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Unread 14-06-2012, 23:04
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AKA: James Killian
FRC #3481 (Bronc Botz)
Team Role: Engineer
 
Join Date: May 2011
Rookie Year: 2010
Location: San Antonio, Texas
Posts: 298
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Re: 2012 FRC Team 1717 Uncut

Quote:
Originally Posted by jakemochas View Post
In order to solve this problem, the drivers rezeroed the gyro every time they lined up for a shot at the fender or the key (the Reset() function). For all of our shots, the robot faced directly forward, which gave the perfect opportunity to rezero. Between each shot, the gyro was good enough to keep the robot oriented in the correct direction.
Ah ha! Oh that's cool. When the robot faced directly forward, did you take that moment to have a keying solution? (see below)

We call a keying solution when we would find a good place to "key" our position and orientation. From that we calibrated where we were on the field, and then could use the feedback from the encoders to make it possible to move around the key to fender area for a little while and still be position aware. We'd interpolate evenly spaced key points in an error correction grid and calibrate shots from those points (i.e. 3x3 grid). IIRC I think Jared (341) used an error correction table as well.

While I'm here... I noticed the tune of the shooter speed sounded very consistent. Did you PID the rate of the shooter to an encoder, and did you use victors or Jags? It seems to lock on to the rate very well!


Quote:
Originally Posted by jakemochas View Post
In the end, we were not satisfied with the performance of the gyro. One of our goals for next year is to find a better gyro solution for our swerve drive system.
So what are your thoughts on using a Magnetometer? I'm googling like crazy right now about this!