NAiS KT7, Instruction Manual

Page: 19 / 26

9. PID auto-tuning of this controller
In order to set each P, I, D values and ARW automatically, this system gives a fluctuation
to the controlled object to get an optimal value.
One of 3 types of fluctuation below is automatically selected.
(1) When the difference between the setting value and processing temperature is large as
the temperature rises.
When AT bias is set to 20 ( ), a fluctuation is applied at the temperature 20 ( ) lower than the setting
value.
Setting
value
Temp.
Time
AT
(1) (2) (3)
Temperature 20 ( ) lower
than the setting value
(4)
:
AT
Auto-tuning starting point
Calculating PID constant
PID contatnt calculated
Controlled by the PID
constant set by auto-tuning.
AT bias value
(1):
(2):
(3):
(4):
(2) When the control is stable
Fluctuation is applied at the setting value.
Temp.
Time AT
(1) (2) (3)
:
AT
Auto-tuning starting point
Setting
value
Calculating PID constant
PID constant calculated
Controlled by PID constant
set by auto-tuning
(3):
(2):
(1):
(3) When the difference between the setting value and processing temperature is large as
the temperature falls
When AT bias is set to 20 ( ), fluctuation is applied at the temperature 20 ( ) higher than the setting
value.
Setting
value
Temp.
Time
AT
(1) (2) (3)
: AT
Auto-tuning starting point
(1): Calculating PID constacnt
(2): PID constant calculated
(3): Controlled by PID constant
set by auto-tuning
(4): AT bias value
(4)
Temperature 20 ( ) higher
than the setting value