cartographer/cartographer/mapping_2d/sparse_pose_graph.cc

627 lines
25 KiB
C++

/*
* Copyright 2016 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/sparse_pose_graph.h"
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <memory>
#include <set>
#include <sstream>
#include <string>
#include "Eigen/Eigenvalues"
#include "cartographer/common/make_unique.h"
#include "cartographer/common/math.h"
#include "cartographer/mapping/sparse_pose_graph/proto/constraint_builder_options.pb.h"
#include "cartographer/sensor/compressed_point_cloud.h"
#include "cartographer/sensor/voxel_filter.h"
#include "glog/logging.h"
namespace cartographer {
namespace mapping_2d {
SparsePoseGraph::SparsePoseGraph(
const mapping::proto::SparsePoseGraphOptions& options,
common::ThreadPool* thread_pool)
: options_(options),
optimization_problem_(options_.optimization_problem_options()),
constraint_builder_(options_.constraint_builder_options(), thread_pool) {}
SparsePoseGraph::~SparsePoseGraph() {
WaitForAllComputations();
common::MutexLocker locker(&mutex_);
CHECK(scan_queue_ == nullptr);
}
std::vector<mapping::SubmapId> SparsePoseGraph::GrowSubmapTransformsAsNeeded(
const int trajectory_id,
const std::vector<std::shared_ptr<const Submap>>& insertion_submaps) {
CHECK(!insertion_submaps.empty());
const auto& submap_data = optimization_problem_.submap_data();
if (insertion_submaps.size() == 1) {
// If we don't already have an entry for the first submap, add one.
if (static_cast<size_t>(trajectory_id) >= submap_data.size() ||
submap_data[trajectory_id].empty()) {
optimization_problem_.AddSubmap(
trajectory_id,
sparse_pose_graph::ComputeSubmapPose(*insertion_submaps[0]));
}
CHECK_EQ(optimization_problem_.num_trimmed_submaps(trajectory_id), 0);
CHECK_EQ(submap_data[trajectory_id].size(), 1);
const mapping::SubmapId submap_id{trajectory_id, 0};
CHECK(submap_data_.at(submap_id).submap == insertion_submaps.front());
return {submap_id};
}
CHECK_EQ(2, insertion_submaps.size());
const int num_trimmed_submaps =
optimization_problem_.num_trimmed_submaps(trajectory_id);
const mapping::SubmapId last_submap_id{
trajectory_id, static_cast<int>(submap_data.at(trajectory_id).size() +
num_trimmed_submaps - 1)};
if (submap_data_.at(last_submap_id).submap == insertion_submaps.front()) {
// In this case, 'last_submap_id' is the ID of 'insertions_submaps.front()'
// and 'insertions_submaps.back()' is new.
const auto& first_submap_pose =
submap_data.at(trajectory_id)
.at(last_submap_id.submap_index - num_trimmed_submaps)
.pose;
optimization_problem_.AddSubmap(
trajectory_id,
first_submap_pose *
sparse_pose_graph::ComputeSubmapPose(*insertion_submaps[0])
.inverse() *
sparse_pose_graph::ComputeSubmapPose(*insertion_submaps[1]));
return {last_submap_id,
mapping::SubmapId{trajectory_id, last_submap_id.submap_index + 1}};
}
CHECK(submap_data_.at(last_submap_id).submap == insertion_submaps.back());
const mapping::SubmapId front_submap_id{trajectory_id,
last_submap_id.submap_index - 1};
CHECK(submap_data_.at(front_submap_id).submap == insertion_submaps.front());
return {front_submap_id, last_submap_id};
}
void SparsePoseGraph::AddScan(
common::Time time, const transform::Rigid3d& tracking_to_pose,
const sensor::RangeData& range_data_in_pose, const transform::Rigid2d& pose,
const int trajectory_id,
const std::vector<std::shared_ptr<const Submap>>& insertion_submaps) {
const transform::Rigid3d optimized_pose(
GetLocalToGlobalTransform(trajectory_id) * transform::Embed3D(pose));
common::MutexLocker locker(&mutex_);
trajectory_nodes_.Append(
trajectory_id,
mapping::TrajectoryNode{
std::make_shared<const mapping::TrajectoryNode::Data>(
mapping::TrajectoryNode::Data{
time, range_data_in_pose,
Compress(sensor::RangeData{Eigen::Vector3f::Zero(), {}, {}}),
tracking_to_pose}),
optimized_pose});
++num_trajectory_nodes_;
trajectory_connectivity_.Add(trajectory_id);
// Test if the 'insertion_submap.back()' is one we never saw before.
