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This Spherical Robot Can Unfurl Its Four Legs After Being Tossed

Researchers in Japan have developed a remarkable new robot that bears a startling resemblance to the Droideka of Star Wars. Called QRoSS, this throwable, sphere-shaped robot can move around either by rolling or walking on all fours. Mercifully, it’s not capable of firing lasers or engaging force least not yet.


This robot was developed by Takeshi Aoki, Satoshi Ito, and Yosuke Sei from the Chiba Institute of Technology in Japan. The team recently showed off their droid at the IROS 2015 conference in Germany, and they’ve got an accompanying paper that describes its features in detail.

The outer body of QRoSS consists of a durable, spherical shell. Hidden inside are four legs that can unfurl and provide for quadrupedal locomotion. For more straightforward maneuvers, QRoSS can just roll around.


QRoSS is similar to MorpHex MKII, a spherical robot that can retract its six legs and transform into a rolling ball.

But unlike MorpHex, QRoSS can be tossed around, a feature that could prove useful in any number of contexts, including emergency work in dangerous locations. Writing in IEEE Spectrum, Evan Ackerman explains:

As far as real robots go, the primary difference between QRoSS and MorpHex is that QRoSS uses a walking system that’s completely independent from the outer shell. The big advantage of this is that the shell acts as a passive shock absorber, allowing the robot to the rolled (or, hypothetically, thrown) without damaging it. In a disaster area, for example, a human could chuck the robot like a baseball into a dangerous area from a safe one, and after bouncing a few times, QRoSS simply sprouts legs and starts walking around. Legs are excellent at dealing with very rough terrain, and the design of QRoSS allows you to use legs when necessary without having to always worry about how fragile they are, since any slip and fall just turns into a bouncy roll.

The latest version of QRoSS weighs about 5.5 pounds (2.5 kg), and it measures 11.8 inches (30 cm) in diameter, so it’s not optimized for throwing. That said, the design appears to be scalable, which may eventually allow for both smaller and larger versions.

More at IEEE Spectrum. And check out the entire study at IEEE Robotics and Automation Society.


Email the author at and follow him at @dvorsky. Top image by T. Aoki et al., 2015

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