YOKOGAWA UP35A, User Manual

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8-28
IM 05P02D41-01EN
8.5 Suppressing Overshoot (Super Function)
Description
The Super function monitors the deviation for evidence that there is a danger of
overshoot, and on sensing such danger automatically changes the setpoint temporarily
to a somewhat lower value (sub-SP).
Once the danger of overshoot appears diminished, the function returns the effective SP
gradually to the true SP. “Fuzzy ratiocination” techniques are employed in the algorithms
used to change the SP to the lower temporary value, and to return it gradually to the true
SP.
Operation Diagram
Start of
fuzzy inference
Original SP
PV
Sub-SP
Time
PV
Control System Block Diagram
SP
SP selector
PV
Manipulated variable
Sub-SP
Target
SP
SP
setting
Sub-SP
setting
PID
computation
Process