if (trajectory_id >= submap_data_.num_trajectories() ||
submap_data_.num_indices(trajectory_id) == 0 ||
submap_data_
.at(mapping::SubmapId{
trajectory_id, submap_data_.num_indices(trajectory_id) - 1})
.submap != insertion_submaps.back()) {
// We grow 'submap_data_' as needed. This code assumes that the first
// time we see a new submap is as 'insertion_submaps.back()'.
const mapping::SubmapId submap_id =
submap_data_.Append(trajectory_id, SubmapData());
submap_data_.at(submap_id).submap = insertion_submaps.back();
}
// Make sure we have a sampler for this trajectory.
if (!global_localization_samplers_[trajectory_id]) {
global_localization_samplers_[trajectory_id] =
common::make_unique<common::FixedRatioSampler>(
options_.global_sampling_ratio());
}
// We have to check this here, because it might have changed by the time we
// execute the lambda.
const bool newly_finished_submap = insertion_submaps.front()->finished();
AddWorkItem([=]() REQUIRES(mutex_) {
ComputeConstraintsForScan(trajectory_id, insertion_submaps,
newly_finished_submap, pose);
});
}
void SparsePoseGraph::AddWorkItem(std::function<void()> work_item) {
if (scan_queue_ == nullptr) {
work_item();
} else {
scan_queue_->push_back(work_item);
}
}
void SparsePoseGraph::AddImuData(const int trajectory_id, common::Time time,
const Eigen::Vector3d& linear_acceleration,
const Eigen::Vector3d& angular_velocity) {
common::MutexLocker locker(&mutex_);
AddWorkItem([=]() REQUIRES(mutex_) {
optimization_problem_.AddImuData(trajectory_id, time, linear_acceleration,
angular_velocity);
});
}
void SparsePoseGraph::ComputeConstraint(const mapping::NodeId& node_id,
const mapping::SubmapId& submap_id) {
CHECK(submap_data_.at(submap_id).state == SubmapState::kFinished);
// Only globally match against submaps not in this trajectory.
if (node_id.trajectory_id != submap_id.trajectory_id &&
global_localization_samplers_[node_id.trajectory_id]->Pulse()) {
constraint_builder_.MaybeAddGlobalConstraint(
submap_id, submap_data_.at(submap_id).submap.get(), node_id,
&trajectory_nodes_.at(node_id).constant_data->range_data_2d.returns,
&trajectory_connectivity_);
} else {
const bool scan_and_submap_trajectories_connected =
reverse_connected_components_.count(node_id.trajectory_id) > 0 &&
reverse_connected_components_.count(submap_id.trajectory_id) > 0 &&
reverse_connected_components_.at(node_id.trajectory_id) ==
reverse_connected_components_.at(submap_id.trajectory_id);
if (node_id.trajectory_id == submap_id.trajectory_id ||
scan_and_submap_trajectories_connected) {
const transform::Rigid2d initial_relative_pose =
optimization_problem_.submap_data()
.at(submap_id.trajectory_id)
.at(submap_id.submap_index -
optimization_problem_.num_trimmed_submaps(
submap_id.trajectory_id))
.pose.inverse() *
optimization_problem_.node_data()
.at(node_id.trajectory_id)
.at(node_id.node_index - optimization_problem_.num_trimmed_nodes(
node_id.trajectory_id))
.point_cloud_pose;
constraint_builder_.MaybeAddConstraint(
submap_id, submap_data_.at(submap_id).submap.get(), node_id,
&trajectory_nodes_.at(node_id).constant_data->range_data_2d.returns,
initial_relative_pose);
}
}
}
void SparsePoseGraph::ComputeConstraintsForOldScans(
const mapping::SubmapId& submap_id) {
const auto& submap_data = submap_data_.at(submap_id);
const auto& node_data = optimization_problem_.node_data();
