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Unread 08-02-2007, 19:29
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Kevin Watson Kevin Watson is offline
La Caņada High School
FRC #2429
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Join Date: Jan 2002
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Re: Camera offset a lot.... odd

Quote:
Originally Posted by billbo911 View Post
Alan pretty much nailed it on the head. This is a "problem" many teams addressed last year as well.
Simply put, the mechanical alignment of the optics to the cmos sensor are not perfect. In addition, the optical components used have some manufacturing tolerances that can add to the "mis-alignment" as well. Just follow the advice Alan gave and you will be in good shape. What you need to be confident in is the cameras ability to reproduce it's positioning each time. If it does that, then you will be able to get accurate tracking information from it.
Yep, this is the case. My code has the ability to track on any pixel, not just the center one. Just allow the camera to find the light and then enter the "Interactive PWM Adjustment Menu" and step the servos until it is aligned. Now unplug your servos from the RC and enter 'p' and then 'x' so that camera data will start to stream to the terminal screen again. If you managed to do this without disturbing the camera, the error values on the screen tell you where the optically-centered pixel is located relative to the center pixel in the imager array. Use those offset values to calculate the new tilt and/or pan target pixels and enter them in to tracking.h or use the interactive tracking menu to set the new values.

-Kevin
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Kevin Watson
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http://kevin.org