User's Manual

HARSFEN0602
Example:
This example illustrates working on a moving object. Consider the application depicted
below:
X axis
Y axis
Moving conveyer
Cake
Circle to
draw
10000
In this application, an x-y stage draws a chocolate picture on a cake while the cake travels
on a conveyer.
The drawing has to be accurate with respect to the cake.
In order to draw a circle of radius 10000 encoder counts on the cake in one second, the x-
axis motor must follow the trajectory
)t(c)t2cos(10000)t(x +π⋅=
Where c(t) is the position of the conveyer. If the conveyer has an encoder, we can use the
conveyer encoder to compensate its motion. Suppose that the resolution of the conveyer
encoder is similar to the resolution of the x-axis encoder.
For drawing an exact circle on the moving cake, we program the motion
)t2cos(10000 π⋅
as PVT, and set RM=1, FR[3]=1.
0 0.2 0.4 0.6 0.8 1
-1
0
1
2
3
4
x 10
4
x motion
relative to cake
Conveyer position, as measured
by the auxiliary encoder input
x motor motion command
Time (sec)