Robotic 'toddler' can walk just like us

Scientists have built robots that can walk on two legs like a toddler.

The researchers say the breakthrough will lead to robots with increasingly human characteristics that could one day become the everyday servants depicted for decades in science fiction.

What makes the robots unique is that they learned to walk on different surfaces without any prior programming information from their inventors at the Massachusetts Institute of Technology (MIT) in Boston, Cornell University in New York and Delft University of Technology in the Netherlands.

The robots also walk in the same way as humans by tilting themselves slightly to one side as they pick up one leg to move it in front of the second leg that is simultaneously used to push the machine forward.

Because walking has to be subtly altered according to the type of surface, the robots have to take the ground on which they stand into account.

A robot called Toddler, made by MIT researchers, can teach itself to walk on a new surface in less than 20 minutes, or about 600 steps, said Russ Tedrake, a researcher in MIT's department of brain and cognitive sciences.

"[The robot] is one of the first walking robots to use a learning program, and it is the first to learn to walk without any prior information built into the controller," said Dr Tedrake.

In addition to walking on a variety of smooth surfaces, the robots may soon be taught to stride over more difficult terrain such as unlevelled sand, pebbles or even snow and ice.

Calculations of the energy used by the robots as they walk suggest they are quite energy-efficient, consuming about the same amount of calories that a human walker would to cover the same distance.

All the robots in the study move using a principle called passive-dynamic walking, which has been used for a century or more in a variety of walking toys that are, in effect, passive mechanical devices with moveable joints enabling them to walk down a slope under the force of gravity.

Writing in the journal Science, the scientists said: "Passive-dynamic walkers have no motors or controllers yet can have remarkably humanlike motions.

"This suggests that these machines are useful models of human locomotion. However, they cannot walk on level ground."

Applying a source of motorised movement to the principle of passive-dynamic walking produced a robot with a remarkable ability to walk like a human toddler.

The researchers said the development of robots capable of walking on two legs like humans would help scientists to understand human movement better as well as aiding the development of a new generation of robotic artificial legs for accident victims.

- INDEPENDENT