Galil Motion Control DMC-18 2 Series User Manual page 172

VOLTAGE SOURCE
V
CURRENT SOURCE
V
VELOCITY LOOP
V
Figure 10.6 - Mathematical model of the motor and amplifier in three operational modes
Encoder
The encoder generates N pulses per revolution. It outputs two signals, Channel A and B, which are in
quadrature. Due to the quadrature relationship between the encoder channels, the position resolution is
increased to 4N quadrature counts/rev.
The model of the encoder can be represented by a gain of
K f = 4N/2π
For example, a 1000 lines/rev encoder is modeled as
K f = 638
DMC-18x2
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E
K
v
I
K
a
1
K (ST +1)
g 1
[count/rad]
1/K
e
(ST +1)(ST +1)
m e
K
t
JS
Chapter 10 Theory of Operation • 161
W P
1
S
W P
1
S
W P
1
S