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Unread 25-03-2014, 16:11
cstelter cstelter is offline
Programming Mentor
AKA: Craig Stelter
FRC #3018 (Nordic Storm)
Team Role: Mentor
 
Join Date: Apr 2012
Rookie Year: 2012
Location: Mankato, MN
Posts: 77
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Re: Hot Goal Timing Issues

Team 3018 was in 18 matches week 4 at Wisconsin (19 autonomous periods since one match had a replay declared partway through telop).

We hit the hot zone in 18 out of 19 attempts. The reason for the one failure was that the hot zone flapper stayed hot on the non-hot goal for the first 5 seconds. We hit the shot in the first 5s because that is what the flapper told us to do.

The robot can score in about 1.8s from the white zone so the auton algorithm is to wait for 2 full seconds before checking for the hotzone (we use vision tracking of 4 pics per second). It begins moving as soon as it sees a hot marker or until a timer set at autonomous_init() hits 5s.

I've seen us start moving *before* the hot goal has moved to our side but it is always hot by the time we hit it. I think this must be due to the long 5-6s interval.

At our first event (Lake Superior week 2) we had unbelievable issues with the hot zone. Originally we waited only 1s and we were using the drive station object (java) to check match time to decide when to go. We were always going early so we first had it start waiting 2s instead of 1s. But we would still always go early. We set our own timer in autonomous_init and things started working like at home, but we kept the 2s wait 'just to be safe'.

Then we discovered the flappers at one end of the field were reversed, and later we had another stuck (both stay hot) scenario. We lost a match by 3 points in one match where the field lied to us about which was hot (we'd have been the first seed instead of second had that worked properly). Finally, (completely unrelated to to hot zone targeting) we had a physical catch to keep our robot in frame that a motor had to break away from. By elims we were bent and battered so even though the robot was moving for the hot zone, the breakaway failed for mechanical reasons (catch too firm all of a sudden) and the shot never happened. We only scored 5pts for about 6 matches in a row. A piece of scored electrical tape allowed us to function properly in the very final match.

Things were certainly better week 4 at Wisconsin (we used a magnet base breakaway which completely solved the one problem), but not quite perfect due to the one bad flapper event.

It's only 5 points, but it can be the difference in some matches, so it is nice when it works properly.
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