For some time now, roboticists have been looking to insects for inspiration, especially those who work on six-legged robots. They are quite common and have many potential uses due to their ability to adapt to different terrains. But for some researchers, those six-legged robots aren’t fast enough.
Six-legged insects like fruit flies can be pretty quick, and they can move on walls and ceilings without difficulty. That’s because they have adhesive pads on their feet that allow them to move in three dimensions. Combined with a “tripod gait” where they always keep three legs on the ground—two legs on one side and one on the other—they are able to move with ease on surfaces that other animals struggle with.
Through the use of computer models, studying fruit flies, and experiments with six-legged robots, researchers in Switzerland have developed a “bipod gait” for their robots, which is even faster. This gait keeps two feet on the ground and all times, and allows their robots to move faster. They even built some robots capable of both gaits to be sure.
“Our findings support the idea that insects use a tripod gait to most effectively walk on surfaces in three dimensions, and because their legs have adhesive properties. This confirms a long-standing biological hypothesis,” said Pavan Ramdya, co-lead and corresponding author of the study. “Ground robots should therefore break free from only using the tripod gait.”
The researchers tested their theory by putting polymer “boots” on fruit flies’ legs to cover their claws and adhesive pads to see how it affected their regular way of walking on the ground. It turned out that they quickly adopted a bipod-like gait.
“There is a natural dialogue between robotics and biology: many robot designers are inspired by nature and biologists can use robots to better understand the behavior of animal species,” said Robin Thandiackal, a co-lead author of the study. “We believe that our work represents an important contribution to the study of animal and robotic locomotion.”
Photo © Alain Herzog/2017 EPFL