Instruction manual

Gain Operation
MELSERVO J2-Super 4 - 31
● Speed control
The following table gives an overview of the parameters used for rotation speed control for the
manual setting of the gain factor.
For the setting please follow the instructions which are given below:
 Set an estimated value to the ratio of inertia (parameter No. 12).
 Set pr. 16 to a low value in the vibration- and noise-free range. Increase the value gradually
and reduce it again as soon as vibrations set in. The optimum value is reached shortly before
vibrations set in.
 Set pr. 17 to a value in the vibration- and noise-free range. Decrease the value gradually
and increase it again as soon as vibrations set in. The optimum value is reached shortly
before vibrations set in.
 If the gain cannot be increased due to mechanical system resonance and the desired
response cannot be achieved used the low-pass filter (parameter No. 25) or the machine
resonance suppression filter (parameter No. 18) for executing steps  and .
The response level of the revolution speed control loop is specified via the gain factor VG2
(pr. 16). Increasing this value enhances response but a too high value will make the mechanical
system liable to vibrate. The actual response frequency of the speed loop is as indicated in the
following expression:
The setting of the I-portion of the speed control loop VIC occurs via pr. 17 and can be calculated
as follows:
Parameter Symbol Name
12 GD2 Ratio of load inertia moment to servo motor inertia moment
16 VG2 Speed control gain 2
17 VIC Speed intergral compensation
Tab. 4-19: Parameter adjusted for speed control
speed loop response frequency [Hz]
VG2
1 ratio of inertia+()2π×
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VIC [ms]
2000 to 3000
VG2 1 ratio of inertia+()⁄
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