IT TAKES humans a year or so to learn to stand and walk on two legs, but a
Swedish robot called Elvis might do it in a matter of weeks.
If Elvis, a 40-centimetre-tall humanoid, manages to stand at all, it will be
a remarkable feat. Designing robots that can balance well has proved to be
extremely difficult. So rather than trying to do it themselves, Elvis’s creators
plan to let “evolutionary” software do all the hard work.
The researchers, at Gothenborg University in Sweden, plan to use algorithms
that mimic genetic mutation to “breed” the robot’s control systems by natural
selection. They hope this will let Elvis not only stand but also walk, navigate
and perceive the world—all without anyone knowing exactly how it does
it.
According to Peter Nordin, the project coordinator, tough problems such as
balance are often skirted around in robot building because they are so difficult
to solve. But with Elvis, they have tried to tackle the problem head on by
making the robot as unconstrained as possible, so it can work in a world
designed for humans. “People are the standard for almost all interactions in our
world—tools and machines are adapted to the abilities, motion capabilities
and geometry of humans,” says Nordin.
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Elvis was named after the king of rock’n’roll because they “thought it had
very good hip movement”, say Anders Eriksson, the team’s artificial intelligence
expert. The robot resembles the foot soldiers in Star Wars Episode 1:
The Phantom Menace. It lacks skin and has a steel skeleton on which are
mounted various devices, such as pressure sensors, limb actuators and
gyroscopes that check its orientation, as well as cameras and microphones.
The evolutionary routine works in much the same way as the biological
process. A simple control system is designed as a starting point, and the string
of binary data that describes it is treated as though it were genetic
code—a digital “chromosome”.
This code is randomly mutated a hundred times and each product is given a
fitness evaluation—in the case of Elvis, based on how well he balances.
The best are bred together to produce a new and hopefully even better
chromosome. This is then mutated again, and the process repeated until a
chromosome is produced that does the job robustly and efficiently.
During the evaluation process, Elvis will sit in a harness to prevent it from
damaging itself when it falls over. Sensors in its feet and gyroscopes will
detect when it is about to topple. Since hundreds of mutations have to be
evaluated, the process should take weeks to complete. Already, Elvis’s vision
and auditory systems have been “evolved”, enabling Elvis to see and hear. “What
we hope for is that we can evolve a way of walking so the robot moves smoothly,
conserves energy and balances when provoked,” says Nordin.
The team will report on their progress next month at the European Conference
on Artificial Life in Lausanne, Switzerland. The first tests are due to begin in
early autumn.
