Sigma II User’s Manual
Chapter 6: Servo Adjustment
6-34
n
Machines with Low Rigidity
These machines are driven by timing belts, chains, or machines with harmonic gear
reducers.
Examples: Conveyor, articulated robot
In speed control operation, the position loop gain is set through the host controller.
If that is not possible, adjust the position loop gain with the speed reference input
gain in Pn300 in the servo amplifier. In speed control operation, the position loop
gain set in Pn102 is enabled in zero-clamp mode only. Position loop gain K
p
is
obtainable from the following formula.
Where: K
p
(
s
-1
)
:
Position Loop Gain
V
s
(
pps
)
: Constant Speed Reference
ε
(
Pulse
)
: Constant error: The number of accumulated pulses of
the error counter at the above constant speed.
Position Loop Gain (Pn102)
Speed Loop Gain (Pn100)
Speed Loop Integral Time Constant
(Pn101)
10 to 20s
-1
10 to 20Hz
50 to 120ms
•
When the inertia ratio is larger than 10, start gain adjustments with the position and speed
loop gains slightly below the ranges given above and the speed loop integral constant
slightly over the range.
•
When the inertia ratio is much larger, start the gain adjustments with the position and
speed loop gains set to the smallest values and the speed loop integral constant to the
large value in the ranges given above.
IMPORTANT
K
p
≥
V
s
ε
