Do It Yourself, Robot; If machines are to emerge from the factory and enter our homes, they'll need to learn to be self-reliant.

Byline: Fred Guterl

Christmas day 2003 was a gloomy time at the National Space Center in Leicester, England. Scientists waited all day for a signal from the European Space Agency's Beagle 2, announcing its successful landing on Mars, but no signal ever came. Beagle 2's failure remains a mystery, but it was never a surprise. A robot ship millions of kilometers from home stands a decent chance of encountering the unexpected. And robots aren't good at handling what their makers can't foresee.

The inability of robots to adapt is a symptom of their growing complexity--the more we want them to do, the harder it is to build them for every contingency. This limitation is the biggest obstacle to making robots more useful around the house, attached to the human body, in our cities and streets. Almost all commercial robots now work in tightly regulated environments such as the factory floor, where objects are always where they're supposed to be, and people are nowhere near. Scientists want to change all that. In last week's issue of the journal Nature, roboticist Hod Lipson and his colleagues at Cornell University report that they've taken a big step closer to endowing robots with adaptability. Lipson's lab built a four-legged robot that teaches itself to walk. When something happens--when Lipson, say, decides to saw off a leg--the robot simply teaches itself to get by with a stump.

Lipson's robot started life with a kernel of programming and then "evolved" its own kind of self-consciousness. The robot makes dozens of copies of its software code, introducing a random mutation each time, and then tests each version to see how effective it is. The robot's programming sends signals to its motors and sees what happens. The beauty of this approach is that the robot can always reprogram itself when circumstances change. When a leg goes missing, the machine stumbles at first. Then it ...