Mitsubishi Electric MELSERVO-J3 Series Manual page 348

Part 5: Common Reference Material
(a) Parameter setting
Setting [Pr. PX36] to [Pr. PX42] enables the lost motion compensation function.
1) Lost motion compensation function selection ([Pr. PX40])
Select the lost motion compensation function.
2) Lost motion compensation ([Pr. PX36]/[Pr. PX37])
Set the same value for the lost motion compensation for each of when the forward rotation
switches to the reverse rotation and when the reverse rotation switches to the forward rotation.
When the heights of protrusions differ depending on the travel direction, set the different
compensation for each travel direction. Set a value twice the usual friction torque and adjust the
value while checking protrusions.
3) Torque offset ([Pr. PX39])
For a vertical axis, unbalanced torque occurs due to the gravity. Although setting the torque offset
is usually unnecessary, setting unbalanced torque of a machine as a torque offset cancels the
unbalanced torque. The torque offset does not need to be set for a machine not generating
unbalanced torque.
4) Lost motion compensation timing ([Pr. PX41])
You can set the delay time of the lost motion compensation start timing with this parameter.
When a protrusion occurs belatedly, set the lost motion compensation timing corresponding to
the protrusion occurrence timing.
5) Lost motion compensation non-sensitive band ([Pr. PX42])
When the travel direction reverses frequently around the zero speed, unnecessary lost motion
compensation is triggered by the travel direction switching. By setting the lost motion
compensation non-sensitive band, the speed is recognized as 0 when the fluctuation of the droop
pulse is the setting value or less.
When the value of this parameter is changed, the compensation timing is changed. Adjust the
value of Lost motion compensation timing ([Pr. PX41]).
6) Lost motion filter setting ([Pr. PX38])
Changing the value of this parameter is usually unnecessary. When a value other than 0.0 ms is
set in this parameter, the high-pass filter output value of the set time constant is applied to the
compensation and lost motion compensation continues.
[Pr. PX40]
0 0
Lost motion compensation selection
0: Lost motion compensation disabled
1: Lost motion compensation enabled
Unit setting of lost motion compensation non-sensitive band
0: 1 pulse unit
1: 1 kpulse unit
5 - 163