Acceleration/Deceleration Processing - Mitsubishi Electric MELSEC Q Series Programming Manual

6 POSITIONING CONTROL

6.1.7 Acceleration/deceleration processing

Acceleration/deceleration are processed by the following three methods.
(1) Trapezoidal acceleration/deceleration processing
This is a conventional linear acceleration/deceleration processing.
The acceleration/deceleration graph resembles a trapezoid, as shown in the
diagram below.
Positioning speed
(2) S-curve acceleration/deceleration processing
S-curve ratio is set as a parameter to smoothly provide acceleration/deceleration
processing than trapezoidal acceleration/deceleration processing. The
acceleration/deceleration graph is a sine curve as shown in the diagram below.
Set the S-curve ratio by the parameter block (Refer to Section 4.3.2) or using the
servo program.
Positioning speed
S-curve ratio set the part of the sine curve used to produce the acceleration and
deceleration curve as shown in the diagram below.
A
B
B/2
sine curve
S-curve ratio = B/A 100[%]
V
0
Acceleration time
V
0
Acceleration time
B/2
6 - 18
Time
Deceleration time
Deceleration time
V
(Example)
Positioning
speed
S-curve ratio 100[%]
V
Positioning
b
speed
a
S-curve ratio 70[%]
t
t
Time
t
b/a = 0.7
t