Rolling a piece of chalk between
your fingers or, adjusting your
grip on a pen, requires dexterity
that comes naturally to humans,
but is incredibly difficult to
program in robots. Now engineers
at MIT have come up with a way
to improve the dexterity of
robots, using the environment.
In an approach they call
"extrinsic dexterity," a simple
robotic gripper exerts specific,
calibrated forces against
fixtures in the environment,
to adjust its grip on an object.
Here, a robot grips a rod lightly
while pushing against a tabletop.
The combination of the table's
surface, and the robot's grip,
rotates the rod between the
robot's fingers: a motion that
would be difficult to perform
only with the robot's grippers.
The robot can also pivot the rod
between its fingers, by pushing
against a book-end.
The researchers say that
extrinsic dexterity may enable
simple industrial robots to
perform more complex tasks,
particularly in manufacturing
and assembly line settings.