[mowbot] mowbot

Ron Woodward (RWoodward nospam at gnn.com)
Wed, 25 Sep 1996 21:01:01

>>You can purchase colored reflective tape (not shiny stuff but the stuff
>>road signs are made of). This stuff can reflect a significant amount of
> light
>>back to the observer. Use a different color or color combination for each
>>post. Your search beacon / detector would send out a white beam and would
> use
>>three different color sensitive detectors. Depending on which ones
>>recieved light
>>back you could tell which beacon you were looking at.
>Unless you limit mowing to dark hours, it would take a significant source
>of light to be detectible in the broad sprectrum of bright summer sunshine.

This tape is whats called retroreflective. It has very small three corner cubes
in it that reflect light directly back to the sender. Just like the reflectors
the astronaughts left on the Moon. It would not take much power in a well focused
beam to be able to detect it comming back even in bright sunlight. Have you ever
been driving down the highway and see the roadsigns light up from the light
reflecting off your windshield? It looks very bright but the reflected light
from a windshield is not nearly as bright as the sunlight.

I have even noticed the reflected light from signs caused by turining on
my headlamps during the day. (I know that sounds kind of strange but I
do automotive lighting and optics for a living and have done some unusual
things testing various lighting systems)

I am going to start running some tests to see how much reflector area is needed
and what kind of light projector, sensors and optics would work best. I will
keep everyone informed of my progress.