Delta ASD-B2-0121-F, User Manual

Page: 96 / 291

ASDA-B2-F Control Mode of Operation
September, 2015
6-7
6
Differentiator
Position Loop
Gain
P2-00
Position Control Unit
Gain Switching
and Switching
Selection
P2-27
Speed
Command
Position Feed
Forward Gain
P2-02
Smooth Constant of
Position Feed
Forward Gain
P2-03
Switching Rate
of Position Loop
Gain
P2-01
Max. Speed
Limit
P1-55
Encoder
Position
Counter
+
-
+
+
+
Figure 6-3 Position Control Unit
When the value of KPP is set to be too large, the bandwidth of position loop will be increased and
diminish the phase margin. And the motor rotor rotates vibrantly in forward and reverse direction
at the moment. Thus, KPP has to be decreased until the rotor stops vibrating. When the external
torque interrupts, the over-low KPP cannot meet the demand of reducing position error. In this
situation, parameter P2-02 may help which can effectively reduce the position error.
6.2.6 Low-frequency Vibration Suppression in Position Mode
If the system stiffness is not enough, the mechanical transmission will continue vibrating even
when the motor stops and the positioning command is completed. The function of low-frequency
vibration suppression can eliminate the vibration of mechanical transmission. The range of
low-frequency vibration suppression is from 1.0Hz to 100.0HZ. Manual setting and auto setting
are provided for this function.
Auto setting:
If the frequency is hard to find, user can enable the function of auto low-frequency vibration
suppression. This function automatically searches the frequency of low-frequency vibration. If
P1-29 is set to 1, the system will disable the function of low-frequency vibration suppression
automatically
and starts to search for the vibration frequency. When the detected frequency
remains at the same level, P1-29 will be set to 0 automatically and set the first frequency to
P1-25 and set P1-26 to 1. The second frequency will be set to P1-27 and then set P1-28 to 1. If
P1-29 is automatically set back to 0 and low-frequency vibration still exists, please check if the
function of P1-26 or P1-28 is enabled. If the value of P1-26 and P1-28 are 0, it means no