ROS wrapper for ORB-SLAM3

A ROS wrapper for ORB-SLAM3. The main idea is to use the ORB-SLAM3 as a standalone library and interface with it instead of putting everything together. For that, you can check out this package.

Tested with ORB-SLAM3 V1.0, primarily on Ubuntu 20.04.

• Pros:
  • Easy to update ORB-SLAM3 indepedently.
  • Easy to replace different variants that are not built for ROS.
• Cons:
  • Dependent on the exposed APIs from ORB-SLAM3.
  • Development involves more steps (1. Make changes in ORB-SLAM3 library -> 2. Build ORB-SLAM3 -> 3. Change the roswrapper if necessary -> 4. Test).
  • Might break when dependencies or upstream changes.

Installation

General guide: first, install ORB-SLAM3 normally with all of its dependencies (any location is fine). Then, install this package in a catkin build environment.

ORB-SLAM3

• Install the prerequisites.
• Clone ORB-SLAM3:

cd ~
git clone https://github.com/UZ-SLAMLab/ORB_SLAM3.git ORB_SLAM3

• Make changes to the source code if necessary to build successfully. For Ubuntu 20.04, you will need to change CMakeList from C++11 to C++14. I have incorporated the changes in this fork.
• Build:

cd ORB_SLAM3
chmod +x build.sh
./build.sh

• Make sure that libORB_SLAM3.so is created in the ORB_SLAM3/lib folder. If not, check the issue list from the original repo and retry.

orb_slam3_ros_wrapper

• Clone the package. Note that it should be a catkin build workspace.

cd ~/catkin_ws/src/
git clone https://github.com/thien94/orb_slam3_ros_wrapper.git

• Open CMakeLists.txt and change the directory that leads to ORB-SLAM3 library at the beginning of the file (default is home folder ~/)

cd ~/catkin_ws/src/orb_slam3_ros_wrapper/
nano CMakeLists.txt

# Change this to your installation of ORB-SLAM3. Default is ~/
set(ORB_SLAM3_DIR
   $ENV{HOME}/ORB_SLAM3
)

• Build the package normally.

cd ~/catkin_ws/
catkin build

• Next, copy the ORBvoc.txt file from ORB-SLAM3/Vocabulary/ folder to the config folder in this package. Alternatively, you can change the voc_file param in the launch file to point to the right location.

• (Optional) Install hector-trajectory-server to visualize the trajectory.

sudo apt install ros-[DISTRO]-hector-trajectory-server

• If everything works fine, you can now try the different launch files in the launch folder.

Installation - DOCKER

In build_docker.sh check DOCKERFILE that you want to build. Build the orb_slam3_ros_wrapper Docker image:

./build_docker.sh

Run the built image as follows:

./run_docker.sh

If the Docker container is already running (the usual case) simply do:

docker start orb_slam3_cpu
docker attach orb_slam3_cpu

Example

ORB SLAM3 ROS WRAPPER with CPU only setup

./build_docker.sh --dockerfile Dockerfile.cpu --image-name orb_slam3_cpu
./run_docker.sh orb_slam3_cpu_container orb_slam3_cpu:bionic

How to run

EuRoC dataset:

• In one terminal, launch the node:

roslaunch orb_slam3_ros_wrapper euroc_monoimu.launch

• In another terminal, playback the bag:

rosbag play MH_01_easy.bag

Similarly for other sensor types.

Topics

The following topics are published by each node:

• /orb_slam3/map_points (PointCloud2): all keypoints being tracked.
• /orb_slam3/camera_pose (PoseStamped): current left camera pose in world frame, as returned by ORB-SLAM3.
• tf: transformation from camera frame to world frame.