Now, acrobatic robot that jumps, flips and does pull-ups

Researchers have developed a six-legged all-terrain robot that can run, leap, back-flip, climb and navigate its way over obstacles even bigger than itself.
RHex is an all-terrain walking robot that could one day climb over rubble in a rescue mission or cross the desert with environmental sensors strapped to its back, researchers said.
RHex is short for "robot hexapod," a name that stems from its six springy legs.
Legs have an advantage over wheels when it comes to rough terrain, but the articulated legs often found on walking robots require complex, specialised instructions for each moving part, researchers said.
To get the most mobility out of RHex's simple, one-jointed legs, researchers from the University of Pennsylvania are essentially teaching the robot Parkour.

Taking inspiration from human free-runners, the team is showing the robot how to manipulate its body in creative ways to get around all sorts of obstacles.

The RHex platform was first developed through a multi-university collaboration more than a decade ago.
Graduate student Aaron Johnson and professor Daniel Koditschek, both of the Department of Electrical and Systems Engineering in the School of Engineering and Applied Science, are working on a version of RHex known as XRL, or X-RHex Lite.
This lighter and more agile version of the robot is ideal for testing new ways for it to run, jump, and climb.

By activating its legs in different sequences, XRL can execute double jumps, flips, and, through a combination of moves, even pull-ups, researchers said.
For the tallest obstacles, the robot can launch itself vertically, hook its front legs on the edge of the object it's trying to surmount, then drag its body up and over.
The researchers fully demonstrated this particular manoeuvre under more controlled conditions in the lab.
"What we want is a robot that can go anywhere, even over terrain that might be broken and uneven. These latest jumps greatly expand the range of what this machine is capable of, as it can now jump onto or across obstacles that are bigger than it is," Johnson said.