YASKAWA E-S Series User Manual

8.8 Manual Tuning
8.8.1 Tuning the Servo Gains
8-35
8
Tuning
 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 the Pn408 = n.X and Pn408 =
n.X.

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.

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.
The notch filter frequency characteristics for different notch filter Q values are shown below.
Note: The above notch filter frequency characteristics are based on calculated values and may be different from
actual characteristics.
Pn401
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
First stage
rst torque
reference
lter:
Pn401
Torque reference
before filter
First order lag filter Notch filter
First stage
notch
filter:
Pn409
Pn40A
Pn40B
Torque-Related
Function Selections
Pn408
Second stage
notch
filter
Pn40C
Pn40D
Pn40E
Notch filter
Torque reference
after filter
0
-5
-10
-20
-15
Q = 0.7
Q = 1.0
Attenuation [dB]
Q = 0.5
Frequency [Hz]

YASKAWA E-S Series Specifications

General

Brand	YASKAWA
Model	E-S Series
Category	Servo Drives
Language	English