Fuji Electric ALPHA7, User Manual

Page: 351 / 662

CHAPTER 5 SERVO ADJUSTMENT
5-34
Special Adjustment (Vibration Suppression)
5
(7) Entering the vibration suppressing workpiece inertia ratio
Ratio of the inertia of the vibrating point such as the arm specifies the portion of the total load
inertia. By setting the vibration suppressing workpiece inertia ratio which is equivalent to amount
to be applied when receiving reaction force from mechanical system (workpiece), the vibration
can be further suppressed.
Setting method
[1] Calculate the inertia of the vibrating point according to specifications of the machine.
Vibration suppressing
workpiece inertia ratio
=
Vibrating point inertia
Entire load inertia
[2] Entering with the PC Loader
(1) Check the anti resonance frequency and resonance frequency by using the servo analyze
function.
(2) Select [Parameter Edit] - [PA1: Control Gain - Filter Setting] and press the "enter vibration
suppressing anti resonance frequency" button to open the exclusive window.
Enter the anti resonance frequency and resonance frequency* to automatically calculate
the ratio of inertia of the workpiece.
* The resonance frequency is not the resonance frequency suppressed with the notch filter.
Use the servo analyze function to check this resonance frequency.
This resonance frequency appears as a set with the anti resonance frequency, and it is about two
times the anti resonance frequency.
[Example of resonance frequency]
Resonance frequency: about 90Hz
Gain
Anti resonance frequency: about 45Hz
Frequency