System philosophy
HARDWARE REFERENCE MANUAL
23
Revision 5.0
O
d
= K
d
·
Ä
E
Derivative gain may create a smoother response. High values may lead
to oscillation. The derivative gain axis parameter is called
D_GAIN
.
•
Output speed gain
The output speed gain
K
ov
produces an output
O
ov
that is proportional to
the change in the measured position
P
m
and increases system damping.
O
ov
= K
ov
·
Ä
P
m
The output speed gain can be useful for smoothing motions but will
generate high Following Errors. The output speed gain axis parameter is
called
OV_GAIN
.
•
Speed feed forward gain
The speed feedforward gain
K
vff
produces an output
O
vff
that is
proportional to the change in demand position
P
d
and minimizes the
Following Error at high speed.
O
vff
= K
vff
·
Ä
P
d
The parameter can be set to minimise the Following Error at a constant
machine speed after other gains have been set. The speed feed forward
gain axis parameter is called
VFF_GAIN
.
The default settings are given in the table along with the resulting profiles.
Fractional values are allowed for gain settings.
/i
2.3.4
Position loop algorithm in the Servo Drive
Refer to the Servo Drive manual for details.
Gain
Default value
Proportional gain
0.1
Integral gain
0.0
Derivative gain
0.0
Output speed gain
0.0
Speed feedforward gain
0.0