Mitsubishi Electric MELSEC Q Series Programming Manual page 154

4 PARAMETERS FOR POSITIONING CONTROL
Speed change command
1) Deceleration from speed
V to 0
0
(5) Speed change (fixed time method)
Operation in which a speed change during deceleration is executed is shown
below.
Command speed V
0
(Before speed change)
Command speed V
2
(After speed change)
Acceleration
V
0
(V - V )
2 1
Servo program start
Fixed position stop acceleration
/deceleration time
(Indirect setting device)
Acceleration/
Speed difference
deceleration time
(V - V )
2 1
POINTS
When a speed change is executed during decreasing acceleration of advanced
S-curve acceleration/deceleration, in order to maintain smoothness of acceleration,
the speed will continue to increase until acceleration reaches zero. Therefore, the
time for speed change is lengthened.
Speed change V (Deceleration)
2
Speed Before speed change
1)
V
1
0
Before speed
change
a
0
b
ON
OFF
a
Maximum
acceleration
b (V - V ) b
2 1
4 - 33
Deceleration from
speed V
Same slope as
acceleration decrease
Deceleration from
speed V to V
1
t1
b
Operation
(a) The acceleration is decreased until the
acceleration becomes from acceleration
to"0" at speed change. This inclination of
acceleration section 2 (acceleration
decrease section) is calculated based on
the acceleration/deceleration time before
speed change.
(b) Deceleration processing is executed.
(Note): The acceleration time "t1" is
lengthened than "b
D2R) 100.0", because the
acceleration continues until the
acceleration reaches zero after a
speed change.
to V
1 2
Time
2
Time
(100.0 + D1R +