Yaskawa Sigma II Series Servo System - Manual (Page 261)

Sigma II User’s Manual Chapter 6: Servo Adjustment
6 - 29
6.3.3 Saving Results of Online Auto-Tuning
Online auto-tuning always processes the latest load inertia to renew data so that the
speed loop gain will reach the target value that has been set. When the servo
amplifier is turned OFF, all the processed data is lost. Therefore, when the servo
amplifier is turned ON again, online auto-tuning is performed by processing the
factory-set values in the servo amplifier.
To save the results of online auto-tuning and use them as the initial values set in the
servo amplifier when the servo amplifier is turned ON again, it is necessary to use
constant Fn007 in the auxiliary function mode. In this case, the inertia value set in
parameter Pn103 will be changed.
On the basis of the rotor inertia of the servomotor, the inertia ratio is expressed in
percentage terms by the load inertia. The value set in Pn103 is used to calculate the
load inertia at the time of online auto-tuning.
The inertia ratio is default set to 0%.
For details on setting Pn103, refer to 7.1.6 Operation in Parameter Setting Mode.
Parameter Signal
Setting
(%)
Description
Pn103 Inertia Ratio
Setting Range: 0 to 10000
Default Setting: 0
Speed/Torque Control,
Position Control
• Before making servo gain adjustments manually, be sure to set the inertia ratio in Pn103.
If the inertia ratio is incorrect, the speed loop gain (in 1Hz increments) set in Pn100 will be wrong .
Inertia Ratio = × 100%
Motor Load Inertia (J
L
)
Rotor Inertia (J
M
)
IMPORTANT