bots IN BRIEF
BIRDS AND THE BUGS
No matter how fancy and complicated we make robots, nature
always seems to have us beat. For example, is there anything more
capable, more efficient, and more indestructible than a cockroach? Of
course not. Well, not yet, anyway. UC Berkeley's Biomimetic Millisystems
Lab is trying to harness all the cleverness of birds and insects to create
an entirely new generation of small robots with insect-like capabilities,
and one of their most recent creations is called "Octoroach."
Octoroach has eight compliant legs and is small enough and light
enough to rest comfortably in your hand. Batteries, sensors, and
navigation are all completely integrated. Eventually, Octoroach is
destined for the military to provide that last 100 meters of vital close-up surveillance. Of course, if 100 meters ends up being too far, you can
just drop off your robo-roaches using robo-birds like BOLT — which
stands for "Bipedal Ornithopter for Locomotion Transitioning." It's got a
pair of little legs under its wings, and it can skitter around on the
ground and over obstacles saving energy by not flying unless it has to.
Berkeley is also working on a second ornithopter called iBird which is
capable of flying towards a reflective target completely autonomously.
PIGORASS is a pneumatically-driven quadruped
robot developed by Yasunori Yamada, Satoshi
Nishikawa, Kazuya Shida, and Yasuo Kuniyoshi at the ISI
(Intelligent Systems and Informatics) Lab — the same
lab that brought us the jumping robot Mowgli and the
running Athlete Robot. PIGORASS: its skeleton (made
of ABS resin and carbon fiber reinforced plastic), 10
artificial pneumatic muscles, and 10 passive spring
muscles weigh only 4 kg ( 8. 8 lbs). Its total body length
is only 35 cm ( 13?) long. The artificial muscles are
driven by an external air compressor, and pressure
sensors and potentiometers replicate how real muscles
sense their length and tension.
What’s noteworthy about PIGORASS is that its
movements are not programmed in advance (as you would with robots using conventional motors). They emerge from the
structure of its body and fluctuating signals from each muscle’s neural oscillator using what is called a spinobulbar model. The
neurons that individually control each muscle can fire in pairs (alternating between front and hind legs) to perform a kind of
gallop, or fire all at once to produce a jumping motion.
22 SERVO 11.2011