Mitsubishi MELDAS MDS-C1 Instruction Manual page 233

(3) Adjusting the servo rigidity
The stopping position precision can be increased by raising the servo rigidity during orientation
stop.
1) Increase the SP001 (PGM) or SP002 (PGE) value to the degree that overshooting does not
occur during orientation stop.
2) Increase SP098 (VGOP) and SP099 (VGOI) by the same amount to the degree that vibration
does not occur.
3) The servo rigidity can be increased momentarily by increasing the SP100 (VGOD) value.
Increasing the SP100 value : Adverse effects may occur such as a drop in the torque in
Setting the SP100 value to 0 : PI control will be applied. The servo rigidity will drop
•
Speed loop delay compensation control and PI control
When stopping orientation for a normal tool change, etc., select delay/advance control.
However, if the spindle's frictional torque is large, and a precise stopping position is required,
select PI control. (SP100=0).
Examples of using PI control
•
Positioning a workpiece with a lathe.
•
Orientation of a machine which indexes a 5-plane machining attachment.
No. Abbr. Parameter name
Speed loop gain
SP098 VGOP* proportional term in
orientation mode
Speed loop gain integral
SP099 VGOI*
term in orientation mode
Speed loop gain delay
SP100 VGOD* advance term in
orientation mode
POINT
CAUTION
5. Spindle Adjustment
respect to the position deflection, or an inconsistency in the
stopping position.
momentarily, but the stopping position precision will increase.
Set the speed loop proportional gain in orientation mode.
When the gain is increased, rigidity is improved in the
orientation stop but vibration and sound become larger.
Set the speed loop integral gain in orientation mode.
Set a speed loop gain delay advance gain in orientation
mode.
When this parameter is set to "0", PI control is applied.
1. If the forward run and reverse run stop positions differ even when using PI
control, the machine's backlash may be large. In this case, the stopping
precision may be improved by fixing the orientation rotation direction to one
direction. (Set with the spindle parameter SP097. bit 0, 1.)
2. If the gear ratio between the spindle and motor is large, the SP001, SP002
and SP006 values will be clamped internally even if changed, so it may not
be possible to set the required value. The parameter setting value will be
changed when these are clamped, but no changes will be visible in the
control.
If the spindle is mechanically locked during orientation stop, always input a
torque limit so that the motor's output torque is restricted. (Recommended
torque limit: 10% or less)
Details
5 - 23
Setting range Standard
0 to 1000 63
0 to 1000 60
0 to 1000 15