Robotic navigation of complex subterranean settings is important for a wide variety of applications ranging from mining and planetary cave exploration to search and rescue and first response. In many cases, these domains are too high-risk for personnel to enter, but they introduce a lot of challenges and hazards for robotic systems, testing the limits of their mobility, autonomy, perception, and communications.
The DARPA Subterranean (SubT) Challenge seeks novel approaches to rapidly map, navigate, and search fully unknown underground environments during time-constrained operations and/or disaster response scenarios. In the most recent competition, called the Urban Circuit, teams raced against one another in an unfinished power plant in Elma, Washington. Each team's robots searched for a set of spatially-distributed objects, earning a point for finding and precisely localizing each object.
Whether robots are exploring caves on other planets or disaster areas here on Earth, autonomy enables them to navigate extreme environments without human guidance or access to GPS.
TEAM CoSTAR, which stands for Collaborative SubTerranean Autonomous Robots, relies on a team of heterogeneous autonomous robots that can roll, walk or fly, depending on what they encounter. Robots autonomously explore and create a 3D map of the subsurface environment. CoSTAR is a collaboration between NASA’s JPL, MIT, Caltech, KAIST, LTU, and industry partners.
“CoSTAR develops a holistic autonomy, perception, and communication framework called NeBula (Networked Belief-aware Perceptual Autonomy), enabling various rolling and flying robots to autonomously explore unknown environments. In the second year of the project, we aimed at extending our autonomy framework to explore underground structures including multiple levels and mobility stressing-features. We were looking into expanding the locomotion capabilities of our robotic team to support this level of autonomy. Spot was the perfect choice for us due to its size, agility, and capabilities.
We got the Spot robot only about 2 months before the competition. Thanks to the modularity of the NeBula and great support from Boston Dynamics, the team was able to integrate our autonomy framework NeBula on Spot in several weeks. It was a risky and aggressive change in our plans very close to the competition, but it paid off and the integrated NeBula-on-Spot framework demonstrated an amazing performance in the competition.” said CoSTAR's team lead Ali Agha of JPL. "The NeBula-powered Spots were able to explore 100s of meters autonomously in less than 60 minutes, negotiate mobility-stressing terrains and obstacles, and go up and down stairs, exploring multiple levels."
Performance of the NeBula-enabled Spots alongside CoSTARs roving and flying robots led to the first place in the urban round of competition for team CoSTAR. For more information about Team CoSTAR's win, see: