A DIM-WITTED robot may survive in circumstances where smarter devices would
fail. Next year, a robotic scorpion built on this principle will try to make its
way 80 kilometres across the Mojave desert in California, using little more than
programmed automatic reflexes to survive.
Unlike many traditionally designed robots, the 50-centimetre-long scorpion
designed by Frank Kirchner and Alan Rudolph at Northeastern University in Boston
does not have the ability to solve extremely complex problems. This, says
Kirchner, is entirely deliberate.
鈥淲e can develop complex machine-learning algorithms that solve high-level
problems,鈥� Kirchner says. But this could get the robot into trouble, if solving
complicated problems led it into simple errors. Simpler robots are more robust,
he argues.
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The researchers spent a long time observing how real scorpions move before
trying to reverse-engineer them. 鈥淲e filmed live scorpions using high-speed
cameras and analysed the video data,鈥� says Kirchner. The team chose scorpions as
the model for their robot partly because the creatures can move so easily over
tough terrain, and partly because their reflexes are much simpler than a
尘补尘尘补濒鈥檚.
The robot scorpion relies almost entirely on its reflexes when confronted by
a problem. This allows it to compensate immediately for anything that might
destabilise it, such as a leg stumbling on a rock. The robot has two ultrasonic
sensors at the front. 鈥淚f it comes across an obstacle more than 50 per cent of
its height it will try to go round it,鈥� says Kirchner. So if the left-hand
sensor detects a high obstacle, the robot automatically turns right.
The robotic scorpion will set out on its desert odyssey next year with little
more than a compass and a map reference to guide it to a target 40 kilometres
away. Its task will be to travel across the desert, reach the target and find
its way back again.
The project has been sponsored by the US Defense Advanced Research Projects
Agency. The military expect the scorpion鈥檚 autonomy to be useful for
reconnaissance. It could be told to go to a particular location to send images
back to base from the camera in its tail. The army was impressed with trials of
the scorpion earlier this year at an urban combat centre in Arizona called
Desolate City.
The robot鈥檚 ability to find its own way to a target area would be
particularly useful in cluttered battlefields such as towns, where changes as
simple as opening a door could put off less adaptable machines.
The importance of reflexes is underestimated when it comes to problem
solving, says Barbara Webb, a roboticist at Stirling University in Scotland who
models the neural activity of crickets. 鈥溾�楩iguring out鈥� doesn鈥檛 necessarily
require logical reasoning. It can occur as much from just trying things out to
see if they work,鈥� she says. To an observer this can look as though there鈥檚 more
going on than simple trial and error.
