YASKAWA SGDV User Manual

6 Adjustments
6.9.3 Speed Feedforward
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6.9.3 Speed Feedforward
The speed feedforward function is used to shorten positioning time.
The speed feedforward function is valid only in position control.
The host controller differentiates the position reference to generate the speed feedforward reference, and
inputs the speed feedforward reference together with the position reference to the SERVOPACK.
(1) Connection Example
Connect a position reference signal line to PULS and SIGN (CN1-7, -8, -11, and -12) and a speed feedforward
reference signal line to V-REF (CN1-5 and -6) from the host controller.
(2) Related Parameters
Speed feedforward value is set using the parameters Pn207 and Pn300.
The factory setting is Pn300 = 6.00 V/rated speed. If, for example, the speed feedforward value is ±6V, then
the speed is limited to the rated speed.
Note: Too high a speed feedforward value will result in overshooting or undershooting. To prevent such troubles, set the
optimum value while observing the system responsiveness.
Model following control is used to set the optimum feedforward value in the servo. There-
fore, the speed feedforward (V-REF) and the torque feedforward (T-REF) cannot be
used together.
If the optimum values for the speed feedforward (V-REF) and torque feedforward
(T-REF) are not set, overshooting may occur.
M
Enc
+
-
+
+
V-REF
+
Position loop
gain
+
-
Current loop
Speed
calculation
Speed loop integral
time constant
Servomotor
Encoder
Host controller
SERVOPACK
Kp: Position loop gain
K
FF
: Feedforward gain
Speed reference
input gain
PULS
SIGN
Differ-
ential
K
FF
Position
reference
Pn300
Pn102
Pn100
Speed loop
gain
Pn101
Parameter Function When Enabled Classification
Pn207
n.
0
Disabled [Factory setting]
After restart Setup
n.
1
Uses V-REF terminal for speed feedforward input.
Pn300
Speed Reference Input Gain
Classification
Setting Range Setting Unit Factory Setting When Enabled
150 to 3000 0.01 V/rated speed 600 Immediately Setup
Speed
Position
Torque

YASKAWA SGDV Specifications

General

Protection Class	IP20
Communication Protocols	MECHATROLINK-III, EtherCAT
Feedback	Incremental encoder, Absolute encoder
Type	Servo Drive
Protection Functions	Overcurrent, Overvoltage, Undervoltage, Overheat, Encoder error
Ambient Temperature	0°C to 55°C
Storage Temperature	-20°C
Vibration Resistance	5.9 m/s² (0.6G)