
4.ADJUSTMENT FANUC AC SPINDLE MOTOR αi series B-65280EN/05
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4.2 MACHINE RESONANCE ELIMINATION
4.2.1 TCMD Filter
(1) Overview
The torque command filter applies a primary low-pass filter to torque
commands. When the machine system resonates at frequencies as high
as several hundreds Hz or higher, this function can avoid such
high-frequency resonance.
(2) Series and editions of applicable spindle software
Series 9D50/A(01) and subsequent editions
Series 9D70/A(01) and subsequent editions
(3) Details
Fig. 4.2.1 shows a velocity loop configuration including the torque
command filter.
When the machine system has a high resonance frequency, the speed
feedback may include a resonance component, and this component
may be amplified by the proportional gain (Kp).
The torque command filter prevents machine resonance by applying a
primary low-path filter to the proportional of the torque command to
remove high-frequency components of the torque command.
Fig. 4.2.1 velocity loop configuration including the torque command filter
Velocity
command
Kt/Jm
⋅
s
K
P
K
I
/s
Velocity feedback
+
-
+
+
Torque command filter
Motor
(4) Setting parameters
15i 16i 30i
3121 4121 4121
Torque command filter time constant
3157 4157 4157
Torque command filter time constant: for low-speed characteristics
Unit of data : 0.5msec
Valid data range : 0 to 32767
Standard setting value : 5
Basically, use the standard setting value 5 (time constant: 2.5 ms).
When a value greater than the standard setting value needs to be set,
make an adjustment and typically set a value not greater than 15.
When a value greater than 15 needs to be set, decrease the velocity
loop gain.