Optimization problem

[kay01-kwon]

Hi, I'm working with the cartographer with tsdf. The environment is quite simple, but whenever the robot goes to its initial position, the value of initial position varies. I think that only local slam is enough for the environment. The environment is like below one.

My question is "are there any way to fix the initial position and to do so how can I tune the lua file?" Sometimes, I saw the position error is below 1 mm, but when it moves further, the initial position is changed and the accuracy becomes bad.

My Lua file is like that, and use 2 velodynes and odometry. Also, I can share you bag file with topics /tf /vlp1/scan_filtered /vlp2/scan_filtered /odom and motion caputre data with mat file.

Just let me know how to tune to fix the initial pose...

-- 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 "map_builder.lua" include "trajectory_builder.lua"

options = { map_builder = MAP_BUILDER, trajectory_builder = TRAJECTORY_BUILDER, map_frame = "map", tracking_frame = "base_footprint", published_frame = "odom", odom_frame = "odom", provide_odom_frame = false, publish_frame_projected_to_2d = false, -- use_pose_extrapolator=true, use_odometry = true, use_nav_sat = false, use_landmarks = false, num_laser_scans = 2, num_multi_echo_laser_scans = 0, num_subdivisions_per_laser_scan = 1, num_point_clouds = 0, lookup_transform_timeout_sec = 0.2, submap_publish_period_sec = 0.3, pose_publish_period_sec = 5e-3, trajectory_publish_period_sec = 30e-3, rangefinder_sampling_ratio = 1., odometry_sampling_ratio = 1., fixed_frame_pose_sampling_ratio = 1., imu_sampling_ratio = 0.1, landmarks_sampling_ratio = 1., }

MAP_BUILDER.use_trajectory_builder_2d = true

TRAJECTORY_BUILDER_2D.use_imu_data = false TRAJECTORY_BUILDER_2D.submaps.grid_options_2d.grid_type="TSDF" TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.range_data_inserter_type="TSDF_INSERTER_2D"

TRAJECTORY_BUILDER_2D.min_range=0.5 TRAJECTORY_BUILDER_2D.max_range=5.0

TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.project_sdf_distance_to_scan_normal=true TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.update_free_space=false TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.update_weight_angle_scan_normal_to_ray_kernel_bandwidth=0.7 TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.update_weight_distance_cell_to_hit_kernel_bandwidth=0.7 TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.update_weight_range_exponent=0

TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.truncation_distance=0.15 TRAJECTORY_BUILDER_2D.submaps.range_data_inserter.tsdf_range_data_inserter.maximum_weight=5.

TRAJECTORY_BUILDER_2D.ceres_scan_matcher.occupied_space_weight = 1 TRAJECTORY_BUILDER_2D.ceres_scan_matcher.translation_weight = 1.3 TRAJECTORY_BUILDER_2D.ceres_scan_matcher.rotation_weight = 1 TRAJECTORY_BUILDER_2D.num_accumulated_range_data = 2

POSE_GRAPH = { --optimize_every_n_nodes = 90, constraint_builder = { sampling_ratio=0.3, max_constraint_distance=5, min_score = 0.55, global_localization_min_score = 0.60, --loop_closure_translation_weight = 1e4, --loop_closure_rotation_weight = 100, --log_matches = true, fast_correlative_scan_matcher = { linear_search_window = 120, angular_search_window = math.rad(0.01), branch_and_bound_depth = 7 }, --ceres_scan_matcher = { -- occupied_space_weight = 50, -- translation_weight = 10., -- rotation_weight = 1., -- ceres_solver_options = { -- use_nonmontonic_steps = true, -- max_num_iterations = 50, -- num_threads = 1, -- } --} } }

--POSE_GRAPH.constraint_builder.ceres_scan_matcher.translation_weight=1e5 --POSE_GRAPH.constraint_builder.ceres_scan_matcher.rotation_weight = 100 --POSE_GRAPH.constraint_builder.ceres_scan_matcher.occupied_space_weight = 50

return options