for (size_t trajectory_id = 0; trajectory_id != node_data.size();
++trajectory_id) {
for (size_t node_data_index = 0;
node_data_index != node_data[trajectory_id].size();
++node_data_index) {
const int node_index =
node_data_index +
optimization_problem_.num_trimmed_nodes(trajectory_id);
const mapping::NodeId node_id{static_cast<int>(trajectory_id),
static_cast<int>(node_index)};
CHECK(!trajectory_nodes_.at(node_id).trimmed());
if (submap_data.node_ids.count(node_id) == 0) {
ComputeConstraint(node_id, submap_id);
}
}
}
}
void SparsePoseGraph::ComputeConstraintsForScan(
const int trajectory_id,
std::vector<std::shared_ptr<const Submap>> insertion_submaps,
const bool newly_finished_submap, const transform::Rigid2d& pose) {
const std::vector<mapping::SubmapId> submap_ids =
GrowSubmapTransformsAsNeeded(trajectory_id, insertion_submaps);
CHECK_EQ(submap_ids.size(), insertion_submaps.size());
const mapping::SubmapId matching_id = submap_ids.front();
const int num_trimmed_submaps = optimization_problem_.num_trimmed_submaps(trajectory_id);
const transform::Rigid2d optimized_pose =
optimization_problem_.submap_data()
.at(matching_id.trajectory_id)
.at(matching_id.submap_index - num_trimmed_submaps)
.pose *
sparse_pose_graph::ComputeSubmapPose(*insertion_submaps.front())
.inverse() *
pose;
const mapping::NodeId node_id{
matching_id.trajectory_id,
static_cast<size_t>(matching_id.trajectory_id) <
optimization_problem_.node_data().size()
? static_cast<int>(optimization_problem_.node_data()
.at(matching_id.trajectory_id)
.size()) +
optimization_problem_.num_trimmed_nodes(
matching_id.trajectory_id)
: 0};
const auto& scan_data = trajectory_nodes_.at(node_id).constant_data;
optimization_problem_.AddTrajectoryNode(
matching_id.trajectory_id, scan_data->time, pose, optimized_pose);
for (size_t i = 0; i < insertion_submaps.size(); ++i) {
const mapping::SubmapId submap_id = submap_ids[i];
// Even if this was the last scan added to 'submap_id', the submap will only
// be marked as finished in 'submap_data_' further below.
CHECK(submap_data_.at(submap_id).state == SubmapState::kActive);
submap_data_.at(submap_id).node_ids.emplace(node_id);
const transform::Rigid2d constraint_transform =
sparse_pose_graph::ComputeSubmapPose(*insertion_submaps[i]).inverse() *
pose;
constraints_.push_back(Constraint{submap_id,
node_id,
{transform::Embed3D(constraint_transform),
options_.matcher_translation_weight(),
options_.matcher_rotation_weight()},
Constraint::INTRA_SUBMAP});
}
for (int trajectory_id = 0; trajectory_id < submap_data_.num_trajectories();
++trajectory_id) {
for (int submap_index = 0;
submap_index < submap_data_.num_indices(trajectory_id);
++submap_index) {
const mapping::SubmapId submap_id{trajectory_id, submap_index};
if (submap_data_.at(submap_id).state == SubmapState::kFinished) {
CHECK_EQ(submap_data_.at(submap_id).node_ids.count(node_id), 0);
ComputeConstraint(node_id, submap_id);
}
}
}
if (newly_finished_submap) {
const mapping::SubmapId finished_submap_id = submap_ids.front();
SubmapData& finished_submap_data = submap_data_.at(finished_submap_id);
CHECK(finished_submap_data.state == SubmapState::kActive);
finished_submap_data.state = SubmapState::kFinished;
// We have a new completed submap, so we look into adding constraints for
// old scans.
