Sanyo Denki SANMOTION 3E S, Instruction Manual, Page: 239 / 488

6.9 Disturbance impact suppression function
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6
Servo Tunin
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6.9.2 Disturbance Observer Function
The Disturbance Observer is a function to suppress the influence of external load torque by
estimating the load torque inside the servo amplifier and adding the load torque compensation to
the torque command.
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How to use
The function will be valid when the condition which is selected at "Index 0x2000-bit11
Disturbance Observer compensation enabling [OBS]" is filled.
 Select appropriate observer characteristic depending on disturbance frequency which
is desired to suppress.
 Increase the value of "Index 0x2016-2 Observer Compensation Gain [OBG]" by little,
and do not start from large value. Disturbance suppression characteristic will improve
by increasing "Observer Compensation Gain [OBG]". However, oscillation might occur
by too large of set value. Please use in range of no oscillation.

"Index 0x2016-2 Observer Output Low-pass Filter [OBLPF]" is able to improve observer
characteristic by setting frequency higher at high encoder resolution or low load inertia
moment ratio etc.
 Use "Observer Output Notch Filter" to suppress vibration when resonance is changed
at high frequency range.
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Parameters for using the Disturbance Observer
 Group9 “Functions enabling conditions settings”
 General parameters Group2
"FF (Feed Forward) vibration suppression control/ Notch filter/ Disturbance observer
settings"
 Disturbance observer characteristics are prepared as "00_Low: Low frequency
disturbance suppression", "01_Middle: Mid-frequency disturbance suppression" and
"02_High: High frequency disturbance suppression".
* Disturbance Observer cannot be used with Auto-tuning at the same time.
* Use “02_High for High frequency disturbance suppression” when encoder resolution is above
1048576 division.
* Torque command might have variation if switches a valid/ invalid of "Index 0x2000-bit11
Disturbance Observer compensation enabling [OBS]" when cutoff frequency of OBLPF is set
higher.
Index/Sub-Idx Symbol Name Setting range
0x2000/0x00 OBS Disturbance Observer compensation enabling 0 to 1
Index/Sub-Idx Symbol Name Unit Setting range
0x2016/0x01 OBCHA Observer Characteristic
－
00 to 02
0x2016/0x02 OBG Observer Compensation Gain % 0 to 100
0x2016/0x03 OBLPF Observer Output Low-pass Filter Hz 1 to 4000
0x2016/0x04 OBNFIL Observer Output Notch Filter Hz 100 to 4000
Frequency Selection Description
10 to 40 Hz 00 Low Low frequency disturbance suppression
40 to 80 Hz 01 Middle Mid-frequency disturbance suppression
80 to 200 Hz 02 High High frequency disturbance suppression