Speed Feedforward - YASKAWA E-V Series User Manual

6 Adjustments

6.8.3 Speed Feedforward

6.8.3 Speed Feedforward

The speed feedforward function is valid only in position control.
The speed feedforward function is used to shorten positioning time. 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.
Host controller
Position
reference
Kp: Position loop gain
K : Feedforward gain
FF
(2) Related Parameters
Speed feedforward value is set using the parameters Pn207 and Pn300.
The factory setting is Pn300 = 600. If, for example, the speed feedforward value is ±6V, then the speed is lim-
ited to the rated speed.
Parameter
Pn207
Speed Reference Input Gain
Pn300
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.
6-54
Model following control sets the optimum feed forward value in the servo. Therefore,
usually model following control does not use the speed feedforward (V-REF) and the
force feedforward (T-REF) together.
If the speed feedforward (V-REF) value and force feedforward (T-REF) value are improp-
erly input, overshooting may occur.
SERVOPACK
V-REF (CN1-5 and -6)
Differ-
K
Pn300
FF
ential
+
PULS
SIGN
n. 0 Disabled
n. 1 Uses V-REF terminal for speed feedforward input.
Setting Range Setting Unit
150 to 3000 0.01 V/rated speed
+
+
Kp ( Pn102 ) Pn100
-
-
Integration
(Pn101)
Speed
calculation
Function
Speed
Factory Setting
Linear
servomotor
+
Current loop
M
+
Enc
Linear scale
When Enabled
After restart
Force
Position
When Enabled
600 Immediately
Classification
Setup
Classification
Setup