User`s guide

3 Operations on LTI Models
3-12
represents the parallel interconnection shown below.
If
sys1 and sys2 are two state-space models with data and
, the state-space data associated with
sys1 + sys2 is
Scalar addition is also supported and behaves as follows: if
sys1 is MIMO and
sys2 is SISO, sys1 + sys2 produces a system with the same dimensions as
sys1 whose ijth entry is sys1(i,j) + sys2.
Similarly, the subtraction of two LTI models
sys = sys1 – sys2
is depicted by the following block diagram.
sys1
sys2
u
+
+
sys
y
1
y
2
y
A
1
B
1
C
1
D
1
,,,
A
2
B
2
C
2
D
2
,,,
A
1
0
0A
2
,
B
1
B
2
,
C
1
C
2
, D
1
D
2
+
sys1
sys2
u
y
+
–
sys
y
1
y
2