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Festo Контроллер позиционирования CPX-CMAX User Manual

Page 368

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B. Basic controlling principles

B−26

Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH

Cushioning factor

Cushioning is a measure for the transition behaviour of the
system from the actual to the setpoint status, especially
when there are fast modifications to the setpoint value. As a
rule the system should guarantee low−vibration behaviour
with setpoint specifications and movement into the target
position without overswing.

By modifying the factor for cushioning, you can influence the
transition behaviour of the system.

Behaviour of the axis

Factor

Bad positioning quality, setpoint position is apĆ
proached only slowly (underswing).

Reduce

The drive tends towards instability (tendency to viĆ
brate during positioning, up to continuous vibration
around the setpoint position, heavy overswing).

Increase

The positioning process is carried out quickly and
accurately.

Optimal

Signal filter factor

Speed and acceleration are derived from the positioning
signal and filtered to improve the signal quality. If in practice
there is bad signal quality, e.g. due to electrical interference,
filtering of the signal can be influenced by the signal filter
factor.

If filtering is too strong it may destabilise control.

Behaviour of the axis

Factor

The drive tends towards instability (despite low gain
and good cushioning).

Reduce

Noise" or loud valve noises (observe gain; this may
be too high).

Increase

The positioning process is carried out quickly and
accurately, low valve noises.

Optimal