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5 POSITIONING CONTROL
5.1 Basics of Positioning Control
Acceleration/deceleration processing
Acceleration/deceleration are processed by the following three methods.
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.
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 (
Page 220 S-curve ratio) or using the servo program.
S-curve ratio set the part of the sine curve used to produce the acceleration and deceleration curve as shown in the diagram
below.
Positioning speed
V
Acceleration time
Deceleration time
Time
t
0
Positioning speed
V
Acceleration time
Deceleration time
Time
t
0
sine curve
A
B
B/2
B/2
S-curve ratio = B/A
×
100[%]
(Example)
Positioning
speed
V
Positioning
speed
V
S-curve ratio 100[%]
S-curve ratio 70[%]
t
t
b
a
b/a = 0.7
Summary of Contents for MELSEC iQ-R16MTCPU
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