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6. GENERAL GAIN ADJUSTMENT
6.2.2 Auto tuning mode operation
The block diagram of real-time auto tuning is shown below.
Servo
motor
Command
Automatic setting
Loop gains
PG1,VG1
PG2,VG2,VIC
Current
control
Current feedback
Load inertia
moment
Encoder
Position/speed
feedback
Real-time auto
tuning section
Speed feedback
Load inertia
moment ratio
estimation section
Gain
table
Parameter No.PB06
Load inertia moment
ratio estimation value
Set 0 or 1 to turn on.
Switch
Response
setting
Gain adjustment mode
selection
Parameter No.PA08
Parameter No.PA09
000
When a servo motor is accelerated/decelerated, the load inertia moment ratio estimation section always
estimates the load inertia moment ratio from the current and speed of the servo motor. The results of estimation
are written to parameter No.PB06 (the ratio of load inertia moment to servo motor). These results can be
confirmed on the status display screen of the MR Configurator.
If the value of the load inertia moment ratio is already known or if estimation cannot be made properly, chose
the "auto tuning mode 2" (parameter No.PA08: 0002) to stop the estimation of the load inertia moment ratio
(Switch in above diagram turned off), and set the load inertia moment ratio (parameter No.34) manually.
From the preset load inertia moment ratio (parameter No.PB06) value and response level (parameter
No.PA09), the optimum loop gains are automatically set on the basis of the internal gain tale.
The auto tuning results are saved in the EEP-ROM of the servo amplifier every 60 minutes since power-on. At
power-on, auto tuning is performed with the value of each loop gain saved in the EEP-ROM being used as an
initial value.
POINT
If sudden disturbance torque is imposed during operation, the estimation of
the inertia moment ratio may malfunction temporarily. In such a case, choose
the "auto tuning mode 2" (parameter No.PA08: 0002) and set the correct load
inertia moment ratio in parameter No.PB06.
When any of the auto tuning mode 1 and auto tuning mode settings is
changed to the manual mode 2 setting, the current loop gains and load inertia
moment ratio estimation value are saved in the EEP-ROM.