Delta ASDA-B2 Series User Manual page 145

Chapter 6 Control Modes of Operation ASDA-B2
Here illustrates the effect via low-pass filter (parameter P2-25). The following diagram is
the system open-loop gain with resonance.
Gain
Frequency
When the value of P2-25 is increased from 0, BW becomes smaller (See as the following
diagram). Although it solves the problem of resonance frequency, the response bandwidth
and phase margin is reduced.
Gain
0dB
Frequency
BW
If users know the resonance frequency, notch filter (parameter P2-23 and P2-24) can
directly eliminate the resonance. The frequency setting range of notch filter is merely from
50 to 1000 Hz. The suppression strength is from 0 to 32 dB. If the resonance frequency is
not within the range, it is suggested to use low-pass filter (parameter P2-25).
Here firstly illustrates the influence brought by notch filter (P2-23 and P2-24) and
low-pass filter (P2-25). The following diagrams are the system of open-loop gain with
resonance.
Resonance suppression with notch filter
Resonance
Resonance
conditions
Gain
Point
Gain Gain
is suppressed
Notch Filter
0db
Low-pass
Low-pass
Attenuation
Frequency
Frequency
Rate P2-24
Frequency
Frequency
Resonance
Resonance
Frequency
Resonance
Frequency
. Frequency .
Frequency
P2-23
6-34
Revision May, 2018