YOKOGAWA UT55A - 8.5 Suppressing Overshoot (Super Function)

8-98
IM 05P01C31-01EN
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