I wonder how many millions universities around the world have spent on robotic wheelchairs alone.  When you Google the subject it seems like every Robotics 101 ( if there is such a thing) class does one.

Here's a bibliography compiled by the VA.  It lists 50 wheelchair research papers published as early as 1986

http://www.rehab.research.va.gov/jour/05/42/4...append.pdf

None of them produced a commercially viable product, so I'd like for someone  to link to any company that has a wheelchair with completely autonomous navigation.

http://www.geckosystems.com/markets/wheelchair.php