YASKAWA SGD7S Product Manual page 337

8.13 Manual Tuning
8.13.1 Tuning the Servo Gains
 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.
Torque
reference
before filter
*
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.
Pn401
Pn40F
Pn410
*
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.
8-82
Torque-Related
torque reference
*
First Second
stage first stage
second
torque
torque
reference
reference
filter:
filter:
Pn401
Pn40F
Pn410
First order Second order
lag filter lag filter
First Stage First Torque Reference Filter Time Constant
Setting Range Setting Unit
0 to 65,535
Second Stage Second Torque Reference Filter Frequency
Setting Range Setting Unit
100 to 5,000
Second Stage Second Torque Reference Filter Q Value
Setting Range Setting Unit
50 to 100
Function
Selections 1
Pn408
First Second
stage stage
notch filter: notch filter:
Pn409 Pn40C
Pn40A Pn40D
Pn40B Pn40E
Notch filter Notch filter
Default Setting
0.01 ms 100
Default Setting
1 Hz 5000*
Default Setting
0.01 50
Torque-Related
Function
Selections 2
Pn416
Fourth
Third
stage stage
notch filter: notch filter:
Pn41A
Pn417
Pn418 Pn41B
Pn419 Pn41C
Notch filter Notch filter
When Enabled
Immediately
When Enabled
Immediately
When Enabled
Immediately
Torque
Fifth
stage reference
notch filter:
after filter
Pn41D
Pn41E
Pn41F
Notch filter
Classification
Tuning
Classification
Tuning
Classification
Tuning