Mitsubishi Electric MELSERVO-JN Series Instruction Manual page 198

6. GENERAL GAIN ADJUSTMENT
(b) Adjustment procedure
Step
1
Brief-adjust with auto tuning. Refer to section 6.3.3.
Change the setting of the tuning mode to the manual mode (Parameter No.
2
PA08: 003)
Set an estimated value to the load to motor inertia moment ratio. (If the
3
estimate value with auto tuning is correct, setting change is not required.)
Set a small value to the model loop gain and the position loop gain.
4
Set a large value to the speed integral compensation.
Increase the speed loop gain within the vibration- and unusual noise-free
5
range, and return slightly if vibration takes place.
Decrease the speed integral compensation within the vibration-free range,
6
and return slightly if vibration takes place.
7
Increase the position loop gain, and return slightly if vibration takes place.
8
Increase the model loop gain, and return slightly if overshooting takes place.
If the gains cannot be increased due to mechanical system resonance or the
like and the desired response cannot be achieved, response may be
9
increased by suppressing resonance with adaptive tuning mode or machine
resonance suppression filter and then executing steps 3 to 8.
While checking the settling characteristic and rotational status, fine-adjust
10
each gain.
(c) Adjustment description
1) Speed loop gain (VG2: parameter No. PB09)
The same as for the internal speed control.
2) Speed integral compensation (VIC: parameter No. PB10)
The same as for the internal speed control.
3) Position loop gain (PG2: parameter No. PB08)
This parameter determines the response level to a disturbance to the position control loop.
Increasing the value increases the response level to the disturbance, but a too high value will
increase vibration of the mechanical system.
Position loop gain
guideline
4) Model loop gain (PG1: parameter No. PB07)
This parameter determines the response level of the model loop. Increasing position loop gain 1
improves trackability to a position command but a too high value will make overshooting liable to
occur at the time of settling.
Model loop gain
guideline
Operation
Speed loop gain 2 setting
(1 load to motor inertia moment ratio)
Speed loop gain 2 setting
(1 load to motor inertia moment ratio)
Increase the speed loop gain.
Decrease the time constant of the speed
integral compensation.
Increase the position loop gain.
Increase the model loop gain.
Suppression of machine resonance.
(Refer to section 7.2.)
Fine adjustment
1
(
to
4
1
(
to
4
6 - 17
Description
1
)
8
1 )
8