cartographer/cartographer/mapping/internal/2d/local_trajectory_builder_2d.cc

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14 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/internal/2d/local_trajectory_builder_2d.h"
#include <limits>
#include <memory>
#include "cartographer/common/make_unique.h"
#include "cartographer/metrics/family_factory.h"
#include "cartographer/sensor/range_data.h"
namespace cartographer {
namespace mapping {
static auto* kLocalSlamLatencyMetric = metrics::Gauge::Null();
static auto* kFastCorrelativeScanMatcherScoreMetric =
metrics::Histogram::Null();
static auto* kCeresScanMatcherCostMetric = metrics::Histogram::Null();
static auto* kScanMatcherResidualDistanceMetric = metrics::Histogram::Null();
static auto* kScanMatcherResidualAngleMetric = metrics::Histogram::Null();
LocalTrajectoryBuilder2D::LocalTrajectoryBuilder2D(
const proto::LocalTrajectoryBuilderOptions2D& options,
const std::vector<std::string>& expected_range_sensor_ids)
: options_(options),
active_submaps_(options.submaps_options()),
motion_filter_(options_.motion_filter_options()),
real_time_correlative_scan_matcher_(
options_.real_time_correlative_scan_matcher_options()),
ceres_scan_matcher_(options_.ceres_scan_matcher_options()),
range_data_collator_(expected_range_sensor_ids) {}
LocalTrajectoryBuilder2D::~LocalTrajectoryBuilder2D() {}
sensor::RangeData
LocalTrajectoryBuilder2D::TransformToGravityAlignedFrameAndFilter(
const transform::Rigid3f& transform_to_gravity_aligned_frame,
const sensor::RangeData& range_data) const {
const sensor::RangeData cropped =
sensor::CropRangeData(sensor::TransformRangeData(
range_data, transform_to_gravity_aligned_frame),
options_.min_z(), options_.max_z());
return sensor::RangeData{
cropped.origin,
sensor::VoxelFilter(options_.voxel_filter_size()).Filter(cropped.returns),
sensor::VoxelFilter(options_.voxel_filter_size()).Filter(cropped.misses)};
}
std::unique_ptr<transform::Rigid2d> LocalTrajectoryBuilder2D::ScanMatch(
const common::Time time, const transform::Rigid2d& pose_prediction,
const sensor::RangeData& gravity_aligned_range_data) {
std::shared_ptr<const Submap2D> matching_submap =
active_submaps_.submaps().front();
// The online correlative scan matcher will refine the initial estimate for
// the Ceres scan matcher.
transform::Rigid2d initial_ceres_pose = pose_prediction;
sensor::AdaptiveVoxelFilter adaptive_voxel_filter(
options_.adaptive_voxel_filter_options());
const sensor::PointCloud filtered_gravity_aligned_point_cloud =
adaptive_voxel_filter.Filter(gravity_aligned_range_data.returns);
if (filtered_gravity_aligned_point_cloud.empty()) {
return nullptr;
}
if (options_.use_online_correlative_scan_matching()) {
// todo(kdaun) add CHECK on options to guarantee grid is a probability grid
double score = real_time_correlative_scan_matcher_.Match(
pose_prediction, filtered_gravity_aligned_point_cloud,
*static_cast<const ProbabilityGrid*>(matching_submap->grid()),
&initial_ceres_pose);
kFastCorrelativeScanMatcherScoreMetric->Observe(score);
}
auto pose_observation = common::make_unique<transform::Rigid2d>();
ceres::Solver::Summary summary;
ceres_scan_matcher_.Match(pose_prediction.translation(), initial_ceres_pose,
filtered_gravity_aligned_point_cloud,
*matching_submap->grid(), pose_observation.get(),
&summary);
if (pose_observation) {
kCeresScanMatcherCostMetric->Observe(summary.final_cost);
double residual_distance =
(pose_observation->translation() - pose_prediction.translation())
.norm();
kScanMatcherResidualDistanceMetric->Observe(residual_distance);
double residual_angle = std::abs(pose_observation->rotation().angle() -
pose_prediction.rotation().angle());
kScanMatcherResidualAngleMetric->Observe(residual_angle);
}
return pose_observation;
}
std::unique_ptr<LocalTrajectoryBuilder2D::MatchingResult>
LocalTrajectoryBuilder2D::AddRangeData(
const std::string& sensor_id,
const sensor::TimedPointCloudData& unsynchronized_data) {
auto synchronized_data =
range_data_collator_.AddRangeData(sensor_id, unsynchronized_data);
if (synchronized_data.ranges.empty()) {
LOG(INFO) << "Range data collator filling buffer.";
return nullptr;
}
const common::Time& time = synchronized_data.time;
// Initialize extrapolator now if we do not ever use an IMU.
if (!options_.use_imu_data()) {
InitializeExtrapolator(time);
}
if (extrapolator_ == nullptr) {
// Until we've initialized the extrapolator with our first IMU message, we
// cannot compute the orientation of the rangefinder.
