rko_slam

ROS2 LiDAR-inertial SLAM and multi-session alignment

A drive that returns to where it started, with rko_lio, and with rko_slam running on top of it

Quick start

rko_slam runs on rko_lio, my LiDAR-inertial odometry, or on your own odometry. Build it with rko_lio:

cd <ws>/src
git clone https://github.com/PRBonn/rko_lio
git clone https://github.com/PRBonn/rko_slam
cd <ws> && rosdep install --from-paths src --ignore-src -y
colcon build --packages-select rko_lio rko_slam

What it needs

• A LiDAR (sensor_msgs/PointCloud2 with per-point timestamps) and an IMU (sensor_msgs/Imu).
• The LiDAR and IMU frames linked to your base frame on TF, e.g. by your URDF.

Run

odometry_and_slam.launch.py starts rko_lio and rko_slam together and finds the LiDAR and IMU topics and your base frame by itself. Start your robot, then:

ros2 launch rko_slam odometry_and_slam.launch.py rviz:=true

From a bag, in two terminals, bag first:

ros2 bag play <bag> --clock
ros2 launch rko_slam odometry_and_slam.launch.py use_sim_time:=true rviz:=true

If your setup differs:

An rko_lio config file, passed with rko_lio_config_file:=<file>, replaces the autodetection (all keys):

lidar_topic: /livox/lidar
imu_topic: /livox/imu
# LiDAR and IMU in one frame, no TF
base_frame: livox_frame
extrinsic_lidar2base_quat_xyzw_xyz: [0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0]
extrinsic_imu2base_quat_xyzw_xyz: [0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0]

With your own odometry

slam.launch.py starts rko_slam alone, on any locally consistent odometry that publishes odom <- base_link on TF:

```bash

File truncated at 100 lines see the full file

Changelog for package rko_slam

0.0.7 (2026-10-15)

• support compressed cloud input (#8)
• build cleanup: rosdep everything, profiling behind a flag (#7)
• reimplement closure detection, drop map closures from the package (#6)
• solve the pose graph ourselves, drop g2o from the package (#5)
• use the imu to level the map, gravity edges in the pose graph, correct height (z) drift (#4)
• launch cleanup, no more autodetect in slam, docs cleaned up (#3)
• always work in the base frame, drop the lidar extrinsic parameter (#2)
• require rko_lio 0.4.2
• odom launch file, further autodetect and launch cleanup, ux cleanup of the launch files and base node
• change default submap split distance to 50m
• docs: overhaul (#1) and again, published and subscribed topics cleanup, readme and index edits
• Contributors: Meher Malladi

0.0.1 (2026-09-11)

• map closures can return a degenerate pose, need the quaternion form to normalize
• cleanup workflows a bit
• clarify rko_lio's dependency situation in the readme
• cleanup readme slightly
• initial commit, port over the entire codebase
• Contributors: Meher Malladi