PR2: the $400,000 personal robot that reached only about 50 labs

$400,000 and two arms for a personal robot

PR2 (Personal Robot 2) was built by Willow Garage, the lab Scott Hassan founded in 2006. It was closer to a platform for researchers to share than to a product. In 2009 CEO Steve Cousins said: “For what Linux is to PCs, we’d like to build the same thing for robots.” A roughly adult-height body stands on a rolling base, with two arms the size of human arms ending in grippers. It carries fingertip pressure sensors, two pairs of stereo cameras and a laser scanner. According to Palo Alto Online, the arms are held up by springs so they “float,” which lowers the risk of injury if the software malfunctions. The software was the open-source ROS. Here “release” means the May 2010 beta placements and the September purchase offer, not a retail launch.

Eleven free loans, then four first buyers

In May 2010 Willow Garage announced it would lend PR2s to 11 institutions for about two years, among them Stanford and MIT. In September it made the robot available at $400,000, with up to $120,000 off for open-source contributors. In December the first buyers were Samsung, France’s LAAS-CNRS, the University of Washington and George Washington University, and 16 institutions were using it. In February 2013 Willow said there were close to 50 PR2 robots in the world. That month it also said it would stop developing new research technology and move toward commercial work. In an August Spectrum interview Hassan said he had concentrated resources on Beam and saw the research as largely done. He also conceded that making PR2 affordable for homes or offices would have been a major challenge. He said: “it takes a hundred times more people to make an actual product.” In January 2014 support passed to Clearpath Robotics. Spectrum reported that Clearpath committed to at least three years of support, through 2016, and estimated about 40 PR2s in use. Bloomberg reported that Hassan had funded the lab with about $20 million of his own money a year. It gave no reason for the closure.

Towel folding from 24 minutes to 2

According to Palo Alto Online, a UC Berkeley PR2 took about 24 minutes per towel in 2010 and later about two. A PR2 that a Stanford student programmed took 40 minutes to fetch a drink from a café, against about 10 for a person. Georgia Tech’s Charles Kemp said that with the same robots, researchers “can run the same code,” so they can compare which methods work better. His lab used the PR2 to study robots that help care for seniors. Stanford’s Kenneth Salisbury said domestic robots should appear friendly and predictable, and warned that a robot moving “blindly” could frighten people. The robot weighed nearly 500 pounds and could not climb stairs.

A robot to run shared code on, not one to bring home

PR2 became a common platform that many labs used to share the same robot and code. Its backer admitted that bringing the price down to what a home or office could afford would have been a major challenge. Beam, which spun out of Willow, took pre-orders at $16,000 in September 2012 (see the Beam record), about one twenty-fifth of PR2’s price. Hassan called Beam “a gateway drug” to more advanced robotics.

Where does a robot that researchers can run shared code on split from one a household can bring in?

What we haven’t confirmed

• The total number of PR2s built (close to 50 is Willow Garage’s own statement)
• How many PR2s still work, and whether Clearpath support continued after 2016
• The specific reason Willow Garage closed (we found nothing beyond Hassan’s explanation)
• We found no published design awards or design reviews