24
Gain adjustment in actual operation
3.6.2
Dancer PID gain adjustment
Set the minimum-diameter roll and connect material from the beginning to the end of machine, and increase the speed
gradually while observing the movement of the dancer roll.
At this time, adjust the line speed for dancer roll to move like the below diagram 2).
Adjust to the speed where the dancer roll works without problems at acceleration, constant speed, deceleration, and sudden
deceleration.
The key is to adjust to the condition where dancer PID gain is high as possible at minimum diameter.
Normally, adjust with
Pr. 129 PID proportional band
and
Pr. 130 PID integral time
.
(1) Adjustment when response is low (fall of dancer is great)
• Decrease
Pr. 129 PID proportional band
by 10% increments.
• Decrease
Pr. 130 PID integral time
by 0.1s increments.
• Make several adjustments for dancer control to move like diagram 2) at each situation of acceleration, constant speed,
deceleration and sudden deceleration through minimum diameter to maximum diameter.
(2) Adjustment when response is high (hunting occurs too frequently)
• Increase
Pr. 129
PID proportional band
by 10% increments.
• Increase
Pr. 130 PID integral time
by 0.1s increments.
• Make several adjustments for the dancer control to move like the diagram 2) at each situation of acceleration, constant
speed, deceleration and sudden deceleration when diameter is minimum to maximum.
POINT
Adjust the line speed for the dancer roll to overshoot once or so before stabilizing to the constant position as shown in
the diagram 2).
REMARKS
Set
Pr. 134
PID differential time
only when it is necessary as it causes hunting.
However, set a small value in
Pr. 134 PID differential time
to cease fluctuation of the dancer roll by disturbance and such at an early point.
(Increase gradually starting at 0.01s.)
1) When response is low
(fall of dancer is great)
3) When response is fast
(hunting occurs and not stabilized)
2) Appropriate