ComputeConstraintsForOldScans(finished_submap_id);
}
constraint_builder_.NotifyEndOfScan();
++num_scans_since_last_loop_closure_;
if (options_.optimize_every_n_scans() > 0 &&
num_scans_since_last_loop_closure_ > options_.optimize_every_n_scans()) {
CHECK(!run_loop_closure_);
run_loop_closure_ = true;
// If there is a 'scan_queue_' already, some other thread will take care.
if (scan_queue_ == nullptr) {
scan_queue_ = common::make_unique<std::deque<std::function<void()>>>();
HandleScanQueue();
}
}
}
void SparsePoseGraph::HandleScanQueue() {
constraint_builder_.WhenDone(
[this](const sparse_pose_graph::ConstraintBuilder::Result& result) {
{
common::MutexLocker locker(&mutex_);
constraints_.insert(constraints_.end(), result.begin(), result.end());
}
RunOptimization();
common::MutexLocker locker(&mutex_);
num_scans_since_last_loop_closure_ = 0;
run_loop_closure_ = false;
while (!run_loop_closure_) {
if (scan_queue_->empty()) {
LOG(INFO) << "We caught up. Hooray!";
scan_queue_.reset();
return;
}
scan_queue_->front()();
scan_queue_->pop_front();
}
// We have to optimize again.
HandleScanQueue();
});
}
void SparsePoseGraph::WaitForAllComputations() {
bool notification = false;
common::MutexLocker locker(&mutex_);
const int num_finished_scans_at_start =
constraint_builder_.GetNumFinishedScans();
while (!locker.AwaitWithTimeout(
[this]() REQUIRES(mutex_) {
return constraint_builder_.GetNumFinishedScans() ==
num_trajectory_nodes_;
},
common::FromSeconds(1.))) {
std::ostringstream progress_info;
progress_info << "Optimizing: " << std::fixed << std::setprecision(1)
<< 100. *
(constraint_builder_.GetNumFinishedScans() -
num_finished_scans_at_start) /
(num_trajectory_nodes_ - num_finished_scans_at_start)
<< "%...";
std::cout << "\r\x1b[K" << progress_info.str() << std::flush;
}
std::cout << "\r\x1b[KOptimizing: Done. " << std::endl;
constraint_builder_.WhenDone(
[this, &notification](
const sparse_pose_graph::ConstraintBuilder::Result& result) {
common::MutexLocker locker(&mutex_);
constraints_.insert(constraints_.end(), result.begin(), result.end());
notification = true;
});
locker.Await([&notification]() { return notification; });
}
void SparsePoseGraph::AddTrimmer(
std::unique_ptr<mapping::PoseGraphTrimmer> trimmer) {
common::MutexLocker locker(&mutex_);
// C++11 does not allow us to move a unique_ptr into a lambda.
mapping::PoseGraphTrimmer* const trimmer_ptr = trimmer.release();
AddWorkItem([this, trimmer_ptr]()
REQUIRES(mutex_) { trimmers_.emplace_back(trimmer_ptr); });
}
void SparsePoseGraph::RunFinalOptimization() {
WaitForAllComputations();
optimization_problem_.SetMaxNumIterations(
options_.max_num_final_iterations());
RunOptimization();
optimization_problem_.SetMaxNumIterations(
options_.optimization_problem_options()
.ceres_solver_options()
.max_num_iterations());
}
void SparsePoseGraph::RunOptimization() {
if (optimization_problem_.submap_data().empty()) {
return;
}
optimization_problem_.Solve(constraints_);
common::MutexLocker locker(&mutex_);
std::vector<int> num_trimmed_submaps;
const auto& submap_data = optimization_problem_.submap_data();
for (int trajectory_id = 0;
trajectory_id != static_cast<int>(submap_data.size()); ++trajectory_id) {
num_trimmed_submaps.push_back(
optimization_problem_.num_trimmed_submaps(trajectory_id));
}
const auto& node_data = optimization_problem_.node_data();
for (int trajectory_id = 0;
trajectory_id != static_cast<int>(node_data.size()); ++trajectory_id) {
int node_data_index = 0;
const int num_nodes = trajectory_nodes_.num_indices(trajectory_id);
int node_index = optimization_problem_.num_trimmed_nodes(trajectory_id);
for (; node_data_index != static_cast<int>(node_data[trajectory_id].size());
++node_data_index, ++node_index) {
const mapping::NodeId node_id{trajectory_id, node_index};
trajectory_nodes_.at(node_id).pose = transform::Embed3D(
node_data[trajectory_id][node_data_index].point_cloud_pose);
}
// Extrapolate all point cloud poses that were added later.
