Robotics

DARPA SubT Finals: Meet the Teams

How the eight Systems Track teams are approaching the final event

DARPA SubT competitors and their robots
DARPA

This is it! This week, we're at the DARPA SubTerranean Challenge Finals in Louisville KY, where more than two dozen Systems Track and Virtual Track teams will compete for millions of dollars in prize money and being able to say "we won a DARPA challenge," which is of course priceless.

We've been following SubT for years, from Tunnel Circuit to Urban Circuit to Cave (non-) Circuit. For a recent recap, have a look at this post-cave pre-final article that includes an interview with SubT Program Manager Tim Chung, but if you don't have time for that, the TLDR is that this week we're looking at both a Virtual Track as well as a Systems Track with physical robots on a real course. The Systems Track teams spent Monday checking in at the Louisville Mega Cavern competition site, and we asked each team to tell us about how they've been preparing, what they think will be most challenging, and what makes them unique.

Team CERBERUS

Team CERBERUS

CERBERUS

Country

USA, Switzerland, United Kingdom, Norway

Members

University of Nevada, Reno

ETH Zurich, Switzerland

University of California, Berkeley

Sierra Nevada Corporation

Flyability, Switzerland

Oxford Robotics Institute, United Kingdom

Norwegian University for Science and Technology (NTNU), Norway

Robots

TBA

Follow Team

Website

@CerberusSubt

Q&A: Team Lead Kostas Alexis

How have you been preparing for the SubT Final?

First of all this year's preparation was strongly influenced by Covid-19 as our team spans multiple countries, namely the US, Switzerland, Norway, and the UK. Despite the challenges, we leveled up both our weekly shake-out events and ran a 2-month team-wide integration and testing activity in Switzerland during July and August with multiple tests in diverse underground settings including multiple mines. Note that we bring a brand new set of 4 ANYmal C robots and a new generation of collision-tolerant flying robots so during this period we further built new hardware.

What do you think the biggest challenge of the SubT Final will be?

We are excited to see how the combination of vastly large spaces available in Mega Caverns can be combined with very narrow cross-sections as DARPA promises and vertical structures. We think that terrain with steep slopes and other obstacles, complex 3D geometries, as well as the dynamic obstacles will be the core challenges.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Our team coined early on the idea of legged and flying robot combination. We have remained focused on this core vision of ours and also bring fully own-developed hardware for both legged and flying systems. This is both our advantage and - in a way - our limitation as we spend a lot of time in its development. We are fully excited about the potential we see developing and we are optimistic that this will be demonstrated in the Final Event!

Team Coordinated Robotics

Team Coordinated Robotics

Coordinated Robotics

Country

USA

Members

California State University Channel Islands

Oke Onwuka

Sequoia Middle School

Robots

TBA

Q&A: Team Lead Kevin Knoedler

How have you been preparing for the SubT Final?

Coordinated Robotics has been preparing for the SubT Final with lots of testing on our team of robots. We have been running them inside, outside, day, night and all of the circumstances that we can come up with. In Kentucky we have been busy updating all of the robots to the same standard and repairing bits of shipping damage before the Subt Final.

What do you think the biggest challenge of the SubT Final will be?

The biggest challenge for us will be pulling all of the robots together to work as a team and make sure that everything is communicating together. We did not have lab access until late July and so we had robots at individuals homes, but were generally only testing one robot at a time.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Coordinated Robotics is unique in a couple of different ways. We are one of only two unfunded teams so we take a lower budget approach to solving lots of the issues and that helps us to have some creative solutions. We are also unique in that we will be bringing a lot of robots (23) so that problems with individual robots can be tolerated as the team of robots continues to search.

Team CoSTAR

Team CoSTAR

CoSTAR

Country

USA, South Korea, Sweden

Members

Jet Propulsion Laboratory

California Institute of Technology

Massachusetts Institute of Technology

KAIST, South Korea

Lulea University of Technology, Sweden

Robots

TBA

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Website

Q&A: Caltech Team Lead Joel Burdick

How have you been preparing for the SubT Final?

Since May, the team has made 4 trips to a limestone cave near Lexington Kentucky (and they are just finishing a week-long "game" there yesterday). Since February, parts or all of the team have been testing 2-3 days a week in a section of the abandoned Subway system in downtown Los Angeles.

What do you think the biggest challenge of the SubT Final will be?

