Omron R88M-W60010T User Manual page 310

Operation
P Control Switching Condition Taken as Speed Command (Pn10B.0 = 1)
●
• When the speed command is equal to or greater than the speed set in the user constant (Pn10D),
the speed loop is switched to P control.
Speed command
Speed
Pn10D
PI P control
• Operation Example
Used to shorten the settling time. In general, the speed loop gain must be raised in order to shorten
the settling time, but in this case overshooting and undershooting are suppressed.
Without P control switching
Speed
command
Servomotor
speed
Long settling time
Speed loop gain raised.
Overshooting
Servomotor
Under-
speed
shooting
Time
● P Control Switching Condition Taken as Acceleration Speed (Pn10B.0 = 2)
• When the Servomotor acceleration speed is equal to or greater than the acceleration speed set in
the user constant (Pn10E), the speed loop is switched to P control.
Servomotor
Command speed
speed
Speed
• Operation Example
When P control switching is not used, and PI control is always used, the torque during acceleration
and deceleration may be saturated and the Servomotor speed may overshoot or undershoot. Using
P control switching suppresses torque saturation and eliminates Servomotor speed overshooting
and undershooting.
Without P control switching
Overshooting
Servomotor
Under-
speed
shooting
Time
4-114
Servomotor
speed
Time
PI control
With P control switching
Servomotor
speed
Servo-
motor
speed
+Pn10E
Acceleration
0
speed
−Pn10E
PI P
With P control switching
Servo-
motor
speed
Settling time
Servomotor acceleration speed
PI control P PI control
Time
Chapter 4