DLIOM with Ouster LiDAR Setup

This repository contains the setup for Direct LiDAR-Inertial Odometry and Mapping (DLIOM) using an Ouster LiDAR sensor with ROS2.

Prerequisites

• Docker installed on your system
• Ouster LiDAR connected via Ethernet
• X11 forwarding support for GUI applications
• The dliom-feature-ros2 package downloaded to the same folder as the Docker images

Hardware Setup

1. Connect the Ouster LiDAR via Ethernet cable
2. Configure Network Settings:
   • Ensure the Ethernet connection is enabled in your network settings
   • Set the connection to use a local link
3. Wait for Hostname Assignment: Allow 60 seconds for the host name to be automatically assigned

Quick Start (Automated)

Use the provided automation script for a one-command setup:

./run_dliom.sh

This script will automatically:

• Detect your Ouster LiDAR IP address
• Build the necessary Docker images
• Start all required containers and ROS2 nodes
• Launch DLIOM with RViz visualization

Manual Setup

If you prefer to run the setup manually or need to troubleshoot:

Step 1: Build and Test Ouster Connection

# Build the DLIOM Docker image
docker build -f Dockerfile.ouster -t ouster:latest .

# Test connection to Ouster (replace with your device's hostname)
ping -4 -c3 os-1222225000331.local

# Note the IP address from the ping response
# Enable X11 forwarding
xhost +local:docker

Step 2: Start Ouster Driver Container

docker run -it --rm \
  --network=host \
  --privileged \
  -v /dev:/dev \
  -v /sys:/sys \
  -v /tmp/.X11-unix:/tmp/.X11-unix \
  -e DISPLAY=$DISPLAY \
  ouster:latest

Step 3: Set Up Topic Relays

In separate terminals, run these commands to create best-effort topic relays:

Terminal 2 - IMU Relay:

ros2 run topic_tools relay /ouster/imu /ouster/imu_best_effort \
  --qos-reliability best_effort --qos-durability volatile

Terminal 3 - Point Cloud Relay:

ros2 run topic_tools relay /ouster/points /ouster/points_best_effort \
  --qos-reliability best_effort --qos-durability volatile

Step 4: Launch DLIOM

Terminal 4:

# Build DLIOM image (if not already built)
docker build -f Dockerfile.dliom -t dliom:latest .

# Enable X11 forwarding
xhost +local:docker

# Run DLIOM container
docker run -it --rm \
  --network=host \
  --privileged \
  -v /dev:/dev \
  -v /sys:/sys \
  -v /tmp/.X11-unix:/tmp/.X11-unix \
  -e DISPLAY=$DISPLAY \
  dliom:latest

# Inside the container, launch DLIOM
ros2 launch direct_lidar_inertial_odometry_and_mapping dliom.launch.py \
  rviz:=true \
  pointcloud_topic:=/ouster/points \
  imu_topic:=/ouster/imu

File Structure

project/
├── dliom-feature-ros2/          # Required ROS2 package
├── Dockerfile.dliom             # DLIOM Docker configuration
├── docker-compose.yml           # Docker Compose configuration
├── run_dliom.sh                # Automated setup script
└── README.md                   # This file

Troubleshooting

Common Issues

1. LiDAR Not Detected:

   • Verify Ethernet connection is active
   • Check if hostname follows format: os-[serial_number].local
   • Wait full 60 seconds for hostname assignment

2. Docker Permission Issues:

   • Ensure user is in docker group: sudo usermod -aG docker $USER
   • Restart terminal session after adding to docker group

3. X11 Display Issues:

   • Run xhost +local:docker before starting containers
   • Verify $DISPLAY environment variable is set

4. Topic Connection Issues:

   • Check if topics are being published: ros2 topic list
   • Verify QoS settings match between publisher and subscriber

Debugging Commands

# List available topics
ros2 topic list

# Check topic information
ros2 topic info /ouster/points
ros2 topic info /ouster/imu

# Monitor topic data
ros2 topic echo /ouster/points --once
ros2 topic echo /ouster/imu --once

# Check Docker containers
docker ps -a

# View container logs
docker logs <container_id>

Configuration

Ouster LiDAR Settings

The Ouster hostname format is: os-[serial_number].local

• Serial number can be found on the device sticker
• Example: os-1222225000331.local

DLIOM Parameters

Key parameters can be modified in the launch command:

• rviz:=true/false - Enable/disable RViz visualization
• pointcloud_topic:=/ouster/points - Point cloud topic name
• imu_topic:=/ouster/imu - IMU topic name

Support

For issues specific to:

• DLIOM: Check the original DLIOM documentation
• Ouster LiDAR: Refer to Ouster SDK documentation
• ROS2: Consult ROS2 documentation and forums

License

Please refer to the individual component licenses for DLIOM and Ouster SDK.