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Rev. 1.0
0006302011
SSM24C User Manual
+86-400-820-9661
positioning control, it can cause objectionable audible or observable noise to the system. The filter
is a very simple single-pole low pass filter that is used to limit this high frequency noise and make
the system quieter and more stable.
5.3 Notch filter
For additional filtering, an over-all notch filter is added to the current command signal. This filter
is similar to the PID Filter in that it is active even when the driveis being used in Torque Control
Mode. Notch filters are typically used to filter at a particular frequency when there is a resonant
component in the mechanical system that may oscillate at that frequency. Couplers between the
motor and the load can commonly do this which may result in a control problem. When gains are
increased to improve performance the system may resonate in an uncontrollable manner. The
Notch Filter allows gain reduction at only the problematic resonant frequency, allowing the over-all
gain to be set higher for better system control.
The notch filter has two parameters that are described below. The notch filter can only be
configured though the Quick Tuner interface where the Quick Tuner software calculates the filter
constants used by the drive.
5.3.1 Frequency: Notch Filter Center Frequency
This defines the center frequency - the frequency where the most gain reduction occurs. For now,
finding the center frequency is a bit of a guessing game and different frequencies can be tried until
the system resonance is eliminated.
5.3.2 BandWidth: Notch Filter Frequency Bandwidth
This defines the frequency span where the signal is reduced by at least 3dB. For example if the
