a big chunk of Google shares. He also helped to build Alexa, the Web traffic monitoring service bought by Amazon in 1999 for $250 million. And on top of all that, he started FindMail, an e-mail list management service that grew into eGroups.com and fetched $413 million when Yahoo bought it in 2000.
If you’ve earned a fortune three times over thanks to the Internet, you’re automatically a big proponent of open source software—and you’re likely to believe that creating a shared platform like the LAMP stack is the best way to kickstart innovation in almost any technical field. “This is a classic chicken-and-egg problem,” Hassan said at the 2010 launch event for Willow Garage’s PR2 Beta initiative, a program aimed at giving away 11 PR2s to research teams around the world. “Without robots we can’t develop useful apps, and without useful apps to run, there are no robots,” Hassand said. “So the question is, how are we going to make this happen? What we are bringing to the table is a platform—a sturdy, robust platform,” meaning the combination of PR2 and ROS.
Gerkey was a logical choice to lead Willow Garage’s effort to develop ROS. Aside from being a veteran of Stanford’s Artificial Intelligence Lab and SRI’s Artificial Intelligence Center, he’s the founding developer of Player, a widely used open-source interface that lets researchers run robots over a network connection. He says ROS began in 2007 as a collaboration with researchers at Stanford. “The motivation was very much parallel to the motivation for building the PR2. It was natural to say that if we are going to build this hardware platform to give people a better starting point, we should match that with a software platform that gives them the nuts and bolts for everything from talking to sensors to inter-process communication, so they don’t have to worry about those things.”
ROS runs on many robot models, but there’s no question that it co-evolved with PR2 as Willow Garage readied the robot for public demos intended to show off its capabilities. “The best example of that was the tabletop manipulation demo,” says Gerkey. “The robot looks at a tabletop with no idea of what’s there, and it identifies objects, recognizes them, decides how to grasp on to them, picks up an object, moves it, and puts it down. That pick-and-place functionality is a basic capability that you would expect out of any robot like PR2—but if you don’t have a system like ROS you have to build an entire system of algorithms just to test it.”
The deep idea behind ROS, Gerkey says, is to save engineering time and let researchers leapfrog over solved problems. If your expertise is in computer vision, you want to put your effort into fine-tuning your object recognition algorithms—not wrestling with your robot over how to get the cameras to talk to the central processor, or how to move the gripper arm toward an object.
“Now you have the possibility of directly and empirically comparing competing approaches,” says Gerkey. “It’s one of the dirty little secrets of robotics that this hasn’t been done regularly. The story of robotics in the research community tends to be, you do a demo and show a video and everyone says ‘Isn’t that cool.’ There isn’t a lot of the head-to-head comparison of results that would really serve the community better.”
Researchers jumped on the ROS bandwagon from very first “0.4” release in 2009. The first stable 1.0 release came in February 2010, and every six months since then, Willow Garage has pushed a new release, each one named after a variety of turtle. (That’s a reference to
