15-02-2006, 02:04
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Suspicious pointer conversion
AKA: Robinson Levin
 FRC #1648 (The Gearbox Gangstaz) Team Role: Programmer
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Join Date: Jan 2006
Rookie Year: 2005
Location: ATL
Posts: 116
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Re: Tuning PID Code
Also, while I am at it, note this post (and the rest of the thread, really)
Quote:
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Originally Posted by Joel J.
PD is pretty much the most common way to go about velocity control.
- Set Kd to 0.
- Increase Kp slowly until the robot starts to oscillate around its setpoint. Watch the oscillations, are they dying down, or staying consistent?
- - + If yes, then set Kp to about 30% of its current value.
- - + If no, then Kp is set way too high, for some reason. Reduce it by 60%, and watch for the oscillations again. When the oscillations are reasonable (staying about constant, or dying away, and aren't too violent), then move to the next step.
- Increase Kd slowly until the robot "snaps" to its setpoint.
- If the robot "snaps" eventually, but there is some error between where it snaps, and the desired setpoint (and you can't live with this error), then you have to add in a bit of Ki.
- Ki is usally ends up being 1/Kd. I don't like Ki for velocity control purposes, but you can fiddle with it if you want.
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from Problems Using PID for Velocity
Send us more luck,
Robinson
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