Delta ASDA-A3 Series, User Manual

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Motion Control ASDA-A3
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7
7.3.4 E-Cam curve
E-Cam curve is created by the mathematic function based on positions of the master and slave
axes. There are various ways to create the table. You can use mathematic tools (software) or
use the tabulation interface for industry-specific applications provided in ASDA-Soft. Regardless
of the tabulation methods, the software coverts the mathematic function into position data and
stores them in the data array. One E-Cam curve can have up to 721 sets of data (divided 720
times). It means the highest resolution is 0.5 degrees. As long as the total point number is within
the data array’s maximum 800, the array can store multiple E-Cam curves. The slave axis curve
between two data points will be interpolated with a cubic curve to smooth the motion at each
point.
See Figure 7.3.4.1 for example. If using E-Cams to replace mechanical cams, divide the
mechanical cam into several segments. The more the segments, the higher the precision. In this
example, the cam is divided into 8 segments, and each interval is 45 degrees (this is for
reference only; you need to delicately segment the cam in the actual application, or the path will
be distorted). Then, enter the distance between the cam shaft and the points (1 – 8) on the cam
edge to the data array. The start point 0 degree and the last point 360 degrees are identical but
you must enter both of the two points to the data array so the the E-Cam can completely go
around the mechanical cam for one cycle. Therefore, you need to enter 9 sets of data to
complete the E-Cam curve table.
Slave axis
position
(PUU)
E-Cam
phase (
°
)
0 45 90 135 180 225 270 315 360
30000
20000
40000
45000
30000
20000
20000
50000
30000
1
2
3
4
5
6 7
8
1
Data array
#50 30000
#51 20000
#52 40000
#53 45000
#54 30000
#55 20000
#56 20000
#57 50000
#58 30000
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
Point
Figure 7.3.4.1 Example of creating E-Cam curve table