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Originally Posted by Rickertsen2
I was thinking about PID loops in situation with rapidly changing w, and the phase lag time of the I term causing problems when this occured to me, and i was wondering if anybody had any input, wanted to tell my why i'm wrong, or if they had tried this before:
The PI algorithm that we use for everything uses a data element we invented called a CSStack for the I term. Its basically a dynamic variable lenght mutable circular buffer. It seems to me that response could be improved by dropping certian old values from the buffer in times of rapid w change. What about dynamically changing Ki according to the derivitave of w? Any input? What other sorts of optimizations have people made to the basic PID algorithm? Is anybody using somethign other than some variation of a PID controller?
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well this buffer was what i was invisioning when i was asking about having the integral last over a certain length of time rather than from initialization. I didnt think about changing this length of time dynamically, but that could make for a pretty complex, if not effective, control. I have been doing a lot of research and some loops do have dynamic coefficients. Regardless, it seems to me that when you are dealing with 8 bit or less precisions and when the systems are so full of unpredicted forces that Larry Barello was right when he described FIRST as being classified as low performance. If you do implement anything this advanced, please post some data comparing it to simpler algorithms. IE response times, or even better, response curves.