CU Denver part of team designing underground search and rescue drones for DARPA

DARPA awards $4.5 million Subterranean Challenge grant to research team from CU Denver and CU Boulder

October 2, 2018

The race is on: Researchers from CU Boulder, CU Denver and the Boston-based Scientific Systems Company (SSCI), Inc., have partnered to design drones that can explore underground environments like subway tunnels, mines and caves.

The U.S. Defense Advanced Research Projects Agency (DARPA) awarded the team a $4.5 million grant to support its participation in its national Subterranean Challenge, which will end in fall 2021. The partners will compete against five other funded teams across the country to complete three increasingly difficult undeground challenges.

Sean Humbert, a professor in CU Boulder’s Department of Mechanical Engineering, said the project will push the bounds of what autonomous systems can do. The work may one day enable teams of flying and rolling drones to work together to search through dark and dangerous environments to find human survivors of earthquakes, chemical spills and more.

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  • Researchers from the University of Colorado Boulder and the University of Colorado Denver will compete in the S. Defense Advanced Research Projects Agency’s Subterranean Challenge.
  • The group received a $4.5 million grant to design teams of drones that can search tunnels, mines and caves for disaster survivors, chemical leaks and more.
  • The national competition will include three search and rescue challenges over the span of three years.


Robotics talent in Colorado

The project, drawing on expertise at both CU Boulder and CU Denver, is evidence of Colorado’s growing bona fides in the field of robotics.

“The DARPA Subterranean Challenge was a great opportunity to pull this team together, leveraging the strengths of both campuses,” said Humbert, who is leading the project. “It’s a great win for the state of Colorado to have two of its major campuses collaborating on this.”

“The solution DARPA wants is clearly beyond the current state-of-the-art and will require interdisciplinary and inter-organization innovation and out-of-the-box thinking,” said Ron Rorrer, professor of mechanical engineering at CU Denver.

The fast-paced challenge will take part in three stages. In September 2019, the group will kick off the competition by sending drones on a mock search and rescue operation down miles of steam tunnels. Six months later, the competing teams will graduate to large tunnels, such as those that make up the New York subway system. And, finally, they’ll travel to natural caves, which will add a host of hazards, including mud, rocks and the potential for cave-ins.

Advancing autonomy

Such a feat of hide-and-seek will bring numerous engineering challenges. To start, typical multirotor drones can only fly for 15 to 20 minutes before their batteries run out. The DARPA competition, in contrast, will require them to keep going for two to three hours. And those drones will have to communicate with each other and the surface from deep underground.

To tackle those challenges, Humbert and his colleagues have brought together a diverse team of engineers. Researchers at CU Denver will focus on the power and communication challenges. The CU Boulder group will develop software and algorithms to enable the drone fleets to work together without a human controlling them.

The desired operational times of the autonomous vehicles are beyond the current state of performance and will require us to develop innovative ways to power and refuel the vehicles.

“The communications are a unique challenge since rock, concrete and metal impede the propagation of wireless signals used in most existing technologies. We will have to design and implement a novel system that is robust and reliable in such an environment,” said Mark Golkowski, associate professor of electrical engineering at CU Denver.

The project will have impacts beyond subterranean search and rescue, too. Making drones that can navigate such difficult environments may also improve how they work in safer settings around people, such as in factories or warehouses.

“We are thrilled by the potential of this project and the collaboration with colleagues in Boulder,” said Martin Dunn, dean of CU Denver’s College of Engineering and Applied Science. “It is a fantastic exemplar of two elements of our college strategy – engaging in interdisciplinary research and education pointed toward industries of the future, and doing so through partnerships across industry, academia and government.”


In addition to Rorrer and Golkowski, the CU Denver team includes Jaedo Park, associate professor in the Electrical Engineering, Department and Chao Liu and Vijay Harid, assistant professors, and Diane Williams, research associate, all from the Department of Electrical Engineering Department.

The CU Boulder team also includes Eric Frew, professor of aerospace engineering sciences, Christoffer Heckman, assistant professor of computer science, and Christopher Williams, research professor from the Colorado Center for Astrodynamics Research (CCAR).