32.16.5.8 PID Constant Adjust
The following explanation uses temperature control as an
example. to optimize the result of the PID control, you need to
optimize the constant values of P (proportional element), I
(Integral element), and D (differential element). You can use the
step-response method to derive a PID temperature constant for
various setpoints. Note that the value might not be optimized
depending on the use and the setpoint. In that case, perform online
monitoring and adjust the value in the PID monitor window. Specify
the setpoint value for the step-response method and output 100% of
the operation volume onto the control target step. At this time,
measure the maximum temperature inclination (R) and lost time (L)
in the temperature graph shown below.
Insert the measured values for maximum temperature slope (R) and
lost time (L) in the following formula to calculate the
proportional constant, integral calculus time, and differential
calculus time constants. Assign the calculated values to the values
in the PID monitor window.
"Proportional Constant" = 100/(0.83·R·L) [%]
"Integral Calculus Time" = 1/(2·L) [events/min] (formula =
unidentified)
"Differential Calculus Time" = 0.5·L [min]
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