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<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Brainstorming Sensors<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>What sensors we need depend on what
we want our robot to do. If I want a robot to paint a car body, sensors
are not a problem. An ultrasonic sensor can detect that a body is in the
work station. Encoders can measure joint angles and from that I can calculate
the location of the paint nozzle. A flow meter can tell me if paint is
actually being painted. I think what many of us want is a robot that can
navigate in the real world and interact with or manipulate objects (including
people) in that world. Hobby robotics contests are simplifications of the
real world as chess is a simplification of war. <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Presently we use ultrasonic sensors
for obstacle detection, sometimes specialized to finding walls and doors, and
sometimes for localization and mapping. Sharp range finders and laser
range finders are used for the same tasks. Bumper switches are used for
obstacle detection. The primary sensor that humans use for these tasks is
vision.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Phototransistors are mostly used for
line following. A human would use vision.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>An Inertial Measurement Unit can
provide an orientation in 3d space. A human would use vision, inner ear,
and general body feel (cannot think of the proper technical term). An
IMU, a compass and encoders can do odometry. Humans usually do not use
odometry to navigate.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Thermopiles can detect heat. A
UV sensor can find a flame. A human would use vision and/or feeling heat
on the skin.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Force sensors measure force.
Humans use touch or general body feel.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Microphones detect sound.
Humans use ears. One use of sound is communications. For robots
there are many radio systems that can be used (WiFi, Bluetooth, Zigbee,
etc.). Another use of sound is as a cue. I look in the direction of
the sound. Some objects can be identified by their sound signatures.
<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>A clock measures time of day and can
be used to measure elapsed time. I am not sure how I do it, but I can
poorly tell the time of day and very inaccurately measure elapsed time.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>Although not technically a sensor,
the brain fuses all that we sense and provides a "picture" of the
environment. <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'>I would put the emphasis on
vision. Several efforts are underway and could perhaps be combined.
Evolution robotics uses object recognition (with the SIFT algorithm) to do
localization and mapping. Flash lidars provide color and range.
People are working on increasing the dynamic range of cameras. Some
people are mimicking early human vision processing in hardware. There was
a project to implement SIFT on a FPGA. LeCun has used neural nets to
recognize objects and to control a robot. Sadly, the cost of these
technologies will probably not come down quickly.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=2 face=Arial><span
style='font-size:10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
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