Drones tapped for nuclear waste site clean-up

By University of Nevada, Reno | January 19, 2017

Cleaning up old nuclear waste sites around the country is a long, expensive and dangerous process—and autonomous robot research at the University of Nevada, Reno promises to help that process with a combination of advanced, intelligent, autonomous aerial and ground robots with a new level of perception, navigation and planning abilities.

The College of Engineering’s Autonomous Robots Lab, under the direction of Assistant Professor Kostas Alexis, has completed a proof of concept for an aerial robot, a drone, that flies by itself in dark corridors looking for nuclear radiation and toxic chemicals.

“We’ve designed and built an aerial robot with multi-model mapping capabilities that includes inertial sensing, LiDAR, cameras with synchronized flashing LEDs, as well as sensors for radiation and chemical sensing to localize itself and comprehensively map its environment in very high quality,” Alexis said. “Basically, it flies itself into a dark corridor, maps the area, including complex structures such as tanks or barrels, and simultaneously finds radioactive areas or toxic chemicals using a variety of sensors. It learns the environment—the space, the contents and the dangers—and reports back to us.”

The intelligent aerial robot runs on algorithms the team programs to give it active perception, use what it needs to navigate, remembers important areas and allows production of high-resolution multi-modal 3-D maps of the area that show the level of radioactivity and toxic chemicals, if any. Their work is part of a National Robotics Initiative project funded by the Department of Energy to clean up the legacy sites of the Manhattan project that have been shuttered for decades.

The information will be used by the Department of Energy to build a clean-up plan based on what the autonomous robots locate, analyze and map.

“Specifically, we are hoping that we can enable the autonomous multi-modal mapping of the PUREX tunnels where multiple train cars are holding nuclear waste,” he said.

The majority of the clean-up work is conducted by human workers in protective clothing with consequences of cost, inefficiency, exposures and inability to access many places that matter. There is a need for robotically and autonomously acquiring, integrating and utilizing radiological, chemical, thermal, spatial and visual data of the inaccessible facilities.  

For the three-year program they have put together an interdisciplinary team of experts in perception, motion-planning, ground robots, micro aerial vehicles, and nuclear robotics. He is working with colleagues at the Robotics Institute of Carnegie-Mellon University.

“We believe that exciting new developments will arise in the intersection of these areas and themes,” Alexis, a faculty member in the Department of Computer Science and Engineering, said. “We are one of several research groups participating in the DOE environmental management program to clean up 107 sites around the country.”

Alexis and his team in the Autonomous Robots Lab use their expertise in a number of cutting-edge projects, including locally in a project to develop driver-assisted technologies for use on buses for the Reno-Sparks area. They are working through the University’s Nevada Center for Applied Research in a collaboration with the Regional Transportation Commission, the Governor’s Office of Economic Development, the Nevada Department of Motor Vehicles, the City of Sparks, bus company Proterra and the German research institute Fraunhofer. The project, Intelligent Mobility, includes integration of several systems. Alexis’s contribution lies in the development of the perception systems and detection systems, as well as in the autonomous navigation and collision avoidance.

“The systems will perceive the environment—identifying signs, signals, avoiding vehicles, pedestrians and other objects and provide data for robust and safe navigation,” Alexis said. “It’s just like we, as humans, drive, perceive the world and make decisions.”

The team has already begun testing the equipment using their own vehicles as they drive around the region and the developed perception and real-time mapping technologies will migrate to the bus routes as the project progresses in the next year.

“We drive around at various times of the day and night so the system can localize itself and we can make a map,” he said. “Our lab develops the multi-modal localization and mapping solution, fusing camera, LiDAR, GPS and inertial sensor data, for the autonomous navigation of the vehicles within the urban environment. The first prototype of this multi-modal mapping unit has been developed and successfully tested in both day- and night-time navigation. In addition, our lab develops small electric vehicles for rapid prototyping of our autonomous driving technologies.”

Coming to the University in 2015 after working in the world-renowned Autonomous Systems Lab of ETH Zurich in Switzerland, Alexis was excited to start his own lab to design, build and program aerial, marine and ground based autonomous robots.

Alexis specializes in autonomous robots with an emphasis on aerial robots, solar-powered UAV, augmented reality, marine and ground robots, robotic perception systems and the algorithms to enable intelligent behaviors. His goal is to make important contributions into making robots fully autonomous.

“The aerial robotics community has moved from flying autonomously with GPS to flying without GPS and navigating with in a safe collision-free manner,” Alexis said. “My next step is to establish cognizant robotics, where we can do complex missions autonomously without prior knowledge, without people commanding and running the mission.”