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7. GENERAL GAIN ADJUSTMENT
7.3 Manual mode 1 (simple manual adjustment)
If you are not satisfied with the adjustment of auto tuning, you can make simple manual adjustment with three
parameters.
POINT
If machine resonance occurs, adaptive tuning mode (parameter No.PB01) or
machine resonance suppression filter (parameter No.PB13 to PB16) may be
used to suppress machine resonance. (Refer to section 8.3.)
(1) For speed control
(a) Parameters
The following parameters are used for gain adjustment.
Parameter No.
Abbreviation
Name
PB06
GD2
Ratio of load inertia moment to servo motor inertia moment
PB07
PG1
Model loop gain
PB09
VG2
Speed loop gain
PB10
VIC
Speed integral compensation
(b) Adjustment procedure
Step
Operation
Description
1
Brief-adjust with auto tuning. Refer to section 7.2.3.
2
Change the setting of auto tuning to the manual mode (Parameter
No.PA08: 0003).
3
Set an estimated value to the ratio of load inertia moment to servo motor
inertia moment. (If the estimate value with auto tuning is correct, setting
change is not required.)
4
Set a slightly smaller value to the model loop gain.
Set a slightly larger value to the speed integral compensation.
5
Increase the speed loop gain within the vibration- and unusual noise-free
range, and return slightly if vibration takes place.
Increase the speed loop gain.
6
Decrease the speed integral compensation within the vibration-free range,
and return slightly if vibration takes place.
Decrease the time constant of the speed
integral compensation.
7
Increase the model loop gain, and return slightly if overshooting takes
place.
Increase the model loop gain.
8
If the gains cannot be increased due to mechanical system resonance or
the like and the desired response cannot be achieved, response may be
increased by suppressing resonance with adaptive tuning mode or
machine resonance suppression filter and then executing steps 3 to 7.
Suppression of machine resonance.
Refer to section 8.2, 8.3.
9
While checking the rotational status, fine-adjust each gain.
Fine adjustment
(c) Adjustment description
1) Speed loop gain (parameter No.PB09)
This parameter determines the response level of the speed control loop. Increasing this value
enhances response but a too high value will make the mechanical system liable to vibrate. The actual
response frequency of the speed loop is as indicated in the following expression.
Speed loop response
frequency(Hz)
Speed loop gain setting
(1 ratio of load inertia moment to servo motor inertia moment)
2
