Designing and Building a
by Brian Benson
for the first time can be
a very daunting task.
Robots consist of many
subsystems, all of which
must work seamlessly
in order for the robot to
function properly. The
challenge in designing
and building a robot
is not only in fully
subsystems and making
them work together, but
doing it in a way that has
never been done before.
When you are creating a
custom robot, there is no manual,
instructions, or tech support. You
start with a blank slate, with
thousands of options available to you.
You have to ask yourself and answer
questions like “How big will it be? What
will power it? What materials will I use
for the frame?” and many more. With
an unstructured approach, this can
seem like an impossible task. However,
if you approach the problem with a
plan, breaking down the problem into
chunks, it is not as difficult as it seems!
In this series of articles, I will
be discussing how to go through the
entire process of designing and
building a custom robot. I’ll show you
how to break the process down into
manageable chunks and see to it that
the idea in your head turns into a reality.
damage. Notice that I didn’t specify how
I wanted to cause large amounts of damage; there should be no “how” in a problem statement — only a “what or why.”
The most common example of a
good problem statement is for mowing
the lawn. “We need a better product to
mow the lawn” is flawed, because it limits you to only ways to mow the lawn.
However, “We need a new, innovate
way to keep lawns looking good” opens
up a completely new set of possibilities.
A good goal statement will help to
direct your design from start to finish.
Identify the Goal
Every engineering challenge begins
with a goal or problem statement that
clearly and concisely lays out what you
want to achieve. It should describe what
the purpose and strategy of the robot
is. It should not, however, limit or direct
what the final design will be.
My background is in combat
robotics, so I will be discussing the design
process for that type of robot. As an
example, I have decided I want to build a
competitive, offensive based robot that
has the capability to knock out other
robots by causing large amounts of
After identifying qualitatively what I
want the robot to do, I need to decide on
a set of design specifications. This is a list
of criteria that describes the robot quantitatively and will begin to answer questions
like “How many wheels? What is the
maximum weight? How fast will it move?”
It needs to be as specific as possible to
make the design process easier later on.
The best type of specifications are
ones that can be measured, so that
throughout the design process you can
evaluate how well your design is meeting your goal. For my planned robot,
the design specifications are as follows:
• Combat robot for fighting in national
• Middleweight weight class (120 pound
• Four-wheel drive
62 SERVO 03.2008