Hopping instead of flying: Toronto video shows a robot foot for sand and ice

Engineers at the University of Toronto have fitted their hopping robot "Hopcopter" with a new, flexible foot pad. The robot is essentially a quadcopter drone sitting on a single spring-loaded leg; pre-stretched rubber bands counteract gravity. The model is birds, which do not fly constantly but hop and rest, conserving energy. The work appeared in the journal "Advanced Intelligent Systems" (DOI 10.1002/aisy.70580); the university presented it on 26 October with a video from the lab.

Until now, the foot slipped on steep or slippery surfaces and sank into sand. The new pad spreads the weight over a larger area like a snowshoe, tilts in any direction via a spherical joint and is snapped back into position by rubber bands after each hop; short spikes grip like crampons. "They reduce the take-off error by up to 66% while improving the efficiency by up to 64%," says lead author Jeeraphat (Owen) Kledkruemas. Performance variation across terrains drops by 84 percent.

Next, the team led by Professor Pakpong Chirarattananon plans to develop autonomous navigation. Possible uses include search and rescue after natural disasters or inspecting remote infrastructure such as pipelines and mining sites. "This improvement enables us to bring this robot out of the lab and into the real world," says Chirarattananon.