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Add a 2D landmark cost function. (#868) 

[RFC=0011](https://github.com/googlecartographer/rfcs/blob/master/text/0011-landmarks.md)
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Alexander Belyaev 2018-02-01 13:39:24 +01:00 committed by GitHub
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cartographer/mapping_2d/pose_graph/landmark_cost_function.h Normal file
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/*
* Copyright 2018 The Cartographer Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_H_
#define CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_H_
#include "Eigen/Core"
#include "Eigen/Geometry"
#include "cartographer/mapping/pose_graph/cost_helpers.h"
#include "cartographer/mapping/pose_graph_interface.h"
#include "cartographer/mapping_2d/pose_graph/optimization_problem.h"
#include "cartographer/transform/rigid_transform.h"
#include "cartographer/transform/transform.h"
#include "ceres/ceres.h"
#include "ceres/jet.h"
namespace cartographer {
namespace mapping_2d {
namespace pose_graph {
// Cost function measuring the weighted error between the observed pose given by
// the landmark measurement and the linearly interpolated pose of embedded in 3D
// space node poses.
class LandmarkCostFunction {
public:
using LandmarkObservation =
mapping::PoseGraphInterface::LandmarkNode::LandmarkObservation;
static ceres::CostFunction* CreateAutoDiffCostFunction(
const LandmarkObservation& observation, const NodeData& prev_node,
const NodeData& next_node) {
return new ceres::AutoDiffCostFunction<
LandmarkCostFunction, 3 /* residuals */,
3 /* previous node pose variables */, 3 /* next node pose variables */,
4 /* landmark rotation variables */,
3 /* landmark translation variables */>(
new LandmarkCostFunction(observation, prev_node, next_node));
}
template <typename T>
bool operator()(const T* const prev_node_pose, const T* const next_node_pose,
const T* const landmark_rotation,
const T* const landmark_translation, T* const e) const {
using mapping::pose_graph::ComputeUnscaledError;
using mapping::pose_graph::ScaleError;
using mapping::pose_graph::SlerpQuaternions;
const std::array<T, 3> interpolated_pose_translation{
{prev_node_pose[0] +
interpolation_parameter_ * (next_node_pose[0] - prev_node_pose[0]),
prev_node_pose[1] +
interpolation_parameter_ * (next_node_pose[1] - prev_node_pose[1]),
T(0)}};
// The following is equivalent to (Embed3D(prev_pose) *
// Rigid3d::Rotation(prev_pose_gravity_alignment)).rotation().
const Eigen::Quaternion<T> prev_quaternion(
(Eigen::AngleAxis<T>(prev_node_pose[2],
Eigen::Matrix<T, 3, 1>::UnitZ()) *
prev_node_gravity_alignment_.cast<T>())
.normalized());
const std::array<T, 4> prev_node_rotation = {
{prev_quaternion.w(), prev_quaternion.x(), prev_quaternion.y(),
prev_quaternion.z()}};
// The following is equivalent to (Embed3D(next_pose) *
// Rigid3d::Rotation(next_pose_gravity_alignment)).rotation().
const Eigen::Quaternion<T> next_quaternion(
(Eigen::AngleAxis<T>(next_node_pose[2],
Eigen::Matrix<T, 3, 1>::UnitZ()) *
next_node_gravity_alignment_.cast<T>())
.normalized());
const std::array<T, 4> next_node_rotation = {
{next_quaternion.w(), next_quaternion.x(), next_quaternion.y(),
next_quaternion.z()}};
const std::array<T, 4> interpolated_pose_rotation =
SlerpQuaternions(prev_node_rotation.data(), next_node_rotation.data(),
T(interpolation_parameter_));
const std::array<T, 6> error = ScaleError(
ComputeUnscaledError(landmark_to_tracking_transform_,
interpolated_pose_rotation.data(),
interpolated_pose_translation.data(),
landmark_rotation, landmark_translation),
T(translation_weight_), T(rotation_weight_));
std::copy(std::begin(error), std::end(error), e);
return true;
}
private:
LandmarkCostFunction(const LandmarkObservation& observation,
const NodeData& prev_node, const NodeData& next_node)
: landmark_to_tracking_transform_(
observation.landmark_to_tracking_transform),
prev_node_gravity_alignment_(prev_node.gravity_alignment),
next_node_gravity_alignment_(next_node.gravity_alignment),
translation_weight_(observation.translation_weight),
rotation_weight_(observation.rotation_weight),
interpolation_parameter_(
common::ToSeconds(observation.time - prev_node.time) /
common::ToSeconds(next_node.time - prev_node.time)) {}
const transform::Rigid3d landmark_to_tracking_transform_;
const Eigen::Quaterniond prev_node_gravity_alignment_;
const Eigen::Quaterniond next_node_gravity_alignment_;
const double translation_weight_;
const double rotation_weight_;
const double interpolation_parameter_;
};
} // namespace pose_graph
} // namespace mapping_2d
} // namespace cartographer
#endif // CARTOGRAPHER_MAPPING_2D_POSE_GRAPH_LANDMARK_COST_FUNCTION_H_

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/*
* Copyright 2018 The Cartographer Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "cartographer/mapping_2d/pose_graph/landmark_cost_function.h"
#include "cartographer/transform/rigid_transform.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
namespace cartographer {
namespace mapping_2d {
namespace pose_graph {
namespace {
using ::testing::DoubleEq;
using ::testing::ElementsAre;
using LandmarkObservation =
mapping::PoseGraphInterface::LandmarkNode::LandmarkObservation;
TEST(LandmarkCostFunctionTest, SmokeTest) {
NodeData prev_node;
prev_node.time = common::FromUniversal(0);
prev_node.gravity_alignment = Eigen::Quaterniond::Identity();
NodeData next_node;
next_node.time = common::FromUniversal(10);
next_node.gravity_alignment = Eigen::Quaterniond::Identity();
auto* cost_function = LandmarkCostFunction::CreateAutoDiffCostFunction(
LandmarkObservation{
0 /* trajectory ID */,
common::FromUniversal(5) /* time */,
transform::Rigid3d::Translation(Eigen::Vector3d(1., 1., 1.)),
1. /* translation_weight */,
2. /* rotation_weight */,
},
prev_node, next_node);
std::array<double, 3> prev_node_pose{{2., 0., 0.}};
std::array<double, 3> next_node_pose{{0., 2., 0.}};
std::array<double, 4> landmark_rotation{{1., 0., 0., 0.}};
std::array<double, 3> landmark_translation{{1., 2., 1.}};
const double* parameter_blocks[] = {
prev_node_pose.data(), next_node_pose.data(), landmark_rotation.data(),
landmark_translation.data()};
std::array<double, 6> residuals;
cost_function->Evaluate(parameter_blocks, residuals.data(), nullptr);
EXPECT_THAT(residuals, ElementsAre(DoubleEq(1.), DoubleEq(0.), DoubleEq(0.),
DoubleEq(0.), DoubleEq(0.), DoubleEq(0.)));
}
} // namespace
} // namespace pose_graph
} // namespace mapping_2d
} // namespace cartographer