Position Control Gain Adjustment - Mitsubishi Electric 800 Series Instruction Manual

Position control under vector control
5.5.10

Position control gain adjustment

Easy gain tuning is provided as an easy tuning method. For details about easy gain tuning, refer to
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
422
Position control gain
B003
1298 Second position control
B013 gain
423 Position feed forward
B004 gain
425 Position feed forward
B006 command filter
446 Model position control
B012 gain
828 Model speed control
G224 gain
Speed feed forward
877
control/model adaptive
G220
speed control selection
880
Load inertia ratio
C114
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.
Movement  condition
Response is slow.
Overshoot, stop-time vibration
or other instable phenomenon
occurs.
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.
236
PARAMETERS
Initial value
-1
25 s
-1
25 s
0%
0 s
-1
25 s
60%
0
7-fold
Increase the setting value.
Increase the setting value by 3 s
vibration or other instable phenomenon occurs, and set about 80 to 90% of that value.
Lower the setting value.
Lower the setting value by 3 s
vibration or other instable phenomenon does not occur, and set about 80 to 90% of
that value.
Setting range
-1
Set the gain for the position loop.
0 to 150 s
-1
Set the position loop gain for the second motor.
0 to 150 s
Function to cancel a delay caused by the droop pulses
0 to 100%
in the deviation counter.
0 to 5 s Input the first delay filter for the feed forward command.
-1
Set the gain for the model position controller.
0 to 150 s
0 to 1000% Set the gain for the model speed controller.
0, 1 Perform position feed forward control.
2 Model adaptive position control becomes valid.
0 to 200-fold Set the load inertia ratio for the motor.
How to adjust Pr.422
-1
until immediately before an overshoot, stop-time
-1
until immediately before an overshoot, stop-time
Vector Vector Vector
page 164.
Description