System philosophy
HARDWARE REFERENCE MANUAL
28
Revi
si
on 3.0
C. Demand position.
D. Position control.
E. Speed reference.
F. Speed control.
G. Motor.
H. Encoder.
I.
Measured speed.
J. Measured position.
2.3.3
Motion control algorithm
The servo system controls the motor by continuously adjusting the
speed reference to the Servo Driver. The speed reference is
calculated by the motion control algorithm of the TJ1-MC__, which
is explained in this section.
fig. 16
The motion control algorithm uses the demand position (A), the
measured position (D) and the Following Error (B) to determine the
speed reference. The Following Error is the difference between the
demanded and measured position. The demand position, the
measured position and the Following Error are represented by the
axis parameters
MPOS
,
DPOS
and
FE
. Five gain values have
been implemented for the user to be able to configure the correct
control operation for each application.
C is the output signal.
•
Proportional gain
The proportional gain
K
p
creates an output
O
p
that is
proportional to the Following Error E.
O
p
= K
p
· E
All practical systems use proportional gain. For many just using
this gain parameter alone is sufficient. The proportional gain
axis parameter is called
P_GAIN
.
•
Integral gain
The integral gain
K
i
creates an output
O
i
that is proportional to
the sum of the Following Errors that have occurred during the
system operation.
O
i
= K
i
·
Σ
E
A
B
C
D
∑
∑
K
p
K
i
K
d
K
vff
K
ov
Δ
Δ
I51E-EN-03.book Seite 28 Donnerstag, 28. Juni 2007 1:05 13
