Minesweeping robots apply to the US Army

CHARLES ARTHUR

Science Correspondent

"I'm not aiming to populate the world with machines that will replace us, but with ones that will go where we don't want to," Mark Tilden said yesterday, as he watched one of his robot creations flop its way methodically across a table.

Despite his Indiana Jones hat, Mr Tilden is very serious: he is presently negotiating a contract which could mean that by the end of the year, some of his robots will have a job sweeping a United States Army testing range for unexploded munitions.

In years to come they could clear minefields in countries such as Vietnam, Korea, the Gulf states and any of 60 others where buried mines still pose a hazard to citizens.

"The object isn't just to make machines that will find the mines, but to make them cheap, and be able to blow them up without human control," he observed, as he showed off the "snakebot" - a four-sectioned, battery- powered robot about 2ft long, which propels itself along the ground sideways, by rotating its sections.

He plans to build a 7ft one: that would be ideal for finding mines as its weight would set them off. He is also devising a "walking machine" 5ft high, to perform the same function.

Mr Tilden, a biophysicist from the Los Alamos research laboratories in New Mexico, builds robots which diverge from the conventional concept of a shuffling humanoid with diodes for eyes and a grating voice.

Instead, he uses the minimum of parts (at most 24 transistors - "fewer than a radio") and gives them simple aims, such as to seek out bright light to power their solar cells. But once they can do that, he can give them more complex aims. More interestingly, he says, once you exceed about eight transistors, the machine's exact behaviour is unpredictable, though its goals remain the same.

If anyone says that his insect-like machines look ugly, he responds: "You can't have a minesweeping robot that looks cute. People will get attached to it, and then they won't send it out to do its job."

Mr Tilden was showing off some of his collection yesterday in Glasgow, at the Robotix '96 show in Barony Hall, Rottenrow. But while they might excel at finding mines, his devices are unlikely to compete in the events today in the "Robot Olympics", which include robots competing at javelin throwing, sumo wrestling, wall-climbing, rugby and sprinting.

Human athletes can probably rest on their laurels a little while longer, though. The present British robot javelin record is 2m - about 50 times less than the human one.