NSK M-EGA-15A2301, User Manual

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6.Adjustments Disturbance observer
6-21
6.8 Using disturbance observer function
The motor speed will fluctuate when an external force is applied to the operating machine, and it
may affect the machine operation.
The Disturbance Observer is a function to suppress the influence of external load torque by
estimating the load torque inside the driver and adding the load torque compensation to the torque
command. To use the Disturbance Observer, set [Group9 ID33: disturbance observer function
[OBS] to [Functions enabled]. Adjust the observer related parameters in [Group2 ID30-33] and
suppression or reject the disturbance.
■
Parameters for using the Disturbance Observer
◆
Group9 [Functions enabling conditions settings]
ID Symbol Contents Setting range
33 OBS Disturbance Observer Function 00 to 27
◆
General parameters Group2 [FF vibration suppression control/Notch filter/
Disturbance observer settings]
ID Symbol Name Unit Setting range
30 OBCHA Observer Characteristic --- 00 to 02
31 OBG Observer Compensation Gain % 0 to 100
32 OBLPF Observer Output Low-pass Filter Hz 1 to 4000
33 OBNFIL Observer Output Notch Filter Hz 100 to 4000
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Explanation of the parameters using the Disturbance Observer.
◆
There are three types of disturbance observer characteristics.
Select a proper type depending on disturbance frequency to be suppressed
Frequency Type
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
◆
Gradually increase Observer Compensation Gain. (Do not set the value at the beginning.)
The higher the Observer Compensation Gain becomes, the more disturbance suppressing
characteristics will improve. However, if the gain is excessively high, oscillation may result. Use this
within a range that will not cause oscillation.
✔
Disturbance Observer cannot be used with Auto-tuning at the same time.
✔
Observer low-pass filter can be used when the resolver resolution is high or the Load inertia moment ratio is
low. Observer characteristics can be improved by setting the frequency high.
✔
Use the Observer notch filter to suppress vibration in case the resonance in high frequency zones has
changed.
✔
Use [02_High for High frequency disturbance suppression] when resolver resolution is above 1048576
division.