YASKAWA SGMPS - Torque Feedforward

6.9 Compatible Adjustment Function
6-65
6
Adjustments
6.9.2 Torque Feedforward
The torque feedforward function shortens positioning time.
The torque feedforward function is valid only in speed control and position control.
The host controller differentiates a speed reference to generate a torque feedforward reference, and inputs the
torque feedforward reference together with the speed or position reference to the SERVOPACK.
(1) Connection Example
Connect a speed reference signal line to V-REF (CN1-5 and -6) and a torque feedforward reference to T-REF
(CN1-9 and -10) from the host controller.
(2) Related Parameters
Torque feedforward is set using the parameters Pn002, Pn400 and Pn415.
The factory setting is Pn400 = 3.0 V/rated torque If, for example, the torque feedforward value is
±3V, then,
the torque is limited to
±100% of the rated torque.
Note 1. Too high a torque feedforward value will result in overshooting. To prevent such troubles, set the optimum value
while observing the system responsiveness.
2. The torque feedforward function cannot be used with torque limiting by analog voltage reference.
• The following settings are required if model following control is used together with the speed feedforward
(V-REF) input and torque feedforward (T-REF) input.
-
V-REF
Speed reference input gain
Kp
Pn100
M
ENC
K
FF
+
+
+
T-REF filter constant
+
+
Pn300
-
Position
reference
Differe-
ntial
Host controller
Current loop
Divider
Speed calculation
Speed loop integral
time constant
Pn101
Servomotor
Encoder
Speed loop gain
Torque reference input gain
Pn400
Pn41
5
T-REF
Kp: Position loop gain
K
FF
: Feedforward gain
SERVOPACK
Parameter Function When Enabled Classification
Pn002
n.
0
Disabled [Factory setting]
After restart Setup
n.
2
Uses T-REF terminal for torque feedforward input.
Pn400
Torque Reference Input Gain
Classification
Setting Range Setting Unit Factory Setting When Enabled
10 to 100 0.1V/rated torque 30 Immediately Setup
Pn415
T-REF Filter Time Constant
Classification
Setting Range Setting Unit Factory Setting When Enabled
0 to 65535 0.01 ms 0 Immediately Setup
Parameter Function When Enabled Classification
Pn140
n.0
Model following control is not used together with
speed/torque feedforward input.
Immediately Tuning
n.1
Model following control is used together with speed/
torque feedforward input.
Speed
Position
Torque
Speed
Position
Torque