AprilTag Autonomous Docking with TurtleBot3

This project demonstrates AprilTag-based autonomous docking using a TurtleBot3 Waffle Pi in ROS 2 Humble with Gazebo simulation.

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📌 Features

• AprilTag detection using apriltag_ros
• Full integration in ROS 2 and Gazebo simulation
• Launch file to start detection node
• Camera topic remapping and tag visualization
• Tested with TurtleBot3 Waffle Pi in Gazebo

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🧠 Project Structure

ros2_docking_ws/src/apriltag_docking/
├── apriltag_docking/
│   └── __init__.py
├── launch/
│   └── detect_apriltag.launch.py
├── package.xml
├── setup.py
├── setup.cfg
├── pyproject.toml
├── resource/
│   └── apriltag_docking

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🚀 Getting Started

1. Clone and Build the Workspace

mkdir -p ~/ros2_docking_ws/src
cd ~/ros2_docking_ws/src
git clone <your-github-repo-url> apriltag_docking
cd ~/ros2_docking_ws
colcon build
source install/setup.bash

2. Launch the AprilTag Detection

ros2 launch apriltag_docking detect_apriltag.launch.py

3. Verify the Tag Detection

In a new terminal:

source ~/ros2_docking_ws/install/setup.bash
ros2 topic echo /tag_detections

4. Visualize in RViz

rviz2

Add the following displays:

• TF
• Image (from /camera/image_raw)
• AprilTag detections (custom marker or topic monitor)

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📷 Demo Video

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⚙️ Dependencies

• ROS 2 Humble
• turtlebot3 packages
• apriltag_ros (built from source)
• Gazebo with TurtleBot3 simulation

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🛠 How it Works

• The TurtleBot3 camera publishes /camera/image_raw and /camera/camera_info.
• The apriltag_ros node subscribes to these and detects the AprilTag.
• Detected tags are published to /tag_detections with their 3D poses.
• These poses can be used for navigation or control logic (coming next).

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📁 Launch File

# detect_apriltag.launch.py
Node(
    package='apriltag_ros',
    executable='apriltag_node',
    name='apriltag_node',
    parameters=[{
        'family': 'tag36h11',
        'size': 0.08,
        'image_transport': 'raw',
        ...
    }],
    remappings=[
        ('/image_rect', '/camera/image_raw'),
        ('/camera_info', '/camera/camera_info')
    ]
)

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📄 License

This project is licensed under the MIT License.

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🌟 Acknowledgements

• ROS 2
• AprilTag ROS
• TurtleBot3 by ROBOTIS