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9. GENERAL GAIN ADJUSTMENT
9.4 Interpolation mode
The interpolation mode is used to match the position loop gains of the axes when performing the interpolation
operation of servo motors of two or more axes for an X-Y table or the lik e. In this mode, manually set the model
loop gain that determines command track abilit y. Other parameters for gain adjustment are set a utomatically.
(1) Parameter
(a) Automatically adjusted parameters
The following parameters are automatically adjusted by auto tuning .
Parameter No. Abbreviation Name
PB06 GD2 Ratio of load inertia moment to servo motor inertia moment
PB08 PG2 Position loop gain
PB09 VG2 Speed loop gain
PB10 VIC Speed integral compensation
(b) Manually adjusted parameters
The following parameters are adjustable manua lly.
Parameter No. Abbreviation Name
PB07 PG1 Model l oop gain
(2) Adjustment procedure
Step Operation Description
1 Set to the auto tuning mode. Select the auto tuni ng mode 1.
2 During operation, increase the response level setting (parameter No.PA09), and
return the setting if vibration occurs. Adjustment in auto tuning mode 1.
3 Check the values of model loop gain. Check the upper setting limits.
4 Set the interpolation mode (parameter No.PA08: 0000). Select the interpolation mode.
5 Set the model loop gain of all the axes to be interpolated to the same value. At that
time, adjust to the setting value of the axis, which has the smallest model loop gain. Set position loop gain.
6 Looking at the interpolation characteristic and rotation status, fine-adjust the gains
and response level setting. Fine adjustment.
(3) Adjustment description
(a) Model loop gain (parameter No.PB07)
This parameter determines the response level of the p osition control loop. Increasing model loop gain
improves track ability to a position command but a t oo high value will make overshooting liable to occur
at the time of settling. The droop pulse value is determined by the following expression.