
Title 90A3 / 90A7 / 90B3 / 90B7
Learning Control Operator’s Manual
03 ’05.01.13 K.Maeda 3
rd
. updated Draw No.
02 '03.01.06 K.Maeda 2
nd
. updated
A - 63639E - 070
01 ‘00.09.20 K.Maeda Newly designed Sheet 080
Edit Date Design Description / 081
Appendix 8. Measurement of velocity loop characteristic by disturbance torque input function
By disturbance torque input function added in 90B3 or 90B7 and sd.exe, you can measure the servo velocity
loop frequency characteristic with connected machine. To measure frequency characteristic, you can check a
limit of velocity gain or a resonance frequency.
If you use Servo Guide, the following parameters setting is automatic.
8.1 Parameters setting
(1) At first, set the following parameters.
No.1820=100 Position gain
No.1829=32767 Position error limit at stop
No.2270#7=1 Disturbance torque input function enable
No.2326=0 Disturbance gain : (Disturbance torque[A]) / (max. amplifier current) x 7282
No.2327=10 Start frequency (Hz)
No.2328=1000 Finish frequency (Hz)
No.2329=3 Repeat number
Servo software outputs Torque command to CH1 and Disturbance frequency to CH2 for SD.EXE.
No.2115=2 Parameter for internal data measurement 1
No.2151=813(L), 841(M) Parameter for internal data measurement 1
No.2152=2 Parameter for internal data measurement 2
No.2153=1989 Parameter for internal data measurement 2
(2) When you set non zero value to No.2326, that motor produces the oscillation disturbance.
From non zero setting, when you change a value of No.2326, that motor produces the oscillation
disturbance.
(Note) Because a machine is oscillation when motor produce disturbance, you should be careful.
Disturbance torque (No.2326) is set below rated torque.
(Note) If "410 EXEC ERROR" happens, you should set No.2228#6 = 1.
This bit must set clear after measurement.
8.2 Measurement
(1) You set the LED of CH1 to "15" and the LED of CH2 to "16" on Digital check board A.
(2) You set "ch0 : TCMD", and "ch1 : POS (1mm/P) in SD.EXE.
(3) When you change No.2326, you start data trace in SD.EXE.
(Example) At first, there was a resonance at 160Hz. We tuned the Acceleration feedback function (No.2066).
As result, a resonance at 160Hz was clear.
first After tuning by Acceleration FB
TCMD
Frequency
resonance
TCMD
Frequency