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Unread 13-01-2012, 01:18
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Sparks333 Sparks333 is offline
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AKA: Dane B.
FRC #1425 (Wilsonville Robotics)
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Re: Gyros and Field Centric Control

FYI, integrating angular rate for any amount of time is going to get very drifty - especially if you get knocked by another robot. A gyro with a high rotational limit and a very high sampling rate are both decent ways around this, but they can't get rid of bias errors and non-smooth motion issues. One way to decrease drift is to do sensor fusion with wheel encoders - using something like a complementary filter can make one system more depended-upon during high rates of rotation, and the other more depended-upon during low rates of rotation. Far better, however, is to use some part of the field that the robot can localize to - in an extreme case, you might be able to use a compass module to find direction (but the hard-iron fields will probably render one useless), or perhaps using the camera for visual servoing. I'd personally recommend the latter - fixate on the targets and keep it always in frame.

Hope this is useful

Sparks
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