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7. ADJUSTMENT
7.4.4
When shortening the settling time
(1) Machine condition
The settling time will be increased by the gains provided by auto tuning.
(2) Adjustment procedure
1) Choose the response setting of slow response.
Set 0101 in parameter No.2.
2) Alternate a start and a stop several times, execute auto tuning, and check whether the machine
does not vibrate.
3) Set the load inertia moment ratio (machine inertia moment ratio in parameter No. 34).
If an exact machine inertia moment ratio is unknown, enter an approximate value.
When the value is set in this parameter, the following parameters are set automatically. When
there is no machine resonance, the value of each parameter is set to the ideal gain for the
parameter No. 34 value.
Parameter No.
Symbol
Name
No. 6
PG1
Position loop gain 1
No. 35
PG2
Position loop gain 2
No. 36
VG1
Speed loop gain 1
No. 37
VG2
Speed loop gain 2
No. 38
VIC
Speed integral compensation
4) Set
2
in parameter No. 2 to make auto tuning invalid.
Make the parameter No. 6, 35 to 38 settings manually adjustable.
5) Check the operating status and adjust the following parameter values:
Parameter No.
Symbol
Name
Description
No. 6
PG1
Position loop gain 1
No. 35
PG2
Position loop gain 2
Higher setting shortens the settling time but
is liable to cause overshooting.
No. 36
VG1
Speed loop gain 1
No. 37
VG2
Speed loop gain 2
Higher setting improves the servo response
level but is liable to cause vibration.
No. 38
VIC
Speed integral compensation
Lower setting keeps the speed constant to
load disturbance and increases holding force
at a stop (servo rigidity) but is liable to cause
overshooting.
Make adjustment by gradually increasing the parameter No. 6, 35 to 37 settings at the same ratio and
reducing the speed integral compensation (parameter No. 38). The optimum value is provided at the
point just before vibration increases. Use of the machine resonance suppression filter (parameter No.
22) may increase the limit point. However, note that the setting increased up to the limit point may
cause resonance due to the machine's variations and changes with time.
