Mitsubishi Electric MR-J4, Instruction Manual

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7. SPECIAL ADJUSTMENT FUNCTIONS
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(d) Lost motion compensation timing ([Pr. PE49])
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.
(e) Lost motion compensation non-sensitive band ([Pr. PE50])
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 travel direction switching due to position droop vibration with the setting
value or lower is recognized as the zero speed. This prevents unnecessary lost motion
compensation.
When the value of this parameter is changed, the compensation timing is changed. Adjust the value
of Lost motion compensation timing ([Pr. PE49]).
(f) Lost motion filter setting ([Pr. PE46])
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.
(2) Adjustment procedure of the lost motion compensation function
The following shows the adjustment procedure of the lost motion compensation function.
(a) Measuring the load current
Measure the load currents during the forward direction feed and reverse direction feed with MR
Configurator2.
(b) Setting the lost motion compensation
Calculate the friction torque from the measurement result of (a) and set a value twice the friction
torque in [Pr. PE44] and [Pr. PE45] as lost motion compensation.
Friction torque [%] =
2
|(load current during feed in the forward rotation direction [%]) -
(load current during feed in the reverse rotation direction [%])|
(c) Checking protrusions
Drive the servo motor and check that the protrusions are corrected.