Page 16 - The Unofficial Guide to Lego Mindstorms Robots

5

He Ain't Heavy, He's My Robot

A good example of the "big iron" approach to mobile robots is Ambler,
developed by Carnegie Mellon University and the Jet Propulsion Laboratory.
This behemoth stands about 5m (16.4ft) tall, is up to 7m (23.0ft) wide,
and weights 2500 kg (5512 lb). It moves at a blistering 35 cm (13.8 in) per
minute. Just sitting still, it consumes 1400 W of power. Ask it to walk and
it sucks up just about 4000 W. You can see a photograph of Ambler at
http://ranier.oact.hq.nasa.gov/telerobotics_page/Photos/Ambler.jpg .

Small Is Beautiful

Little robot people like to tease the big robot people for building tremendously large, tremendously expensive machines that
don't have the dexterity of a six-month-old baby. The little robot people make small mobile robots based around inexpensive,
off-the-shelf parts. They like to see themselves as mavericks, achieving decent results at a fraction of the cost and complexity
of big robotics.

One of the interesting ideas behind small robot research is the idea that quantity might get the job done rather than quality.
Instead of building a single bulky, complex robot to explore the surface of Mars, why not send a thousand robots the size of
mice to do the same job? So what if a few of them fail? Small robots offer a new and innovative way to approach big
problems.

The small robotics approach reduces the number of engineers you need in your basement. It makes robotics accessible to
sophisticated hobbyists—people with technical knowledge and some extra time and money. If you take the small robot
approach, you'll probably use standard batteries for power, which eliminates the need for a chemical engineer to design a
power supply. Small robots are usually based on an existing, cheap microprocessor, which makes the electrical engineer's job a
little easier. But you still need quite a bit of expertise:

• The electrical engineer still has to select sensors and actuators and wire them to the microprocessor. These parts are
inexpensive and can be bought from hobby stores or electronics part stores.

• The computer programmer still needs a pretty low-level understanding of the microprocessor and the attached sensors and
actuators.

• You still need a mechanical engineer to design the robot's body.