Mitsubishi Electric MELDAS MDS-B-SVJ2 Series, Specifications And Instruction Manual

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Chapter 5 Adjustment
5-10
(4) Adjusting the settling time
The settling time is the time required for
the position droop to enter the in-position
width after the feed command (F
⊿
T) from
the CNC reaches 0.
The settling time can be shortened by
raising the position loop gain or using
SHG control. However, a sufficient
response (sufficiently large VNG1 setting)
for the speed loop is required to carry out
stable control.
The settling time during normal control
when the CNC is set to linear
acceleration/deceleration can be
calculated using the following equation.
During SHG control, estimate the settling
time by multiplying PGN1 by
2
.
PGN1 : Position loop gain1 (SV003) (rad/sec)
F : Rapid traverse rate (mm/min)
G0tL : Rapid traverse linear acceleration/
deceleration time constant (msec)
INP : In-position width (SV024) (
μ
m)
Example of speed/current command waveform during acceleration/deceleration
(Reference) The rapid traverse acceleration/deceleration time setting value G0tL for when linear
acceleration/deceleration is set is calculated with the following expression.
G0tL =
(J
L
+ J
M
)
×
No
95.5
×
(0.8
×
T
MAX
– T
L
)
6000
( PGN1
×
K)
2
(msec) –
N
O
: Motor reach speed (r/min)
J
L
: Motor shaft conversion load inertia (kg·cm
2
)
J
M
: Motor inertia (kg·cm
2
)
T
MAX
: Motor max. torque (N·m)
T
L
: Motor shaft conversion load (friction, unbalance) torque (N·m)
PGN1 : Position loop gain 1 (rad/sec)
K : "1" during normal control, "2" during SHG control
0
0
3000
200
-200
-3000
Time
Time
Speed command
(r/min)
Current command
(Stall %)
0
0
F
⊿
T
Position
droop
F
Time
Setting time
In-position
In-position width
G0tL
Settling time (msec)
＝－ ×
PGN1
10
3
ln
INP
F
×
10
6
60
×
G0tL
×
PGN1
2
×
1
－
exp
PGN1
×
G0tL
10
3
－