
4.SERVO FUNCTION DETAILS B-65270EN/05
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(5) Adjustment method
• Check the torque commands for the main axis and sub-axis and
velocity feedback vibration by using a check board. (See Item
(6).)
• If the vibration phase is shifted by 180 degrees, the cause of
resonance is assumed to be inter-axis interference.
• Enable tandem disturbance elimination control, and adjust
integral gain Ki.
• Increase the value of integral gain Ki gradually from 0, and
observe vibration. Ki has an optimal value. When the value of Ki
is increased excessively, vibration becomes stronger.
• When the velocity loop gain is changed, the frequency of
vibration changes. So, adjust Ki to minimize vibration.
• If the frequency of vibration exceeds 100 Hz, the effect of
tandem disturbance elimination control decreases. In such a case,
set phase compensation coefficients α and 2T/t or increase the
current loop gain with the current 1/2 PI control function.
Effect of tandem disturbance elimination control
* Velocity feedback and vibration frequency when the sub-axis is
vibrated
(6) Method of checking the frequency of vibration
In this adjustment, use the disturbance input function for the sub-axis,
measure the velocity feedback for the main axis, check for
interference between the axes, and check and adjust the effect of
tandem disturbance elimination control.
The following explains how to use the disturbance input function and
how to make settings for data measurement.
Main axis velocity
Sub-axis
vibration
Interference is
improved.