Then
and
NOW
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Sensors for Mobile Robots — Part 4
by Tom Carroll
There comes a time in the minds of every robot
experimenter when they just sit back and wonder
what would be the ideal robot. I know that I
have. Notice that I didn't say what a robot would
look like or even act like. It’s what they could be,
as in a personality of sorts. I never wanted a
robot that looked so much like a human that it
would fall into the depths of the 'Uncanny Valley,'
where it was close to a human likeness but just
enough unlike a human to be weird and creepy.
Having a robot that looked like Robin Williams in
the very first scenes of the movie, Bicentennial
Man, would be great since Williams had just
enough of a robot costume on (as shown in
Figure 1) that he was unmistakably a robot and not a human. I believe we are finally
coming a lot closer to this type of robot with smart sensors like Microsoft's Kinect and
similar gesture and speech recognition devices. It is these very smart sensors that I will
discuss to close this series on sensors.
FIGURE 1. Robin Williams as the 'robot' in the film
Bicentennial Man.
74 SERVO 09.2012
The previous part of my sensor series (in the July ‘ 12 issue) covered localization and some specialized types of
sensors, such as gas sensors. Robot-specific sensors can
range from a simple resistor in series with a motor to
measure current and loading, to complex laser imagers,
range finders, and similar devices. Today’s sensors —
especially vision sensors — are many magnitudes better than
those of just a few years ago.
I want to cover some of the more unique sensors in
this final part, such as visual image and voice recognition
sensors. These are not necessarily video cameras that just
convert the image of a particular scene into a video signal
that a human can view, but are actually intelligent sensors
that process an image or verbal command into useful
information that a robot can utilize for control functions.
Facial recognition is another capability of these newer
sensors that can give the robot the appearance of having a
distinct personality.
Early Speech Recognition
for Robots
Let’s step back a few years and imagine you live in a
‘smart’ house. It’s 1987 and in this scenario, you unlock the
front door of your house and enter. A PIR (passive infrared
sensor) is mounted on the far wall and has detected your
presence.
Across the room you hear, “Welcome. Who is this?”
“It’s Joe, Lucy. Please turn on the lights.” The black
Mastervoice box mounted on the wall sends an X- 10 signal
through the house’s wiring to an X- 10 receiver module
plugged into a wall socket. The table lamp lights up.
“Turn on the TV, Lucy.” The TV turns on and warms up
(it’s a CRT type TV) and you find that a soap opera is on
the channel. You hunt for the remote, find it, and flip
through some channels to find the news station that you
wanted.
