PNAS: Walking and sliding are not as different as you might think

The Code of Abraham sees crawling as a special insult to evil snakes, but evolution may draw a more continuous line

A new study has found that all of these motions can be well represented

"It's not out of thin air — it's real robot data from us," said Dan Zhao, the first author of the study in the Proceedings of the National Academy of Sciences and recently received his Ph.

"Even though the robot looks like it's sliding, like its feet are sliding, its speed is still proportional to the speed at which it moves its body

Unlike the dynamic movements of gliding birds, sharks, and galloping horses— whose speeds are at least partly driven by momentum — every bit of speed of ants, centipedes, snakes, and swimming microbes

A deep understanding of kinematic motion could change the way robotics experts think about programming multi-limbed robots, for example by opening up new possibilities for walking planetary probes

Shai Revzen, a professor of electrical and computer engineering at the University of Michigan and a senior author of the study, explains that two- and four-legged robots are popular because more legs are modeled using current tools that are very complex

"It's always uncomfortable for me because my job is to study cockroach movements

If cockroaches can walk without solving extremely complex equations, there must be an easier way to program

Sliding feet complicate a typical model of motion for a robot, assuming it might add momentum to the motion of a multi-legged robot

Because microbes are small, water looks thicker and stickier — like humans trying to swim in honey

The team found a link

The team also collaborated with Glenna Clifton, an assistant professor of biology at the University of Portland in Oregon, who provided data on ants walking on flat surfaces

Even so, ants and robots follow the same equation, and their speed is proportional to the speed at which they move their legs

As for how this illustrates how walking evolved, the team notes that worms are thought to be the last common ancestor

Researchers believe that the technique of controlling momentum — running on four or fewer legs, walking or running on two legs, flying or gliding — is more important