LOG(INFO) << "Extrapolator not yet initialized.";
return nullptr;
}
CHECK(!synchronized_data.ranges.empty());
// TODO(gaschler): Check if this can strictly be 0.
CHECK_LE(synchronized_data.ranges.back().point_time[3], 0.f);
const common::Time time_first_point =
time +
common::FromSeconds(synchronized_data.ranges.front().point_time[3]);
if (time_first_point < extrapolator_->GetLastPoseTime()) {
LOG(INFO) << "Extrapolator is still initializing.";
return nullptr;
}
if (num_accumulated_ == 0) {
accumulation_started_ = std::chrono::steady_clock::now();
}
std::vector<transform::Rigid3f> range_data_poses;
range_data_poses.reserve(synchronized_data.ranges.size());
bool warned = false;
for (const auto& range : synchronized_data.ranges) {
common::Time time_point = time + common::FromSeconds(range.point_time[3]);
if (time_point < extrapolator_->GetLastExtrapolatedTime()) {
if (!warned) {
LOG(ERROR)
<< "Timestamp of individual range data point jumps backwards from "
<< extrapolator_->GetLastExtrapolatedTime() << " to " << time_point;
warned = true;
}
time_point = extrapolator_->GetLastExtrapolatedTime();
}
range_data_poses.push_back(
extrapolator_->ExtrapolatePose(time_point).cast<float>());
}
if (num_accumulated_ == 0) {
// 'accumulated_range_data_.origin' is uninitialized until the last
// accumulation.
accumulated_range_data_ = sensor::RangeData{{}, {}, {}};
}
// Drop any returns below the minimum range and convert returns beyond the
// maximum range into misses.
for (size_t i = 0; i < synchronized_data.ranges.size(); ++i) {
const Eigen::Vector4f& hit = synchronized_data.ranges[i].point_time;
const Eigen::Vector3f origin_in_local =
range_data_poses[i] *
synchronized_data.origins.at(synchronized_data.ranges[i].origin_index);
const Eigen::Vector3f hit_in_local = range_data_poses[i] * hit.head<3>();
const Eigen::Vector3f delta = hit_in_local - origin_in_local;
const float range = delta.norm();
if (range >= options_.min_range()) {
if (range <= options_.max_range()) {
accumulated_range_data_.returns.push_back(hit_in_local);
} else {
accumulated_range_data_.misses.push_back(
origin_in_local +
options_.missing_data_ray_length() / range * delta);
}
}
}
++num_accumulated_;
if (num_accumulated_ >= options_.num_accumulated_range_data()) {
num_accumulated_ = 0;
const transform::Rigid3d gravity_alignment = transform::Rigid3d::Rotation(
extrapolator_->EstimateGravityOrientation(time));
// TODO(gaschler): This assumes that 'range_data_poses.back()' is at time
// 'time'.
accumulated_range_data_.origin = range_data_poses.back().translation();
return AddAccumulatedRangeData(
time,
TransformToGravityAlignedFrameAndFilter(
gravity_alignment.cast<float>() * range_data_poses.back().inverse(),
accumulated_range_data_),
gravity_alignment);
}
return nullptr;
}
std::unique_ptr<LocalTrajectoryBuilder2D::MatchingResult>
LocalTrajectoryBuilder2D::AddAccumulatedRangeData(
const common::Time time,
const sensor::RangeData& gravity_aligned_range_data,
const transform::Rigid3d& gravity_alignment) {
if (gravity_aligned_range_data.returns.empty()) {
LOG(WARNING) << "Dropped empty horizontal range data.";
return nullptr;
}
// Computes a gravity aligned pose prediction.
const transform::Rigid3d non_gravity_aligned_pose_prediction =
extrapolator_->ExtrapolatePose(time);
const transform::Rigid2d pose_prediction = transform::Project2D(
non_gravity_aligned_pose_prediction * gravity_alignment.inverse());
// local map frame <- gravity-aligned frame
std::unique_ptr<transform::Rigid2d> pose_estimate_2d =
ScanMatch(time, pose_prediction, gravity_aligned_range_data);
if (pose_estimate_2d == nullptr) {
LOG(WARNING) << "Scan matching failed.";
return nullptr;
}
const transform::Rigid3d pose_estimate =
transform::Embed3D(*pose_estimate_2d) * gravity_alignment;
extrapolator_->AddPose(time, pose_estimate);
sensor::RangeData range_data_in_local =
TransformRangeData(gravity_aligned_range_data,
transform::Embed3D(pose_estimate_2d->cast<float>()));
std::unique_ptr<InsertionResult> insertion_result =
InsertIntoSubmap(time, range_data_in_local, gravity_aligned_range_data,
pose_estimate, gravity_alignment.rotation());
auto duration = std::chrono::steady_clock::now() - accumulation_started_;
kLocalSlamLatencyMetric->Set(
std::chrono::duration_cast<std::chrono::seconds>(duration).count());
return common::make_unique<MatchingResult>(
MatchingResult{time, pose_estimate, std::move(range_data_in_local),
std::move(insertion_result)});
}
std::unique_ptr<LocalTrajectoryBuilder2D::InsertionResult>
LocalTrajectoryBuilder2D::InsertIntoSubmap(
const common::Time time, const sensor::RangeData& range_data_in_local,
const sensor::RangeData& gravity_aligned_range_data,
const transform::Rigid3d& pose_estimate,
const Eigen::Quaterniond& gravity_alignment) {
if (motion_filter_.IsSimilar(time, pose_estimate)) {
return nullptr;
}
// Querying the active submaps must be done here before calling
// InsertRangeData() since the queried values are valid for next insertion.
