There is a different path for creating robust powerful robot brains. However, you’re gonna have to go backwards to go forward with these alternate
If you ask 10 robot builders to describe the brain used
for controlling h/is/er creation, you’d hear names like
Arduino, PICAXE, and BASIC Stamp. Maybe even an Intel®
Edison, LEGO®, and Raspberry Pi will make the top 10 in
your robot builder’s survey. Regardless of the brand, all of
these “brains” are, in fact, microcontrollers which act like
miniature programmable computers for driving motors,
reading sensors, and flashing light emitting diodes (LEDs),
and, in general, controlling all of a robot’s hardware.
The emphasis on “all” is important in the above
microcontroller generality: Without programming, these
computerized robots are just expensive doorstops.
Programming a microcontroller is such a vital, yet daunting
task that the time consumed by developing robot software
can sometimes dwarf the time spent building the hardware.
Beyond the “resistor and transistor” robots of
yesteryear, today’s program-less robot brain is built from
digital integrated circuits (ICs) that require no programming.
Just design, build, and go. Likewise, these aren’t simple
robots, either. These are complex sensing/reacting robots
that are able to provide robust functions without high cost
components or labor-intensive programming. Make no
mistake — even within the context of the best ever written
generic description of robots, these microcontroller-less
robots are still robots.
So, rest assured, this article is not some wild,
harebrained, loopy attempt at discrediting microcontrollers
for employment as robot brains. Rather, it is a proposal for
an inexpensive complete robot controller alternative that
can deliver the equivalent functionality of programmed
control without the coding chore overhead.
So, let’s begin at the beginning ... bug brains!
An Introduction to Insects
Insects rule the world! Well, more
specifically, insects (or, even more
specifically, Class Insecta of the Phylum
Arthropoda) are the largest group of
animals in the world. Representing
nearly three-fourths of all known animal
types, insects collectively include around
one million identified species.
Unfortunately, most of us humans think
that all insects are pests. Swat a
mosquito. Pest! Swish away a fly. Pest!
Smash a cockroach. Pest! Pest! Pest!
Not every insect is a pest, however.
Honey bees, butterflies, and ladybird beetles are all
benevolent to humans. Some insects with disgusting habits
(e.g., carrion beetles) benefit humans by scavenging on
dead animals and decaying vegetation. (Hey, it’s better a
beetle does this dirty work than us, right?) Then, there are
the countless numbers of insects that serve as a food
source for vertebrates, such as caddisflies which are
beneficial to freshwater fish.
Yes, it’s a mixed bag with the insect world. From
disease vectors and agricultural pests to pollinators and
essential food chain units or producers, insects can be both
a nuisance and an invaluable ingredient for life.
While all insects have six legs (see Figure 1), it’s the
size and shape of a bug’s leg that determines the movers
from the swimmers and the jumpers from the walkers.
Regardless of the type of locomotion, an insect’s leg begins
at the body with the coxa segment, followed by the
trochanter, femur, and tibia, then, concludes at the tip of
the leg with the tarsus.
In order to move, an insect must have some sort of
controller or system for triggering leg movement. This
control is the function of an insect’s nervous system.
The nervous system in insects consists of ganglia or
masses of nerve cells that are organized in the insect’s head
(i.e., brain), as well as a long nerve cord that runs along the
underside of its body (i.e., ventral nerve cord). Nerves also
extend from these centralized ganglia into other parts of
the bug’s body.
Getting from point A to point B looks effortless for an
insect. Although the reasoning behind a bug’s movements
seems equally pointless to us, they do appear to be
relentless in the pursuit of their goal — whatever that goal is.
Ants, butterflies, and bees all act like they’re going to
some big event. But what? A lot of seemingly anxious, well
orchestrated mass movement — but where’s the party,
Build a Better Bot Brain
SERVO 11.2015 39
Figure 1. Newly emerged Eastern Lubber grasshoppers.