Auto Tuning Mode Basis - Mitsubishi Electric MELSERVO-J3 Series Instruction Manual

9. GENERAL GAIN ADJUSTMENT

9.2.2 Auto tuning mode basis

The block diagram of real-time auto tuning is shown below.
Command
Parameter No.PA08 Parameter No.PA09
0 0 0
Gain adjustment mode
selection
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 section.
If the value of the load inertia moment ratio is already known or if estimation cannot be made properly, set the
"auto tuning mode 2" (parameter No.PA08: 0002) to stop the estimation of the load inertia moment ratio
(Switch in above diagram turns off), and set the load inertia moment ratio (parameter No.PB06) 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 table.
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.
Automatic setting
Loop gains
PG1,VG1
PG2,VG2,VIC
Set 0 or 1 to turn on.
Gain
table
Parameter No.PB06
Load inertia moment
ratio estimation value
Response
setting
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.
Current
control
Current feedback
Real-time auto
tuning section
Load inertia
moment ratio
estimation section
Switch
9 - 4
Load inertia
moment
Encoder
M
Servo motor
Position/speed
feedback
Speed feedback