Pid Gain Adjustment - Mitsubishi Electric A800 Plus Series Function Manual

3.4.4

PID gain adjustment

Adjust the PID gain of dancer feedback speed control.
Adjustment by tension PI gain tuning (recommended)
The PID gain is adjusted by tension PI gain tuning (refer to
adjustment.
Manual adjustment
• Set the minimum-diameter roll for winding and the maximum-diameter roll for unwinding. Connect the material from the
beginning to the end of the machine, and increase the line speed gradually while observing the movement of the dancer
roll. Adjust the line speed so that the dancer roll moves properly.
• Adjust the PID gain so that the dancer roll works without problems at acceleration, constant speed, deceleration, and
sudden deceleration.
• It is important to adjust the dancer PI gain as high as possible for the minimum-diameter roll.
• Normally, adjust the gain with Pr.129 PID proportional band and Pr.130 PID integral time.
Slow response
(the dancer roll position is too low)
POINT POINT
• Adjust the gain so that overshooting occurs once or so before the dancer roll returns to the set position.
• Refer to the following according to the dancer roll condition.
Status
• Decrease Pr.129 PID proportional band by 10%.
When the response is
• Decrease Pr.130 PID integral time by 0.1 s.
slow (the dancer roll
• Repeat the adjustment procedure in the range from the minimum diameter to the maximum diameter so that
position is too low)
the dancer roll moves properly at acceleration, constant speed, deceleration, and sudden deceleration.
• Increase Pr.129 PID proportional band by 10%.
When the response is
• Increase Pr.130 PID integral time by 0.1 s.
fast (hunting occurs too
• Repeat the adjustment procedure in the range from the minimum diameter to the maximum diameter so that
frequently)
the dancer roll moves properly at acceleration, constant speed, deceleration, and sudden deceleration.
NOTE
• Set Pr.134 PID differential time only when it is necessary as it causes hunting. However, set a small value in Pr.134 to
cease fluctuation of the dancer roll by disturbance and such at an early point. (Set 0.01 s at first and gradually increase the
value.)
Parameter setting procedure for dancer feedback speed control
page 76). Tension PI gain tuning is recommended for PID gain
Proper condition
Adjustment method
DANCER FEEDBACK SPEED CONTROL
Fast response
(hunting occurs too frequently)
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