beautypg.com

Encoder speed at a ratio of fr[3], as depicted in, Figure, M oving conveyer – ElmoMC SimplIQ Digital Servo Drives-Bell Command Reference User Manual

Page 268

background image

0

0.005

0.01

0.015

0.02

0.025

0.03

0

200

400

600

800

1000

1200

1400

1600

1800

Time

PY - Auxiliary Position
DV[6] - External Position Reference

FR[3]=1

FR[3]=2

FR[3]
changes

Figure 6-11: Follower Ratio

Example:
This example illustrates how a moving object is handled by the application:

X axis

Y a

x

is

M oving 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 conveyor. The drawing must be accurate with respect to the cake.

In order to draw a circle of radius 10,000 encoder counts on the cake in one second, the
x-axis motor must follow the trajectory:
x(t) = 10,000 * cos(2

πt) + c(t)

where c(t) is the position of the conveyor.

If the conveyor has an encoder, it can be used to compensate for its motion.

SimplIQ for Steppers Application Note

The Position Reference Generator

MAN-STECR (Ver. 1.1)

69