A popular approach to designing robots that can navigate a world built for living creatures is to simply copy Mother Nature’s designs. But while trying to improve how a six-legged robot walks, researchers at the École Polytechnique Fédérale de Lausanne actually found a faster way for six-legged creatures to get around.


While many vertebrates are able to run quickly and with minimal ground contact, six-legged insects take a different approach to speed. They use what’s called a tripod gait, which means that when scurrying across flat terrain, they always have at least three legs touching the ground—two on one side, and one on the other.

Better than Mother Nature’s insects?

The researchers at EPFL, who also worked with the University of Lausanne, were curious to know if the tripod gait really was the fastest way for a six-legged creature to get around. So they pressed the fast-forward button on evolution and used a series of computer simulations and real-life experiments to see if there was a more efficient alternative. They eventually discovered that a bipod gait, where a six-legged creature has only two legs on the ground at any one time, allowed it to move faster, without any hardware upgrades.

But let’s not a point a finger and laugh at Mother Nature just yet. While the bipod approach to six-legged running works great on flat terrain, the simulations the researchers ran also revealed that the more traditional tripod approach is actually better for insects who use sticky feet to walk on walls, ceilings, and other surfaces where they’re constantly fighting gravity.

When crawling through a jungle where the terrain changes from inch to inch, it makes sense that insects would use an evolved approach to getting around that allows them to navigate every possible hazard—as opposed to one that prioritizes speed. But since the robots humans design are usually created and customized for very specific tasks, this discovery shows that copying Mother Nature verbatim isn’t always the best approach. Sometimes, we can improve on it.


[EPFL via Robotics Trends]