Full-Closed Torsion Compensation Function - Mitsubishi Electric MDS-E Series Instruction Manual

MDS-E/EH Series Instruction Manual
5 Servo Adjustment

5.4.4 Full-closed Torsion Compensation Function

This function performs compensation by setting the torsion compensation amount based on the distance between the
motor-end position and the machine-end position when the direction is reversed. Setting the torsion compensation
amount in addition to the conventional lost motion compensation enables to reduce the distance from the machine end
and smooth the tracking to the position command. When "SV116/bit1" is set to "1", compensation is performed not only
in the reverse direction but also in the forward direction. Compensation in the forward direction performs the starting
torque compensation by restoring the torsion compensation amount based on the distance between the motor-end
position and the machine-end position when stopped.
Position droop
Position
+
command
-
compensation
amount (SV206)
Machine-end position FB
< Movement of machine end/motor end in the reverse direction >
< Movement of machine end/motor end in the forward direction >
Movement stop
Motor end
Torsion
amount
Machine end
CAUTION
Always readjust the lost motion compensation when setting the torsion compensation amount (SV206).
IB-1501229-F
Position control
Torsion
Filter
Motor-end position FB
Full-closed torsion compensation
Motor end
Torsion
amount
Machine end
Torsion of the
reverse direction
The torsion is gradually cleared
during the stop.
Torsion retract amount
Determine the compensation amount
in the forward direction restart from
the torsion retract amount of the
motor-end position from when
movement is stopped.
Speed command
Servo
+ +
motor
ENC
When the direction
is reversed
Reverse
Required compensation amount =
Torsion compensation amount
(SV206)
Movement restart
Motor end (without compensation)
Machine end (without compensation)
294
Table
Linear scale
If the torsion is large, the response of
machine-end position may be delayed
when no compensation is performed.