RTAB-Map's ROS2 package (branch ros2). ROS2 Foxy minimum required: currently most nodes are ported to ROS2, however they are not all tested yet. The interface is the same than on ROS1 (parameters and topic names should still match ROS1 documentation on rtabmap_ros).

ROS 1
ROS 2

ROS 1	Noetic
ROS 2	Humble
	Iron
	Rolling
Docker	rtabmap_ros

rtabmap.launch is also ported to ROS2 with same arguments. If you see ROS1 examples like this:

roslaunch zed_wrapper zed_no_tf.launch

roslaunch rtabmap_ros rtabmap.launch \
    rtabmap_args:="--delete_db_on_start" \
    rgb_topic:=/zed/zed_node/rgb/image_rect_color \
    depth_topic:=/zed/zed_node/depth/depth_registered \
    camera_info_topic:=/zed/zed_node/rgb/camera_info \
    frame_id:=base_link \
    approx_sync:=false \
    wait_imu_to_init:=true \
    imu_topic:=/zed_node/imu/data

The ROS2 equivalent is (with those lines set to false to avoid TF conflicts):

ros2 launch zed_wrapper zed.launch.py

ros2 launch rtabmap_launch rtabmap.launch.py \
    rtabmap_args:="--delete_db_on_start" \
    rgb_topic:=/zed/zed_node/rgb/image_rect_color \
    depth_topic:=/zed/zed_node/depth/depth_registered \
    camera_info_topic:=/zed/zed_node/rgb/camera_info \
    frame_id:=base_link \
    approx_sync:=false \
    wait_imu_to_init:=true \
    imu_topic:=/zed/zed_node/imu/data \
    qos:=1 \
    rviz:=true

qos (Quality of Service) argument should match the published topics QoS (1=RELIABLE, 2=BEST EFFORT). ROS1 was always RELIABLE.

sudo apt install ros-$ROS_DISTRO-rtabmap-ros

• Make sure to uninstall any rtabmap binaries:

  sudo apt remove ros-$ROS_DISTRO-rtabmap*
  

• RTAB-Map ROS2 package:

  cd ~/ros2_ws
  git clone https://github.com/introlab/rtabmap.git src/rtabmap
  git clone --branch ros2 https://github.com/introlab/rtabmap_ros.git src/rtabmap_ros
  rosdep update && rosdep install --from-paths src --ignore-src -r -y
  export MAKEFLAGS="-j6" # Can be ignored if you have a lot of RAM (>16GB)
  colcon build --symlink-install --cmake-args -DCMAKE_BUILD_TYPE=Release

• To build with rgbd_cameras>1 support and/or subscribe_user_data support:

  colcon build --symlink-install --cmake-args -DRTABMAP_SYNC_MULTI_RGBD=ON -DRTABMAP_SYNC_USER_DATA=ON -DCMAKE_BUILD_TYPE=Release

1. Launch Turtlebot3 simulator:

   export TURTLEBOT3_MODEL=waffle
   ros2 launch turtlebot3_gazebo turtlebot3_world.launch.py
   
   export TURTLEBOT3_MODEL=waffle
   ros2 run turtlebot3_teleop teleop_keyboard

2. Launch RTAB-Map:

   ros2 launch rtabmap_demos turtlebot3_scan.launch.py
   
   # OR with rtabmap.launch.py
   ros2 launch rtabmap_launch rtabmap.launch.py \
      visual_odometry:=false \
      frame_id:=base_footprint \
      subscribe_scan:=true depth:=false \
      approx_sync:=true \
      odom_topic:=/odom \
      scan_topic:=/scan \
      qos:=2 \
      args:="-d --RGBD/NeighborLinkRefining true --Reg/Strategy 1" \
      use_sim_time:=true \
      rviz:=true
   

3. Launch navigation (nav2_bringup package should be installed):

   ros2 launch nav2_bringup navigation_launch.py use_sim_time:=True
   ros2 launch nav2_bringup rviz_launch.py
   

See rtabmap_demos/launch and rtabmap_examples/launch subfolders for some other ROS2 examples with turtlebot3 in simulation and a RGB-D camera.