The aspiration of many robot hobbyists is to create a machine that
uses autonomous behavior to achieve a goal. Unfortunately, many
roboticists assume that such goals are limited to simple tasks like
avoiding objects or following a line. This article discusses how giving
your robot even a rudimentary ability to identify objects can increase
its ability to cope with more complex situations.
Robotic Sensors
Part 1: Identify
and Distinguish
by John Blankenship and Samuel Mishal
www.servomagazine.com/index.php?/magazine/article/march2013_Blankenship
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Atypical hobby-level robot might avoid objects while it randomly roams around a room. Nearly all hobbyists
have observed such a behavior,
and only a novice will be overly
impressed by the capabilities of
such a robot. In actuality, the
robot’s random movement is the
source of discontent. The robot’s
only goal is the avoidance of
anything that gets in its way. If the
robot could identify important
objects, then its ability to react to
its environment could be greatly
improved.
If, for example, the robot
could identify both a soccer ball
and a goal, then it could be
programmed to find the ball and
deliver it to that goal. The task of
avoiding other objects during this
endeavor then becomes a means
58 SERVO 03.2013
to an end, rather than a goal of its
own.
Programming a robot to
actually play soccer can be very
ambitious, but a simplified version
of this activity can help
demonstrate how even just a
hobby robot can identify objects
within its environment.
The Needed Sensors
In order to achieve this task, our
robot will need to have several types
of sensors. The details of the
algorithm we develop will depend
heavily on the actual sensors used. So,
we will use a modular approach to
make it easy to implement the
principles discussed here with sensors
you might already have.
First, our robot will need a
ranging sensor capable of measuring
the distance to objects. We’ll use an
ultrasonic sensor mounted with a
forward orientation. The purpose of
this sensor will be to locate objects
that are reasonably close to the robot.
