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From: jmasters@fxrs.intel.com (Justin Masters)
Newsgroups: sci.electronics
Subject: How can you 'track' something back and forth?
Message-ID: <304@fxrs.intel.com>
Date: 23 Jan 91 21:59:06 GMT
Reply-To: jmasters@fxrs.intel.com (Justin Masters)
Organization: Intel FMD, Folsom, CA
Lines: 36


I was wondering how one might go about tracking something back and forth.  I
intend to use either an IR transmitter or a FM transmitter as a source, but my
question is how do I track it?

Some ideas that I had...

IR.  Utilizing a diamond grid of two receptive elements (recessed, or shielded
from stray IR energy), I would use some kind logic to simulate the following
way a human centers his eyes on a light.  He sees some light from the right
side, and turns his head towards it, until the amount of light being received
in both eyes is equal (looking straight at it), and then stopping your head.

FM.  Somehow receive a pulsed signal on an FM signal to two different points,
and combining the signal to each other to see which pulse 'arrived' first.


How would you go about doing a comparison to see which receptor/receiver had
received its signal first or was closer to the point desired?

What kind of motor do you try to use (12v or less) to turn towards the
originating signal, and how do you control it?  How do you keep from
having constant 'over-compensation'?  In otherwords, how would you keep the
motor from going back and forth in slight increments while trying to center on
a stationary point?


Are there any really good articles on how to do this?


Any help would be appreciated.
-- 
"We are greatful for the dedication of the men and women serving in the gulf
and our prayers are with them.  Some say they are just doing their job, but it
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what we believe in." - Glenn Ballard.          |  jmasters@fws136.intel.com