Torque Feed-Forward - YASKAWA SGDH User Manual

9 Adjustments

9.4.2 Torque Feed-forward

9.4.2 Torque Feed-forward
Parameter
Pn002
Pn400
The torque feed-forward function is valid only in speed control (analog reference).
The torque feed-forward function shortens positioning time, differentiates a speed reference at the host controller to gener-
ate a torque feed-forward reference, and inputs the torque feed-forward reference together with the speed reference to the
SERVOPACK.
Too high a torque feed-forward value will result in overshooting or undershooting. To prevent such troubles, set the opti-
mum value while observing the system responsiveness.
Connect a speed reference signal line to V-REF (CN1-5 and -6) and a torque forward-feed reference to T-REF (CN1-9 and
-10) from the host controller.
Host controller
Position
reference
Torque feed-forward is set using the parameter Pn400.
The factory setting is Pn400 = 30. If, for example, the torque feed-forward value is
±
100% of the rated torque.
The torque feed-forward function cannot be used with torque limiting by analog voltage reference described in 8.9.3
Torque Limiting Using an Analog Voltage Reference.
n. 0
Disabled
n. 2
Uses T-REF terminal for torque feed-forward input.
Torque Reference Input Gain
Setting Range
10 to 100
(1.0 to 10.0V/Rated
torque)
Differ-
ential
+
Kp
+
-
Kp: Position loop gain
K : Feed-forward gain
FF
Setting Unit
0.1V/Rated torque
SERVOPACK
T-REF (CN1-9)
K
FF
+
V-REF (CN1-5)
Pn300
-
Speed
calculation
Divider
9-16
Meaning
Speed Position
Factory Setting
30
Pn400
+ +
Pn100
Current loop
+ +
Integration
(Pn101)
±
3V, then, the torque is limited to
Torque
Setting Validation
Immediately
Servomotor
M
PG
Encoder