VEX robot (which we called Oedipus RHex) started to
undulate across the floor. The gear train appeared to have
the perfect amount of torque to move the bot around,
even if the gait was nowhere as smooth as the OutRunner
(or Kod*Lab's RHex, for that matter).
We positioned Oedipus RHex at the start of our
obstacle course. The bot climbed over the thinner physics
textbooks like a nimble animal (or perhaps tipsy was more
like it), negotiating uneven terrain in the wild. When it
reached the thick calculus textbook, it sailed over the
volume of differential equations and integrals like many a
newly minted undergrad only wished they could.
Encouraged by the success of Oedipus RHex, we
equipped the Scribbler with two of the legs to see if it
might fare better than it did the first time. Despite the
Scribbler's lower torque, the legs allowed it to at least
climb over the first obstacle. Not much, but an
improvement nonetheless. Overall, we were very amused
by the gaits achieved by the robots.
With our home-hacked version of RHex motion, we
learned that it takes more than a torque heavy drive train
and some legs to make a walking robot — even if the
walking you're referring to is merely the recreation of a
simple mechanical model for the efficiencies of an
animal's gait. The Scribbler demonstrated that it takes
more than just slapping some legs onto rotary motors to
make a walker. You also need torque to overcome the
momentum created by the legs.
Oedipus RHex was better able to surmount obstacles
with its new appendages, but our design did not seem to
take great advantages of the efficiencies of a SLIP. Our
As we've shown here, you don't necessarily need
a university lab or Kickstarter funding to build a fun
robot that draws inspiration from biological systems
and sophisticated mechanical models. As always, the
only thing you need is your imagination and the
curiosity to go out and build something SV
74 SERVO 08.2014
READY TO GIVE CALCULUS ANOTHER TRY.
LEAPING SEVERAL COURSE’S WORTH OF
MATHEMATICS IN A FEW BOUNDS.