entrants with their robots at
the Sample Return Robot
Challenge at the Worcester
Polytechnic Institute held back
in June 2012. This NASA-sponsored contest was
designed to attract teams and
their autonomous robots that
could perform a realistic lunar
(or even Martian) sampling
mission. Though the actual
runs were performed on the
grassy hills of the institute’s
campus, the robots were
designed to operate as if on
another world’s surface.
Eleven teams initially
registered for the
competition, but only six
made it to WPI in
Massachusetts for the start of
the challenge. With no air for
sonic distance and object
detection, the autonomous
machines had to rely on light
measurements in their
environment. No GPS or earth
magnetic field sensors could be used.
Laser Range Finder
Okay, your robot is on the Moon
and you want to avoid rocks and other
obstacles while you locate the cached
Moon soil sample and return it back to
the lander for eventual return to Earth.
What do you use as a visual sensor?
How about a Lightware SF02 laser
range finder (that’s also available at
Parallax for $349)? Yep, it’s a bit more
expensive, but the ultrasonic range
finder wouldn’t work on the Moon,
anyway. The SF02 shown in Figure 9
has a range of zero to 130 feet, and
measures distance via ‘time-of-flight’
pulsed laser bursts.
For earthly applications, it is not
affected by ambient light outdoors or
indoors (or on the Moon), wind, air
temperature, or changes in barometric
pressure. For a range distance four
times that of the ultrasonic range
finder — plus the fact it can work in
sunlight — this is a real deal.
Hacking a Neato
Laser Ranger and a
When Neato Robotics came out
with their line of vacuum cleaners
several years ago, the experimental
robotics community took notice. The
LIDAR unit shown in Figure 10 is from
a random-workshop blog where the
rotating unit has been
removed, opened up,
and then the plastic
tubes in front of the
sensors have been
Figure 11 is from
a National Instruments’
site where an
autonomous robot was
built using the Neato
laser ranger and a
sensor. Many people
have found used Neato
SERVO 10.2014 79
Figure 7. MaxBotix EZL1
10-meter range finder sensor.
Figure 8. NASA Sample Return Robot
Challenge at WPI.
Figure 9. Lightware SF02 40 meter
laser range finder.
Figure 10. Neato laser range finder.
Figure 11. Neato laser ranger and
Microsoft Kinect on a robot.