That will be a tough one to answer in advance. The expected CoSTAR-specific challenges are of course the complexity of the test-site that DARPA has prepared, fatigue of the team, and the usual last-minute hardware failures: we had to have an entire new set of batteries for all of our communication nodes FedExed to us yesterday. More generally, we expect the other teams to be well prepared. Speaking only for myself, I think there will be 4-5 teams that could easily win this competition.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Previously, our team was unique with our Boston Dynamic legged mobility. We've heard that other teams maybe using Spot quadrupeds as well. So, that may no longer be a uniqueness. We shall see! More importantly, we believe our team is unique in the breadth of the participants (university team members from U.S., Europe, and Asia). Kind of like the old British empire: the sun never sets on the geographic expanse of Team CoSTAR.

Team CSIRO Data61

Team CSIRO Data61

CSIRO Data61

Country

Australia, USA

Members

Commonwealth Scientific and Industrial Research Organisation, Australia

Emesent, Australia

Georgia Institute of Technology

Robots

TBA

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Website

Twitter

Q&A: SubT Principal Investigator Navinda Kottege

How have you been preparing for the SubT Final?

Test, test, test. We've been testing as often as we can, simulating the competition conditions as best we can. We're very fortunate to have an extensive site here at our CSIRO lab in Brisbane that has enabled us to construct quite varied tests for our full fleet of robots. We have also done a number of offsite tests as well.

After going through the initial phases, we have converged on a good combination of platforms for our fleet. Our work horse platform from the Tunnel circuit has been the BIA5 ATR tracked robot. We have recently added Boston Dynamics Spot quadrupeds to our fleet and we are quite happy with their performance and the level of integration with our perception and navigation stack. We also have custom designed Subterra Navi drones from Emesent. Our fleet consists of two of each of these three platform types. We have also designed and built a new 'Smart node' for communication with the Rajant nodes. These are dropped from the tracked robots and automatically deploy after a delay by extending out ground plates and antennae. As described above, we have been doing extensive integration testing with the full system to shake out bugs and make improvements.

What do you think the biggest challenge of the SubT Final will be?

The biggest challenge is the unknown. It is always a learning process to discover how the robots respond to new classes of obstacle; responding to this on the fly in a new environment is extremely challenging. Given the format of two preliminary runs and one prize run, there is little to no margin for error compared to previous circuit events where there were multiple runs that contributed to the final score. Any significant damage to robots during the preliminary runs would be difficult to recover from to perform in the final run.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Our fleet uses a common sensing, mapping and navigation system across all robots, built around our Wildcat SLAM technology. This is what enables coordination between robots, and provides the accuracy required to locate detected objects. This had allowed us to easily integrate different robot platforms into our fleet. We believe this 'homogenous sensing on heterogenous platforms' paradigm gives us a unique advantage in reducing overall complexity of the development effort for the fleet and also allowing us to scale our fleet as needed. Having excellent partners in Emesent and Georgia Tech and having their full commitment and support is also a strong advantage for us.

Team CTU-CRAS-NORLAB

Team CTU-CRAS-NORLAB

CTU-CRAS-NORLAB

Country

Czech Republic, Canada

Members

Czech Technological University, Czech Republic

Université Laval, Canada

Robots

TBA

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Website

Twitter

Q&A: Team Lead Tomas Svoboda

How have you been preparing for the SubT Final?

We spent most of the time preparing new platforms as we made a significant technology update. We tested the locomotion and autonomy of the new platforms in Bull Rock Cave, one of the largest caves in Czechia. We also deployed the robots in an old underground fortress to examine the system in an urban-like underground environment. The very last weeks were, however, dedicated to integration tests and system tuning.

What do you think the biggest challenge of the SubT Final will be?

Hard to say, but regarding the expected environment, the vertical shafts might be the most challenging since they are not easy to access to test and tune the system experimentally. They would also add challenges to communication.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Not sure about the other teams, but we plan to deploy all kinds of ground vehicles, tracked, wheeled, and legged platforms accompanied by several drones. We hope the diversity of the platform types would be beneficial for adapting to the possible diversity of terrains and underground challenges. Besides, we also hope the tuned communication would provide access to robots in a wider range than the last time. Optimistically, we might keep all robots connected to the communication infrastructure built during the mission, albeit the bandwidth is very limited, but should be sufficient for artifacts reporting and high-level switching of the robots' goals and autonomous behavior.

Team Explorer

Team Explorer

Explorer

Country

USA

Members

Carnegie Mellon University

Oregon State University

Robots

TBA

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Website

Facebook

Q&A: Team Co-Lead Sebastian Scherer

How have you been preparing for the SubT Final?

