ROBOGAMES Prep
months planning, researching, and
finding parts.” Two weeks to build a
suit – and here you have six months
to get ready for the June 2007
competition.
“As a 17-year-old kid at the time, I
really didn’t know what I was doing,
nor did I have a lot of capital available.
All I had was my hobbyist knowledge
and whatever calculus and physics I
had learned in high school. I had no
CAD software so I had to be very care-
ful designing things. The entire project
was done in my garage with only basic
tools and a Sherline milling machine. I
had just about everything working
against me and I still believe it was a
miracle that the suit worked at all.” But
it did work! Think what Bryan will be
able to do next time.
If you’re worried about control,
you should be. Both Bryan and Alex
make the point that balance and
controls are crucial. “Without good
TETSUJIN RULES
● Suit can be up to three meters ( 9. 84
feet) in height and cannot exceed 1.5
meters ( 4.92 feet) in diameter.
● Challenge 1 — Ascend stairs in
your suit to the lifting platform and
lift a load of from 100 to 1,000 lbs
from a squatting position to a height
of at least 24 inches, return the
load to the ground in a controlled
manner, and descend the stairs.
Stair-climbing may be unpowered.
The winner is the competitor who
lifts the largest weight.
human operator (e.g., to make the
suit squat, the operator squats; to
lift a load with the suit arms, the
operator’s arms make the necessary
lifting motions). This can be as simple
as micro-switches and limit switches
or as complex as closed-loop servo
control and bio-electric sensors.
● All power for the exoskeleton and
any required support systems must
be provided by a self-contained
system. The system may incorporate
remote components connected via
a tether, wireless link, etc.
● Challenge 2 — Dexterity. Stack nine
concrete cylinders weighing ~70
pounds each in a 4-3-2 vertical
arrangement. The winner is the
competitor who arranges the
cylinders in the shortest time.
● Challenge 3 — Walking Race. Walk
the challenge course carrying a load
in the shortest time. A time bonus is
granted based on the load carried.
● The tasks(s) must be accomplished by powered elements
that are an integral part of the
exoskeleton in response to the
operator’s movements. External
devices such as winches, support
frames, jacks, etc., are not allowed.
● The operator must be inside the
suit in order to operate it.
● The suit must provide sufficient
articulation in the powered
components to track the movements
of the human operator to meet the
challenge.
● The exoskeleton must be able to
balance and support itself, the
operator, and the load without the
use of outriggers, auxiliary braces,
etc., other than its own legs and feet.
A fixed base is allowed for the
Cylinder Stacking challenge.
● Stored mechanical energy devices
such as springs, torsion bars, gas
struts flywheels, etc., are all allowed.
● Movement of the suit’s powered
components must be initiated by —
and track — the movements of the
● The exoskeleton shall have a
removable power link that disables
all operation.
controls, it is very difficult to attain
balance which is the biggest problem
that I faced in the competition,” says
Brian. “My suit lost balance on several
occasions throughout the competition
which was a pretty scary experience.”
Alex adds, “Most people focus
their attention on the mechanics
because that is the area they are
most comfortable with. They ignore
the control system which can be very
complex.”
“The coolest part of the suit was
that the control system read the
electrical signals directly from my
muscles and controlled the pneumatic
suit based on these signals. This
resulted in my muscles receiving
assistance from the suit ‘on demand’
(as my muscles required more
assistance, the pneumatic system
would deliver more assistance to the
muscles that required it).”
Like all robots, failures are bound
to happen while building your suit.
Although Alex had tested all of the
components of the suit, he did
not leave enough time to test all
components of the suit together. His
pneumatic hose connections developed leaks because they were not
properly fastened, and he ended up
losing air pressure. This resulted in him
not being able to complete the walking
competition at RoboGames 2006.
Start simple and enhance as you
succeed. As Alex says, “In the original
Tetsujin competition and in RoboGames 2006, I talked to many people
who were interested in competing.
Most of them had grand ideas that
sounded really cool but I have never
seen one of them work. Start with
small successes and build from there.”
But just building a suit is success
in itself. Bryan says, “to this day, I contribute more and more of my success
[in life] to the Tetsujin competition. It
was amazing to finally get the suit
working the morning of the competition and to get up on the platform in
front of hundreds of people to perform
the lifts. That was the instant success
but it was only a taste of what was to
come. As I was only a high school
junior at the time of the competition, I
70 SERVO 01.2007
