One small step for mankind remains too much for robots

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WOULDN’T it be nice to have your own butler, chauffeur or cook? Robotics holds the promise of servants for everyone. Unfortunately, there’s still some way to go before that promise is fulfilled. Scientists have learned the hard way just how complicated day-to-day tasks can be.

Last year the Pentagon sponsored a race for robotic cars. About 26 million was spent on designing and building a total of 20 vehicles. In theory, the cars were designed to drive themselves across 150 miles of the burning-hot Mojave desert.

In reality, many of them did not even make it through a short obstacle course of traffic cones. Those that survived the traffic cones failed with the desert. Within a few miles they had all crashed into rocks or become stuck in ditches. The best managed just seven miles.

Robotics began in earnest in 1961, when workers at the General Motors plant in New Jersey were joined by a strange new colleague.

It was called Unimate, weighed nearly two tonnes, worked unnaturally fast at an unpleasant task - and could do so all day without losing concentration or needing a tea break. It also never answered back. Soon thousands of robots like Unimate were doing production line jobs such as welding, soldering or painting.

There, however, the robot invasion stalled. So far, robots haven’t made it beyond performing the most simple and menial of jobs.

It’s just as well Unimate didn’t need a tea break. Going to the coffee room and making a cup of tea is a task that would defeat even the most sophisticated robot.

Why, after decades of research and billions of pounds of investment, are robots so ineffective? It turns out that many of the things we take for granted are very difficult indeed.

Take walking, for example. Walking is a complicated and dangerous affair. It involves throwing yourself forward, falling from foot to foot, and somehow maintaining your balance while weaving around obstacles (including moving ones).

Computers which are powerful enough to beat a chess master quite literally fall down when it comes to walking. Androids (humanoid robots) make do with a pigeon-step shuffle, which is stable but slow - and only works on smooth floors. They also bump into things a lot.

Wheels offer an easier alternative: in robotics, it’s "Four wheels good, two legs bad". Unfortunately for the machines, legs are unbeatable when it comes to moving around those parts of the world that haven’t been paved. Unlike wheels, legs can handle rough terrain and clamber over all sorts of obstacles.

The difficulty is not in engineering the joints and limbs, but in sensing changes in the outside world and responding appropriately to them. The world is an unpredictable and constantly changing place. Handling these changes is what throws the robots.

In the factory, things can be arranged to be just as required - with each piece in exactly the right place, a robot simply repeats a pre-recorded set of moves.

The rest of the world is not so precisely ordered. With walking, small imbalances are inevitable. Unchecked, these wobbles quickly grow until, within a few paces, the robot has fallen over.

As you walk, you are integrating a flood of data. Proprioception - the sense of what your body is doing - gives information on the position of your limbs and changes in your balance.

To stay upright you have to take this information, factor in the effects of momentum and react almost instantaneously with dozens of muscles.

The mathematics of this makes sending a rocket to the moon look like primary-school arithmetic - and yet you do it without even noticing.

Meanwhile your eyes supply a stream of raw vision data - in effect, an ever-changing grid of numbers. Processing this to recognise the objects in your path is a remarkably difficult task. Which is why, in spite of having arrays of cameras, range-finding lasers and sonar sensors, the Pentagon’s robot cars still drove head-first into big rocks.

Slowly, progress is being made. Japan’s Riken Institute, with Edinburgh University, have built a robot that can throw and catch well enough to juggle three balls.

At a press conference in Japan, a figure resembling a miniature spaceman slowly walks on stage.

This is Sony’s QRIO robot; almost insufferably cute, but also one of the most advanced robots yet built. Its gait, though still more of a shuffle than a walk, is more fluid than previous machines, and it can cope with shallow stairs and slightly uneven surfaces. It waves, bows and chirps.

The audience clap enthusiastically. They then leave to do a hundred and one things that QRIO can’t - without any applause at all.

Robot butlers will arrive eventually, but it will probably be 15 years or more before RoboJeeves serves you a drink.

For the time being, when you put this newspaper down, reflect on the impressive brainpower such ordinary acts require - and remember to clap next time you see someone walking.

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