Improvement Of Overshooting - Mitsubishi Electric MDS-E Series Instruction Manual

MDS-E/EH Series Instruction Manual
5 Servo Adjustment
(3) Setting and adjusting LMC compensation type 4
LMC compensation type 4 is enabled by being used with LMC compensation type 3. Make sure to adjust the LMC
compensation type 3 before setting the LMC compensation type 4.
< Adjustment method >
[1] Set about 5-fold SV016 setting value in SV091. (Set about 10% of machine friction.)
[2] Increase SV0091 in increments of about 20%, and confirm the limit value where vibration does not occur. Note
that the limit value is about 500.
[3] Set 50% of the limit value.
【#2291】 SV091 LMC4G Lost motion compensation 4 gain
Use this with LMC compensation type 3. As the delay in path tracking is monitored and
compensated, the delay in path tracking will be minimized even if machine friction amount changes
by aging. Use the lost motion compensation amount (SV016) * 5 (10% of the dynamic friction torque)
as the target. The higher the setting value is, the more accurate the quadrant change be; however,
the more likely vibrations occur.
---Setting range---
0 to 20000 (Stall current 0.01%)

5.3.6 Improvement of Overshooting

The phenomenon when the machine position goes past or exceeds the command during feed stopping is called
overshooting. Overshooting is compensated by overshooting compensation (OVS compensation). Overshooting occurs
due to the following two causes.
[1] Machine system torsion: Overshooting will occur mainly during rapid traverse settling.
[2] Machine system friction: Overshooting will occur mainly during one pulse feed.
Either phenomenon can be confirmed by measuring the position droop.
Speed
FB
Position
droop
0
0
Overshoot
Time
[1] Overshooting during rapid traverse settling
Position
command
0
Position
droop
0
Overshoot
[2] Overshooting during pulse feed
285
Time
IB-1501229-F