Twin Tweaks ...
HOUSE ROBOT MARK III.
most entertaining way to test the capabilities of our
projects is through a little friendly competition. Our dad’s
Mark III robot is as ready to perform as a fixture at a Las
Vegas hotel, even though the low profile Sumo robot is far
more used to flat terrain than the uneven track of the
Cirque du Robot.
To make our obstacle course, we started with the LEGO
THE STOCKY MARK III DOES NOT APPRECIATE OBSTACLES.
74 SERVO 01.2011
line following track and put ramps to one side of the line.
We wanted one wheel of the robot to be picked up by the
ramp, shifting the center of mass beyond the wheelbase
until the robot tipped over in maladroit shame. To make
sure that our ramps were sufficiently devious, we tested
them on our balancing robot sans balancing rod. Our line
following program toodled along just fine until it hit a
ramp, but then our top heavy bot tipped over like a drunk
elephant on a tightrope. Oh the Zumanity!
Likely buoyed by the embarrassing performance of its
rival, the Mark III was ready to take a run around the track.
The Mark III has a fairly low center of gravity, as is
characteristic of a robot designed for Sumo competition.
The robot also has a narrow wheelbase, and a ramp of
decent height would knock it over. The ramps on the track
were indeed high enough, and the Mark III pratfalled like a
Now that the suspense had been deftly cultivated, we
reattached the balancing arm to our NXT bot for another
run. The line following began without incident, and as the
robot ascended the ramp our balancing arm swung to life.
Like a well trained performer, the SmartSensor Lite directed
the arm back to a level position, and the robot was able to
conquer the ramp. The obstacle didn’t even distract the bot
from the line following track. Thus, the SmartSensor Lite
and NXT programming was vindicated by the less rapid
balancing act of the balancing beam, which demonstrated
that the NXT kit is accommodating to sophisticated third
party sensors and the CATCAN sensor adds useful motion
measuring capability to the NXT.
C’estla Fin de l’Article
Even though our project focused more on a plug and
play application of the CATCAN device, the charms of the
SmartSensor Lite for advanced roboticists are obvious. The
module can create sophisticated robot behaviors (like
balancing on two wheels) implementing more advanced
WITHOUT A BALANCING ROD, THE BOT IS A