Bio-Mimetic "Moose Shoes" Give Robots a Big Locomotive Boost Over Muddy Terrain
Inspired, as the name implies, by the hooves of the moose, these silicone shoes let quadrupedal robots traverse mud with ease.
Researchers from the Tallinn University of Technology (TalTech) have come up with a way to give quadrupedal robots better grip on muddy and slipper terrain — by equipping them with shoes inspired by the majestic moose.
"Muddy and slippery terrains are some of the most difficult to traverse for robots and animals, including humans," explains Maarja Kruusmaa, a professor of biorobotics and project lead, on the problem the team set out to solve. "This means that most robots cannot access a wide range of highly important terrestrial environments, including wetlands, bogs, coastal marshes, river estuaries and fields, which are abundant in nature."
Inspiration for the solution came from Simon Godon, a doctoral candidate at the TalTech Center for Biorobotics and first author on the paper, and his experiences on his parent's cattle farm: high-tech hooves, dubbed "moose shoes," which provide off-the-shelf quadrupedal robots with greater traction — splaying out, like their biological equivalent, to both increase their surface area and to break the suction force of mud as they are raised.
"We found that the moose’s hoof behaves similarly to a suction cup, like how you manage to stick your fingernail under its surface and break the suction force," Godon says of how the shape and movement of the animal's foot helps it walk in muddy terrain. "Mud acts in a similar manner to a wet bathroom tile, creating [suction] under the animal's feet, making it difficult to get the leg out. Moving hooves breaks that tension."
The prototype "moose shoe" design, manufactured from silicone, proved to cut a commercial robot's sinkage and resulting suction force over muddy terrain in half and boosted its speed by 55 per cent — while reducing overall energy consumption while traversing the muck by 70 per cent compared to the stock feet. "We speculate that […] the split hooves may even have advantages on uneven terrains, giving the robot or the animal some extra stability," adds Kruusmaa. "We therefore recommend robots to keep their shoes on at all times!"
The team's work has been published in the journal Bioinspiration & Biomimetics, under open-access terms.
