
2.EXPLANATION OF OPERATION MODES FANUC AC SPINDLE MOTOR αi series B-65280EN/05
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(3)-3 Specifying a velocity loop gain
Refer to Section 4.1 “VELOCITY LOOP GAIN ADJUSTMENT” for
details of the velocity loop proportional/integral gain. Adjust the
velocity loop proportional/integral gain so that the velocity error
decreases.
During the adjustment, observe the velocity error and motor speed.
Sample waveforms before and after the adjustment are shown below:
(a) Waveform before adjustment (No. 4044 =
10, No. 4052 = 10)
CH1 : Velocity deviation
12.5 min
-1
/div
CH2 : Motor speed
2048 min
-1
/div
(b) Waveform after adjustment (No. 4044 =
20, No. 4052 = 60)
CH1 : Velocity deviation
12.5 min
-1
/div
CH2 : Motor speed
2048 min
-1
/div
(3)-4 Specifying an acceleration/deceleration time constant (2) :
Specifying an optimum value
Observing the torque command and motor speed, make a final
adjustment of the time constant. Adjust the time constant in
consideration of the actual cutting load, so that the peak torque at air
cut becomes about 70% to 80% (3.5 to 4.0 V) of the maximum value.
Sample waveforms before and after the adjustment are shown below:
(a) Waveform before adjustment (No. 5261 = 800)
(b) Waveform after adjustment (No. 5261 = 480)
CH1 : Torque command
50% / div
CH2 : Motor speed
2048 min
-1
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CH1 : Torque command
50% / div
CH2 : Motor speed
2048 min
-1
/ div