Since we expect DARPA to have some surprises on the course for us, we have been practicing in a wide range of different courses around Pittsburgh including an abandoned hospital complex, a cave and limestone and coal mines. As the finals approached, we were practicing at these locations nearly daily, with debrief and debugging sessions afterward. This has helped us find the advantages of each of the platforms, ways of controlling them, and the different sensor modalities.

What do you think the biggest challenge of the SubT Final will be?

For our team the biggest challenges are steep slopes for the ground robots and thin loose obstacles that can get sucked into the props for the drones as well as narrow passages.

What is one way in which your team is unique, and why will that be an advantage during the competition?

We have developed a heterogeneous team for SubT exploration. This gives us an advantage since there is not a single platform that is optimal for all SubT environments. Tunnels are optimal for roving robots, urban environments for walking robots, and caves for flying. Our ground robots and drones are custom-designed for navigation in rough terrain and tight spaces. This gives us an advantage since we can get to places not reachable by off-the-shelf platforms.

Team MARBLE

Team MARBLE

MARBLE

Country

USA

Members

University of Colorado, Boulder

University of Colorado, Denver

Scientific Systems Company, Inc.

University of California, Santa Cruz

Robots

TBA

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Twitter

Q&A: Project Engineer Gene Rush

How have you been preparing for the SubT Final?

Our team has worked tirelessly over the past several months as we prepare for the SubT Final. We have invested most of our time and energy in real-world field deployments, which help us in two major ways. First, it allows us to repeatedly test the performance of our full autonomy stack, and second, it provides us the opportunity to emphasize Pit Crew and Human Supervisor training. Our PI, Sean Humbert, has always said "practice, practice, practice." In the month leading up to the event, we stayed true to this advice by holding 10 deployments across a variety of environments, including parking garages, campus buildings at the University of Colorado Boulder, and the Edgar Experimental Mine.

What do you think the biggest challenge of the SubT Final will be?

I expect the most difficult challenge will is centered around autonomous high-level decision making. Of course, mobility challenges, including treacherous terrain, stairs, and drop offs will certainly test the physical capabilities of our mobile robots. However, the scale of the environment is so great, and time so limited, that rapidly identifying the areas that likely have human survivors is vitally important and a very difficult open challenge. I expect most teams, ours included, will utilize the intuition of the Human Supervisor to make these decisions.

What is one way in which your team is unique, and why will that be an advantage during the competition?

Our team has pushed on advancing hands-off autonomy, so our robotic fleet can operate independently in the worst case scenario: a communication-denied environment. The lack of wireless communication is relatively prevalent in subterranean search and rescue missions, and therefore we expect DARPA will be stressing this part of the challenge in the SubT Final. Our autonomy solution is designed in such a way that it can operate autonomously both with and without communication back to the Human Supervisor. When we are in communication with our robotic teammates, the Human Supervisor has the ability to provide several high level commands to assist the robots in making better decisions.

Team Robotika

Team Robotika

Robotika

Country

Czech Republic, USA, Switzerland

Members

Robotika International, Czech Republic and United States

Robotika.cz, Czech Republic

Czech University of Life Science, Czech Republic

Centre for Field Robotics, Czech Republic

Cogito Team, Switzerland

Robots

Two wheeled robots

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Website

Twitter

Q&A: Team Lead Martin Dlouhy

How have you been preparing for the SubT Final?

Our team participates in both Systems and Virtual tracks. We were using the virtual environment to develop and test our ideas and techniques and once they were sufficiently validated in the virtual world, we would transfer these results to the Systems track as well. Then, to validate this transfer, we visited a few underground spaces (mostly caves) with our physical robots to see how they perform in the real world.

What do you think the biggest challenge of the SubT Final will be?

Besides the usual challenges inherent to the underground spaces (mud, moisture, fog, condensation), we also noticed the unusual configuration of the starting point which is a sharp downhill slope. Our solution is designed to be careful about going on too steep slopes so our concern is that as things stand, the robots may hesitate to even get started. We are making some adjustments in the remaining time to account for this. Also, unlike the environment in all the previous rounds, the Mega Cavern features some really large open spaces. Our solution is designed to expect detection of obstacles somewhere in the vicinity of the robot at any given point so the concern is that a large open space may confuse its navigational system. We are looking into handling such a situation better as well.

What is one way in which your team is unique, and why will that be an advantage during the competition?

It appears that we are unique in bringing only two robots into the Finals. We have brought more into the earlier rounds to test different platforms and ultimately picked the two we are fielding this time as best suited for the expected environment. A potential benefit for us is that supervising only two robots could be easier and perhaps more efficient than managing larger numbers.

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