Aruco detector

With this ROS2-Node can be determined the pose of different ArUco Markers. The goal of this project was to attach a marker on different robots, and get the absolute positions and orientations via a camera on the ceiling. However, this localization can also be applied to any other arbitary object. This project was created as an project thesis (MSY-Master).

Requirements

• Transforms3D

  For computing the pose the node requires this library. A detailed description can be found on: https://matthew-brett.github.io/transforms3d/)

  pip install transforms3d
  

• usb_cam

  Usb_cam is a frequently used ros driver for V4L USB cameras. A detailed description can be found here: http://wiki.ros.org/usb_cam

  sudo apt get install ros-<ros2-distro>-usb-cam
  

  Important: It’s necessary to work with compressed images. Therefor you can use the image_transport library. A detailed description can be found here: http://wiki.ros.org/image_transport

Running the code

For an easy start there is already created a launch file. All required parameters can be set and edited centrally here. The launch-file starts:

• aruco_detector_node
• usb_cam

• rqt_image_view

  cd launch/
  ros2 launch aruco_launch.py
  

An overview about the running topics is illustrated in the next picture.

Output

• topic: /aruco/aruco_poses

  The aruco_detector_node publishes a custom ros2 message.

      int64[] marker_ids
      geometry_msgs/Pose[] poses
  

  The array marker_ids contains all detected ids of the ArUco Markers. The array poses contains all poses of the detected ArUco Markers. This message will be published to the topic .

• topic: /aruco/aruco_output_images/compressed

  To this topic will be published the output images. In this images the detected ArCuo Marker is highlighted and the pose is drawn using a coordinate system.