Yaskawa Sigma Mini - Manual (Page 99)

2.6Minimizing Positioning Time
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Using Speed Reference as a Detection Point of Mode Switch
If a speed reference exceeds the value set in pa-
rameter Cn-0D, the speed loop switches to P con-
trol.
• Example of Use:
The mode switch is used to reduce settling time.
Generally, speed loop gain must be increased to reduce settling time. Using the mode
switch suppresses the occurrence of overshoot and undershoot when speed loop
gain is increased.
Without mode switch
Speed reference
Motor
speed
Motor speed
Settling time is long
Increase speed loop gain
Without mode switch
Motor
speed
Overshoot
Undershoot
Time
With mode switch
Motor
speed
Settling time
Suppress the occurrence
of overshoot and
undershoot.
Using Acceleration as a Detection Point of Mode Switch (Standard Setting)
If motor acceleration exceeds the value set in pa-
rameter Cn-0E, the speed loop switches to P con-
trol.
• Example of Use:
If a mode switch is not used and PI control is
always performed, torque may enter a satura-
tion state during acceleration or deceleration,
causing the motor speed to have overshoot or
undershoot.
Using the mode switch suppresses torque sat-
uration and prevents the motor speed from
having overshoot and undershoot.
Without mode switch
Motor
speed
Overshoot
Undershoot
Time
With mode switch
Motor
speed
Time
2
Speed
Speed reference Motor
speed
PI control P control PI control
Speed
Reference
speed Motor speed
Motor
acceleration
Acceleration
PI control
P control P control
PI control PI control