const auto local_to_new_global = ComputeLocalToGlobalTransform(
submap_data, num_trimmed_submaps, trajectory_id);
const auto local_to_old_global = ComputeLocalToGlobalTransform(
optimized_submap_transforms_, num_trimmed_submaps_at_last_optimization_,
trajectory_id);
const transform::Rigid3d old_global_to_new_global =
local_to_new_global * local_to_old_global.inverse();
for (; node_index < num_nodes; ++node_index) {
const mapping::NodeId node_id{trajectory_id, node_index};
trajectory_nodes_.at(node_id).pose =
old_global_to_new_global * trajectory_nodes_.at(node_id).pose;
}
}
optimized_submap_transforms_ = submap_data;
num_trimmed_submaps_at_last_optimization_ = num_trimmed_submaps;
connected_components_ = trajectory_connectivity_.ConnectedComponents();
reverse_connected_components_.clear();
for (size_t i = 0; i != connected_components_.size(); ++i) {
for (const int trajectory_id : connected_components_[i]) {
reverse_connected_components_.emplace(trajectory_id, i);
}
}
TrimmingHandle trimming_handle(this);
for (auto& trimmer : trimmers_) {
trimmer->Trim(&trimming_handle);
}
}
std::vector<std::vector<mapping::TrajectoryNode>>
SparsePoseGraph::GetTrajectoryNodes() {
common::MutexLocker locker(&mutex_);
return trajectory_nodes_.data();
}
std::vector<SparsePoseGraph::Constraint> SparsePoseGraph::constraints() {
common::MutexLocker locker(&mutex_);
return constraints_;
}
transform::Rigid3d SparsePoseGraph::GetLocalToGlobalTransform(
const int trajectory_id) {
common::MutexLocker locker(&mutex_);
return ComputeLocalToGlobalTransform(optimized_submap_transforms_,
num_trimmed_submaps_at_last_optimization_,
trajectory_id);
}
std::vector<std::vector<int>> SparsePoseGraph::GetConnectedTrajectories() {
common::MutexLocker locker(&mutex_);
return connected_components_;
}
int SparsePoseGraph::num_submaps(const int trajectory_id) {
common::MutexLocker locker(&mutex_);
if (trajectory_id >= submap_data_.num_trajectories()) {
return 0;
}
return submap_data_.num_indices(trajectory_id);
}
mapping::SparsePoseGraph::SubmapData SparsePoseGraph::GetSubmapData(
const mapping::SubmapId& submap_id) {
common::MutexLocker locker(&mutex_);
return GetSubmapDataUnderLock(submap_id);
}
std::vector<std::vector<mapping::SparsePoseGraph::SubmapData>>
SparsePoseGraph::GetAllSubmapData() {
common::MutexLocker locker(&mutex_);
std::vector<std::vector<mapping::SparsePoseGraph::SubmapData>>
all_submap_data(submap_data_.num_trajectories());
for (int trajectory_id = 0; trajectory_id < submap_data_.num_trajectories();
++trajectory_id) {
all_submap_data[trajectory_id].reserve(
submap_data_.num_indices(trajectory_id));
for (int submap_index = 0;
submap_index < submap_data_.num_indices(trajectory_id);
++submap_index) {
all_submap_data[trajectory_id].emplace_back(GetSubmapDataUnderLock(
mapping::SubmapId{trajectory_id, submap_index}));
}
}
return all_submap_data;
}
transform::Rigid3d SparsePoseGraph::ComputeLocalToGlobalTransform(
const std::vector<std::deque<sparse_pose_graph::SubmapData>>&
submap_transforms,
const std::vector<int>& num_trimmed_submaps,
const int trajectory_id) const {
if (trajectory_id >= static_cast<int>(submap_transforms.size()) ||
submap_transforms.at(trajectory_id).empty()) {
return transform::Rigid3d::Identity();
}
const mapping::SubmapId last_optimized_submap_id{
trajectory_id,
static_cast<int>(submap_transforms.at(trajectory_id).size() +
num_trimmed_submaps.at(trajectory_id) - 1)};
// Accessing 'local_pose' in Submap is okay, since the member is const.
