Robotics Reference
In-Depth Information
Figure 64.
A Golem project robot-produced robot (Courtesy of Hod Lipson and Jordan
Pollack)
ality. Their bodies, which exist only as points and lines, were first con-
verted into a solid model, with ball-joints and housings for motors ac-
cording to the evolved design. This solidifying stage was performed
by a program which combined the various pre-designed components.
The virtual solid bodies were then manufactured using commercial rapid
prototyping technology. This prototyping machine used a temperature-
controlled head to squeeze out a heated plastic material layer by layer,
so that the evolved shape emerged as a solid three-dimensional structure
without the need for human intervention. The entire pre-assembled ma-
chine was printed as a single unit, with fine plastic supports connecting
between moving parts; these supports broke away the first time the struc-
ture moved, leaving structures containing complex joints that would be
difficult to design or manufacture using traditional methods. Motors
were then snapped in, and the evolved neural network was run on a
micro-controller in order to activate the motors. The physical machines
faithfully reproduced their virtual ancestors' behavior. In spite of the rel-
atively simple task and environment, surprisingly different and elaborate
solutions were evolved.
Although prototyping machines such as three-dimensional printers
are large and cumbersome, Lipson believes that much smaller ones could
one day be built into a robot, allowing it to change parts of its body,
for example, to reshape an arm in order to produce a new tool for a
