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Unread 03-03-2004, 11:50
Dave Flowerday Dave Flowerday is offline
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Re: Why not analog sensors??

Quote:
Originally Posted by gnormhurst
But if each tracker's IR sensor put out an analog value proportional to the "brightness" of the IR it was seeing, then small pointing errors could be determined as the difference between the values, without having to hunt back and forth with the servo. Integrate the sensor difference and apply to the servo -- or something like that.
Except that brightness would also vary by the distance your robot is from the beacon. So, if you read a value of 120 from your analog light sensor, does that mean you're pointed right at it but 20 feet away, or does it mean you're right next to it, but pointed 45 degress away from it?
Quote:
If two analog line sensors were pointed, "defocused", at the left and right edges of the line such that the output was a measure of how far off the edge the sensor was, then, again, the small error signal would be the difference of the sensors. Negative means "too far left", positive means "too far right", and zero means right on.
Do such sensors exist? If they do, you could always buy them as a custom electronic component and use it - you're not limited to just the sensors provided in the kit. I'd be a little surprised if something like this really exists, though (at least something that would work for this application).