8.13 Manual Tuning
8.13.1 Tuning the Servo Gains
8
T
uning
8-77
Precautions
Vibration may occur while you are tuning the servo gains. We recommend that you enable
vibration alarms (Pn310 = n.
2) to detect vibration. Refer to the following section for infor-
mation on vibration detection.
6.15 Initializing the Vibration Detection Level
Vibration alarms are not detected for all vibration. Also, an emergency stop method is neces-
sary to stop the machine safely when an alarm occurs. You must provide an emergency stop
device and activate it immediately whenever vibration occurs.
Tuning Procedure Example (for Position Control or Speed
Control)
Adjusted Servo Gains
You can set the following gains to adjust the response characteristic of the SERVOPACK.
•
Pn100: Speed Loop Gain
•
Pn101: Speed Loop Integral Time Constant
•
Pn102: Position Loop Gain
•
Pn401: First Stage First Torque Reference Filter Time Constant
Position Loop Gain
The position loop gain determines the response characteristic of the position loop in the
SERVOPACK. If you can increase the setting of the position loop gain, the response character-
istic will improve and the positioning time will be shortened. However, you normally cannot
increase the position loop gain higher than the inherit vibration frequency of the machine
system. Therefore, to increase the setting of the position loop gain, you must increase the rigid-
ity of the machine to increase the inherit vibration frequency of the machine.
Step
Description
1
Adjust the first stage first torque reference filter time constant (Pn401) so that vibration does not
occur.
2
Increase the Speed loop gain (Pn100) and reduce the speed loop integral time constant (Pn101) as
far as possible within the range that does not cause machine vibration.
3
Repeat steps 1 and 2 and return the settings about 10% to 20% from the values that you set.
4
For position control, increase the position loop gain (Pn102) within the range that does not cause
vibration.
If you greatly change any one servo gain parameter, you must adjust the other parameters
again. Do not increase the setting of just one parameter. As a guideline, adjust the settings of
the servo gains by approximately 5% each. As a rule, change the servo parameters in the fol-
lowing order.
•
To Increase the Response Speed
1. Reduce the torque reference filter time constant.
2. Increase the speed loop gain.
3. Decrease the speed loop integral time constant.
4. Increase the position loop gain.
•
To Reduce Response Speed and to Stop Vibration and Overshooting
1. Reduce the position loop gain.
2. Increase the speed loop integral time constant.
3. Decrease the speed loop gain.
4. Increase the torque filter time constant.
Pn102
Position Loop Gain
Setting Range
Setting Unit
Default Setting
When Enabled
Classification
10 to 20,000
0.1/s
400
Immediately
Tuning
Information
Position
