ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference - Manual (Page 248)

0 500 1000 1500 2000 2500
0
1
2
3
4
5
6
7
8
D ifference
(counts)
msec
It can be seen that with only 23 PVT points, the interpolated path never differs from the
original ellipse by more than 8 counts (remember that the ellipse axes are 100,000 and
50,000 counts respectively!) At the PVT points, the interpolation error is zero.
The next figure displays the interpolated trajectories generated by the drive for the x-axis
and for the y-axis.
0 500 1000 1500 2000 2500
-6
-4
-2
0
2
4
6
x 10
4
msec
C ounts
X axis trajectory
Y axis trajectory
Example 3:
The drive normally produces maximally smooth interpolating trajectories, which is why
the ellipse in the previous example could be interpolated using so few points. Accurate
corners, however, require non-smooth interpolation. Specifying zero speed for the corner
points generates hard corners. The following graph shows a 2-axis synchronized PVT
trajectory of an accurate rectangle.
SimplIQ for Steppers Application Note The Position Reference Generator
MAN-STECR (Ver. 1.1)
49