[Robotgroup] One Simple Rink Sensing Option Re: Drive a Droid proposal

[Bruce Waters]

Vern, 
     I was weighing the various ways of making a rink
which was easy to sense.   One interesting option is
to use rubber cement to glue down aluminum foil to
mark the rink.   Then robots could attach an inch or
so of conductive tinsel garland to pull down maybe
5 volts through a 10k ohm resistor as a sensor.  
Conductive tinsel garland is like a potentiometer 
sweep with multiple contacts.   It is easily hidden 
under say the wheel covers of an R2D2.  A robot 
would also have installed several segments of 
garland connected to its sensor common ground
to complete the pulldown current path.  A sensor
which is not pulled down is sensing "off rink" and
would tell the bot to "pause" its opposite wheel.
Software or something as simple as a normally 
open automotive relay(probably without a discrete
resistor) could implement the behavior.
    The garland is very cheap and the foil and the rubber
cement is not prohibitively pricey.   The track foil can
be applied directly to most floors without ill effect since
the rubber cement can usually be "rolled off".   If rubber 
cement is too risky or incompatible with a particular floor 
(perhaps carpet) then one can make a large cardboard
surface and rubber cement the foil to the cardboard
leaving swivel space on the cardboard past the foil.
   The broad-swath tinsel sensors allow mosaic painting 
of the foil through a stencil grid or with pinstripe painters 
tape used liberally to expose enough conductive foil to 
keep the sensors sensing.  One can decorate the rink 
with painted (competition or whatever) lines and sponsor 
(or TRG) logos on top of the foil without preventing rink 
sensing.   Note that the relatively rare, incidentally 
conductive floor would look like rink to these rink-sensing 
bots.
 
Bruce Waters