"Karl Townsend" wrote in message
...

As an old process engineer, i would take just the opposite approach.

i don't completely understand this process. Looks to me like a default
machine speed vs. batch weight equation could be empiracly determined.
Spend some time getting as good a curve as you can. The control PLC
would then just need to look at how much it missed by and adjust the
offset. I'd use a technique called exponetial smoothing to prevent the
control chasing itself. This is simpler to implement than it sounds.

My approach was always KISS (keep it simple stupid)

Karl

On what I did, I calculate the new value + the old value then divide by 2,
making 50% correction, keeps it from chasing its tail too much.

Sometimes the flow speeds up, the calculations evidently aren't linear, if
it keeps feeding at this higher flow, it learns and works fine, but it
speeds up and slows down. I'm trying a rate of change of flow,
acceleration, to see if I can hit the target better.

RogerN