sulfuric acid. Some experimenters
opted for 110 volts from a wall plug
as AC motors were cheaper and
more available. Of course, the poor
robot was tethered to the wall by a
long cord.
Early Toys and
Toy Robots
Toys in the ‘50s began to have
battery-powered DC motors; usually
three volts. Remotely controlled cars with
a wired handheld remote control were
popular. Some toys even had attached
gear trains — great for the slower speeds
with the greater torque needed for
robots. It was a real plus if you could start
with one of those tinny imported robots
and peel it apart to modify it with
moving arms and head, or change its
walking mechanism in some way.
There were no LEDs in those days,
but many toy robots had little colored
three volt incandescent bulbs for
eyes that could be used in another
location. Of course, the purists would
scream if the robot was even taken
out of its original box and would cry
in their beer if it was taken apart.
Today’s Selection
of Robots
Let’s jump ahead 50 years to the
present without even looking at the
robots available 20 or 30 years ago.
Money is a bit tight these days for all of
us but that hasn’t stopped entrepreneurial
companies from developing some
amazing robots for experimenters.
For that matter, experimenters have,
themselves, developed some cutting-edge robots that have been exhibited
at conferences and exhibitions around
the world.
Kids as young as kindergarten age
have learned robotic techniques and
programming that wasn’t even
available to university level students a
few decades ago. Companies such as
LEGO, Robotis, Parallax, and others
have brought affordable and capable
robotics kits to youngsters to teach
them this exciting science.
What were the key ingredients
that made all this possible? Well, I
believe that all of us will probably say
80 SERVO 08.2008
that it was the personal computer and
the ability for the average person to
program simple microcontrollers to
control some fairly sophisticated
robots. The microprocessor came
first as the core of the PC, with the
microcontroller making the scene a bit
later. The latter did not require the
higher level languages needed to
communicate with humans; only for a
robot to understand a suite of sensors
and control some functions by driving
a motor(s). Simple languages and low
prices brought the microcontroller
within the budget of even the most
cost-conscious robot experimenter.
You might ask, “What about the
mechanical aspects of robotics?” A
robot is not a robot without some
sort of mechanical means to affect its
environment; whether that be to just
roam about an area or manipulate
something with an arm and end-effector. Low cost motors, and
especially gearmotors, allowed
builders to add all sorts of movement
to their robots. The model airplane
servo that I mentioned earlier was a
boon for those who did not have the
mechanical expertise to hook up a
set of surplus gearmotors to some
wheels. These ready-made drive
motors were ideal to drive small tabletop robots when they were hacked to
obtain continuous rotation.
They also had the advantage of
being able to listen to a microcontroller’s generated series of pulses
right out of the box. Inexpensive
active IR and ultrasonic rangefinders,
compass modules, GPS receivers, color
detectors, image recognizing cameras,
and a host of other sensors provide
today’s robot experimenters with
amazing capabilities.
Combat Robots
Another real turning point in
build-it-yourself robots was the growing
interest in combat robots — robots that
battled each other until one finally
beat the other. In the beginning and for
many years afterward, there were no
kits available for these types of robots
so the prospective robot warrior had
to design and build his or her own.
The earliest combat robots had fairly
weak weapons and many went on to
win a contest by simply sliding under its
opponent to prevent it from moving
away. Virtually all of the combat robots
were and are remotely controlled by
model aircraft types of radio systems,
though there are a few purists who
have built some fairly sophisticated
autonomous robots for the combat
arena. The sport reached a pinnacle
when the Comedy Channel aired the
popular BattleBots series. The weight
classes greatly expanded from the initial
light-middle-heavy weights to categories
from ant weight to super heavyweight.
Robots Progress
to the Future
So, how have things changed
over the years in the way we’ve
constructed our robots? We started
out with simple sketches on paper
and many of us have progressed to
CAD programs and finite element
analysis software on our computers.
Grey Walter’s robot tortoise (amazing
for the time) was a simply constructed
thing with a bent tin structure and
household-type fasteners. We have
progressed from mostly plywood and
wood with steel inner structures to
plastic with aluminum structures, and
even titanium for many combat robots.
Battery technology has advanced
from the early dry cells and lead acid
batteries of Walter’s time past nickel
cadmium to expendable alkaline cells
and lithium polymer, lithium-ion batteries,
and even fuel cells. Robot power
started with inefficient series-wound DC
motors and evolved to the very efficient
rare-earth field and coreless motors of
today. Relay and hard-wired logic gave
way to microprocessors such as the
6502 and the latter microcontrollers
such as the 68HC11, PIC, and others.
Rudimentary light detection and
vision arose from the lowly cadmium
sulfide photo cell to true vision with video
cameras and intelligent CCD/CMOS
cameras such as the CMU cam. The
dream of affordable speech recognition
systems is now a reality for our robots.
Have we reached the epitome of
robot evolution? Our robots cannot
only recognize our faces but they can
respond to our voices and commands
