As much as we like to go on about bio-inspired robots (and we do go on about them), there are some things that nature hasn’t quite figured out yet. Wheels are almost one of those things—while some animals do roll, and have inspired robots based on that rolling, true wheeled motion isn’t found in nature above the microscopic level. When humans figured out how useful wheels were, we (among other things) strapped them to our feet to make our motion more efficient under certain conditions, which really showed nature who was boss. Our smug wheeled superiority hasn’t lasted very long, though, because robots are rapidly becoming more skilled with wheels than we can ever hope to be.
The key difference between a human on roller skates and a robot on actuated wheels is that the robot, if it’s engineered properly, can exert control over its wheels with a nuance that we’ll never be able to match. We’ve seen this in action with Boston Dynamics’ Handle, Handle, although so far, Handle hasn’t seemed to take full advantage of the fact that it’s got legs, too. To understand why wheels and legs together are such a game-changer for robotic mobility, we can take a look at ANYmal, which seamlessly blends four legs and four wheels together with every movement it makes.