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2.2.4 S-curve Acceleration/Deceleration Driving [Symmetrical]
S-curve acceleration / deceleration driving performs acceleration and deceleration to a specified drive speed with a smooth curve
that forms a secondary parabolic curve. This IC creates a S-curve by increasing/reducing acceleration/deceleration in a primary
line at acceleration and deceleration of a drive speed.
Fig. 2.2-8 shows the operation of S-curve acceleration / deceleration driving where acceleration and deceleration are symmetrical.
Section a. When driving starts, the acceleration increases on a straight line at a specified jerk. In this case, the speed data
forms a quadratic curve.
Section b. If the difference between a specified drive speed and the current speed becomes less than the speed that was
utilized at acceleration increasing, the acceleration starts to decrease on a straight line at a specified jerk.
The decrease ratio is the same as the increase ratio.
In this case, the rate curve forms a parabola of reverse direction.
Section c. When the speed reaches a specified drive speed or the acceleration reaches 0, the driving keeps that speed.
In fixed pulse driving of S-curve acceleration / deceleration where acceleration and deceleration are symmetrical,
when the rest of output pulses becomes less than the number of pulses that were utilized at acceleration,
deceleration starts (automatic deceleration).
Section d,e. Also in deceleration, the speed forms a S-curve by increasing/decreasing deceleration in a primary linear form.
The same operation is performed in acceleration/deceleration where the drive speed is changed during continuous pulse driving.
However, in S-curve acceleration / deceleration driving, change of a drive speed during acceleration / deceleration is invalid.
Acceleration
/ Deceleration
a
b
c
d e
Acceleration
Deceleration
Acceleration increasing rate (slope)
Speed
time
Initial Speed
Drive Speed
time
Fig. 2.2-8 S-curve Acceleration/Deceleration Driving (Symmetry)
To perform symmetry S-curve acceleration / deceleration driving using automatic deceleration, bits D2 to 0 of WR3 register and
the following parameters must be set.
Table2.2-6 Mode Setting
：
S-curve Acceleration / Deceleration (Symmetry)
Mode Setting Bit Symbol Setting Comment
WR3/D0 MANLD 0 Automatic deceleration
WR3/D1 DSNDE 0 When in deceleration, acceleration and jerk setting values are used.
WR3/D2 SACC 1 S-curve acceleration / deceleration
Table 2.2-7 Setting Parameters
：
S-curve Acceleration / Deceleration (Symmetry)
Parameter Symbol Comment
Jerk JK
Acceleration AC Set the maximum value
：
536,870,911 (1FFF FFFFh).
Initial speed SV
Drive speed DV
Drive pulse number / Finish point TP Not required for continuous pulse driving.