A pair of wheeled robots and a pair of drones, assembled by researchers at Carnegie Mellon University and Oregon State University, will work together to autonomously map and search an underground mine as competition begins this month in the $2 million DARPA Subterranean Challenge.
The first scored event in the multi-year competition, sponsored by the Defense Advanced Research Projects Agency, will be Aug. 15-22 in the research mine operated by the National Institute for Occupational Safety and Health in South Park Township, outside of Pittsburgh.
The Carnegie Mellon/Oregon State team, Explorer, is one of 11 teams qualified by DARPA to compete in the event, where the robots will face a mine disaster scenario. The robots will be scored on their ability to develop a 3D map of the mine and identify a variety of objects positioned in the mine, including simulated human survivors.
"This is a task that requires robot autonomy, perception, networking, and mobility for us to be successful," said Sebastian Scherer, who leads the team with Matt Travers, both of whom are faculty members in CMU's Robotics Institute. "Underground operations pose many unique challenges for robots, but we've benefited from the Robotics Institute's depth of experience in developing robots that can work in enclosed spaces and dark, dank environments."
Geoff Hollinger, an assistant professor of mechanical engineering at Oregon State and a CMU robotics alumnus, and his students provide additional expertise in multirobot systems.
The team, which includes about 30 faculty, staff members and students, has tested its robots and procedures extensively at the Tour-Ed Mine in Tarentum, Pa.
One of the major challenges has been maintaining communications between the robots and with the human operator who oversees the robots from outside the mine, said Steven Willits, Explorer's lead test engineer. The rock walls block radio signals, which means radios are largely useless unless they are in line of sight with each other. So the ground robots, named Rocky 1 and Rocky 2, periodically drop WiFi nodes on the mine floor, creating a communications network as they go.
Even so, the number of nodes they carry is limited, so the robots eventually must venture beyond their ad hoc network, operating autonomously to gather data, said Kevin Pluckter, a master's student in robotics who is the lead operator. The robots will relay that information back to the operator once they return within range of the WiFi network.
Under DARPA's rules, the teams will have 60 minutes to complete their mapping and search missions. Rocky 1 and Rocky 2 both are capable of running the entire time, but the drones have more limited flight times. The drones will therefore be used when the ground robots meet an obstruction that they can't surmount, flying ahead to complete the mission.
The Tunnel Circuit is one of three circuit events that lead up to the final event. An Urban Circuit, in which robots will explore complex underground facilities, will be in February 2020 and a Cave Circuit will be in August 2020. A final event incorporating all three environments will be in August 2021 and will determine the winner of the competition's $2 million grand prize.
The challenge will develop technologies needed by military and civilian first responders when faced with underground environments that are damaged and are suspected to be unsafe for humans.
Explorer competes in the Subterranean Challenge's systems track, in which the teams develop physical robotic systems that compete in live environments. The challenge also includes a virtual track, in which teams develop software and algorithms and compete in simulation-based events. Nine teams began the virtual competition in July; the winners will be announced during this month's event.
Explorer is one of seven teams that will receive up to $4.5 million to develop their hardware and software for the competition. It also is sponsored by the Richard King Mellon Foundation, Schlumberger, Microsoft, Boeing, FLIR Systems, Near Earth Autonomy, Epson, Lord, and Doodle Labs. More information about the team and sponsorships is available here.