Mitsubishi Electric MELSEC-Q Series - S-Curve Ratio

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4 PARAMETERS FOR POSITIONING CONTROL
4.3.2 S-curve ratio
S-curve ratio can be set as the acceleration/deceleration processing method for S-
curve acceleration/deceleration processing.
(Refer to Section 6.1.7 for details of S-curve acceleration/deceleration processing.)
Setting range of the S-curve ratio is 0 to 100[%].
If it is set outside the range, an error occurs at the start and control is executed with the
S-curve ratio set as 0[%] (Trapezoidal acceleration/deceleration).
Errors are set in the error item information (SD517).
Setting of the S-curve ratio enables acceleration/deceleration processing to be
executed gently.
The graph for S-curve acceleration/deceleration is a sine curve as shown below.
Positioning speed
Sine curve
0
Acceleration
time
Deceleration
time
Time
t
V
As shown below, the S-curve ratio setting serves to select the part of the sine curve to
be used as the acceleration/deceleration curve.
A
B
B/2 B/2
Sine curve
S-curve ratio = B/A 100[%]
A
B
Positioning speed
B/A=1.0
V
t
Positioning speed
V
A
B
B/A=0.7
S-curve ratio is 100[%]
S-curve ratio is 70[%]
t