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The Learning Brick Sorter • Masterpiece 2 41

NOTE
I designed it to be easy to replicate from parts available in LEGO sets in current
production. If you own the RIS kit and the Ultimate Accessory Kit, you will need
very few additional parts. Moreover, most of the parts can be easily replaced
with other ones if you don’t have them. During the building steps, I will provide
some suggestions for replacing the less common parts.

Introduction

A few weeks after the LEGO MINDSTORMS Robotics Invention System (RIS) was
released in October1998, Huw Millington published an Automatic Brick Sorter on his
Web page www.brickset.com/huwhomepage/moc/mindstorms/abs1.At that time, I
believe this was the first robot of this type. Next, Dave Baum created a second type of
brick sorting machine, which can be seen at www.baumfamily.org/lego/creations/
sorter.html. In my eyes, this brick sorter was a work of genius as David’s interpretation of
a brick sorting robot solves the task with minimal configuration.
These examples are only the first two milestones; however, since the release of the
RIS, the theme of placing LEGO bricks into different bins according to their color has
been explored quite thoroughly through a variety of different of robotic creations.
That said, you might wonder what makes this particular Brick Sorter worthy of this
book? Although it shows some interesting building techniques and is a pleasant machine
to see in action, what sets this robot apart from other brick sorter is not its ability to sort
bricks by color, but rather its ability to learn how. Why is this feature so important? To
understand the point we must step back a bit from our brick sorter and consider a wider
perspective.

Machines that Learn

Let’s jump back to the time when you were a toddler and your parents taught you how
to walk. Did they really teach you how to walk in the same way a teacher explains his/her
pupils how to solve quadratic equations? I bet they didn’t. Parents don’t explain their chil-
dren how to walk, they show them how to walk.The difference is very important: if par-
ents had to explain the processes behind the apparently simple action of walking, they
should wait for their children to be old enough to understand the many principle of
physics which are involved, and would be a very challenging task for both the master and
the apprentice. In fact, if the aim of physics is to explain the world, then, from the
learner’s point of view, the contrary is equally true: the world is the best possible explana-
tion for physics.