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Originally Posted by gwross
Kevin,
Any hints on how to "severly limit" the sensors' view above and below. I don't see evidence from the pictures on your website.
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If the sensors rotate in a plane that includes the beacon, the tracker will work just fine if it can't see (reflections) above or below that plane. Our original prototype looked like a side-by-side shotgun mounted to the servo. Imagine looking through a long, dark piece of tube while you slowly spin around a dark room that also has a friend holding an LED flashlight at the same height as the tube. As you spin around, what are the chances that you'll see a reflection off of any surface? Pretty slim because the point of reflection must also reside on that idealized plane. The chances are also made even slimmer when you realize that not only does the point of origin have to reside on the plane, but the photon must also pass through one specific spot on the plane: your eye.
We found this setup to work pretty well until the servo had to try to keep up with a moving target. So we had a minor epiphany and realized that if we
cut a slit down the tubes such that one of the sensors would always have a view of the beacon, we would always know which direction to move the servo to catch up. This greatly simplified the tracking state-machine to this:
Right Left
Sensor Sensor Action
0 0 Search until one sensor sees the beacon
0 1 Rotate left
1 0 Rotate right
1 1 Do nothing
0 = Beacon "quality" == 0
1 = Beacon "quality" > 0
Hope this helps.
-Kevin