Nuclear safetyRobots to operate in nuclear no-go zones

Published 28 January 2019

Sturdy, intelligent robots which react to their surroundings are being developed to work in situations which are too dangerous for humans, such as cleaning up Europe’s decades-old radioactive waste or helping during a nuclear emergency.

When Japan’s Fukushima nuclear disaster struck in 2011 following a devastating earthquake and tsunami, the robots that were deployed to support rescue workers were very basic and largely ineffective, says robotics expert Professor Sven Behnke at the University of Bonn in Germany.

Spurred by this problem, Prof. Behnke and his team developed a robust disaster-response system through a project called CENTAURO. The robot is controlled by a human from a safe distance while various sensors allow it to perceive its environment and relay information back to its operator.

“The main operator controls the robot through a telepresence suit which measures the motions of the operator’s arms, wrists and fingers and transfers them to the robot,” said project coordinator Prof. Behnke. A head-mounted display worn by the operator allows them to see in 3D what the robot sees from its own perspective, he adds.

Named Centauro, the 1.5-metre-tall robot weighs 93 kilograms, is made of lightweight metals like aluminum and has 3D-printed plastic skin.

“The robot has a centaur-like body plan with four articulated legs ending in steerable wheels,” said Prof. Behnke. Those four legs make it more stable than bipedal robots. As it is able to rotate at the hip, knee and ankle, Centauro can take on numerous postures and navigate in challenging environments.

Centauro’s upper body has two arms with multi-fingered hands which allow it to lift objects and manipulate tools and doors. Although tele-operated, the robot has some degree of autonomy. For example, if it is told to move to specific locations or grasp an object it will plan and execute the action.

Last year, Centauro was tested in real-world, challenging scenarios at the German nuclear disaster-response provider Kerntechnische Hilfsdienst GmbH. It successfully climbed stairs, navigated debris, overcame gaps, unlocked a door, operated valves and power tools, and more, says Prof. Behnke. “The CENTAURO disaster-response system provided the high degree of flexibility needed for realistic missions,” he said.

Prof. Behnke hopes the technology may one day play a crucial role in disaster relief efforts although it isn’t ready to face radiation just yet. However, researchers at the University of Birmingham, UK, are in the process of developing robots that can handle high radiation levels to clean up nuclear waste from the past half century.