mola_lidar_odometry

LIDAR odometry component based on the MOLA and MRPT frameworks, compatible with ROS 2.

Contents

This repository provides a C++ library mola_lidar_odometry implementing LIDAR odometry. Sensor input is provided via MOLA components, and ROS 2 example launch files are provided in ros2-launchs.

A CLI interface mola-lidar-odometry-cli is also provided for running on offline datasets.

Build and install

Refer to: https://docs.mola-slam.org/latest/#installing

Lidar Inertial Odometry (LIO) demo with Oxford Spires:

Lidar Odometry (LO) demo with KITTI:

Documentation and tutorials

See: https://docs.mola-slam.org/

ROS build farm status

Distro	Develop branch	Releases	Stable release
ROS2 Humble (u22.04)		amd64 arm64
ROS 2 Jazzy @ u24.04		amd64 arm64
ROS 2 Kilted @ u24.04		amd64 arm64
ROS 2 Rolling (u24.04)		amd64 arm64

EOL Distro	Last release
ROS2 Iron (u22.04)

Citation

The latest publication on MOLA is (ArXiV).

@article{blanco2025mola_lo,
    author = {Blanco-Claraco, Jose Luis},
    title ={{A flexible framework for accurate LiDAR odometry, map manipulation, and localization}},
    journal = {The International Journal of Robotics Research},
    volume = {44},
    number = {9},
    pages = {1553--1599},
    year = {2025},
    doi = {10.1177/02783649251316881},
    URL = { https://doi.org/10.1177/02783649251316881},
    eprint = {2407.20465},
}

License

Copyright (C) 2018-2025 Jose Luis Blanco jlblanco@ual.es, University of Almeria

This package is released under the GNU GPL v3 license as open source, with the main intention of being useful for research and evaluation purposes. Commercial licenses available upon request.

Changelog for package mola_lidar_odometry

0.9.0 (2025-08-26)

• FIX: bug in formula for pitch-roll initialization from IMU
• Store local IMU velocity buffer in key-frame simplemaps
• mola-lidar-odometry-cli: New CLI arguments to support datasets with IMUs
• Implement precise IMU-based deskew (requires latest mp2p_icp library)
• fix clang-format
• Modernize copyright notices
• rosbag2 mola-cli launch file: add [MOLA_ROS2BAG_EXPORT_TO_RAWLOG_FILE]{.title-ref} optional env var
• Contributors: Jose Luis Blanco-Claraco

0.8.0 (2025-06-06)

• Publish mp2p_icp metric map metadata, if existing in loaded maps.
• state estimation config yaml file: expose IMU sensor name env var
• Update mola_lo_pipelines.rst: explicitly show an example of using the NDT pipeline
• ros2 launch: add new argument to control the scan validity filter based on minimum point count (now, enabled by default)
• Update broken link to ROS Index
• mola-lidar-odometry-cli: now also forward raw sensor data to state estimator
• Fix build against mola <1.8.0
• Docs: better explain existing variables to override sensor poses
• gui option: implement show as orthographic camera
• Contributors: Jose Luis Blanco-Claraco

0.7.3 (2025-05-25)

• feature: new threshold to discard state estimation as invalid if uncertainty is too high
• Fixed unit tests in CI
• Prepare GUI for ortho camera option
• progress implementing init pitch/roll from IMU
• pipelines YAML files reformated with RedHat YAML formatter
• Update env var name to explicitly mention LO: MOLA_LO_INITIAL_LOCALIZATION_METHOD
• docs: on initial localization methods
• ROS2 launch: Add new [mola_state_estimator_reference_frame]{.title-ref} argument. It should be used together with [mola_lo_reference_frame]{.title-ref} to use an alternative reference map TF frame than the default [map]{.title-ref}.
• Fix wrong namespace in class name (it worked anyway because of a fall-back mechanism using unqualified names)
• Expose env vars to change the reference frame_id for smoother (MOLA_TF_MAP)
• fix: potential missing publication of updated poses if there is no map subscriber
• lidar 3d pipeline: add rendering options for local map
• Contributors: Jose Luis Blanco-Claraco

0.7.2 (2025-04-23)

• better integration of clang-tidy, colcon_defaults, and clangd with vscode
• Expose two more env vars: MOLA_MAP_CLOUD_DECIMATION, MOLA_ICP_CLOUD_DECIMATION
• FIX: also initial pose for localmap
• BUGFIX: Initial twist was wrong for custom initial poses
• Contributors: Jose Luis Blanco-Claraco

0.7.1 (2025-03-15)

• FIX: Handle correctly the case of input scans with non-normal numbers
• docs: format of ros2 launch argument
• FIX: reset map to start again might lead to divergence; Add new 'reset_state' command via MOLA dynamic variables
• Force requiring valid poses for IMU and GNSS inputs
• Refactor implementation source into several smaller files
• FIX: mola-lo didn't exit due to waiting ICP queue if fed faster than ICP processing
• FIX: mola-lo-gui apps may show duplicated UI controls in particular circumstances
• Drop frames warning message now tells the exact drop ratio
• Initial localization method is now loadable from yaml or ros2 launch file
• MOLA-LO no longer subscribes to wheels odometry. That is now delegated directly to state estimation modules.
• Add new ROS2 launch argument: [forward_ros_tf_odom_to_mola]{.title-ref}
• Contributors: Jose Luis Blanco-Claraco

0.7.0 (2025-02-22)

• Implement new mola_kernel diagnostics API
• Ensure map is published after ROS2 bridge is already listening (FIXES: potential loss of map publication if MM map is given via env var)
• FIX: Proper configurable dropped frames mechanism and stats
• FIX: Update GUI, publish maps, correctly independently of whether MolaGUI is enabled
• launch: fix localization source name
• FIX: Do not ever reset the map when in localization mode

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