Saturday, January 6, 2007

Robot, fix thyself

Cornell University researchers have developed a robot that has the ability to discover itself and adapt to injury after losing one of its limbs.

The four-legged robot is not pre-programmed to walk. Like a newborn animal, it explores itself and learns to use its limbs to move. When a leg gets damaged, it repeats the process and works out a new method of locomotion.

Researches say though the test robot is a simple four-legged device, the underlying algorithm could be used in future to build more complex robots that can deal with uncertain situations, like space exploration, and may help in understanding human and animal behaviour.

"Most robots have a fixed model laboriously designed by human engineers. We showed, for the first time, how the model could emerge within the robot. It makes robots adaptive at a new level, because they can be given a task without requiring a model. It opens the door to a new level of machine cognition and sheds light on the age-old question of machine consciousness, which is all about internal models," said Hod Lipson, assistant professor of mechanical and aerospace engineering at Cornell University.

Professor Lipson carried out the research with Josh Bongard, a former Cornell postdoctoral researcher now on the faculty at the University of Vermont, and Cornell graduate student Viktor Zykov.

The robot, which looks like a four-armed starfish, starts out by knowing only what its parts are, and not how they are arranged or how to use them to fulfil its prime directive to move forward.

"The result is usually an ungainly but functional gait; the most effective so far is a sort of inchworm motion in which the robot alternately moves its legs and body forward. Once the robot reaches that point, we remove part of one leg. When the robot can’t move forward, it again builds and tests 16 simulations to develop a new gait,"
Professor Lipson added.

"The machine does not have a single model of itself—it has many simultaneous, competing, different, candidate models. The models compete over which can best explain the past experiences of the robot," he said.

"We limited the robot to 16 test cycles with space exploration in mind. You don’t want a robot on Mars thrashing around in the sand too much and possibly causing more damage," Bongard added. — ANI