Skip to content

Robot Operating System

Robot Operating System (ROS) is a set of software libraries and tools for building robot applications.1 It provides functionality for hardware abstraction, device drivers, communication between processes over multiple machines, tools for testing and visualization, and much more.2

We use ROS because it is open-source, language-agnostic, and built with cross-collaboration in mind. It enables our sub-teams to work independently on well-defined components of our software system without having to worry about the hardware it runs on or the implementation of other components.

The official ROS 2 documentation contains everything you need to get started using ROS. From it we have hand-picked the resources that are most relevant to our current and expected future usage of ROS assuming that you use our preconfigured workspace. To run our software on your device without our workspace, you would have to install ROS and the dependencies that are in our Docker images yourself.

Tutorial

Workspace Configuration

To get our workspace configuration running on your computer:

  1. Set it up by following the setup instructions
  2. Uncomment the ROS 2 tutorials section in .devcontainer/Dockerfile, then run the "Dev Containers: Rebuild Container" VS Code command, to install the tutorials' dependencies
  3. Clone the repositories used in the tutuorials: ros_tutorials (humble branch), py_pubsub_ex, and cpp_pubsub_ex, then run the setup VS Code task to install their dependencies

Our workspace configuration contains easier methods of accomplishing some of the tutorial steps, or eliminates the need for them altogether.

Tutorial step Sailbot Workspace configuration
Install a package All packages used in the tutorials are already installed (step 2 above)
Clone a sample repo (ros_tutorials) ros_tutorials is already cloned (step 3 above)
Resolve dependencies Run the "install dependencies" VS Code task
Build the workspace Run the "Build" VS Code task, AKA Ctrl+Shift+B
Source the overlay Run the srcnew terminal command
Create a package with a node Run the "new ament_(python|cmake) package with a node" VS Code task

Tutorials

We encourage all software members to work through the ROS tutorials that are listed below in order. For tutorials that have both C++ and Python versions, NET members should do the C++ version while CTRL and PATH members should do the Python version.

  • Beginner: CLI tools
    • Introducing turtlesim and rqt
    • Understanding nodes
    • Understanding topics
    • Understanding services
    • Understanding parameters
    • Understanding actions
    • Using rqt_console to view logs
    • Recording and playing back data
  • Beginner: Client libraries
    • Creating a workspace
    • Creating a package
    • Writing a simple publisher and subscriber (C++ or Python)
    • Writing a simple service and client (C++ or Python)
    • Using parameters in a class (C++ or Python)
    • Using ros2doctor to identify issues
  • Intermediate
    • Launch
    • Testing
  • Demos
    • Logging

Concepts

We encourage all software members to read the following documentation on key ROS concepts:

  • About logging and logger configuration
  • About ROS 2 interfaces
  • About parameters in ROS 2

ROS 1 Bridge

There are two major versions of ROS, aptly named ROS 1 and ROS 2. Our previous project, Raye, uses ROS 1 because it was the only version available during her design process. Our new project will use ROS 2, a complete re-design of the framework that tackles the shortcomings of ROS 1 to bring it up to industry needs and standards.3 If you are curious about the changes made in ROS 2 compared to 1, this article is a worthwhile read.

ROS 2 includes the ROS 1 Bridge, a collection of packages that can be installed alongside ROS 1 to help migrate code from ROS 1 to ROS 2. As we will be reusing parts of Raye's codebase, it is essential to know how to use these packages. Until we are completely done with Raye, our preconfigured workspace will have ROS 1, ROS 1 Bridge, and ROS 2 installed.

We encourage all software members work through the ROS 1 Bridge README. For PATH members, the Migrating launch files from ROS 1 to ROS 2 page will be a helpful reference when we do so.

  1. https://docs.ros.org/en/humble/index.html ↩

  2. https://www.toptal.com/robotics/introduction-to-robot-operating-system ↩

  3. https://ubuntu.com/robotics/what-is-ros ↩