std::vector<std::shared_ptr<const Submap2D>> insertion_submaps;
for (const std::shared_ptr<Submap2D>& submap : active_submaps_.submaps()) {
insertion_submaps.push_back(submap);
}
active_submaps_.InsertRangeData(range_data_in_local);
sensor::AdaptiveVoxelFilter adaptive_voxel_filter(
options_.loop_closure_adaptive_voxel_filter_options());
const sensor::PointCloud filtered_gravity_aligned_point_cloud =
adaptive_voxel_filter.Filter(gravity_aligned_range_data.returns);
return common::make_unique<InsertionResult>(InsertionResult{
std::make_shared<const TrajectoryNode::Data>(TrajectoryNode::Data{
time,
gravity_alignment,
filtered_gravity_aligned_point_cloud,
{}, // 'high_resolution_point_cloud' is only used in 3D.
{}, // 'low_resolution_point_cloud' is only used in 3D.
{}, // 'rotational_scan_matcher_histogram' is only used in 3D.
pose_estimate}),
std::move(insertion_submaps)});
}
void LocalTrajectoryBuilder2D::AddImuData(const sensor::ImuData& imu_data) {
CHECK(options_.use_imu_data()) << "An unexpected IMU packet was added.";
InitializeExtrapolator(imu_data.time);
extrapolator_->AddImuData(imu_data);
}
void LocalTrajectoryBuilder2D::AddOdometryData(
const sensor::OdometryData& odometry_data) {
if (extrapolator_ == nullptr) {
// Until we've initialized the extrapolator we cannot add odometry data.
LOG(INFO) << "Extrapolator not yet initialized.";
return;
}
extrapolator_->AddOdometryData(odometry_data);
}
void LocalTrajectoryBuilder2D::InitializeExtrapolator(const common::Time time) {
if (extrapolator_ != nullptr) {
return;
}
// We derive velocities from poses which are at least 1 ms apart for numerical
// stability. Usually poses known to the extrapolator will be further apart
// in time and thus the last two are used.
constexpr double kExtrapolationEstimationTimeSec = 0.001;
// TODO(gaschler): Consider using InitializeWithImu as 3D does.
extrapolator_ = common::make_unique<PoseExtrapolator>(
::cartographer::common::FromSeconds(kExtrapolationEstimationTimeSec),
options_.imu_gravity_time_constant());
extrapolator_->AddPose(time, transform::Rigid3d::Identity());
}
void LocalTrajectoryBuilder2D::RegisterMetrics(
metrics::FamilyFactory* family_factory) {
auto* latency = family_factory->NewGaugeFamily(
"/mapping/internal/2d/local_trajectory_builder/latency",
"Duration from first incoming point cloud in accumulation to local slam "
"result");
kLocalSlamLatencyMetric = latency->Add({});
auto score_boundaries = metrics::Histogram::FixedWidth(0.05, 20);
auto* scores = family_factory->NewHistogramFamily(
"/mapping/internal/2d/local_trajectory_builder/scores",
"Local scan matcher scores", score_boundaries);
kFastCorrelativeScanMatcherScoreMetric =
scores->Add({{"scan_matcher", "fast_correlative"}});
auto cost_boundaries = metrics::Histogram::ScaledPowersOf(2, 0.01, 100);
auto* costs = family_factory->NewHistogramFamily(
"/mapping/internal/2d/local_trajectory_builder/costs",
"Local scan matcher costs", cost_boundaries);
kCeresScanMatcherCostMetric = costs->Add({{"scan_matcher", "ceres"}});
auto distance_boundaries = metrics::Histogram::ScaledPowersOf(2, 0.01, 10);
auto* residuals = family_factory->NewHistogramFamily(
"/mapping/internal/2d/local_trajectory_builder/residuals",
"Local scan matcher residuals", distance_boundaries);
kScanMatcherResidualDistanceMetric =
residuals->Add({{"component", "distance"}});
kScanMatcherResidualAngleMetric = residuals->Add({{"component", "angle"}});
}
} // namespace mapping
} // namespace cartographer