Chapter 8 Adjustment
8–13
(1) Machine resonance suppression filter (Notch filter)
The resonance elimination filter will function at the set frequency. Use the D/A output function to
output the current feedback and measure the resonance frequency. Note that the resonance
frequency that can be measured is 0 to 500 Hz.
<Setting method>
1. Set the resonance frequency in the machine resonance suppression filter frequency (SV038:
FHz).
2. If the machine starts to vibrate at another frequency, raise (make shallower) the notch filter
depth compensation value (SV033: SSF2.nfd), and adjust to the optimum value at which the
resonance can be eliminated.
3. When the vibration cannot be completely eliminated, use another vibration suppression
control (jitter compensation).
No.
Abbrev.
Parameter name
Explanation
Setting range
SV038
FHz
Notch filter frequency
Set the resonance frequency to be suppressed. (Valid at 72 or
more).
Set 0 when the filter is not to be used.
0 to 3000
SV033
SSF2 Special servo function
selection 2
The notch filter depth compensation is set with the following parameters.
15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
nfd
bit
Descriptions
0~3 nfd
Set the filter depth for the notch filter.
Deeper
←
→
Shallower
Setting value
0
2
4
6
8
A
C
E
Depth (dB)
∞
−
18.1
−
12.0
−
8.5
−
6.0
−
4.1
−
2.5
−
1.2
(2) Jitter compensation
The load inertia becomes extremely small if the motor position enters the machine backlash
when the motor is stopped. Because this means that an extremely large VGN1 is set for the load
inertia, vibration may occur.
Jitter compensation is the suppression of vibration occurring when the motor stops by ignoring
the backlash amount of speed feedback pulses when the speed feedback polarity changes.
Increase the number of ignored pulses by one pulse at a time, and set a value at which the
vibration can be suppressed. (Because the position feedback is controlled normally, there is no
worry of positional deviation.)
When an axis that does not vibrate is set, vibration could be induced, so take care.
No.
Abbrev.
Parameter name
Explanation
SV027
SSF1 Special servo function
selection 1
Set the jitter compensation with the following parameter.
15 14 13 12 11
10
9
8
7
6
5
4
3
2
1
0
aflt zrn2
ovs2 ovs1 lmc2 lmc1
vfct2 vfct1
bit
No jitter
compensation
One pulse
compensation
Two pulse
compensation
Three pulse
compensation
4 vfct1
0
1
0
1
5 vfct2
0
0
1
1
POINT
Jitter compensation vibration suppression is only effective when the motor is
stopped.
