Kato leverages the overhead camera trick in this system, though in a bit different way. See "A Toolkit for Easy Development of Mobile Robot Applications with Visual Markers and a Ceiling Camera:"
Thanks for the excellent link. I only took a quick look, so maybe the information is somewhere on the site, but do you know if this person (or others) are doing similar work for robots in 3d?
http://junkato.jp
More specifically see phybots:
http://junkato.jp/phybots/
Kato leverages the overhead camera trick in this system, though in a bit different way. See "A Toolkit for Easy Development of Mobile Robot Applications with Visual Markers and a Ceiling Camera:"
http://junkato.jp/publications/uist2009-sakamoto-andy.pdf