Delta ASDA-A3 Series User Manual page 367

Operation Mode
The servo drive provides two methods for suppressing the resonance: one is the Notch filter
and the other is the low-pass filter. See the following diagrams for the results of using these
filters.
6
System open-loop gain with resonance:
◼ Notch filter
(1) Resonance point; (2) Notch filter; (3) Resonance point suppressed by the Notch filter
◼ Low-pass filter
To conclude from these two examples, if you increase the value of P2.025 from 0, the
bandwidth (BW) becomes smaller. Although it solves the problem of resonance, it also reduces
the response bandwidth and phase margin, making the system unstable.
If knowing the resonance frequency, you can suppress the resonance by using the Notch filter,
which is better than using the low-pass filter in this condition. If the resonance frequency drifts
significantly with time or due to other causes, using the Notch filter is not suggested.
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(1) Resonance point; (2) Attenuation rate (-3 dB);
(3) Low-pass filter (Cutoff frequency of low-pass filter = 1000 / P2.025 Hz);
(4) Resonance point suppressed by the low-pass filter
ASDA-A3