NOVA electronics Inc.
MCX514 -
32
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32
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Example of Parameter Setting (Non-symmetry S-curve Acceleration / Deceleration)
The figure shown below is the example of non-symmetry S-curve acceleration / deceleration that reaches from the initial speed
(SV) 100pps to the drive speed (DV) 40kpps in 0.2 seconds by acceleration, and decreases from the drive speed (DV) 40kpps to
the initial speed (SV) 100pps in 0.4 seconds by deceleration. This is that drive pulse number (TP) is 20,000 and relative position
driving.
100
40K
0.2
0.4
JK = 3.99 Mpps/sec
DJ = 0.9975 Mpps/sec
2
2
Speed
(pps)
time (sec)
Fig. 2.2-15 Example of Non-symmetry S-Curve Acceleration/Deceleration Driving
Use the formula of the example of parameter setting (symmetry S-curve acceleration / deceleration) as described previously, and
find a jerk and a deceleration increasing rate.
Jerk
2
2
Mpps/sec
3.99
0.2
100)
4(40000
JK
=
−
=
Deceleration increasing rate
2
2
Mpps/sec
0.9975
0.4
100)
4(40000
DJ
=
−
=
Next, set a deceleration point (DP) manually because automatic deceleration is not available in non-symmetry S-curve
acceleration / deceleration. As a manual deceleration point, set the number of output pulses from the start of driving to the start of
deceleration in fixed pulse driving. In relative position driving, it should be the value calculated by subtracting the number of
pulses (Pd) that were utilized at deceleration from the number of drive pulses (TP), so first, find the number of pulses (Pd) that
were utilized at deceleration.
Pulses utilized at deceleration
8020
10
0.9975
100
40000
100)
(40000
DJ
SV
DV
SV)
(DV
Pd
6
=
×
−
+
=
−
+
=
If the number of pulses (Pd) that were utilized at deceleration is 8,020 where the number of drive pulses (TP) is 20,000 in relative
position driving, the manual deceleration point will be as follows.
Manual deceleration point
DP = TP
–
Pd = 20000
–
8020 = 11980
Therefore, parameter setting is shown below.
Mode setting
WR3←0007h
Mode setting of WR3 register
Jerk
JK = 3990000
Deceleration increasing rate
DJ = 997500
Acceleration
AC = 536870911
Set the maximum value
：
(1FFF FFFFh)
Deceleration
DC = 536870911
Set the maximum value
：
(1FFF FFFFh)
Initial speed
SV = 100
Drive speed
DV = 40000
Drive pulse number
TP = 20000
Manual deceleration point
DP = 11980
[Note]
•
The above expression used for calculating the number of pulses that were utilized at deceleration is an ideal expression.
In the actual IC operation, creep or premature termination occurs depending on the parameter values that are set.
