It's entirely possible for robots to juggle or play catch. They've usually been relegated to playing with their own kind, however, which is as good an excuse as any for Disney Research to experiment with a ball-tossing robot tailored to games with humans. The animatronic creation uses a depth-aware motion camera -- there's conflicting mentions of using both the Microsoft Kinect and ASUS' Xtion Pro Live that we're hoping to sort out -- to track any mid-air balls as well as throw them back to a human participant. Disney's robot does more than just move the robot's arm to account for imperfect tosses, too, as it knows to feign a dejected look after a botched reception. The company suggests that its invention would ideally bring two-way interaction to theme parks, so it's more likely to show up at Disneyland before it stands in for a parent in the backyard. It's just as well; when the Robopocalypse comes, the last thing we'll want at home is a machine that can toss grenades.
Update: Team member Jens Kober has filled us in on just why both cameras are mentioned. The team started off using the Kinect and switched to the Xtion Pro Live, once it was available, to get hardware-synced timing between a regular camera and the depth camera. The project didn't require the panning motor or microphone array of Microsoft's system.
ASUS WAVI Xtion PRO LIVE