SubT Part 1: Introduction
Robotic competitions have a long history of spurring innovation and attracting people with varied backgrounds and interests. DARPA first jumped into the robotic competition arena with the Grand Challenge in 2004 to inspire new development in the challenging domain of autonomous driving. Since 2004, DARPA has held numerous challenges including subsequent Grand Challenges and the DARPA Robotics Challenge (DRC), a humanoid robotic challenge. Late this past year DARPA’s most recent challenge, the Subterranean Challenge (SubT), wrapped up. As in the DRC, Open Robotics was the simulation provider for the virtual track of SubT.
This is the first in a series of five blog posts about SubT from the perspective of Open Robotics. We’ll cover basics about the challenge, offer insights about how we established the competition infrastructure, describe new features developed for SubT, and add commentary to the final results.
The challenge
DARPA offered two tracks for competitors, a systems track and a virtual track. The systems track required competitors to utilize physical hardware to compete in real environments. Robots in the systems track could be teleoperated, but most were semi-autonomous due to poor communication in underground environments. Competitors in the virtual track utilized Ignition and were required to develop fully autonomous solutions. Open Robotics did not play a role in the systems track, and we will therefore focus on the virtual track.
The SubT Challenge sought novel approaches to explore, map, and search underground environments using a team of autonomous ground and aerial robots. The challenge came with an extensive rule book. In short, the goal was to find objects of interest, termed artifacts, in an unknown underground environment. Successfully identifying an object and its location would earn you a point. The team with the most points wins.
Each competitor can configure their robot fleet from a library of available robots, and provide control code via docker images. Three circuit events, each held in a different domain, led up to the final event held in late 2021. The domains, in chronological order, were Tunnel, Urban, and Cave.
Here is Dr. Timothy Chung, the SubT Program Manager, describing the challenge:
You can find a lot more information about the challenge including results, media, team information and rules at https://subtchallenge.com.
Ignition highlights
SubT started in 2018 and ran through 2021. During this development period we added many great features to Ignition including a thermal camera sensor, large environment support, particle effects, GUI model editor, cloud simulation, SQLite3 logging, physically based rendering (PBR), web visualization, and hundreds or new models. We will go into more detail on these features in subsequent articles.
Getting Started
It’s very easy to jump into developing a SubT solution. Docker images, tutorials, and even a web application designed to run solutions on cloud infrastructure are available. The following is a list of resources that will get you started. In particular, the SubT Hello World will walk you through the process of creating a new SubT Solution from scratch.
SubT Simulator: This github repository contains the plugins, worlds, and robots that were used to run the SubT Virtual Challenge.
SubT Hello World: A github repository with an example SubT Solution, along with a set of tutorials. Go here to get your feet wet as quickly as possible.
SubT Rules: Documents that contain all of the rules and guidelines for the SubT Challenge.
Ignition App: A web application that supports running a SubT solution using cloud resources.