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Juggling Robots Get Fancier

Teaching a robot to juggle is no easy task, especially when you ask it to juggle five balls at once or one ball while blind

2 min read

UPDATE: The Czech roboticists updated their video with labels and a slow motion sequence, making it easier to see how the robot juggles three, and then four, and finally five balls, and also how it drops one ball at the end.

Robots are especially good at juggling. This is not to say that juggling is a particularly easy problem to tackle, because it's not, but it's a fun excuse to design a robot to demonstrate precision control and high-speed object tracking. The robot in the video above, for example, was built by three masters students from the Department of Control Engineering at the Czech Technical University in Prague. It uses three linear motors, including one for each arm and a third for a central ball deployment system, along with two pivoting "hands" to catch and toss up to five balls at once. The feedback loop is closed using data from encoders built in the motors, and a high-speed camera helps to fine-tune the trajectories of the balls.

You don't actually need a high-speed vision system to juggle, though. We first met the "blind juggler" with it's fascinating passively adaptive single ball juggling capability back in 2009. Since then, it's gotten a fairly significant upgrade over the past year or so, which its designer, Philip Reist from ETH Zurich, presented last month at ICRA:

Remember, there's no sensing going on here. No cameras, no force sensors, no microphones, nothing at all. The robot is able to juggle without having any idea what the ball is doing, simply by virtue of the level of feedback control inherent in its design. It's really quite beautiful... You know, from a mechanical perspective. You can read about how this is possible here.

The Pendulum Juggler robot was presented in an ICRA paper unsurprisingly entitled "Design of the Pendulum Juggler," by Philipp Reist and Raffaello D’Andrea from the Institute for Dynamic Systems and Control, ETH Zurich, Switzerland.

[ Five Ball Juggler ] via [ Hack a Day ]

[ Blind Juggler ]

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The Bionic-Hand Arms Race

The prosthetics industry is too focused on high-tech limbs that are complicated, costly, and often impractical

12 min read
A photograph of a young woman with brown eyes and neck length hair dyed rose gold sits at a white table. In one hand she holds a carbon fiber robotic arm and hand. Her other arm ends near her elbow. Her short sleeve shirt has a pattern on it of illustrated hands.

The author, Britt Young, holding her Ottobock bebionic bionic arm.

Gabriela Hasbun. Makeup: Maria Nguyen for MAC cosmetics; Hair: Joan Laqui for Living Proof

In Jules Verne’s 1865 novel From the Earth to the Moon, members of the fictitious Baltimore Gun Club, all disabled Civil War veterans, restlessly search for a new enemy to conquer. They had spent the war innovating new, deadlier weaponry. By the war’s end, with “not quite one arm between four persons, and exactly two legs between six,” these self-taught amputee-weaponsmiths decide to repurpose their skills toward a new projectile: a rocket ship.

The story of the Baltimore Gun Club propelling themselves to the moon is about the extraordinary masculine power of the veteran, who doesn’t simply “overcome” his disability; he derives power and ambition from it. Their “crutches, wooden legs, artificial arms, steel hooks, caoutchouc [rubber] jaws, silver craniums [and] platinum noses” don’t play leading roles in their personalities—they are merely tools on their bodies. These piecemeal men are unlikely crusaders of invention with an even more unlikely mission. And yet who better to design the next great leap in technology than men remade by technology themselves?

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