Introduction to ROS 2

The objective of this course is to introduce students to the use of ROS 2 as a powerful robotics tool. Specifically, a familiarization with the middleware concept and the software structure of a robotic system. There will be a special emphasis on sensing and control of robotic systems using ROS 2, both in simulation and in real environments.

The teaching methodology will combine lectures together with supervised exercises based on the current ROS version and tools. All classes will be organized with the theoretical sessions at the beginning and practical exercises and team work at the end. The initial part will consist on the explanation of theoretical concepts by the lecturer, promoting the active participation of students. The practical part will be focused on the student’s solving skills. The main theoretical concepts will be shown in practical simulation examples and finally on a real robot test.

The source code of the examples of these tutorials is organized in packages stored in the GIT repository all_introduction_to_ROS2_packages.

The course is divided in 7 tutorials and some appendices:

• Tutorial 1: ROS basic concepts and development tools
  • Introduction
  • Some applications
  • Core components
  • Command-line tools
  • The ROS 2 ecosystem
  • Creating a ROS 2 workspace and a package
  • EXERCISE 1
• Tutorial 2: Communications using topics
  • The rclcpp::Node class
  • A publisher program
  • A subscriber program
  • Standard and common messages
  • Custom messages
  • EXERCISE 2
  • The rosbag Tool
  • The Quality of service (QoS)
  • Executors
• Tutorial 3: Tools
  • The launch utility
  • Parameters
  • EXERCISE 3a
  • The tf2 library
  • Robot Modeling: The Unified Robot Description Format (URDF)
  • Visualization tool
  • EXERCISE 3b
• Tutorial 4: Communications using services
  • Communication features
  • Service interfaces
  • A server program
  • A client program
  • Callbacks and Callback Groups
  • EXERCISE 4
• Tutorial 5: Simulation
  • Gazebo basics
  • Integration between ROS and Gazebo
  • Using images and the ArUco library for pose estimation
  • EXERCISE 5
• Tutorial 6: Communications using actions
  • Communication features
  • Using actions
  • Action interfaces
  • The Action Client Library: rclcpp_action
  • The pan-tilt example
• Tutorial 7: Robot control
  • ros2_control overview
  • Hardware Abstraction Layer
  • Controllers
  • ros2_control implementation
  • Preparing Gazebo for ros2_control
  • Working with ros2_control using actions
• FINAL WORK
  • Motivation and aim
  • Setup
  • Provided packages
  • Testing
  • Development
  • Evaluation
• APPENDICES
  • Appendix 1: Linux basics
  • Appendix 2: ROS 2 install instructions
  • Appendix 3: Setup
  • Appendix 4: Version control using GIT
  • Appendix 5: Writing, compiling and linking C++ programs
  • Appendix 6: Good practices: naming, documentation, logging

The course information sheet can be downloaded here.