9.13 Manual Tuning
9.13.1 Tuning the Servo Gains
9-80
Torque Reference Filter
As shown in the following diagram, the torque reference filter contains a first order lag filter and
notch filters arranged in series, and each filter operates independently.
The notch filters can be enabled and disabled with Pn408 = n.
X
X and Pn416 = n.
XXX.
*
The second stage second torque reference filter is disabled when Pn40F is set to 5,000 (default setting) and it is
enabled when Pn40F is set to a value lower than 5,000.
Torque Reference Filter
If you suspect that machine vibration is being caused by the Servo Drive, try adjusting the
torque reference filter time constant. This may stop the vibration. The lower the value, the bet-
ter the control response characteristic will be, but there may be a limit depending on the
machine conditions.
*
The filter is disabled if you set the parameter to 5,000.
Notch Filters
The notch filter can eliminate specific frequency elements generated by the vibration of sources
such as resonance of the shaft of a ball screw.
The notch filter puts a notch in the gain curve at the specific vibration frequency (called the
notch frequency). The frequency components near the notch frequency can be reduced or
removed with a notch filter.
Notch filters are set with three parameters for the notch filter frequency, notch filter Q value,
and notch filter depth. This section describes the notch filter Q value and notch filter depth.
•
Notch filter Q Value
The setting of the notch filter Q value determines the width of the frequencies that are filtered
for the notch filter frequency. The width of the notch changes with the notch filter Q value. The
larger the notch filter Q value is, the steeper the notch is and the narrower the width of frequen-
cies that are filtered is.
Pn401
(2401h)
First Stage First Torque Reference Filter Time Constant
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
0 to 65,535
0.01 ms
100
Immediately
Tuning
Pn40F
(240Fh)
Second Stage Second Torque Reference Filter Frequency
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
100 to 5,000
1 Hz
5000
*
Immediately
Tuning
Pn410
(2410h)
Second Stage Second Torque Reference Filter Q Value
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
50 to 100
0.01
50
Immediately
Tuning
Torque
reference
before filter
First
stage first
torque
reference
filter:
Pn401
Second
stage
second
torque
reference
filter:
Pn40F
Pn410
First
stage
notch filter:
Pn409
Pn40A
Pn40B
Second
stage
notch filter:
Pn40C
Pn40D
Pn40E
Torque
reference
after filter
Torque-Related
Function
Selections 1
Pn408
First order
lag filter
Second order
lag filter
*
Notch filter
Notch filter
Notch filter
Notch filter
Notch filter
Torque-Related
Function
Selections 2
Pn416
Third
stage
notch filter:
Pn417
Pn418
Pn419
Fourth
stage
notch filter:
Pn41A
Pn41B
Pn41C
Fifth
stage
notch filter:
Pn41D
Pn41E
Pn41F
Speed
Position
Torque
Speed
Position
Torque
Speed
Position
Torque
