Mitsubishi Electric MELSERVO MRJ2S-B, Instruction Manual

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Gain Operation
MELSERVO J2-Super 4 - 27
Auto tuning mode operation
The block diagram of real-time auto tuning is shown below:
When a servo motor is accelerated/decelerated, the inertia ratio estimation section always
estimates it from the current and speed of the servo motor. The results of estimation are written
to parameter No. 12. These results can be confirmed on the status display screen of setup-
software.
If the value of the load inertia moment ratio is already known or if estimation cannot be made
properly, choose the "auto tuning mode 2" (parameter No. 8: 0003) and set the load inertia
moment ratio (parameter No. 12) manually.
From the preset load inertia moment ratio (parameter No. 12) value and response level
(parameter No. 9), the optimum control gains are automatically set on the basis of the internal
gain table.
The auto tuning results are saved in the E²PROM of the servo amplifier every 6 minutes since
power-on. At power-on, auto tuning is performed with the value of each control gain saved in the
E²PROM being used as an initial value.
S000987C
Fig. 4-6: Block diagram of auto tuning
NOTE
If sudden disturbance torque is imposed during operation, the estimation of the inertia ratio
may malfunction temporarily. In such a case, choose the "auto tuning mode 2" (parameter
No. 8: 0003) and set the correct load inertia moment ratio in parameter No. 12.
0 0 0 0 0 0 5 1
+
-
+
-
Load inertia
moment
Servo
motor
Encoder
Current
control
Current feedback
Real-time auto tuning
section
Mass inertia
ratio
estimation
Pr. 12:
Mass inertia
ratio
Gain
table
Control gain
PG1, VG1, PG2,
VG2, VIC
Automatic
setting
Set 0 or 1 to turn on
Command
Parameter No. 8 Parameter No. 9
Auto tuning
Response level
S1
Position/speed
feedback