void PreintegrationBase::Params::print(const string& s) const {
PreintegratedRotation::Params::print(s);
cout << "accelerometerCovariance:\n[\n" << accelerometerCovariance << "\n]"
<< endl;
cout << "integrationCovariance:\n[\n" << accelerometerCovariance << "\n]"
<< endl;
if (omegaCoriolis && use2ndOrderCoriolis)
cout << "Using 2nd-order Coriolis" << endl;
if (body_P_sensor)
body_P_sensor->print(" ");
cout << "n_gravity = (" << n_gravity.transpose() << ")" << endl;
}
//------------------------------------------------------------------------------
void PreintegrationBase::resetIntegration() {
deltaTij_ = 0.0;
deltaXij_ = NavState();
delRdelBiasOmega_ = Z_3x3;
delPdelBiasAcc_ = Z_3x3;
delPdelBiasOmega_ = Z_3x3;
delVdelBiasAcc_ = Z_3x3;
delVdelBiasOmega_ = Z_3x3;
}
//------------------------------------------------------------------------------
void PreintegrationBase::print(const string& s) const {
cout << s << endl;
cout << " deltaTij [" << deltaTij_ << "]" << endl;
cout << " deltaRij.ypr = (" << deltaRij().ypr().transpose() << ")" << endl;
cout << " deltaPij [ " << deltaPij().transpose() << " ]" << endl;
cout << " deltaVij [ " << deltaVij().transpose() << " ]" << endl;
biasHat_.print(" biasHat");
}
//------------------------------------------------------------------------------
bool PreintegrationBase::equals(const PreintegrationBase& other,
double tol) const {
return fabs(deltaTij_ - other.deltaTij_) < tol
&& deltaXij_.equals(other.deltaXij_, tol)
&& biasHat_.equals(other.biasHat_, tol)
&& equal_with_abs_tol(delRdelBiasOmega_, other.delRdelBiasOmega_, tol)
&& equal_with_abs_tol(delPdelBiasAcc_, other.delPdelBiasAcc_, tol)
&& equal_with_abs_tol(delPdelBiasOmega_, other.delPdelBiasOmega_, tol)
&& equal_with_abs_tol(delVdelBiasAcc_, other.delVdelBiasAcc_, tol)
&& equal_with_abs_tol(delVdelBiasOmega_, other.delVdelBiasOmega_, tol);
}
//------------------------------------------------------------------------------
pair<Vector3, Vector3> PreintegrationBase::correctMeasurementsByBiasAndSensorPose(
const Vector3& j_measuredAcc, const Vector3& j_measuredOmega,
OptionalJacobian<3, 3> D_correctedAcc_measuredAcc,
OptionalJacobian<3, 3> D_correctedAcc_measuredOmega,
OptionalJacobian<3, 3> D_correctedOmega_measuredOmega) const {
// Correct for bias in the sensor frame
Vector3 j_correctedAcc = biasHat_.correctAccelerometer(j_measuredAcc);
Vector3 j_correctedOmega = biasHat_.correctGyroscope(j_measuredOmega);
// Compensate for sensor-body displacement if needed: we express the quantities
// (originally in the IMU frame) into the body frame
// Equations below assume the "body" frame is the CG
if (p().body_P_sensor) {
// Correct omega to rotation rate vector in the body frame
const Matrix3 bRs = p().body_P_sensor->rotation().matrix();
j_correctedOmega = bRs * j_correctedOmega;
// Correct acceleration
j_correctedAcc = bRs * j_correctedAcc;
// Jacobians
if (D_correctedAcc_measuredAcc) *D_correctedAcc_measuredAcc = bRs;
if (D_correctedAcc_measuredOmega) *D_correctedAcc_measuredOmega = Matrix3::Zero();
if (D_correctedOmega_measuredOmega) *D_correctedOmega_measuredOmega = bRs;
// Centrifugal acceleration
const Vector3 b_arm = p().body_P_sensor->translation().vector();
if (!b_arm.isZero()) {
// Subtract out the the centripetal acceleration from the measured one
// to get linear acceleration vector in the body frame:
const Matrix3 body_Omega_body = skewSymmetric(j_correctedOmega);
const Vector3 b_velocity_bs = body_Omega_body * b_arm; // magnitude: omega * arm
j_correctedAcc -= body_Omega_body * b_velocity_bs;
// Update derivative: centrifugal causes the correlation between acc and omega!!!
