Yaskawa LEGEND-MC - Manual (Page 35)

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LEGEND-MC User’s Manual
System Modeling
Basic Block Diagram
The elements of a servo system include the motor, driver, encoder and the controller. These elements are
shown in the following illustration. The mathematical model of the various components is given below:
Controller
Functional Elements of a Motion Control System
Motor-Amplifier
The motor amplifier is configured for current mode:
Current Drive
The current drive generates a current I, which is proportional to the input voltage, V, with a gain of Ka, a
torque constant of K
t
, and inertia J. The resulting transfer function in this case is:
P/V = K
a
K
t
/ Js
2
Motion
Generator
[PA][PR][SP][AC]
[DC][JG][IP]
Scurve
Smoothing
[IT]
Velocity
Feed Forward
[FV]
Acceleration
Feed Forward
[FA]
Proportional
Gain
[KP]
Derivative
Gain
[KD]
Integral
Gain
[KI]
Integrator
Limit
[IL]
Notch Filter
[NF] [NB] [NZ]
Torque Limit
[TL]
Offset
[OF]
Speed
Acceleration
+
+
+
+ +
+
+
Encoder
Feedback
-
+
+
D/A
To Legend Amp
DIGITAL
FILTER
Σ
ZOH DAC
ENCODER
AMP MOTOR
CONTROLLER
R
C
X Y V E
P