Mitsubishi Electric MELSERVO-J3W Series, Instruction Manual

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6. GENERAL GAIN ADJUSTMENT
6 - 10
(c) Adjustment description
1) Speed loop gain (VG2: parameter No.PB09)
This parameter determines the response level of the speed control loop. 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.
Speed loop gain setting
Speed loop response
frequency(Hz)
(1 Load to motor inertia moment ratio 2
2) Speed integral compensation (VIC: parameter No.PB10)
To eliminate stationary deviation against a command, the speed control loop is under proportional
integral control. For the speed integral compensation, set the time constant of this integral control.
Increasing the setting lowers the response level. However, if the load inertia moment ratio is large
or the mechanical system has any vibratory element, the mechanical system is liable to vibrate
unless the setting is increased to some degree. The guideline is as indicated in the following
expression.
2000 to 3000
Speed loop gain setting/
Speed integral compensation
setting(ms)
(1 Load to motor inertia moment
ratio setting)
3) Position loop gain (PG2: Parameter No.PB08)
This parameter determines the response level to a disturbance to the position control loop.
Increasing the value increases the response level to the disturbance, but a too high value will
increase vibration of the mechanical system.
Position loop gain
guideline
Speed loop gain setting
(1 load to motor inertia moment ratio)
to
1
4 1
8
4) Model loop gain (PG1: parameter No.PB07)
This parameter determines the response level to a position command. Increasing position loop
gain 1 improves track ability to a position command but a too high value will make overshooting
liable to occur at the time of settling.
Model loop gain
guideline
to
Speed loop gain setting
1
4 1
8
(1 Load to motor inertia moment ratio)