if (D_correctedAcc_measuredOmega) {
double wdp = j_correctedOmega.dot(b_arm);
*D_correctedAcc_measuredOmega = -(diag(Vector3::Constant(wdp))
+ j_correctedOmega * b_arm.transpose()) * bRs.matrix()
+ 2 * b_arm * j_measuredOmega.transpose();
}
}
}
// Do update in one fell swoop
return make_pair(j_correctedAcc, j_correctedOmega);
}
//------------------------------------------------------------------------------
NavState PreintegrationBase::updatedDeltaXij(const Vector3& j_measuredAcc,
const Vector3& j_measuredOmega, const double dt,
OptionalJacobian<9, 9> D_updated_current,
OptionalJacobian<9, 3> D_updated_measuredAcc,
OptionalJacobian<9, 3> D_updated_measuredOmega) const {
Vector3 j_correctedAcc, j_correctedOmega;
Matrix3 D_correctedAcc_measuredAcc, //
D_correctedAcc_measuredOmega, //
D_correctedOmega_measuredOmega;
bool needDerivs = D_updated_measuredAcc && D_updated_measuredOmega && p().body_P_sensor;
boost::tie(j_correctedAcc, j_correctedOmega) =
correctMeasurementsByBiasAndSensorPose(j_measuredAcc, j_measuredOmega,
(needDerivs ? &D_correctedAcc_measuredAcc : 0),
(needDerivs ? &D_correctedAcc_measuredOmega : 0),
(needDerivs ? &D_correctedOmega_measuredOmega : 0));
// Do update in one fell swoop
Matrix93 D_updated_correctedAcc, D_updated_correctedOmega;
NavState updated = deltaXij_.update(j_correctedAcc, j_correctedOmega, dt, D_updated_current,
(needDerivs ? D_updated_correctedAcc : D_updated_measuredAcc),
(needDerivs ? D_updated_correctedOmega : D_updated_measuredOmega));
if (needDerivs) {
*D_updated_measuredAcc = D_updated_correctedAcc * D_correctedAcc_measuredAcc;
*D_updated_measuredOmega = D_updated_correctedOmega * D_correctedOmega_measuredOmega;
if (!p().body_P_sensor->translation().vector().isZero()) {
*D_updated_measuredOmega += D_updated_correctedAcc * D_correctedAcc_measuredOmega;
}
}
return updated;
}
//------------------------------------------------------------------------------
void PreintegrationBase::update(const Vector3& j_measuredAcc,
const Vector3& j_measuredOmega, const double dt,
Matrix3* D_incrR_integratedOmega, Matrix9* D_updated_current,
Matrix93* D_updated_measuredAcc, Matrix93* D_updated_measuredOmega) {
// Save current rotation for updating Jacobians
const Rot3 oldRij = deltaXij_.attitude();
// Do update
deltaTij_ += dt;
deltaXij_ = updatedDeltaXij(j_measuredAcc, j_measuredOmega, dt,
D_updated_current, D_updated_measuredAcc, D_updated_measuredOmega); // functional
// Update Jacobians
// TODO(frank): we are repeating some computation here: accessible in F ?
Vector3 j_correctedAcc, j_correctedOmega;
boost::tie(j_correctedAcc, j_correctedOmega) =
correctMeasurementsByBiasAndSensorPose(j_measuredAcc, j_measuredOmega);
Matrix3 D_acc_R;
oldRij.rotate(j_correctedAcc, D_acc_R);
const Matrix3 D_acc_biasOmega = D_acc_R * delRdelBiasOmega_;
const Vector3 integratedOmega = j_correctedOmega * dt;
const Rot3 incrR = Rot3::Expmap(integratedOmega, D_incrR_integratedOmega); // expensive !!
const Matrix3 incrRt = incrR.transpose();
delRdelBiasOmega_ = incrRt * delRdelBiasOmega_
- *D_incrR_integratedOmega * dt;
double dt22 = 0.5 * dt * dt;
const Matrix3 dRij = oldRij.matrix(); // expensive
delPdelBiasAcc_ += delVdelBiasAcc_ * dt - dt22 * dRij;
delPdelBiasOmega_ += dt * delVdelBiasOmega_ + dt22 * D_acc_biasOmega;
delVdelBiasAcc_ += -dRij * dt;
delVdelBiasOmega_ += D_acc_biasOmega * dt;
}
//------------------------------------------------------------------------------
Vector9 PreintegrationBase::biasCorrectedDelta(
const imuBias::ConstantBias& bias_i, OptionalJacobian<9, 6> H) const {
// Correct deltaRij, derivative is delRdelBiasOmega_
const imuBias::ConstantBias biasIncr = bias_i - biasHat_;
Matrix3 D_correctedRij_bias;
const Vector3 biasInducedOmega = delRdelBiasOmega_ * biasIncr.gyroscope();
const Rot3 correctedRij = deltaRij().expmap(biasInducedOmega, boost::none,
H ? &D_correctedRij_bias : 0);
if (H)
D_correctedRij_bias *= delRdelBiasOmega_;
Vector9 xi;
Matrix3 D_dR_correctedRij;
// TODO(frank): could line below be simplified? It is equivalent to
