Biomedical Engineering Reference
In-Depth Information
FIGURE 4-53
Op
amp circuits used to
implement
proportional and
integral control
strategies.
The controller transfer function for the proportional case is
R
2
R
1
G
c
(
s
)
=
K
p
=
(4.97)
and, for the integral case,
K
i
s
=
1
/
R
5
C
1
s
G
c
(
s
)
=
(4.98)
The PI controller can be implemented by combining the feedback elements of the previous
circuits, as shown in Figure 4-54. In this case the transfer function is
R
11
R
8
+
1
/
R
8
C
2
s
G
c
(
s
)
=
(4.99)
FIGURE 4-54
Op
amp circuit used to
implement PI control
strategy.
