Mitsubishi Electric 800 Series, Инструкция по эксплуатации, Страница: 237 / 727

Position control under vector control
236
PARAMETERS
5.5.10
Position control gain adjustment
 Position loop gain (Pr.422, Pr.1298)
• Make adjustment when any of such a phenomena as unusual vibration, noise and overcurrent of the motor/machine
occurs.
• Increasing the setting improves traceability for the position command and also improves servo rigidity at a stop, but
oppositely makes an overshoot and vibration more liable to occur.
• Normally set this parameter within the range about 5 to 50.
 Position feed forward gain (Pr.423)
• This function is designed to cancel a delay caused by the droop pulses in the deviation counter. Set this parameter when a
sufficient position response cannot be obtained after setting Pr.422 .
• When a tracking delay for command pulses poses a problem, increase the setting gradually and use this parameter within
the range where an overshoot or vibration will not occur.
• This function has no effects on servo rigidity at a stop.
• Normally set this parameter to 0.
• When setting
Pr.423 , set Pr.877 ="0 or 1" to enable position feed forward control.
 Model adaptive position control (Pr.446)
• Set each response for position commands and for load and external disturbances individually.
• Set this parameter when a sufficient position response cannot be obtained after setting
Pr.422 .
• When setting Pr.446 , set Pr.877 ="2" to enable the model adaptive position control, Pr.828 Model speed control gain

"0",
and a load inertia ratio in Pr.880 Load inertia ratio .
• Set a small value in Pr.446 first, and then increase the setting gradually and use this parameter within the range where an
overshoot or vibration will not occur.
Easy gain tuning is provided as an easy tuning method. For details about easy gain tuning, refer to page 164 .
If it does not produce any effect, make fine adjustments by using the following parameters.
Set "0" to
Pr.819 Easy gain tuning selection before setting the following parameters.
Pr. Name Initial value Setting range Description
422
B003
Position control gain
25 s
-1
0 to 150 s
-1
Set the gain for the position loop.
1298
B013 Second position control
gain
25 s
-1
0 to 150 s
-1
Set the position loop gain for the second motor.
423
B004 Position feed forward
gain
0% 0 to 100%
Function to cancel a delay caused by the droop pulses
in the deviation counter.
425
B006 Position feed forward
command filter
0 s 0 to 5 s Input the first delay filter for the feed forward command.
446
B012 Model position control
gain
25 s
-1
0 to 150 s
-1
Set the gain for the model position controller.
828
G224 Model speed control
gain
60% 0 to 1000% Set the gain for the model speed controller.
877
G220
Speed feed forward
control/model adaptive
speed control selection
0
0, 1 Perform position feed forward control.
2 Model adaptive position control becomes valid.
880
C114
Load inertia ratio
7-fold 0 to 200-fold Set the load inertia ratio for the motor.
Movement  condition How to adjust Pr.422
Response is slow.
Increase the setting value.
Increase the setting value by 3 s
-1
until immediately before an overshoot, stop-time
vibration or other instable phenomenon occurs, and set about 80 to 90% of that value.
Overshoot, stop-time vibration
or other instable phenomenon
occurs.
Lower the setting value.
Lower the setting value by 3 s
-1
until immediately before an overshoot, stop-time
vibration or other instable phenomenon does not occur, and set about 80 to 90% of
that value.
Vector Vector Vector