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Unread 04-01-2014, 07:58
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Re: 2013 Lessons Learned for a Vision Co-Processor

Quote:
Originally Posted by Jerry Ballard View Post
8) Hard Stop and Rebuild during competition: During the build season, we made the decision not to find a graceful method to shutdown the system during competition. Instead we let the system hard stop when the power was shutdown and then did a reboot and fsck'ed (file system checked) between matches. Also, we maintained multiple copies of the complete OS on memory cards and often did card swaps between short match times. Swaping OS memory cards allowed for some simple diagnostics of target tracking and provided redundancy in case of severe system crash.

9) Diagnostic photos are good: During the matches, we captured and saved frames from the camera once a second (sometimes less) to help us determine how the targeting system was doing. It turned out that these images were very useful to the pilot/copilot of the robot to quickly replay the previous match. Visual cueing from these images helped the students recall better what happened during the match (from the robot's point of view). I've attached an example image below. The blue circle is the aim point of the shooter, cross-hairs identify targets in range, the red dot is the predicted frisbee hit, and the green circle is the target selected.
Thanks for sharing your experiences.
Your success with hard stop is particularly helpful as clean shutdown was a significant concern. I like the pragmatic approach of having spare memory cards to swap between matches.

Great tip about the diagnostic images.