return transform::Embed3D(submap_transforms.at(trajectory_id).back().pose) *
submap_data_.at(last_optimized_submap_id)
.submap->local_pose()
.inverse();
}
mapping::SparsePoseGraph::SubmapData SparsePoseGraph::GetSubmapDataUnderLock(
const mapping::SubmapId& submap_id) {
if (submap_data_.at(submap_id).state == SubmapState::kTrimmed) {
return {};
}
auto submap = submap_data_.at(submap_id).submap;
if (submap_id.trajectory_id <
static_cast<int>(optimized_submap_transforms_.size())) {
const size_t submap_data_index =
submap_id.submap_index -
num_trimmed_submaps_at_last_optimization_.at(submap_id.trajectory_id);
if (submap_data_index <
optimized_submap_transforms_.at(submap_id.trajectory_id).size()) {
// We already have an optimized pose.
return {submap, transform::Embed3D(optimized_submap_transforms_
.at(submap_id.trajectory_id)
.at(submap_data_index)
.pose)};
}
}
// We have to extrapolate.
return {submap, ComputeLocalToGlobalTransform(
optimized_submap_transforms_,
num_trimmed_submaps_at_last_optimization_,
submap_id.trajectory_id) *
submap->local_pose()};
}
SparsePoseGraph::TrimmingHandle::TrimmingHandle(SparsePoseGraph* const parent)
: parent_(parent) {}
int SparsePoseGraph::TrimmingHandle::num_submaps(
const int trajectory_id) const {
return parent_->optimization_problem_.submap_data().at(trajectory_id).size() +
parent_->optimization_problem_.num_trimmed_submaps(trajectory_id);
}
void SparsePoseGraph::TrimmingHandle::MarkSubmapAsTrimmed(
const mapping::SubmapId& submap_id) {
// TODO(hrapp): We have to make sure that the trajectory has been finished
// if we want to delete the last submaps.
CHECK(parent_->submap_data_.at(submap_id).state == SubmapState::kFinished);
// Compile all nodes that are still INTRA_SUBMAP constrained once the submap
// with 'submap_id' is gone.
std::set<mapping::NodeId> nodes_to_retain;
for (const Constraint& constraint : parent_->constraints_) {
if (constraint.tag == Constraint::Tag::INTRA_SUBMAP &&
constraint.submap_id != submap_id) {
nodes_to_retain.insert(constraint.node_id);
}
}
// Remove all 'constraints_' related to 'submap_id'.
std::set<mapping::NodeId> nodes_to_remove;
{
std::vector<Constraint> constraints;
for (const Constraint& constraint : parent_->constraints_) {
if (constraint.submap_id == submap_id) {
if (constraint.tag == Constraint::Tag::INTRA_SUBMAP &&
nodes_to_retain.count(constraint.node_id) == 0) {
// This node will no longer be INTRA_SUBMAP contrained and has to be
// removed.
nodes_to_remove.insert(constraint.node_id);
}
} else {
constraints.push_back(constraint);
}
}
parent_->constraints_ = std::move(constraints);
}
// Remove all 'constraints_' related to 'nodes_to_remove'.
{
std::vector<Constraint> constraints;
for (const Constraint& constraint : parent_->constraints_) {
if (nodes_to_remove.count(constraint.node_id) == 0) {
constraints.push_back(constraint);
}
}
parent_->constraints_ = std::move(constraints);
}
// Mark the submap with 'submap_id' as trimmed and remove its data.
auto& submap_data = parent_->submap_data_.at(submap_id);
CHECK(submap_data.state == SubmapState::kFinished);
submap_data.state = SubmapState::kTrimmed;
CHECK(submap_data.submap != nullptr);
submap_data.submap.reset();
parent_->constraint_builder_.DeleteScanMatcher(submap_id);
parent_->optimization_problem_.TrimSubmap(submap_id);
// Mark the 'nodes_to_remove' as trimmed and remove their data.
for (const mapping::NodeId& node_id : nodes_to_remove) {
CHECK(!parent_->trajectory_nodes_.at(node_id).trimmed());
parent_->trajectory_nodes_.at(node_id).constant_data.reset();
parent_->optimization_problem_.TrimTrajectoryNode(node_id);
}
}
} // namespace mapping_2d
} // namespace cartographer