If you look closely at the background, you will see a Microsoft Kinect Motion controller on a black poll which is tracking the persons movement, so the robot knows where to move. At 1:33 minutes on the video, a guy said he is using MS Kinect to sense the persons position.
I agree, and it seems rather slow. It would be cool if it has a mind of its own, and can attack the human by looking for weaknesses in the human's sword fighting style, so it can whack the guy with its sword.