Opening doors on the way to a personal robot

Consider it one small step--or a roll, actually--for a robot, one not giant, but significant step for robotics.

Willow Garage, a Silicon Valley robotics research group, said that its experimental PR2 robot, which has wheels and can travel at speeds up to a mile and a quarter per hour, was able to open and pass through 10 doors and plug itself into 10 standard wall sockets in less than an hour. In a different test, the same robot completed a marathon in the company's office, traveling 26.2 miles. PR2 will not compete with humans yet; it took more than four days.

For the person who wants to buy a fully functioning robot butler, this may not seem so impressive. But for roboticists and a new generation of technologists in Silicon Valley, this is a significant achievement, a step along the way to the personal robot industry.

Willow Garage was founded by Scott Hassan, one of the designers of the original Google search engine. The company's name is a reference to a small garage on Willow Road in Menlo Park, Calif., which was Google's first office. The company is trying to develop a new generation of robotic personal assistants. Roboticists here and at other companies envision creating something on the scale of the personal computer industry, with mechanical personal assistants taking over a lot of drudgery, from cleaning up to fetching a beer from the refrigerator.

This is not a new hope, nor is it the first time that robots have tried to open doors, navigate rooms and recharge themselves. The Beast, a robot built at Johns Hopkins University in the mid-1960s, was able to locate standard wall sockets to refuel. And devices like the inexpensive iRobot Roomba vacuum cleaner can locate and dock with a specially designed charging station.

But roboticists said that the Willow Garage robot was the first to integrate the ability to do a number of operations in a real-world environment.

"There are other groups that have opened doors before," said Andrew Ng, a Stanford roboticist with several students who have gone to work for the company. But, Ng said, this seemed to be the first robot able to repeatedly and reliably open doors and plug itself in.

William L. Whittaker, a Carnegie Mellon University roboticist and the winner of a Defense Department urban challenge robot driving contest, said it was "unprecedented" for a robot to navigate in a building reliably and repeatedly recharge itself. "These guys are the real deal," he said.

The Willow Garage laboratory is less than a mile from another pioneering mobile robot project that was developed at SRI International in the late 1960s. The robot, known as Shakey, had little onboard computing capability and was remotely controlled by a combination of a mainframe and a minicomputer.

"In 40 years there has been a lot of progress, but not progress you notice," said Nils Nilsson, a pioneering artificial intelligence researcher who was one of Shakey's designers. "A lot of the progress has been made in removing the cheats we used."

To help Shakey navigate, he said, the baseboards in the room were painted black to help identify walls, and objects were painted red so they could be identified by the vision system.

An open-source OS for robots
The ultimate goal of the Willow Garage researchers is to build a Robot Operating System, or ROS, that would greatly facilitate the work of a generation of software developers.

Microsoft is developing a similar system based on a version of the Windows operating system, but the Willow Garage effort is an open-source project intended to leverage the contributions of a number of robotics experts around the world.

Toward that end, a team of roboticists from the University of Tokyo recently modified the Willow Garage ROS to run on a robot they were developing, said Steve Cousins, Willow Garage's president and chief executive.

"The eventual goal is to provide a set of capabilities that are so generic and so universal that they can be used as building blocks in more complicated applications," said Sebastian Thrun, director of the Stanford Artificial Intelligence Laboratory and a Willow Garage board member.

The current PR2 robot is powered by several Intel microprocessor chips and "sees" with a combination of sensors including scanning lasers and video cameras. It is able to locate electrical outlets and navigate in a building that is designed to accessibility guidelines in the Americans With Disabilities act. Such buildings do not have doors with round door knobs, which simplifies the task of opening a door for a robot. The PR2 carries its plug on a magnet at its base.

In the recent test, one of the plugs was behind a locked door, so the robot needed to be intelligent enough to abort its effort and move on to the next plug. The doors it needed to navigate were alternately closed, open and partially open.

One of the scientists summed up his feelings about the milestone in a succinct e-mail message:

"Now they can escape and fend for themselves."

Entire contents, Copyright © 2009 The New York Times. All rights reserved.