YASKAWA SIEMENS CNC Series, Maintenance Manual, Serviceman Handbook

Page: 254 / 373

Drive set-up procedure
14.2.7 Speed feedback compensation
14-44
14.2.7 Speed feedback compensation
You can suppress vibration and increase speed loop gain by using speed feedback compen-
sation.
The following explains about parameters for speed feedback compensation.
• MD3046 digit 1 (Pn110 digit 1) SWITCH_ONLINE_AUTO_TUNING (For each axis)
Meaning: Selects speed feedback compensation function
Setting value: 0 --- Enabled
1 --- Disabled
Note: Pay attention to the polarity of "Enabled" and "Disabled".
• MD3047 (Pn111) SPEED_FEEDBACK_COMP_GAIN (For each axis)
Meaning: Speed feedback compensation gain
Setting value: [%]
• MD3048 (Pn112) SPEED_FEEDBACK_DELAY_COMP (For each axis)
Meaning: Speed feedback delay compensation
(Speed feedback compensation inertia gain)
Setting value: [%]
Note: Previous parameter "Speed feedback compensation attenuation fac-
tor" is no longer used.
Adjustment procedures
1. Check an axis to which you want to make an adjustment to disable speed feedback func-
tion (MD3046 digit 1 (Pn110 digit 1) = 1) by watching its torque waveform or others on
the analog monitor, and confirm that the axis vibrates.
2. Assign the following values to the parameters above for the axis you want to make an
adjustment.
• MD3047 = 100
• MD3048 = Setting value of MD3033 (Load inertia ratio) + 100
3. Enable speed feedback function (MD3046 digit 1 (Pn110 digit 1) = 0)
4. Adjust only the 1st-stage torque filter time constant by assigning a large value to
MD3351 (Pn401) as far as no vibration happens at any feed speed. If a vibration hap-
pens, decrease the value.
The maximum value that can be assigned to the MD3351 (Pn401) is calculated from the
speed loop gain MD3030 (Pn100) as follows. Notice that you should assign a smallest
possible value to it.
• MD3351 = 600000/(MD3030
×
2
π
)
5. If no vibration happens in the procedure 4, increase speed loop gain MD3030 (Pn100).
6. If vibration starts while you are increasing MD3030, increase MD3351 paying attention
to the above-mentioned maximum value.