// LogMap(deltaRij_.compose(Expmap(biasInducedOmega)))
NavState::dR(xi) = Rot3::Logmap(correctedRij, H ? &D_dR_correctedRij : 0);
NavState::dP(xi) = deltaPij() + delPdelBiasAcc_ * biasIncr.accelerometer()
+ delPdelBiasOmega_ * biasIncr.gyroscope();
NavState::dV(xi) = deltaVij() + delVdelBiasAcc_ * biasIncr.accelerometer()
+ delVdelBiasOmega_ * biasIncr.gyroscope();
if (H) {
Matrix36 D_dR_bias, D_dP_bias, D_dV_bias;
D_dR_bias << Z_3x3, D_dR_correctedRij * D_correctedRij_bias;
D_dP_bias << delPdelBiasAcc_, delPdelBiasOmega_;
D_dV_bias << delVdelBiasAcc_, delVdelBiasOmega_;
(*H) << D_dR_bias, D_dP_bias, D_dV_bias;
}
return xi;
}
//------------------------------------------------------------------------------
NavState PreintegrationBase::predict(const NavState& state_i,
const imuBias::ConstantBias& bias_i, OptionalJacobian<9, 9> H1,
OptionalJacobian<9, 6> H2) const {
// correct for bias
Matrix96 D_biasCorrected_bias;
Vector9 biasCorrected = biasCorrectedDelta(bias_i,
H2 ? &D_biasCorrected_bias : 0);
// integrate on tangent space
Matrix9 D_delta_state, D_delta_biasCorrected;
Vector9 xi = state_i.correctPIM(biasCorrected, deltaTij_, p().n_gravity,
p().omegaCoriolis, p().use2ndOrderCoriolis, H1 ? &D_delta_state : 0,
H2 ? &D_delta_biasCorrected : 0);
// Use retract to get back to NavState manifold
Matrix9 D_predict_state, D_predict_delta;
NavState state_j = state_i.retract(xi, D_predict_state, D_predict_delta);
if (H1)
*H1 = D_predict_state + D_predict_delta * D_delta_state;
if (H2)
*H2 = D_predict_delta * D_delta_biasCorrected * D_biasCorrected_bias;
return state_j;
}
//------------------------------------------------------------------------------
Vector9 PreintegrationBase::computeErrorAndJacobians(const Pose3& pose_i,
const Vector3& vel_i, const Pose3& pose_j, const Vector3& vel_j,
const imuBias::ConstantBias& bias_i, OptionalJacobian<9, 6> H1,
OptionalJacobian<9, 3> H2, OptionalJacobian<9, 6> H3,
OptionalJacobian<9, 3> H4, OptionalJacobian<9, 6> H5) const {
// Note that derivative of constructors below is not identity for velocity, but
// a 9*3 matrix == Z_3x3, Z_3x3, state.R().transpose()
NavState state_i(pose_i, vel_i);
NavState state_j(pose_j, vel_j);
/// Predict state at time j
Matrix99 D_predict_state_i;
Matrix96 D_predict_bias_i;
NavState predictedState_j = predict(state_i, bias_i,
H1 || H2 ? &D_predict_state_i : 0, H5 ? &D_predict_bias_i : 0);
Matrix9 D_error_state_j, D_error_predict;
Vector9 error = state_j.localCoordinates(predictedState_j,
H3 || H4 ? &D_error_state_j : 0, H1 || H2 || H5 ? &D_error_predict : 0);
// Separate out derivatives in terms of 5 arguments
// Note that doing so requires special treatment of velocities, as when treated as
// separate variables the retract applied will not be the semi-direct product in NavState
// Instead, the velocities in nav are updated using a straight addition
// This is difference is accounted for by the R().transpose calls below
if (H1)
*H1 << D_error_predict * D_predict_state_i.leftCols<6>();
if (H2)
*H2
<< D_error_predict * D_predict_state_i.rightCols<3>()
* state_i.R().transpose();
if (H3)
*H3 << D_error_state_j.leftCols<6>();
if (H4)
*H4 << D_error_state_j.rightCols<3>() * state_j.R().transpose();
if (H5)
*H5 << D_error_predict * D_predict_bias_i;
return error;
}
//------------------------------------------------------------------------------
PoseVelocityBias PreintegrationBase::predict(const Pose3& pose_i,
const Vector3& vel_i, const imuBias::ConstantBias& bias_i,
const Vector3& n_gravity, const Vector3& omegaCoriolis,
const bool use2ndOrderCoriolis) {
// NOTE(frank): parameters are supposed to be constant, below is only provided for compatibility
boost::shared_ptr<Params> q = boost::make_shared<Params>(p());
q->n_gravity = n_gravity;
q->omegaCoriolis = omegaCoriolis;
q->use2ndOrderCoriolis = use2ndOrderCoriolis;
p_ = q;
return PoseVelocityBias(predict(NavState(pose_i, vel_i), bias_i), bias_i);
}
//------------------------------------------------------------------------------
}/// namespace gtsam