Thread: Tracking beacon without servo
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Unread 10-02-2004, 03:36
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Re: Tracking beacon without servo
Detection of the IR beacon can be done in a very straightforward manner WITHOUT using any motors or servos.

Think "phased array."

Make a simple linear array of detectors, each with a limited field of view (use the heat shrink tubing suggestion from above, which will act as a light baffle for the IR signal). The total array may have a FOV of 90-180 degrees (or whatever view you want), but each individual element within the array will be limited to 10 degrees or less.

Then use the control system to scan across each element of the array and record the perceived signal strength. Strongest signal in the array identifies the array element pointing toward the beacon.

If you think about this for a while, you will realize with a little clever programming you will be able to get sub-pixel resolution and accuracy from the array (clue: read Chris Hibner's white paper on increasing A/D resolution using noise, while holding it sideways to gain a new perspective).

There are always multiple ways to skin a cat...

-dave
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