Thread: PID Help
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Unread 29-01-2015, 20:32
wildaburk3160 wildaburk3160 is offline
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Re: PID Help

This video refers to the gains as Kp, Ki, and Kd. In the PID gains cluster connected to the PID.vi, the I and D terms are labeled Ti and Td, as in derivative time and integral time.

So, are these functioning the same as an Ki and Kd, or are they functioning in some other way?

On another note, I went through the Zeigler-Nichols process described in the video, and after calculations, the Kd I was supposed to have came out to be ~ .0004, which is beyond the three decimal accuracy of the PID gains control. I ended up having to settle for .001.

After some testing, the minimum overshoot averaged around 4 pulses, with varying amounts of greater overshoot. This could have been caused by having to settle for a Td of .001 instead of .0004.

One thing mentioned in the video is sensor lag, where a sensor can't send pulses fast enough for the PID to process it correctly. Could there be an issue of the PWM cables not having a high enough frequency to keep up? Would an analog sensor be a viable fix to this supposed problem?

Last edited by wildaburk3160 : 29-01-2015 at 20:43.
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