How to make a robotic arm that is able to flex in an infinite number of ways
and order it to do so without disorder and confusion? Get yourself an octopus
and study
it. That is exactly what researchers funded by the Office of Naval Research
are doing.
Octopuses are boneless, brainy, and ancient invertebrates. They also have
quite a problem on their hands, er, arms. Because they lack a rigid skeleton,
the
octopus can perform its tasks— reaching for a target, for example —
in practically infinite ways. But, in order not to spend too much time in untying
its eight arms,
each arm must not move independently of one another.
“How the octopus controls each arm so that tasks can be performed without
chaos, and without the need to spend enormous time in deciding how to perform
a
specific arm movement, is precisely what robotics designers would like to know,”
says Tom McKenna, ONR Program Manager on this study.
What McKenna’s researchers* have discovered is quite remarkable. Apparently
the brain of an octopus, unlike our own brain, operates much like a general
in
command of his troops. The general issues an order, and while the troops carry
it out, the general goes on to other things, unaware of the details in how that
order
is carried out. Each arm appears to contain an independent peripheral nervous
system and neural circuitry, which carries out the order independent of any
further
involvement on the part of the brain itself.
The octopus is considered to be among the most developed and intelligent animals
in the invertebrate kingdom. Scientists have long been interested in how they
learn, memorize, and even solve rather complicated behavioral problems. Some
of these skills can be attributed to the high maneuverability of the arms and
the
capacity of the peripheral nervous system to perceive and process information.
“The objective of our study is to characterize control of the octopus
arm, which has no joints and is highly flexible,” says McKenna. “This
could very well be the basis
of next-generation robotic arms for undersea, space, as well as terrestrial
applications.”
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*Binyamin Hochner at the Hebrew University of Jerusalem and Tamar Flash at the Weizmann Institute in Rehovot Israel.
File Date: 01.08.02