Improvement Of Protrusion At Quadrant Changeover - Mitsubishi Electric MELDAS MDS-R Series Technical Specification And Instruction Manual

9-3-4 Improvement of protrusion at quadrant changeover

The response delay (caused by non-sensitive band from friction, torsion, expansion/contraction, backlash,
etc.) caused when the machine advance direction reverses is compensated with the lost motion
compensation (LMC compensation) function.
With this, the protrusions that occur at the quadrant changeover in the DBB measurement method, or
the streaks that occur when the quadrant changes during circular cutting can be improved.
Circle cutting path before compensation
(1) Lost motion compensation (LMC compensation)
LMC compensation compensates the response delay during reversal by adding the torque
command set with the parameters when the speed direction changes. There are two types of LMC
compensation.
<Setting method>
<1> Set the special servo function selection 1 (SV027 (SSF1)) bit 9. (The LMC compensation type 2 will
start).
<2> Set the compensation amount with a stall % (rated current % for the general-purpose motor) unit in
the lost motion compensation 1 (SV016 (LMC1)). The LMC1 setting value will be used for
compensation in the positive and negative directions when SV041 (LMC2) is 0.
<3> If the compensation amount is to be changed in the direction to be compensated, set LMC2. The
compensation direction setting will be as shown below with the CW/CCW setting in the NC parameter.
If only one direction is to be compensated, set the side not to be compensated as -1.
Compensation
point
A
B
C
D
No. Abbrev. Parameter name
SV016 LMC1 Lost motion
compensation 1
SV041 LMC2 Lost motion
compensation 2
SV027 SSF1 Special servo
function selection 1
9. Adjustment
Cutting
direction
CW CCW
X axis: LMC2 X axis: LMC1
Y axis: LMC1 Y axis: LMC2
X axis: LMC1 X axis: LMC2
Y axis: LMC2 Y axis: LMC1
C
Set the compensation value using the motor's stall current as a reference.
The standard setting value is double the friction torque. The compensation
amount will be 0 when "0" is set.
Set this with SV016 (LMC1) only when you wish to set the lost motion
compensation amount to be different depending on the command
directions.
Set to "0" as a standard.
F E
zrn2
bit
8
lmc
9
Compensation
Circle cutting path after compensation
-X
The X axis command direc-
tion changes from - to +.
Explanation
D C B A 9 8
lmc
Meaning when "0" is set
Set the compensation amount with SV016 (LCM1) and SV041 (LCM2).
00: Lost motion compensation stop 10: Lost motion compensation type 2
01: Setting prohibited
9 - 18
DBB: Double Ball Bar
The Y axis command direc-
D
+Y
tion changes from + to -.
The X axis command direc-
A
tion changes from + to -.
+X
The Y axis command direc-
B
-Y
tion changes from - to +.
Setting range
(Stall current %)
(Stall current %)
7 6 5 4 3 2
vfct
Meaning when "1" is set
11: Setting prohibited
-1 to 200
-1 to 200
1 0